Textbook of Chemical Peels - Superficial, Medium, and Deep Peels in Cosmetic Practice (PDFDrive) PDF [PDF]

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Textbook of Chemical Peels

Series in Cosmetic and Laser Therapy Series Editors

Nicholas J. Gary P. Lask, and David J. Goldberg Philippe Deprez, Textbook of Chemical Peels, Second Edition: Superficial, Medium, and Deep Peels in Cosmetic Practice, ISBN 9781482223934 Jenny Kim, Gary Lask, and Andrew Nelson, Comprehensive Aesthetic Rejuvenation: A Regional Approach, ISBN 9780415458948 David J. Goldberg and Alexander L. Berlin, Disorders of Fat and Cellulite: Advances in Diagnosis and Treatment, ISBN 9780415477000 Neil S. Sadick, Paul J. Carniol, Deborshi Roy, and Luitgard Wiest, Illustrated Manual of Injectable Fillers: A Technical Guide to the Volumetric Approach to Whole Body Rejuvenation, ISBN 9780415476447 Kenneth Beer, Mary P. Lupo, and Vic A. Narurkar, Cosmetic Bootcamp Primer: Comprehensive Aesthetic Management, ISBN 9781841846989 Anthony Benedetto, Botulinum Toxins in Clinical Aesthetic Practice, Second Edition, ISBN 9780415476362 Robert Baran and Howard I. Maibach, Textbook of Cosmetic Dermatology, Fourth Edition, ISBN 9781841847009 Neil Sadick, Diane Berson, Mary P. Lupo, and Zoe Diana Draelos, Cosmeceutical Science in Clinical Practice, ISBN 9780415471145 Paul Carniol and Gary Monheit, Aesthetic Rejuvenation Challenges and Solutions: A Global Perspective, ISBN 9780415475600 Avi Shai, Robert Baran, Howard I. Maibach, Handbook of Cosmetic Skin Care, Second Edition, ISBN 9780415467186 Benjamin Ascher, Marina Landau, and Bernard Rossi, Injection Treatments in Cosmetic Surgery, ISBN 9780415386517 David J. Goldberg, Laser Hair Removal, Second Edition, ISBN 9780415414128 Paul J. Carniol and Neil S. Sadick, Clinical Procedures in Laser Skin Rejuvenation, ISBN 9780415414135 C. William Hanke, Gerhard Sattler, and Boris Sommer, Textbook of Liposuction, ISBN 9781841845326 David J. Goldberg, Fillers in Cosmetic Dermatology, ISBN 9781841845098

Textbook of Chemical Peels Superficial, Medium, and Deep Peels in Cosmetic Practice SECOND EDITION

Philippe Deprez, M.D. Medical Director Policlinica Estetica & Anti-Aging Empuriabrava, Spain

CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2017 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group, an Informa business No claim to original U.S. Government works Version Date: 20160328 International Standard Book Number-13: 978-1-4822-2394-1 (eBook - PDF) This book contains information obtained from authentic and highly regarded sources. While all reasonable efforts have been made to publish reliable data and information, neither the author[s] nor the publisher can accept any legal responsibility or liability for any errors or omissions that may be made. The publishers wish to make clear that any views or opinions expressed in this book by individual editors, authors or contributors are personal to them and do not necessarily reflect the views/opinions of the publishers. The information or guidance contained in this book is intended for use by medical, scientific or health-care professionals and is provided strictly as a supplement to the medical or other professional’s own judgement, their knowledge of the patient’s medical history, relevant manufacturer’s instructions and the appropriate best practice guidelines. Because of the rapid advances in medical science, any information or advice on dosages, procedures or diagnoses should be independently verified. The reader is strongly urged to consult the relevant national drug formulary and the drug companies’ and device or material manufacturers’ printed instructions, and their websites, before administering or utilizing any of the drugs, devices or materials mentioned in this book. This book does not indicate whether a particular treatment is appropriate or suitable for a particular individual. Ultimately it is the sole responsibility of the medical professional to make his or her own professional judgements, so as to advise and treat patients appropriately. The authors and publishers have also attempted to trace the copyright holders of all material reproduced in this publication and apologize to copyright holders if permission to publish in this form has not been obtained. If any copyright material has not been acknowledged please write and let us know so we may rectify in any future reprint. Except as permitted under U.S. Copyright Law, no part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers. For permission to photocopy or use material electronically from this work, please access www.copyright.com (http://www.copyright.com/) or contact the Copyright Clearance Center, Inc. (CCC), 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400. CCC is a not-for-profit organization that provides licenses and registration for a variety of users. For organizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged. Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe. Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com and the CRC Press Web site at http://www.crcpress.com

Contents

Acknowledgment......vii 1. Definition and classification of chemical peels........................................................ 1 2. Prepeel care...................................................................................................................... 7 3. Postpeel care.................................................................................................................. 13 4. Factors influencing the skin’s reactions to chemical peels.................................. 29 5. Selection of the right peel........................................................................................... 32 6. Alpha hydroxy acids: Chemistry, pH and pK a, and mechanism of action........ 45 7. Alpha hydroxy acids: Histology and factors influencing penetration............... 50 8. Alpha hydroxy acids: Indications and results........................................................ 52 9. Alpha hydroxy acids: Application as cosmetics and as peels.............................. 55 10. Alpha hydroxy acids: Side effects of AHAs............................................................ 63 11. Alpha hydroxy acids: A new slow-release AHA complex with no neutralization required............................................................................................... 65 12. Trichloroacetic acid: General information, toxicity, formulations, and histology......................................................................................................................... 74 13. Trichloroacetic acid: Indications and contraindications....................................... 89 14. Trichloroacetic acid: Classic semiology................................................................... 98 15. Easy TCA and Easy TCA Pain Control: Description and basic protocols...... 102 16. Treating melasma, chloasma, and postinflammatory hyperpigmentation........ 116 17. Treating acne............................................................................................................... 126 18. Treating multiple keratoses on the scalp............................................................... 132 19. Treating aging skin of the hands and forearms................................................... 136 20. Treating the neck and décolletage.......................................................................... 144 21. Stretch marks, scars, and pilar keratosis: Anterior chemabrasion................... 152 22. Face and hands: Actinic keratoses and lentigines............................................... 183 23. Trichloroacetic acid to the papillary dermis: Unideep....................................... 198 24. Resorcinol: Unna’s paste/Jessner’s solution.......................................................... 206 25. Phenol: Chemistry, formulations, and adjuvants................................................ 213 26. Phenol: Properties and histology............................................................................ 221 27. Phenol: Skin penetration and detoxification........................................................ 226

vi   Contents

28. Phenol toxicity: Causes, prevention, and treatment............................................ 230 29. Phenol: Choice of peel and combination treatments.......................................... 239 30. Phenol: Indications..................................................................................................... 250 31. Phenol: Contraindications, precautions, and safety............................................ 264 32. Phenol: Prepeel preparation..................................................................................... 269 33. Full-face phenol: Nerve block anesthesia and/or sedation................................ 275 34. Full-face phenol: Application................................................................................... 285 35. Full-face phenol: Postpeel care................................................................................ 295 36. Phenol: Chemical blepharoplasty and cheiloplasty............................................ 307 37. Complications of chemical peels............................................................................. 325 38. Combination peels..................................................................................................... 374 Index................... 387

Acknowledgment

The publication of this work has been assisted by an educational grant from Skin Tech pharma group (www.skinstechpharmagroup.com and www.skintech.info). It should be noted that this textbook is comprehensive about all available peel products but that there are many ancillary products (such as sunscreens) manufactured in comparable formulations about which it cannot be expected to be comprehensive; the author is most familiar with and recommends those from Skin Tech but does not imply by this that other products may not be comparable.

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1 Definition and classification of chemical peels DEFINITION OF A CHEMICAL PEEL A chemical peel is a skin treatment intended to visibly improve the structure of treated tissue by the external application of a caustic solution. It can simply accelerate the natural processes of exfoliation, but can also completely destroy the epidermis and a more or less large proportion of the dermis, essentially by protein coagulation or lysis. The effect of any peel reaches the dermis, directly or indirectly and to varying depths, where the processes of regeneration are induced to a greater or lesser degree, depending on the molecule or molecules used and the application procedure. Chemical peels are among the oldest forms of skin rejuvenation and form a group of treatments in their own right. They are both flexible and effective, with a histological, chemical, toxicological, and clinical basis. They have an ancient history, have evolved rapidly, and can be adapted to almost any circumstances within the limits of their indications. Most peels, to varying degrees, cause the same types of histological changes, whose clinical results lead to a more or less rejuvenating effect on all or part of the skin. Classification is always restrictive, as it forces highly variable events into a rigid framework. So many different factors come into play that it becomes difficult to fit all chemical peels into a simplified and rigid classification of “superficial,” “medium,” and “deep.” Let us take the well-known glycolic acid peel as an example: its depth of action depends on the patient’s skin type; the presence of associated disorders (e.g., seborrheic dermatitis); skin preparation in the long, medium, and short term; the type of presentation (gel, liquid, mask, or self-neutralizing pseudogel); the concentration of the product; the m/m (or w/w), m/v (or w/v), or m+v (or w+v) calculation, whether or not it is combined with other acid molecules (e.g., lactic or kojic); the pH of the solution (e.g., 0.5 or 3.5) and therefore the fraction of free glycolic acid; what it is applied with (brush, cotton pad, etc.); the number of coats; how forcefully it is applied; whether it is applied on the face or body; the exact location on the face (e.g., nostrils or eyelids1); the contact time; how or whether it is neutralized or diluted at the end of the peel; the immediate postpeel care; the quality of care between peels; the number and frequency of repeat sessions; and the list goes on. It is clear that it does not take much to turn a very light glycolic acid peel into a medium-depth peel that can even reach the deeper layers of the dermis and risk discoloration or even scarring. All it takes is for the peel not to be neutralized properly. The same is true for all of these caustic molecules, which is why a thorough knowledge of chemical peels and skin anatomy is necessary before undertaking this kind of treatment. Every practitioner, through personal experience and practice, should aim to standardize his or her treatments to eliminate the maximum number of variables. Fortunately, new chemical peel formulas are easier, safer, and quicker to use, allowing young physicians to get on with the job of peeling without losing sleep

or having postpeel nightmares. Sound knowledge and experience are still essential for peels to the papillary dermis.

CRITERIA FOR CLASSIFICATION Molecular Dependence It is very simple to understand that phenol is more aggressive than lactic acid but less simple to understand that a light trichloroacetic acid (TCA) peeling can give deeper results compared to deep phenol peel, when it is applied after a physical abrasion (see Combined peelings). Note that phenol peel should not be applied after abrasion for toxicological reasons.

Doctor Dependence Classification may be personal; it may be related to the practice of one particular doctor who has standardized his methods of treatment with a view to limiting uncontrollable variables. But such a classification would not allow for any scientific exchange. What would produce a superficial peel with one practitioner could in fact result in a medium peel with another who uses the same product with a different application technique. This is why peels are often considered to be doctor-​dependent. How can we give a valid classification for a treatment that is doctor-dependent? We should also compare products of the same type only, and yet the quality of the preparations and excipients is highly variable and impossible to control.

Chemical Dependence TCA crystals, for example, are very hydrophilic, which means that they must be kept in perfect conditions so that the pharmacist can prepare the solutions we prescribe properly. How can we know how long the pharmacist’s bottle of TCA crystals has been open? If the crystals have not been hydrated inadvertently (if the pharmacist closes the bottle immediately after taking out the required amount), the final concentration will be correct. If, on the other hand, the crystals are mostly hydrated (if the pharmacist leaves the bottle of TCA open while serving another customer), the concentration of the solution provided by the pharmacy will be abnormally low and not very effective. Peels therefore are also considered to be chemical-dependent.

Patient Dependence Each patient has a skin type that is genotypically and phenotypically unique. The doctor must know each patient’s skin history. Stable products that are properly prepared and applied with precise methodology, in the same way, by the same doctor, on the same day, can produce different results on different patients. Every morning, or maybe several times a day, patients go through their own particular skincare routine that the doctor doing the peel does not necessarily know about. For example, some teenagers secretly apply large quantities of topical benzoyl peroxide for acne. It reduces the thickness of the stratum corneum and makes the skin more permeable. This of

2      Textbook of Chemical Peels

course makes it easier for the acids used for skin peeling to penetrate the skin and can, in some cases, cause unexpected burns. A similar situation arises with patients who want to present their doctors with perfectly clean skin and use abrasive creams. Their intention is noble, but the consequences are sometimes unpleasant. Therefore, a peel is also patient-dependent. If we leave aside these variables, we can fit the different types of peels into their appropriate slots. This is just for the beauty of the exercise, however, as the variables still need to be taken into account. It is clearly possible to perform a superficial or medium peel using phenol. But, given the inherent toxicity of phenol, what would be the point? What is more, 70% unbuffered glycolic acid that is left for 10–15 minutes on a thin, sensitive skin that has been prepared with retinoic acid can result in a cosmetic disaster. It is possible to conduct good-quality, deep peels with TCA, but the risks can be greater than if phenol is used correctly.

PEELING CLASSIFICATION Peelings are traditionally classified as superficial, medium, and deep peels. While these classifications seem simple and understandable, the literature gives us little comprehensive data about the different depths. What some authors consider as superficial is considered as medium by others, and what some consider medium others may consider as deep. A link with the concentration that is used is especially pointless, because, as described in Chapter 12, many details about the usable acid concentration interfere. The depth reached by a 25% TCA is different if the concentration is calculated in weight/weight (w/w), weight/volume (w/v), weight plus volume (w+v), or by dilution of a more concentrated solution prepared using one of these methods. Dramatic differences appear, generating side effects. Usually, acid concentrations are simply quoted in percentage, without specifying %w/w or w/v for example. In addition, the depth of action of an acid solution of x% will be different if one

coat or several coats are applied, if the skin is thick or thin, if the skin is dry or oily, if the applicator is a brush or a gauze, if the pressure is soft or strong on the skin, and so forth. The usual classification as superficial, medium, or deep is therefore obsolete. In reality, it is better to determine the depth of a peel by clinically observing what is happening to the skin during the course of the treatment than by blindly applying preset recipes. When we say, for example, that the result of a glycolic acid peel is time-dependent, this does not mean having to watch the clock but rather continuously analyzing how the skin is reacting to determine the best moment to start neutralization. One basic principle must be respected: a peel should not be unnecessarily deep or unnecessarily superficial. There is no point in completely destroying the papillary dermis when treating a purely epidermal problem, and it is both pointless and ineffective to use an intraepidermal peel, even repeatedly, to treat a dermal problem.

Depths of Peelings I usually consider seven depths of peelings (Figure 1.1). Depth 1: Exfoliation (Very High Security) The most superficial peel consists of a simple exfoliation of stratum corneum dead cells; it gives a good skin cleansing and a touch of better hydration. This “hydration touch” in reality results in skin damage: the peel removed the protective stratum corneum layer and the fingers are now directly in contact with superficial keratinocytes. Keratinocytes are living cells (only the most superficial layers are near to death) containing more water than stratum corneum cells. Depth 2: Intraepidermal Peel (Very High Security) The peel solution penetrates deeply into the epidermis, removing more cells; nevertheless, it does not touch any part of the

Stratum disjunctum Stratum compactum Kertinocytes

Exfoliation Very High Security

K

Basal layer

K

GZ

GZ

GZ

GZ

GZ

Lower limit of papillary dermis

GZ

GZ

GZ

GZ

GZ

GZ

GZ

GZ

GZ

Basal layer peel Grenz zone peel

Intraepidermal peel High Security Papillary dermis peel Still secure zone Superficial reticular dermis peel Quite secure zone Deep reticular dermis peel Difficult, dangerous Over peel Unsecure

Hypodermis

Figure 1.1  The seven possible depths of peel.

Definition and classification of chemical peels   3

dermis or even the basal layer. The final touch of the skin is still more hydrated than in the case of a simple exfoliation, depth 1. After the peel, living keratinocytes are suddenly directly exposed to air, sun, pollution, and dryness. They react, synthesizing more tumor necrosis factor alpha (TNFa) (inducing a faster transformation of keratinocytes into corneocytes) and sending a message to the basal layer to stimulate the basal layer

turnover and substitute the removed cells with new ones. At the same time another message reaches the fibroblasts, which respond with a stronger synthesis of the entire dermal intercellular matrix. Intraepidermic peels (depth 2) give better results than depth 1 peels and can be used for treating superficial epidermal melasma and many keratinization problems.

Table 1.1  Exfoliation Level Main types Action mode

Clinical signs Desquamation Risks and problems

Alpha hydroxy acid (AHA) peels are primarily used for exfoliation. The activity of AHA on the corneocytes seems to be secondary to an action on ionic charges, to the inhibition of enzymes involved in the formation of ionic links. For example, AHAs could compete with sulfates and phosphates at the level of sulfotransferases, phosphotransferases, or kinases, involved in the formation of sulfated or phosphorylated mucopolysaccharides, glycoproteins, sterols, and lipids. This could produce a lower quantity of electrically negative groups on the surface of keratinocytes and corneocytes and lower the adhesion forces with amines or basic aminated acids (electrically positive). AHAs penetrate between cells, unsticking the proteins responsible for corneo-desmosomes adhesivity (the adhesion is a noncovalent, electric link) and allowing the cells to separate from each other, inducing a desquamation. Because there is no strict chemical reaction during this process, AHAs are not consumed much and have to be neutralized. Rinsing with a basic solution stops their action. Irritative erythema is usually the only visible sign. Typically, no desquamation is seen. In general, this is not a risky depth. The main risks are a higher sensitivity to the sun and a greater risk of skin infections. Neutralization is the main problem: if too early, it gives no result; if too late, it could induce more side effects. We will see later that this problem can be avoided by using specific slow-release and self-neutralizing AHA mixtures.

Table 1.2  Intraepidermic Peels Main types Action mode Clinical signs Desquamation Risks and problems

Alpha hydroxy acid (AHA), alpha-ketoacids, trichloracetic acid (TCA), resorcine, and salicylic acid peels can be used. TCA is a proteocoagulant chemical. When in contact with proteins, it coagulates them, modifying their tridimensional structures in a way that does not allow their normal function. All membrane proteins are therefore damaged, making the keratinocytes unable to survive. At the same time, intercellular proteins are also coagulated. Visible erythema can be seen, but no white pinpoints appear yet. It can look like very thin dandruff. Intraepidermic peels are usually not dangerous. Nevertheless, cases of postinflammatory hyperpigmentations (PIH) have been seen, making the prevention of this side effect necessary when the skin is known to be sensitive. Neutralization of AHAs remains the main problem because it must be done following difficult rules. Neutralization has to be done when an erythema (always irregular erythema) appears and before any sign of protein coagulation that would appear as skin frosting points. It is difficult to foresee the right moment for an ideal neutralization. Regarding TCA, no neutralization can reverse the proteinic coagulation; therefore the total amount of TCA that is applied on the skin has to be perfectly calculated in relation to skin permeability. The TCA application technique has to be perfect for an even penetration. Resorcine and salicylic acid are phenol derivatives that are not widely used outside of the United States; large surfaces treatments using phenol derivatives are suspected to potentially induce toxic reactions. TCA and AHAs, on the other hand, are not toxic products.

Table 1.3  Basal Layer Peels Main types Action mode Clinical signs Desquamation Risks and problems

AHAs should not be used at this depth because side effects are likely here, are difficult to treat, and affect the patient’s social life. TCA is the best choice for this depth if the right concentration, formula, and postpeel care are selected. Keratinocyte destruction induces a basal layer strong reaction, dramatically stimulating the turnover of basal cells. TCA coagulates proteins, and its entry through the domes of papillae induces a specific proteinic coagulation; dermal protein coagulation points occur, clinically appearing as little white marks (white pinpoints) called “frosting points.” It looks like a sunburn desquamation and does not affect the patient’s social life in the majority of the cases. Basal layer peels are usually not dangerous peels. The application technique is important because a perfect protocol is very secure. If the peeling application is a bit too strong, basal layer peeling can nevertheless result in a vicious cycle of inflammation based on free radical liberation that induces cell damage and other problems. If we allow a self-stimulation of this inflammatory vicious cycle, melanocytes could react and cause postinflammatory hyperpigmentations (PIH). Cases of PIH have been seen, making the control of this postpeel inflammatory vicious cycle necessary. No herpes prevention is necessary. Problems primarily are linked to a melanocytary stimulation that is too strong without adequate treatment, to an irregular application, to an application that is too deep, or to infectious rebounds in case of acne. Prepeel skin conditioning can be used at this point if the peeling used does not penetrate evenly or does not control the postpeel inflammatory reaction. Using the Easy TCA® peel or Easy TCA® Pain Control, which is a stronger yet less painful form of Easy TCA®, no prepeel conditioning is necessary. Except in cases of deep scratching and/or strong local infection, no scar is expected from this peel depth.

4      Textbook of Chemical Peels

Depth 3: Basal Layer Peel (High Security) This is a very interesting peeling level because it is easily reached and gives good results. Stratum corneum cells are completely removed; keratinocytes are largely damaged up to the level of basal layer keratinocytes. Nevertheless, the epidermis is not completely destroyed. Because many keratinocytes—less prone to damage by ultraviolet (UV) light—live in deep epidermal papillae, skin regeneration is fast and easy.

Basal layer peels can be used, as serial peelings, to treat aging skin (Glogau I–II), fine lines, epidermal melasma, keratoses, and acne (from black dots up to papule-pustule acne). Together with a good control of melanin synthesis (Blending Bleaching Cream), a TCA basal layer peel can treat many cases of melasma. If the patient’s skin is adequately cleaned (black dots removed, microcysts opened, etc.) and if the patient applies disinfecting creams and creams limiting sebum production, then practitioners can treat active acne, usually without antibiotics.

Table 1.4  Grenz Zone Peels Main types Action mode Clinical signs Desquamation Risks and problems

TCA is a must for these depths. AHAs are not used because of their irregular penetration. It is difficult to use resorcine and salicylic acids to reach the Grenz zone. Phenol should be reserved for other indications. TCA coagulates keratinocyte proteins and dermal proteins, inducing a wider skin “frosting.” No more pinpoints of frosting occur, but “frosting clouds” are seen, together with a diffuse erythema. Easy TCA® Pain Control reaches the frosting clouds more quickly than the classic Easy TCA® because it contains minute amounts of phenol. Desquamation looks like a strong sunburn, which is easy for fair-skinned patients to live with. Dead skin becomes dark brown on darker phototypes. For dark phototype patients, social life can be difficult for a few days. At the same time, the risk of PIH becomes higher, making a “pigment synthesis sedation” quite interesting before and after this peel depth. PIH prevention is mandatory if the patient is phototype Fitzpatrick 4 or more or works outside in a sunny environment. Infections are uncommon at this depth because the immune system is still working. Herpes prevention is not required except in special cases of frequent recurrent herpes attacks. Other problems are the same as for basal layer peels.

Table 1.5  Papillary Dermis Peels Main types Action mode Clinical signs

Desquamation

Risks and problems

AHAs, salicylic acid, alpha-ketoacid, and resorcine are not good choices. Phenol has been used to perform depth 5 peels, but the related toxicity (cardiac, renal, hepatic) contradicts its use at this depth. A TCA peel, correctly applied, is the best choice for a safe and efficient papillary dermis peel. Same as the TCA action mode. After application, frosting clouds progressively or rapidly become pink-white uniform frosting that can progressively or rapidly turn into a pure white frosting. Why does this happen progressively or rapidly? Passing from clouds to even frosting is progressive when we use relatively low concentrations, as with Unideep (23% w/w) or Easy TCA® Pain Control. This concentration allows the practitioner to stop the application as soon as he or she sees the desired frosting begin to appear. An even, pure white frosting rapidly appears when using higher TCA concentrations, such as 35% or 40% (w/w). In this case, it is not possible to stop the TCA action. It can be compared to lighting the fuse of a firecracker; once lit, it is impossible to stop it or to modify the course of future events. Similarly, it is impossible to undo TCA by using neutralization. Frosting appears as pink-white, as long as the acids did not coagulate the blood vessel proteins. When acids have been strong enough for coagulating the well-defended perivascular area, blood cannot pass until the top of the dermal papillae, close to epidermis basal layer, and frosting tonality passes from pink-white to pure white. At the same time the acids penetrate the dermis, they coagulate proteins, sticking epidermis to dermis, and “epidermal sliding” appears. This sign will last for a while and disappear when dermal edema is strong enough for tensing the epidermis over it. It looks like a snake changing its skin and lasts from 6 days (Unideep Peel, Skin Tech) to 8–12 days (usual TCA in water solution, pharmacy made). The patient usually can resume a normal social life the evening after the treatment but not the next morning. Days 2 to 6 are days of reclusion during which the skin will peel in more or less dark plaques, in relation to the patient’s phototype. The most immediate risk is infection: viruses, bacteria, and mycoses find the skin totally open and without defenses. It is easy for them to penetrate and locally proliferate. It is therefore mandatory to prevent viral infections using herpes prevention (i.e., valacyclovir 3–4 days before and 4–5 days after the peel). Bacterial and mycotic infections can be avoided by proper hand and material cleaning and by avoiding any other source of iatrogenic infections. The patient must wash his hands before any contact with his skin (such as scratching), avoid direct contact with pets, and call the doctor immediately with question or concerns. Scratching the skin after a papillary dermis peel usually induces infection. Nontreated or poorly treated infections could induce PIH, depigmentation, or scarring. Another risk results from the fact that some peeling solutions do not evenly penetrate the skin. Simple TCA-in-water solutions irregularly penetrate the tissues and can give uneven results: some areas are too deeply treated (causing local erythema, pigmentations, depigmentations, infections, scarring, etc.). Because the real action of TCA is largely hidden during the application, damage can occur that the practitioner cannot see immediately and cannot correct. Therefore, the concentration of the peeling solution and, more important, the total amount of TCA applied to the skin must be strictly calculated before application. No neutralization of TCA is possible. When using a simple TCA-in-water solution, skin conditioning is mandatory for four main reasons: to allow a more even penetration, to allow a deeper penetration and hence a better result, to keep melanocytes in rest and limit the occurrence of PIH, and to stimulate the basal layer turnover and facilitate postpeel skin regeneration. Mixtures of AHAs, tretinoin, and hydroquinone are often used for this purpose.

Definition and classification of chemical peels   5

Depth 4: Grenz Zone Peel (High Security) This is a very interesting peel level. These peels are easy to perform, are not very painful for the patient, present a low level of risk, and offer good results. Stratum corneum and a large portion of keratinocytes are destroyed. Acids penetrate slightly into the more superficial layers of the papillary dermis, eliminating abnormal cells from the epidermis (treatment of lentigines, keratoses), and eliminating many keratinocytes excessively charged in melanin and melanocytes producing the melanine (melasma). A Grenz (German for “border area”) zone peel also directly stimulates the superficial coats of the papillary dermis, allowing a strong collagen and elastin deposit into the Grenz zone. Grenz zone peels and basal layer peels are the types of peels I use most frequently. Depth 5: Papillary Dermis Peeling (Secure) A depth 5 peel is at the border between secure and insecure depths. This type of peel reaches some limits. It reaches positive limits in the sense that a depth 5 peel is able to treat many skin

defects such as lentigines, solar keratoses, melasma, freckles, and fine lines. It reaches negative limits because a papillary dermis peel is not able to treat real wrinkles or skin sagging. When strictly respected, this depth is safe from scarring; scars should never appear when a peel is strictly limited at the level of the papillary dermis. Depths 6 and 7: Reticular Dermis Peeling (from “Quite Secure” to “Difficult/Dangerous”) A reticular dermis peel can be considered the Holy Grail of peeling: this depth of peel treats nearly all pigment problems, tenses the skin, and removes wrinkles. However, patients with thick and oily skin are not the best candidates for a reticular dermis peel because these skin types resist the action of the acids. Unfortunately, folds usually resist the action of deep peelings. Often, practitioners have to present patients with two therapeutic options: surgical lifting or deep peeling. At Hera Clinic in Empuriabrava, Spain, our first guide is a simple list of options (Table 1.6). Naturally, this list must be adapted to each

Table 1.6  Reticular Dermis Peels Main types

Action mode

Clinical signs

Desquamation

Risks and problems

Two main molecules are used for reaching this depth: TCA and phenol. I use concentrated TCA for focal deep peels and for deeply treating lentigines and keratoses with diameters less than 1 cm (Only Touch, for example, is a 45% w/w TCA), but I would not be keen to use it for large areas, such as a full-face peeling. In this case, phenol seems to be a better choice; its activity depth can be more easily kept under control and the results of phenol are definitively better, even at a similar depth as TCA. It seems that phenol has a stronger “rebuilding effect” on the skin than TCA. My favorite phenol peel is Lip & Eyelid Formula by Skin Tech. It is an oil of phenol that penetrates the skin slowly, which limits its general toxicity (giving the liver, the lungs, and the kidneys more time to detoxify it) and allows a longer contact time between phenol and skin proteins, inducing potentially more protein coagulation and hence a better result. A lighter form of the Lip & Eyelid Formula, a hybrid peeling between a TCA and a phenol peel, is the Easy Phen Light from Skin Tech. Both products are CE Class II certified. Phenol is proteolytic or proteocoagulant, depending on the concentration. Higher concentrations are proteocoagulant and lower concentrations are proteolytic. For peeling purposes, the best concentration range is between 40 and 60% (w/w). Nevertheless, many substances can interfere with its action and speed up or slow down its penetration. These substances are described in Chapters 25–36. Acids reach the reticular dermis after having largely coagulated the papillary dermis, showing a pink- or pure-white frosting. (Depending on the concentration, an aggressive peel will result in an immediate pure-white frosting, without first resulting in a pink-white one.) Quite quickly after the typical papillary dermis frosting, the tonality will shift to a gray-white or to a gray frosting. It is possible to reach this depth by applying various acid concentrations. However, I always feel more secure using less concentrated products and applying more coats. When we use proteocoagulant products, the final result depends on the total amount of active acid molecules that have been able to interact with the skin proteins. A very strong and aggressive peeling solution could induce a superficial thick coagulation, allowing the acids to pass only at the level of higher skin permeability, which could induce irregular results and local overpeelings. When using a progressive application technique, we can always decide to apply no more acid to the higher permeability areas and to keep applying acid to the areas where the desired frosting did not appear. Using this method, I have performed no overpeels during the last 30 years. Desquamation is a major issue that can force a patient into social retirement for 7–8 days. Dead skin layers should be kept as natural protection and extracted only at around day 6 or 7, if this extraction is easy and atraumatic. A phenol peel can be used under a complete 24-hour occlusion, inducing a maceration of the upper coats of the skin. During occlusion, skin melts (in open techniques, skin usually dries) and has to be protected by using bismuth subgallate powder. On day 5 or 6, sterile petroleum jelly can be applied to the dead skin to help the desquamation. Occlusion makes the phenol peel deeper and more efficient. TCA occlusion does not have the same result. Histologically, there is only one reticular dermis, situated between the papillary dermis and subcutaneous tissues. However, with regard to peelings, we face two different depths. In the more superficial reticular dermis, overall at the face level, we still can find keratinocytes (mainly at the level of hair roots and sebaceous glands; sebocytes are phenotypically differentiated keratinocytes, able to undifferentiate into normal keratinocyctes when necessary to repair the skin). The superficial reticular dermis still has material to rebuild the skin. The deep reticular dermis is devoid of this reservoir but contains large fibroblasts, also differentiated to be able to synthesize a thick bundle of collagen that will stick to the neighboring fibroblast. The fibroblasts are considered contractile nonmuscular cells, able to contract when necessary. They are one of the main groups of cells responsible for the scarring process: when these cells are strongly stimulated during a self-maintained inflammatory vicious circle, scarring can appear. All possible side effects can appear when using deep peelings. Pigment problems are common because deep TCA kills melanocytes and phenol can make them impotent, which makes them unable to synthesize melanin. As a result, many cases of unaesthetic depigmentation were seen in the past. A new formulation (Lip & Eyelid Formula from Skin Tech) seems to be much safer in this regard because it primarily induces postinflammatory hyperpigmentations (PIHs) that are easy to treat rather than “porcelain skin” that cannot be treated. Chapters 25–36 give details of many of the possible side effects.

6      Textbook of Chemical Peels Table 1.7  Summary of Skin Problems and Preferred Treatments Problem

Preferred treatment

Pigmentary problems Wrinkles Photo aging Acne Acne scars Sagging skin Pigmentation and sagging Thick skin Thin skin Stretch marks

Peelings Peelings Peelings Peelings Anterior chemoabrasion Surgery Surgery, followed by phenol peel in 6 months Surgery or pixel peel Peeling Anterior chemoabrasion

Deprez P. Chemical Peelings. In: Baran R, Maibach H, eds. Textbook of Cosmetic Dermatology. 4th ed. London: Informa, 2010: 482–93.

type of skin and situation. Typically, we will not recommend a phenol peel to patients with thick, sagging skin and no sun aging problems. On the other hand, we will not recommend surgery to patients who have thin skin without sagging but with important pigment or sun aging problems. The quest for the Holy Grail is risky, as is deep reticular peeling. Not only does the selected peeling solution have to be perfectly adapted to the doctor’s and the patient’s aims, but the application technique and postpeel care also have to be professionally done. Full-face reticular peeling is a very aggressive treatment that does not allow rough improvisation. Any mistake can result in scarring, and pigmentary problems are common. Nevertheless, reticular peels are valuable treatments in the good hands and minds of able practitioners. Because there are no specific diplomas or certifications for these types of peels, experience and knowledge are crucial.

2 Prepeel care IS IT NECESSARY TO PREPARE THE SKIN? Depending on the type of peel, preparing the skin can be essential, pointless, or even dangerous. The chapters devoted to the different types of peels give details of the preparation recommended in each particular case. This chapter deals with the generalities of prepeel care.

Medium- and Long-Term Preparation Alpha hydroxy acid (AHA) peels produce the best results if they are preceded by careful preparation and followed by long-term daily cosmetic care. Easy Phytic® solution, on the other hand, does not allow any prepeel preparation that is likely to accelerate penetration of the acids, as the stratum corneum must be intact for the peel to be safe. In this specific case, prepeel conditioning is to be avoided. Classic trichloroacetic acid (TCA) peels, in a simple aqueous solution in gel or mask form (TCA–SAS = trichloroacetic acid in simple aqueous solution) always require approximately 1 month of intensive prepeel preparation. This preparation stimulates keratinocyte regeneration and reduces the risk of postinflammatory pigmentary changes and scarring. It blocks the first stages of the biochemical conversion of tyrosine into indole groups and melanin, and limits the reaction of melanocytes to ultraviolet light. Easy TCA® and Easy TCA® Pain Control require no preparation under their basic protocol (until scattered pinpoint or cloudy white frosting appears). The preparation required for their special deep-peel protocol or when combined with abrasion is discussed later in this book. Resorcinol produces far better results and fewer complications if the skin is well prepared. Phenol usually does not require any specific preparation but needs careful postpeel care. As a general rule, it is worthwhile to prepare the skin carefully with tyrosinase inhibitors (such as Blending Bleaching® cream from Skin Tech) if there is any risk of postpeel pigmentary changes or to optimize results when treating melasma. Retinoic acid and sometimes glycolic acid are used to make transepidermal penetration more even or to deepen the action of the acid solution.

Immediate Prepeel Preparation Generally, patients must wash their skin with soap and water before going to the appointment. The doctor will disinfect the skin with alcohol and degrease it with acetone or ether. These degreasing products allow the peel solutions, which are usually hydrophilic and have difficulty penetrating the skin’s protective oils, to penetrate more deeply and evenly. The products break down some of the proteins and phospholipids in the cell membranes, which enhances the action of the acids applied afterward. AHA peels require very careful preparation before being applied. The skin should be cleaned with soapy water, rinsed

thoroughly, degreased with acetone, and disinfected with alcohol. Unlike the classic AHA peels, with Easy Phytic®, the skin must be cleaned with a gentle, non-aggressive cleansing foam that contains only surfactants, so that the acids do not penetrate the skin too quickly and saturate its natural buffer capacity, making it impossible for it to neutralize the sudden inflow of acids in time. Thorough cleansing and degreasing of the skin before Easy Phytic® would oblige the doctor to neutralize it in the classic manner; when there is no prior preparation, there is no need to neutralize it. For TCA–SAS, resorcinol, salicylic acid, azelaic acid, or phenol peels, the skin needs to be thoroughly cleansed of makeup, degreased, and disinfected. Easy TCA® solution, on the other hand, contains saponins that make prepeel makeup removal and degreasing unnecessary; the skin’s natural defenses are only very slightly diminished by this peel, and therefore there is no need for any particular prepeel preparation against infections.

PRODUCTS USED TO PREPARE THE SKIN The products usually used to prepare the skin are sunscreens, tretinoin, AHAs, and tyrosinase inhibitors. Jessner’s solution is sometimes used as a prepeel preparation. It is often necessary to take measures to prevent infection, especially herpes.

Prevention of Infection Prevention of the herpes simplex virus is essential for patients who have a history of the infection (a single incidence of herpes is enough). Herpes prevention is necessary with a peel to the papillary dermis. It is also worthwhile when a more superficial peel is usually accompanied by a severe inflammatory reaction, as is the case with resorcinol, “classic” AHAs, and TCA–SAS. It is not necessary when using Easy TCA® under its basic protocol or Easy Phytic®. General infection prevention measures should be taken, depending on the depth of the peel. For more information, see the discussion of infections in Chapter 37.

Prepeel Sun Protection It can be beneficial to protect the skin against the sun before certain peels. Effective sun protection should start 2 weeks before a medium or deep peel and even before a series of superficial peels to inhibit melanocyte activity and avoid excessive stimulation of melanin production before the peel.

Prevention of Pigmentary Changes Before any “classic” peel, steps must be taken to limit the risk of pigmentary changes. Preparing the skin with tyrosinase inhibitors (hydroquinone, kojic acid, azelaic acid, arbutin, Morus Alba, licorice extracts, etc.) is especially recommended to curb the enthusiasm that certain melanocytes have for converting

8   Textbook of Chemical Peels

Figure 2.1  Confetti-like depigmentation.

tyrosine into melanin. Preventive measures should begin 3–4 weeks before a medium or deep peel. Combinations of hydroquinone (2%–4%) plus kojic acid (2%–3%) or hydroquinone (2%–4%) plus glycolic acid (8%– 10%) are effective, as are certain formulas containing several tyrosinase inhibitors, antioxidants, and concentrated retinol (Blending Bleaching® cream). Some patients may develop hyperpigmentation, or even ochronosis, when treated with hydroquinone. Patients with dark skin types are most at risk. Long-term use of high-concentration hydroquinone can also cause confetti-like depigmentation (Figure 2.1). Hydroquinone is prohibited from sale as an ingredient in cosmetic or cosmeceutical products in many countries (although it is available by medical prescription) and has been successfully replaced by new formulas combining other tyrosinase inhibitors. Creams containing azelaic acid (usually at a concentration of 20%) are considered slightly bleaching when used for at least 4–6 months. Azelaic acid is an irritant and is used mainly when other formulations cannot be used. For oily or thick skins, tyrosinase inhibitors can be prescribed in a gel form that penetrates the skin more easily and allows instant and easy application of makeup. For more information, see the discussion of pigmentary changes in Chapter 37.

Even Penetration of Acids and Stimulation of Skin Regeneration To perform a medium or deep TCA–SAS peel, the active molecule in the peel solution has to penetrate more deeply and the skin must regenerate more quickly. Two large groups of molecules are at the practitioner’s disposal: AHAs and retinoids. AHAs (e.g., 10%–15% glycolic acid) break down corneodesmosomes that maintain intercorneocyte cohesion; they make it easier to shed this layer of dead cells (which are, however, essential to the skin’s defenses, as they are largely responsible for maintaining the permeability barrier function in the skin as a whole). The epidermis is thinned by the AHAs, making the stratum corneum more permeable, and the acids can penetrate more deeply and evenly. The risk with this preparation is that the epidermis may become too permeable and the effect of the peel can go too deep. A peel that is meant to reach the papillary dermis could penetrate as far as the reticular dermis as a result

of too “strong” a preparation of AHAs. A peel that is meant to remain intraepidermal could become intradermal and result in postpeel complications and more downtime: an intraepidermal peel removes several layers of “skin-color” keratinocytes in light flakes for around 3 days, whereas an intradermal peel removes the entire epidermis in the form of strips of brownish skin. The darker the skin type, the more visible the flaking. Retinoids form a growing range of products with everwidening indications. The retinoid most used in prepeel preparation is tretinoin. Among other things, it stimulates keratinocyte growth in the basal layer and causes an overall thickening of the epidermis but also a relative thinning of the stratum corneum. The prepeel use of tretinoin enhances penetration of the acids while stimulating the regeneration processes in the keratinocytes of the basal layer. Determining which of these molecules to use depends on the condition of the patient’s skin. Tretinoin is not used if the patient has many telangiectasias; AHAs are avoided if the skin is very thin. Conversely, the two products can be mixed in the same prescription, in variable concentrations, depending on the patient’s skin type and the desired effect. The concentration of tretinoin would be increased to stimulate reepithelialization; the concentration of glycolic acid would be increased to improve and even out transcorneal penetration.

Tretinoin Tretinoin (all-trans-retinoic acid, ATRA) is the carboxylic acid form of vitamin A (retinol). It is one of the first-generation retinoids and has been used since the 1970s to treat acne complaints and dyskeratosis. It is important to have full knowledge about this molecule to obtain benefit from its actions. Histological Changes During long-term treatment with tretinoin, the results can first be seen through a microscope, long before they are clinically visible. These histological changes explain the indisputable clinical efficacy of continuous treatment. The epidermis increases in thickness by 10%–40%, with a thickening of the stratum granulosum to the detriment of the superficial stratum corneum (which decreases by about 25%); the overall water content of the epidermis is thus increased and the skin appears more hydrated. This epidermal hyperplasia is observed both on the face and on the rest of the body, especially on the arms or forearms. Unfortunately, it is not certain whether the improvement is permanent, as some studies show a reversibility of the action of tretinoin (a habituation phenomenon?) after 6 months’ treatment on the forearms and the disappearance of histological improvement altogether 1 year after the start of the treatment, whereas clinically the improvement persists. Normal epidermal differentiation is restored and keratinocyte abnormalities gradually decrease. The atypical keratinocytes are eliminated, and the tretinoin prevents or delays keratoses from reappearing. The melanocyte clusters in the basal layer gradually disperse as a result of the increased cell turnover. The marks on the skin thus tend to be more diffuse, or even to disappear. The overall pigmentation in the epidermis decreases in patients with black skin (32%1 and 23%2) and in patients with yellow skin (41%3). One year after the start of treatment, the melanin content of the epidermis continues to decrease and causes the skin to lighten in the long term. As with chemical peels, a newly formed collagen layer appears, in horizontal bands, just beneath the basal membrane, in the Grenz zone. New active fibroblasts appear in the dermis, and new elastic and collagen fibers are secreted.

Prepeel care   9

An increase in glycosaminoglycans thickens the dermis, and elastotic tissue is pushed deeper down. After 26 months of daily treatment with 0.05% tretinoin, the events described above are extensive enough to push the elastotic tissue deep down and hide it under the new vascular, elastic, collagen, and epidermal growth. It must be noted, however, that not all authors accept the existence of these histological changes in the dermis in the long term. In particular, a study by Gilchrest4 on 500 biopsies carried out during a 5-year observation of daily topical tretinoin treatments (in concentrations between 0.001% and 0.1%) could not find any evidence of histological changes in the dermal parameters. This is surprising and contradicts the established fact that clinically visible angiogenesis exists. Mechanism of Action Tretinoin is a synthetic (all trans) retinoic acid. Retinol and retinaldehyde are also converted into retinoic acid in the target cell where it participates in metabolic activity. The retinoic acid penetrates the cell’s nucleus, where it binds with a retinoic acid receptor (RAR). The complex formed by the retinoic acid and the RAR (RA–RAR) interferes with certain areas of DNA by modulating the expression of some genes. It appears that retinoic acid alters the regulation of the cell cycle.4 For many years, tretinoin was considered capable of reducing sebum production in the sebaceous glands, but serious doubt has been cast on this theory. It is generally thought that the mode of action of tretinoin is essentially linked to the increase in epidermal turnover and enhanced exfoliation of the stratum corneum, which makes it easier for the pilosebaceous units to drain. A reduction in melanin production has also been observed. Used specifically as a prepeel preparation, tretinoin evens out the thickness of the stratum corneum and reduces overall skin thickness. In these conditions, skin permeability increases significantly. Tretinoin also stimulates keratinocyte division and thus facilitates the regeneration phase, which can sometimes be too slow with certain peels. Topical tretinoin stimulates fibroblast production of collagen as well as other components of the dermal extracellular matrix, and sometimes creates a new layer of “repair” collagen that is laid on top of the photodamaged collagen. Indications Clinical results appear slowly and gradually, after histological improvement. The skin soon appears to be intensely hydrated, once the erythema has disappeared or subsided. Clinically, it takes a year for the rejuvenating action of tretinoin to show. Patients who hope to see rapid improvement typically are not pleased with these slow clinical results on aging skin. Progress can sometimes be seen more quickly when treating dyschromia: some results may be seen after 1 month of daily application of 0.1% tretinoin cream. Comedonal acne and acne rosacea respond well to tretinoin. In fact, the anti-aging effect of tretinoin was first observed in patients being treated with tretinoin for comedonal acne: their skin texture and skin tone were gradually seen to improve. Oral isotretinoin (9-cis-retinoic acid) is often used in treating severe or stubborn acne rosacea. A 1994 study5 compared the treatment of rosacea with 10 mg/day low-dose oral isotretinoin, 0.025% low-dose topical tretinoin, and a combination of the two. The results showed that before the 16th week of treatment, isotretinoin was more effective, but that afterward there was no difference between tretinoin and isotretinoin. The

combination of systemic and topical treatment does not give any further improvement in low doses. It is generally accepted that tretinoin with a concentration of 0.05% is as active as 5% benzoyl peroxide. Topical tretinoin makes the skin smoother: the same patients who benefited from the visible rejuvenating effect of tretinoin when being treated for acne noticed, among other things, that their skin had become smoother and softer after treatment. The improvement brought about by this topical treatment is therefore visual as well as tactile. The application of topical tretinoin improves senile atrophy of the skin. A decrease in cell abnormalities and dysplasias can be seen, as well as an antitumor effect that persists after the end of treatment if it has been administered correctly and for a sufficiently long period.6 Topical tretinoin reduces the size and number of lentigines and other age-related discolorations. In some cases, however, because of its photosensitizing potential, tretinoin can aggravate certain types of dyschromia. This can be problematic for Asian patients, for whom hyperpigmentation is more of a problem than wrinkles as they age. The study by Griffiths and colleagues3 proved (clinically, histologically, and by colorimetry) that 0.1% tretinoin significantly improved hyperpigmentation in these patients. There was a 41% improvement with tretinoin, compared with a 37% aggravation in patients receiving the vehicle alone. Postinflammatory hyperpigmentation is also improved by tretinoin, as proved clinically, histologically, and by colorimetry, in a study by Bulengo-Ransby and colleagues2 on subjects with black skin. A 40% improvement can be expected after 40 weeks of treatment with 0.1% tretinoin. In the treatment of melasma, topical 0.1% tretinoin was studied in comparison with the vehicle alone in black patients.1 A 10-month treatment lightened the melasma by 32% (an improvement factor established both clinically and by colorimetry). Histological studies have shown a significant decrease in epidermal pigmentation in patients treated with tretinoin compared with placebo. Of the patients treated with tretinoin, 67% developed only one side effect, a mild “retinoid dermatitis” (which is to be expected when using a concentration of 0.1%). This study also showed that the finest wrinkles disappeared and other wrinkles improved. Overall, skin tone improves because of the combination of histological events in the dermis and epidermis described above. The skin takes on a rosier complexion as a result of angiogenesis occurring deep down. How to Prescribe Tretinoin One study7 showed that a tretinoin concentration of 0.01% is effective for the face, hands, and forearms, whereas another8 showed that there is no difference between placebo, 0.01% tretinoin, and 0.001% tretinoin. A concentration between 0.05% and 0.1% is, on the other hand, always considered active. The average concentration used is 0.05%, but different skin types or sensitivities may require different concentrations, and it is recommended to start any treatment with a trial dose of 0.02% or 0.03%. The following is one frequently used formulation (0.025%): Tretinoin 15 mg Urea (carbamide) 6 g Water 4 g Neribase® cream ad 60 g, or Eucerin® O/W ad 60 g

10   Textbook of Chemical Peels

If this dose is well tolerated, it is possible to go immediately or gradually to a concentration of 0.05%. This concentration is common in proprietary medicines, but if prescription medicines are preferred, it is possible to prescribe 0.05% tretinoin in the following formulation: Tretinoin, 30 mg Urea (carbamide), 6 g Water, 4 g Neribase® cream, ad 60 g, or Eucerin® O/W, ad 60 g Formulations in alcohol gels dry out the skin, increase the penetration of the tretinoin, and make the treatment more uncomfortable. Gels should only be used on thick and oily skin. When the patient can tolerate a concentration of 0.05% without any notable side effects, the concentration can gradually be increased to 0.07%, 0.09%, and 0.1%. Concentrations higher than this are rarely used. If, on the other hand, the skin is very sensitive and becomes irritated in spite of a low concentration of 0.025%, the concentration must be decreased to 0.0125%9 or the patient should be asked to do one of the following. The skin can be sprayed with warm water immediately before applying a small quantity of cream. The cream will spread more easily, and less of the active ingredient will be applied on the skin. Alternatively, the tretinoin cream can be mixed in the palm of the hand with an equal quantity of hydrating vitamin E cream10 to halve the final concentration. If the skin is still sensitive to the treatment, as a last resort the treatment can be applied every other day or once every 3 days for the first month. Experience shows that daily application of low concentrations is a better way to prepare the skin for higher doses than applying higher concentrations two or three times a week. The “normal” concentration for daily application (0.05%) is reached gradually over 2–3 months. It makes little sense to combine tretinoin with a topical corticosteroid to limit the inflammatory reaction. It may well be that this combination is supposed to stop inflammation, but inflammation is beneficial in that it stimulates the process of skin repair. Furthermore, the combined effect of corticosteroid and tretinoin could potentially cause telangiectasia. The tretinoin would stop skin atrophy as a result of the application of topical corticosteroid, whereas it should increase the thickness of the epidermis overall. A large part of the effect would therefore be lost. Finally, corticosteroids should not be applied to the skin for a prolonged period, whereas long-term application of tretinoin is necessary. If the skin is resistant from the start and does not respond at all to the above formulation at 0.05%, a concentration of 0.1% can be used. This high concentration has been shown to produce results rapidly but can often have serious side effects. Therefore, before such a sudden increase in concentration, a few “therapeutic tricks” can be tried: When the skin appears not to respond to a single daily application of 0.05%, a 0.05% cream can be applied twice a day—once in the morning followed by a sunscreen and again in the evening. To increase the effect, it is possible to prescribe an alcohol gel, starting with a concentration of 0.05% and increasing to 0.1% if the patient can tolerate this. To increase the potency of the tretinoin, the impermeability of the skin barrier can be decreased, either by applying a 10% glycolic acid cream 20 minutes before applying the tretinoin or by using a mildly abrasive sponge (Buf-Puf®) on the skin before using the tretinoin. In some extreme cases, a light

facial or body scrub twice a week increases skin permeability and makes it easier for the tretinoin to penetrate. Very superficial microdermabrasion with corundum crystals or sandpaper can also make the skin more permeable. Age for Starting Treatment The lighter the patient’s phototype, the better it is to start treatment at a young age. For example, individuals with skin phototype II can start treatment in their 20s, whereas individuals with skin phototype IV should only start in their 30s. Various Recommendations Tretinoin cream should be kept out of direct sunlight and away from heat sources, to which it is sensitive. In spite of these precautions, it gradually loses its efficacy and it is recommended that the prescription be renewed every 3 months. Tretinoin is sensitive to oxidation, heat, and ultraviolet light; the refrigerator (4°C) seems to be the best place to store this cream. The byproducts of degradation turn the cream a yellowish color, in which case it should no longer be used. Tretinoin is photosensitizing, and it is therefore preferable to apply the cream in the evening and to use a hydrating antioxidant or a cream such as Blending Bleaching® combined with a sunscreen (UVB + UVA + HSP [heat shock protein]) of factor 20 or above in the morning. The tretinoin cream is applied after washing the skin with a mild soap (Avène® or Skin Tech’s Pre-Peel Cleanser® pH5), and is rubbed gently onto the face and neck (very gently on the neck where the skin is more sensitive). It is striking to note that the earlobe is often missed in skin rejuvenation or tretinoin cream treatments and can be a telltale sign of a person’s real age. When tretinoin is applied to skin with seborrheic dermatitis (even when this is subclinical), it is common for erythema to develop, often in the middle of the face. One week’s preventive treatment with topical nystatin can often prevent erythema, and considerably improves treatment compliance. Men whose skin tends to become irritated or infected after shaving can use Dermasebex® foam as a shaving foam or the lotion as a chronic maintenance treatment for avoiding seborrheic dermatitis flares. Shaving soon becomes more comfortable: within 48 hours, the irritation or potential acneform dermatitis has subsided or disappeared altogether. A tretinoin cream could be applied every day for at least 12–18 months and two or three times a week thereafter to maintain the results. When the treatment ends, the effect does not last indefinitely, and the skin slowly returns to a state close to its original condition. However, if the treatment is followed with one to three applications a week afterward, the positive effects remain visible.11 When the treatment lasts 5–6 years, the elastotic material in the dermis is gradually replaced by new collagen and elastic structures.12 The results should last a long time if the skin is protected from factors that accelerate the aging process. Combining tretinoin and benzoyl peroxide could inactivate the tretinoin. If absolutely necessary, benzoyl peroxide can be applied in the morning and tretinoin in the evening. Side Effects Patients should be warned of the high probability of adverse effects, which fortunately are only temporary. Tretinoin is more irritant than glycolic acid. The irritation is usually mild but can take the form of “retinoid dermatitis” if high concentrations are used or if the skin is delicate.

Prepeel care   11

This dermatitis is in fact a positive side effect when tretinoin is used to prepare for a TCA–SAS peel, at least to the level of the papillary dermis, as it helps the TCA penetrate more deeply and evenly. A concentration of 0.05% tretinoin should be used once or twice a day (depending on the thickness and sensitivity of the skin) for 1 week; the following week, the concentration is increased to 0.07% and the third week to 0.1%. This relatively aggressive preparation improves the penetration, evenness, and reepithelialization of the TCA–SAS peel, but will not improve the cosmetic results (or will do so only very slightly). If the skin is not properly hydrated during treatment with tretinoin, it will usually flake visibly and fairly rapidly after a few days of treatment. Erythema is to be expected with effective tretinoin treatment. This is not an adverse effect but rather is collateral and natural. The skin of a patient properly treated with tretinoin is pinker than normal, and this provides the doctor with an essential means of observation. A patient showing no erythema is undertreated or incorrectly treated. Erythema that appears very rapidly, 2–3 days after treatment begins, and that is localized in patches may be seborrheic dermatitis; it soon clears up with nystatin cream. Erythema that appears in the medium or long term, 1 or more weeks later, can spread over the whole face and sometimes to the neck in patients with very sensitive skin. If this should happen, treatment should be stopped for 1–2 weeks and started again at a lower dose, as explained above, to avoid excessive neoangiogenesis. More often than not, retinoid erythema does not last long in patients with a dark skin phototype, whereas patients with a lighter phototype can suffer from persistent, if not permanent, retinoid erythema. Sometimes, the redness is more of a passing flush than fully established erythema. The skin becomes more sensitive to the sun, perfumes, and detergents. In fact, from the start of treatment, the skin becomes more sensitive to any irritant. Patients should beware of chemical hair removal products, waxes, dyes, and similar products. People who use tretinoin often report that their skin is more sensitive to the sun and burns more easily. This photosensitization is better explained by the thinning of the stratum corneum rather than by a photochemical reaction between the tretinoin and the sun’s rays. It is therefore essential to recommend the use of a sunscreen (SPF 25–50 UVA + UVB + HSP induction) to patients being treated with tretinoin. It should also be borne in mind that there is a potential risk of skin cancers developing as a result of the stratum corneum thinning and the enhanced penetration of the sun’s rays. Nevertheless, it appears that patients on long-term tretinoin treatment do not have a higher incidence of skin cancers. Tretinoin has in fact proved to be effective in the treatment of photoaging and actinic keratoses. Teratogenicity of Tretinoin To date, and in spite of the fact that no teratogenicity has been officially attributed to tretinoin,13 we do not have all the necessary facts at our disposal to allow its unreserved use during pregnancy or in women who wish to become pregnant. Despite the fact that application of tretinoin under occlusion on more than 30% of the body has not been found to lead to any abnormal increase in plasma levels, and despite there being no higher incidence of fetal deformities among the children of women who have used tretinoin during the first months of

pregnancy, it is nonetheless possible for retinoic acid to penetrate the cell nucleus and alter the expression of certain genes.4 Caution dictates that one should not go ahead with treatment in a particular case until all the necessary facts are available to allow a risk-free choice to be made. Hypervitaminosis A is theoretically possible and could be insidious and chronic.14 Practitioners should remain on their guard and make sure that patients are not taking extra vitamin A supplements.

BENEFITS OF SKIN PREPARATION Major Benefits Avoiding Various Side Effects Preparing the skin before a TCA–SAS peel helps prevent herpes and bacterial and mycotic infections. It also helps reduce the risk of inadequate results (thanks to combination with other treatments). Improved Penetration of the Active Product Preparation with AHAs or tretinoin reduces the thickness of the stratum corneum, the skin’s natural barrier. As the barrier is not as thick, it is easier for the products applied to the skin to penetrate to the basal layer of the epidermis and more deeply into the dermis. It should be noted that not all peels require this kind of preparation.15 Even Penetration of the Peel The skin does not have the same thickness all over, and this can produce differences in the level of penetration. Correct preparation with AHAs and/or tretinoin tends to even out the thickness of the skin and allow the active products of the peel to penetrate evenly. Areas of hyperkeratosis (senile keratoses, and flat and seborrheic warts) are a perfect example of this difference in the level of penetration. Keratoses, which are characterized by a localized thickening of the stratum corneum, are less permeable to the acids. Prepeel preparation with tretinoin evens out the thickness of the stratum corneum and hence the overall permeability of the epidermis. Reduced Risk of Pigmentary Change Patients with olive and dark skin, or of Hispanic or Asian origin, are more prone to pigmentary changes than patients of Caucasian origin. It should be remembered that genotype does not always correspond to phenotype and that there are light skins that react in the same way as dark skins.16 Tretinoin, even more than AHAs, disperses melanin granules and reduces the overall quantity of melanin in the epidermis. This reduces the risk of postinflammatory or postpeel pigmentary changes. Tyrosinase inhibitors should be used in postpeel treatment as well as in prepeel preparation (1 month before the peel when there is a risk of pigmentary change, i.e., when TCA–SAS or AHA peels are used). Some commercial creams have interesting formulations with AHAs (to enhance penetration of the other active products), tretinoin precursors, lactic acid, extracts of Morus Alba, and kojic acid, combined with Transcutol®, an adjuvant that concentrates the active products near the basal layer and the melanocytes. Accelerated Healing of the Skin After a peel, the skin needs to heal as quickly as possible to maintain homeostasis of the whole organism. Tretinoin

12   Textbook of Chemical Peels

accelerates reepithelialization if used before the peeling. For this it must be used at a dose of 0.05%–0.1%, sometimes to the point of irritative dermatitis. Ideally, the treatment should start 3–4 weeks before a TCA–SAS peel. It is accepted scientifically that the preventive application of tretinoin promotes postpeel healing of the skin. In contrast, applying tretinoin during the postpeel period appears to slow down skin regeneration. Not all peels require this help with re-epitheliazation.

Minor Benefits

Testing Patient Compliance A patient who refuses to comply with instructions for preparing the skin before a peel will not be naturally inclined to heed advice for care during or after the peel sessions either. It is always preferable not to “peel” a patient who is incapable of understanding or accepting these instructions. Testing patient compliance is all the more important because preparing the skin and keeping up cosmetic care afterward affect the quality of the results. Getting an Idea of Follow-Up Care For patients who accept it, preparation gives them a taste of between- and postpeel care. Monitoring Skin Preparation Monitoring the preparation process can give the practitioner an idea of how reactive and sensitive the skin is. Thus, a patient who cannot tolerate hydroquinone during prepeel preparation will tolerate it even less in the days following the treatment as the skin becomes more sensitive to any irritant. Similarly, if the patient develops an allergy to one of

Figure 2.2  Treatment of telangiectasias by (Ellman ®) radiofrequency immediately before the application of Easy TCA®. Scattered pinpoint frosting signals the penetration of the acid at each point treated by radiofrequency. This combination significantly reduces scabbing and includes a “pixillized” deeper peeling.

the products used in the preparation, it can be isolated and avoided after the peel. Combination Treatments Other treatments can be combined with the prepeel preparation: shave excision, electrocoagulation, ablations, botulinum toxin, dermal filling, mesotherapy, and so forth. Some peels can be used simultaneously with these techniques. For example, a phenol peel can be immediately preceded by shave excision of raised benign lesions. Easy TCA® can be immediately preceded by botulinum toxin, dermal filling, electrocoagulation of telangiectasias (Figure  2.2), mesolift, intense pulsed light (IPL), depilation, and other treatments. For more information about combination treatments, please refer to Chapter 38.

NOTES 1. Kimbrough-Green CK, Griffiths CE, Finkel LJ, et al. Topical retinoic acid (tretinoin) for melasma in black patients. A vehiclecontrolled clinical trial. Archives of Dermatology. 1994; 130: 727–33. 2. Bulengo-Ransby SM, Griffiths CE, Kimbrough-Green CK, et al. Retinoic acid treatment for hyperpigmented lesions caused by inflammation of the skin in black patients. New England Journal of Medicine. 1993; 328: 1486–7. 3. Griffiths CE, Goldfarb MT, Finkel LJ, et al. Retinoic acid treatment of hyperpigmented lesions associated with photoaging in Chinese and Japanese persons. Journal of the American Academy of Dermatology. 1994; 30: 76–84. 4. Gilchrest BA. Retinoids and photodamage. British Journal of Dermatology. 1992; 127(Suppl 41): 14–20. 5. Ertl GA, Levine N, Kligman AM. A comparison of the efficacy of topical tretinoin and low-dose oral isotretinoin in rosacea. Archives of Dermatology. 1994; 130: 319–24. 6. Published studies disagree on the efficacy of tretinoin. 7. Andreano JM, Bergfeld WF, Medandorp SV. Tretinoin emollient cream 0.01% for the treatment of photoaged skin. Cleveland Clinic Journal of Medicine. 1993; 60: 49–55. 8. Olsen EA, Katz HI, Levine N, et al. Tretinoin emollient cream: A new therapy for photodamaged skin. Journal of the American Academy of Dermatology. 1992; 26: 215–29. 9. By altering the formulations given above: 7.5 mg tretinoin in 60 g of cream. 10. Vit. E Anti-oxydant ® (Skin Tech) or a similar cream. 11. Thorne EG. Long-term clinical experience with a topical retinoid. British Journal of Dermatology. 1992; 127 (Suppl 41): 31–6. 12. Not all studies endorse this long-term treatment. 13. Guzzo CA, Lazarus GS, Werth VP. Dermatological Pharmacology. In: Hardman JG, Limbird LE, Molinoff PB, Ruddon RW, Gilman AG, eds. Goodman & Gilman’s The Pharmacological Basis of Therapeutics. 9th ed. New York: McGraw-Hill, 1996: 1600. 14. Farnes SW, Setness PA. Retinoid therapy for aging skin and acne. Postgraduate Medical Journal. 1992; 92: 191–6, 199–200. 15. For example, Easy TCA® and Easy Phytic® need no prepeel preparation. 16. This is why it is important to question the patient.

3 Postpeel care IMMEDIATE POSTPEEL CARE Immediate postpeel care is described in detail in the chapters dealing with each type of peel. As a general rule, tretinoin and creams with an alpha hydroxy acid (AHA) concentration of more than 10% should be avoided before the exfoliation phase is completely finished.

ABOUT ACIDS NEUTRALIZATION Acids neutralization is a recurrent problem. Questions often arise as to what should be neutralized and why, when neutralization should be done, and how it should be performed. The concept of neutralization emerged with the dermatological use of AHAs. Preexisting peelings, such as with phenol derivatives and trichloroacetic acid (TCA), had not and could not be neutralized, because proteocoagulant molecules definitively interact with the skin’s proteins, combining with them and forming a conglomerate that cannot be separated. As a result of this interaction, non-AHAs are largely and automatically neutralized and trapped into destroyed proteins whose tridimensional structure has changed, inducing the wellknown sign of “frosting.” Neutralization of proteocoagulant acids is therefore impossible after their action has begun. At a maximum we could neutralize an eventual floating excess over the skin, before this excess could penetrate the skin. However, is this even possible? Neutralizing proteocoagulant acids (such as TCA) is very challenging because we have to consider timing: Frosting is a signature of past events. The frosting that we see does not represent what is happening but rather what happened to the skin some time ago. Frosting events have a kind of invisible inertia; they are not an immediately appearing phenomenon. Proteocoagulation will continue during the neutralization process. It is therefore very risky to apply too much of the (phenol derivative or TCA) acid on the skin, thinking that it will be possible to neutralize it after a frosting appears. Applying too much of the acid can result in overpeeling. Trying to neutralize TCA after seeing frosting can be compared to trying to stop an arrow just before it touches the target. Moreover, neutralizing a proteocoagulant acid never reverses the potential damage to cellular proteins or matrix proteins. When an acid combines with amino acids to form a protein, it is transformed into a salt that sticks to the amino acids and modifies the volumetric, tridimensional, proteinic appearance. A safe procedure is to rub on the skin the right amount of acids to get the desired frosting, without any neutralization. Remember that proteocoagulant acids pass through the epidermis in only a few seconds. Therefore, phenol induces skin anesthesia only 12 seconds after its application. AHAs have a very low proteocoagulant power; they do not easily combine with proteins. Their natural neutralization by the skin occurs using the skin buffer potential, which is slow acting. Without neutralization, pure, nonpartially neutralized AHAs would eventually burn the skin.

We cannot neutralize an acid by adding water to it. When we pour water into an acid solution, we just dilute the acid; a huge dilution is necessary to lower the resulting pH. Pouring water on the face after a peel therefore cannot be considered neutralization. Pouring a basic solution in a recipient containing acid will induce chemical acid–base reactions; the acid will become a salt that has no more protons to liberate in solution and therefore is no longer an acid. Neutralization changes the chemical structure of acids. Simple sodium bicarbonate in a saturated solution can be used to neutralize AHAs. The answer to the question of what should be neutralized is simple: We neutralize AHAs, but we cannot neutralize proteocoagulant molecules. A slightly basic solution, in good volume, will be poured on the skin until the chemical reactions (usually seen as little bubbles) cease. Neutralization of AHAs should begin as soon as an erythema can be seen and before any frosting appears. The next question is: When should we neutralize AHAs? A too early neutralization does not give the acids enough time to interact with the skin, and the result will be very poor. A too late neutralization allows the acids to burn the skin and induces many side effects. For these reasons, the industry proposes partially neutralized AHAs (pH 2.5, 3, 3.5), which are less dangerous. They can be washed with simple water because they are between 10 and 1,000 times less aggressive (efficient) than pure AHA solutions, without partial preneutralization. One exception to this rule is Easy Phytic Solution® (EPS). Despite the solution’s very acid pH (0.5–1) and an average total acids concentration of 60%, this AHA solution does not need to be neutralized. Its time-controlled technology permits a slow release, a complete progressive penetration, and a full action of all acids. Because neutralization is not necessary, this solution offers greater efficacy. The best indications for EPS are acne treatment, and photoaging prevention and treatment. EPS comprises three AHAs: glycolic acid, lactic acid, and mandelic acid. AHA is adsorbed on the polar groups of keratin chains and inhibits the reactions between these groups. This improves the elasticity of the skin and AHAs are better for that than beta hydroxy acids (BHAs) because the alpha position of the hydroxyl group allows a better penetration between keratin chains than the beta position. The three AHAs show different velocities of penetration through the skin. Glycolic acid penetrates first, followed by lactic acid and then mandelic acid. These acids begin their action at the level of the upper layers of the epidermis. Because there is no neutralization, they continue their action, slowly moving down to the epidermis and reaching the dermis, without interfering with the skin’s capacity to naturally neutralize itself. The EPS acids progressively become less aggressive, producing their full effect. Phytic acid is not an AHA but is a large molecule of inositol hexaphosphoric acid that is considered an excellent antioxidant and an antityrosinase. It binds out iron. Phytic acid cannot produce a peeling effect. So why is

phytic acid in this peeling formula? Every peeling produces an inflammation; this inflammation produces free radicals (FRs) and vasodilatation. Vasodilatation brings more oxygen in situ, allowing the formation of more FRs. FRs bind immediately with the closest structure, damaging it. Therefore, a peeling always promotes skin regeneration but induces many FRs that can damage the structures that are supposed to regenerate the skin during the postpeel period. Science generally identifies FRs as among the major causes of cell degeneration in the aging process. It is important to fight these FRs during the postpeel period. Phytic acid slowly penetrates the skin, after the other acids: It is present in the skin when FRs are produced, when inflammation develops. Scavenging FRs stop the vicious cycle of inflammation–vasodilatation–FR. It is known that AHAs make a thicker epidermis, produce more polymuccosaccharides in the dermis, and make a better quality elastin. The density of papillary dermis collagen is better after application of the solution, and patients treated with EPS describe a tightening sensation after peeling and a visible difference in the skin. To use EPS, first cleanse the skin twice with Skin Tech Cleanser, rinse, and dry. Apply a maximum total volume of 2.5 cc of EPS on the face, using a small cotton ball that has been dipped only once in the peeling solution. Apply EPS in successive coats, checking the face between every coat for uniform application. Two or three coats are usually sufficient. When the patient indicates that he or she feels a tingling sensation, apply the last coat, using the same cotton ball. No frosting should occur. DO NOT NEUTRALIZE. One exception: In the event of accidental frosting, neutralize immediately (using a sodium bicarbonate solution). For more information about the details of the application technique, please refer to the directions provided with the solution or visit www.skintech.info. Another neutralization system from Skin Tech is the Easy Droxy Complex Peel & Versicolor Neutralizer. The peel is a mixture of AHA, BHA, carboxylic acids, and kojic acid, in a thick liquid crystal gel that is neutralized by the application of a neutralizing cream that changes color when the skin is totally neutralized. The cream is naturally blue; it turns yellow when the skin is acid and green when the skin is at pH 7. This patented system allows perfect control and uniform neutralization.

SUN PROTECTION Every peel, even a very superficial one, reduces the thickness of the stratum corneum that protects the skin against the effects of radiation. The diffractive and reflective protection usually afforded in these outermost layers is no longer available, and the overall quantity of rays that penetrate the skin increases. This extra radiation can cause actinic damage in cells that are usually physically protected by the thickness of the skin. Melanocytes are more strongly stimulated, and there is an increased likelihood of pigmentary change. All peels thus allow the sun’s rays to penetrate more easily to at least the basal layer of the epidermis, where keratinocytes ensure reepitheliali­ zation and melanocytes can induce hyperpigmentations. Greater irradiation increases the risk of these cells being genetically modified. All peels put the skin at risk of light stress, which makes the use of sun protection creams essential. A powerful, broad-spectrum sunscreen provides greater protection. The deeper the peel, the more important it is to use sun protection. After any medium or deep peel, the patient must use an effective sunscreen of sun protection factor (SPF) 30 or

% UVB blocked

14   Textbook of chemical peels

110 100 90 80 70 60 50 40 30 20 10 0

96

98

SPF25

SPF50

90

50

0 SPF0

SPF2

SPF10

Figure 3.1  An SPF of 50 protects the skin against 98% of UV. A higher protection factor is not necessary.

50+ (ultraviolet A [UVA] + ultraviolet B [UVB] + heat-shock protein [HSP] inducers) for 6–12 weeks (depending on the depth of the peel) (Figure 3.1). The sunscreen should be applied immediately after washing in the morning, preferably with a cleansing lotion. Postpeel sun protection should be reapplied every 3 hours on average under any makeup, even if the makeup itself is considered to be photoprotective. After a peel, sun protection is necessary even if the patient does not go outside and even in foggy or cloudy weather: windows block out most UVB but not UVA, and not all clouds filter UV. Halogen lamps and spotlights and cathode-ray screens also appear to produce a sufficient quantity of radiation to induce postinflammatory hyperpigmentation (PIH) in sensitive individuals.

Effective Sun Protection Factor The SPF should be even more “aggressive” when treating postinflammatory hyperpigmentation, and should protect against UVA as well as UVB. Protection from the sun means not only avoiding lying on the beach but also avoiding daylight. The skin is subjected to many light shocks; it is constantly under attack from the sun and daylight. One pitfall to be avoided is applying sunscreens that contain tanning accelerators that could have a harmful effect.1 Between peels and during the first few weeks after a peel, a generous amount of Melablock HSP® 50+ sun cream, for example, should be applied every 3 hours.2 Thereafter, daily sun protection can be lighter: for example, Melablock HSP® 30 applied at 9:00 a.m., 12:00 p.m., and 3:00 p.m. (Figure 3.1a). Patients should be advised to keep their backs to the sun and to wear light protective clothing (Figure 3.1b). UV is not the only cause of hyperpigmentary reactions; infrared rays can also cause them.

Heat-Shock Proteins The process of wound healing after thermal injury (e.g., from laser treatment) involves reepithelialization that starts within the first few hours after injury and continues throughout the different proliferative phases of skin repair. Viable keratinocytes (Figure 3.2) that are at the edge of the wound and have not suffered lethal or sublethal heat shock migrate horizontally and centripetally to form an initial single cell layer of keratinocytes, the “new basal layer,” before starting vertical growth that will regenerate a normal epidermal structure. Reepithelialization uses up a lot of proteins, both during the synthesis of the temporary matrix that acts as a protein highway for the new keratinocytes and during the intense mitotic activity that creates new skin cells. Proteins are absolutely essential to cell life; each enzyme in the body is a protein whose

Postpeel care   15

Laser target

Peripheral damage

Figure 3.2  Diagram of the peripheral thermal damage after ablative laser treatment. The number of lethal lesions is proportional to the degree of shading. The skin is repaired from peripheral keratinocytes: some have suffered sublethal damage. Heat-shock protein (HSP) inducers help improve keratinocyte resistance to heat shock.

Figure 3.1a  Under Wood lamp: Melablock HSP 50+ has been applied on the right half of the face of this patient. This shows that there is no latency in the sun protective effect.

unique three-dimensional structure is responsible for its highly specific action. Proteins have vital functions that are specific and strictly linked to their three-dimensional structure. The spatial structure of proteins is altered by even the slightest increase in temperature;3 any thermal stress can “unfold” the cell proteins,

Figure 3.1b  Sun exposure of 2 hours, during summer: The back was protected by white clothing and shows no erythema. The shoulder was protected by one coat of Melablock HSP 50+, but the patient could not correctly apply the sun protection cream on the back side of the arm (triceps area). The protected area shows the same absence of sun damage as the covered area. In the center, there is a surface that was sun exposed without any protection: dark erythema, edema, and blisters appeared.

making them ineffective and leading to apoptosis (programmed cell death). In laser or flashlamp treatments, the temperature of the target must be raised in order to destroy it, but the normal cells around the target also undergo sufficient heat stress to induce apoptosis or severely disrupt cell function. The rise in temperature thus creates a central zone of lesions that are lethal to cells, surrounded by a peripheral zone of sublethal damage in which the heat-damaged cells must be repaired or replaced. As a result, skin regeneration may be slower than it should be as the cells on the edge of the treated area grow and migrate. Preventive protection of the proteins in the cells surrounding the target, increasing their resistance to heat, can help enhance the skin healing process and reduce the incidence of complications associated with slow reepithelialization. Where there is sublethal damage, or very light damage, the cells must eliminate or repair the damaged and ineffective proteins, increase protection of the proteins that did resist the heat, and synthesize new replacement proteins. This is where HSPs or stress proteins are necessary. HSPs were discovered in the early 1960s in the fruit fly in response to an increase in cell temperature of just a few degrees. These proteins were subsequently found in all types of living cells; they are secreted in response to any kind of stress, not only in response to increased temperatures. HSP70 and other similar stress proteins appear rapidly in the cytoplasm and mitochondrial matrix of cells that are subjected to stress. Essentially, their role is to ensure protein viability. HSP70 binds to polypeptide chains as soon as the latter have been synthesized in ribosomes (which translate RNA information into the amino acid sequence of the polypeptide) and facilitate the folding of these chains into the three-dimensional structure essential for protein activity. HSP70 then separates from the folded protein. HSP70 is a member of a group of diverse proteins (also including HSP60 and the chaperonins) that play an essential role in creating the appropriate three-dimensional structures of other proteins but do not themselves form part of that final structure. This group of proteins are also known as molecular chaperones and have a fourfold role: in addition to providing the correct spatial structure for a new protein coming out of the ribosome, they also protect the structure of existing proteins, repair damaged proteins by refolding them correctly, and act as protein transporters, carrying proteins from one place to another within the cell and

H

H

H

HO

O H

OH

O

HO

O OH

H

OH HO

H

H

H H

H

Keratinocytes percentage survival

16   Textbook of chemical peels

40 35 30 25 20 15 10 5 0

OH HO

Figure 3.3  Chemical structure of trehalose.

eliminating proteins that are irreparable. Some HSPs are constitutional and others are inducible. The latter are synthesized in greater numbers after stress and give the cell increased resistance to future stress, thus allowing the cell more time to repair itself without having to resort immediately to apoptosis. With age, HSP function deteriorates in human skin, and aging cells are increasingly more prone to protein destruction.

Sun Protection and HSPs It is beneficial to boost the synthesis of HSPs in the cytoplasm and mitochondrial matrix of cells subjected to heat and light stress, thus improving not only their resistance but also their defenses and better equipping them to repair proteins in case of stress. An interesting disaccharide, trehalose (Figure 3.3), was isolated from cells of organisms that can survive in extreme conditions such as dehydration; having this disaccharide in sufficient concentrations allows these organisms to increase their resistance to the lack of water. It has been shown4 that trehalose can stimulate HSP70 production. An interesting experiment showed that this disaccharide increases cell viability after exposure to UVB. The study involved subjecting a culture of keratinocytes to a slight increase in temperature of 3°C for 1 hour in order to induce slight heat stress. The keratinocytes were then cultured for 6 hours either in a medium containing trehalose or in a medium without the disaccharide. After 6 hours, the culture medium was replaced by a physiological saline solution and the keratinocytes were exposed to UVB radiation. Cell viability was studied after 48 hours. There was a huge difference in keratinocyte survival in the cells from the different culture media: only around 4% of viable keratinocytes remain when cultured without trehalose ester, whereas the survival rate was nearer to 40% in the group of keratinocytes cultured in the medium rich in trehalose (Figure 3.4).

SPECIFIC CARE FOR DIFFERENT PEELS AHAs If an AHA peel is done correctly, no particular medical care is necessary, no matter what concentration or pH is used. In general, after an AHA peel, all that is necessary is good hydration and effective sun protection for 2 weeks. AHA peels weaken the barrier function of the stratum corneum and thus increase its permeability; they make it easier for the active molecules to penetrate the epidermis when creams are applied both immediately after and between peeling sessions. The type of cream depends on the problem being treated. The results for acne treatment can, for example, be improved by applying a layer of anti-acne cream

0% 0.5% Trehalose ester concentration

1%

Figure 3.4  The viability of keratinocytes exposed to UV after a 3ºC increase in temperature is very low, only a few percent. When cultivated in an environment rich in trehalose ester, the viability is close to 40% under the same conditions.

immediately after a “classic” AHA peel has been neutralized and leaving it to act under an occlusive dressing5 for around 30 minutes. The patient can apply the same cream twice daily thereafter. The same applies for melasma and aging or sagging skin.6 After an AHA peel, the patient’s daily care routine plays an essential role in determining the quality of the results. Mesotherapy can be combined with AHA peels in a number of ways: the “mesolift” mixture7 can be injected before the peel or immediately after the peel has been neutralized and before creams are applied under occlusion. There is no danger of the glycolic acid penetrating beneath the skin through the perforations made by the mesotherapy needle. Most often, however, the treatments are alternated every other week: in the first week, the peel and the cream under occlusion are applied, and in the following week, the mesolift is injected, followed by the cream under occlusion. If an AHA peel is done correctly, there is usually no downtime. Nevertheless, there can be complications, which are described in Chapter 10.

Resorcinol Resorcinol in paste form9 is used in a very specific manner: the paste is usually applied three times, once a day for 3 days in a row. Postpeel care is very important during the following week: the skin should not be hydrated at all, as it has to dry out completely for the peel to be effective and, above all, the patient must not pull off or pick at the flaking skin. Only the doctor can safely cut off any strips of flaking skin with sterile scissors. Cosmeceutical creams for age spots, acne, aging or sagging skin, and other conditions should only be applied after the skin has flaked. Effective sun protection (UVA + UVB + HSP inducers) is absolutely essential for approximately 6 weeks after the peel. Downtime may be around 4–5 days. After the first application of the paste, the patient can usually have a normal social life, but subsequent applications dry out the skin and leave it looking papery.

TCA–SAS TCA in simple aqueous solution (TCA–SAS) involves prepeel preparation, application of the TCA–SAS solution to the required depth (usually the papillary dermis), flaking, natural skin regeneration, and postpeel care. The postpeel period for TCA–SAS requires special attention and, even if the peel is applied correctly, pigmentary changes are the most common and benign complication. It is clear from the many illustrations in books on TCA–SAS peels that there is

Postpeel care   17

an astonishing variety of post-TCA pigmentary changes, with varying degrees of severity. If prepeel prevention does not prove effective, or in cases of localized overpeeling, postinflammatory hyperpigmentation (PIH) usually appears within a week after the peel in the form of dark patches or persistent erythema that will become pigmented under the effect of the sun’s rays. For more information, see the section on hyperpigmentation in Chapter 37. These genuine pigmentary changes should not be confused with the darkening of epidermal melasma appearing the next day after the peeling, and caused by dehydration of the hydrophilic spaces between melanosomes, which makes the skin seem to have a greater concentration of melanin and hence appear darker. This darkening, which is temporary, is a positive sign and will fade at the end of the first week. Flaking should not be helped along under any circumstances. Peeling off any bits of skin can result in uneven skin tone, infection, hyperpigmentation, scars, or localized achromia. It is also essential to take preventive measures against infection after a papillary TCA–SAS peel, as the latter destroys most of the skin’s defenses. An antibiotic cream is applied during the first week after the peel. The skin should be cleaned before each application of cream, and any occurrence of contact allergies, which can sometimes be confused with secondary infections, should be monitored. The results of a TCA–SAS peel also depend on the quality and consistent use of cosmeceuticals after the peel. It is clear that a melasma treatment will produce better results if the TCA–SAS peel is followed by the application of a retinol–antityrosinase–antioxidant cream or a hydroquinone-based preparation. For acne or aging or sagging skin, the same comments apply as for AHAs above. These creams can be applied as soon as flaking is finished, usually on the seventh day. Effective sun protection is essential and should be used in the first few days after the peel, before the skin has stopped flaking. Even a total sunblock is not enough to avoid pigmentary changes altogether, and the patient should be told to completely avoid exposure to the sun. Sun creams containing tanning accelerators should, of course, not be used after the peel.9 Chemical tanning with sprays containing dihydroxyacetone should also be avoided, as these products, which are nontoxic when picked up by the corneocytes and eliminated within 1 week, are not intended for keratinocytes, which are the cells exposed to the external environment during the first days after a peel. Downtime is around 1 week following a TCA–SAS peel, after which makeup can be used from the eighth day to cover up any persistent erythema.

Easy TCA® Easy TCA is an exception among TCA peels, as is Easy TCA Pain Control, and should be distinguished from TCA–SAS as it does not require prepeel care in the medium term nor any immediate prepeel preparation, and pigmentary changes are very rare if the “basic protocol” is followed.10 Some brown discoloration is possible after the first or second application, but this should fade after the following peel. Flaking skin can be peeled off or a light cosmetic scrub can be used. With deeper protocols, which are not usually necessary with this peel, there is a greater likelihood of complications. Combining Easy TCA with appropriate postpeel cosmeceuticals helps improve and maintain results. The cosmeceuticals should be applied the day after the first peel and continued between sessions and for at least 6 weeks after the

last application. As with any peel, effective sun protection is necessary to make up for the temporary loss of the stratum corneum. Easy TCA causes the skin to flake, but not so much as to disrupt the patient’s social life, although certain activities may be compromised: television presenting, customer contact in the food industry, and so forth. Easy Phytic is recommended in these cases as there is almost no visible flaking of the skin (see Chapter 11).

Phenol Phenol entails the most complex postpeel care: occlusive masks, healing masks, and cosmetic care during the months following the peel. Chapters 25–36 are devoted to this technique. The expected downtime is between 7 and 15 days, depending on the formula used. The patient will have to wear camouflage makeup to hide any redness, which can last for several weeks or months.

POSTPEEL COSMETICS Chemical peels do not always treat the underlying cause of a skin problem. For example, there can be many causes of acne, and chemical peels do not alter the synthesis of testosterone or the potency of the 5-alpha reductase that converts testosterone into its active derivative, dihydrotestosterone. Acne may also be partly due to excessive cell cohesion that blocks the sebaceous glands or to an immunodeficiency of genetic origin. Chemical peels do not alter an individual’s genetic makeup. Follow-up care should come after the peel, which is only the first phase of the treatment. Topical anti-acne treatments or cosmetics should be used between and after the peels to improve and prolong results. The same goes for blemishes, melasma, and aging. Peels can provide quick cosmetic results, but it is the care between and afterward that improves and maintains them. This is why the same peel may be indicated for the treatment of acne, which typically affects young patients, as for aging, which affects older patients. In short, we can say that chemical peels regenerate, restructure, and stimulate the skin, and that care between and after peels widens their indications to problems such as acne, dyschromia, and aging.11 Cosmetic products have been specially created for application very soon after a peel. For example, products such as Easy Phytic or Easy TCA can be used the morning after the first AHA peel. With TCA–SAS, Only Touch®, or phenol peels, cosmetics usually are not applied until the eighth day after the peel. With Unideep®, an antioxidant cream (Nutritive ACE Lipoic Complex®) can be applied two days after the peel. IPLase Mask (Skin Tech) has a strong anti-erythema and anti-inflammatory efficiency, allowing its use after deep procedures generating pain, erythema, or swelling. It has been used with success after papillary dermis peel, reticulary dermis peel, laser and intense pulsed light (IPL) treatment, and even against radiodermitis, a side effect of anticancer radiotherapy treatments.

Treatment for Acne Tretinoin should be avoided between and after sequential peels, as it can irritate the skin and increase penetration of the acids during the next peel. Other topical products can be used. Glycolic acid can be applied in low concentrations (8%); it makes the skin softer to the touch. Like retinol, it prevents pores from clogging, helps the pilosebaceous units to drain, and stimulates skin turnover. Tocopheryl acetate can be used as an antioxidant to combat the FRs generated by inflammation. Triclosan12 is antiseptic, anti-inflammatory, and antimycotic. Glycyrrhetinic acid is used

18   Textbook of chemical peels

for its hydrating, antipruritic, and anti-allergic properties. It stops patients scratching. Tea tree oil (Melaleuca alternifomlia) is extracted from an Australian shrub and has a similar action to benzoyl peroxide but without its peroxidative effects. It is antiseptic (antibacterial: anti-gram-positive and -negative), anti-­inflammatory (it can suppress the production of pro-inflammatory mediators), antimycotic (anticandida and antidermatophyte), and even antiviral, acting before and after viral adsorption. Other topical treatments can also be applied: azelaic acid, antibiotic creams, disinfectants, and others. For more details, please see Table 17.2.

Treatment for Hyperpigmentation Chemical peels are one of the preferred indications for hyperpigmentation. A number of cosmetics can be used between and after peels. Hydroquinone has been used for a long time and still is used in many countries. Its cosmetic use, however, is forbidden in Europe. Many depigmenting derivatives can be used in its place. Kojic acid can be used pure or as an extract of Aspergillus and has an antityrosinase and antioxidant action. It even potentializes leukocyte phagocytosis. Glabridin (a licorice extract) inhibits the pigmentation and erythema caused by UV; it is antityrosinase and anti-inflammatory. Liquiritin contains glycyrrhizin and glycyrrhetinic acid (which are anti-inflammatory as they inhibit the degradation of endogenous cortisol) and antioxidant flavonoids. Extracts of Morus alba contain arbutin and mulberroside F, which are both tyrosinase inhibitors. Mulberroside F is also an antioxidant. Transcutol® helps build up a reserve of active products near the dermoepidermal junction and improves the action of tyrosinase inhibitors. AHAs can be used to enhance penetration of active products through the skin. Lactic acid has also been described as having a tyrosinase-inhibiting action. Finally, vitamins (A, C, and E) can be used in the treatment of hyperpigmentation: they are antioxidant and anti-inflammatory, protect against UV damage, and stimulate epidermal turnover. The well-known Kligman’s formulas combine the action of tretinoin, a corticosteroid, and hydroquinone but are more

irritating than medical cosmetics. The cosmetics used for hyperpigmentation should be applied very soon after the peels (if possible, the next day). If possible, they should be applied two or three times a day, before effective sun protection. For more information on topical depigmenting agents, see the section on hyperpigmentation in Chapter 37.

Treatment for Aging The author’s cosmetic postpeel treatment for aging skin is described in the following paragraphs. Patients under 40–45 Years Old The main thrust of the treatment is daily oxidation. In the morning, an antioxidant cream with vitamin E should be applied, and in the evening another antioxidant cream: Nutritive ACE Lipoic Complex. Vit. E Anti-oxydant® is a cream with a relatively complex but complete formulation. It does not contain AHAs, so it can be applied daily without the risk of interference with the protective function of the corneocytes. It has been specially formulated for use very soon after a chemical peel. Its qualitative formulation is listed in Table 3.1. Nutritive ACE Lipoic Complex is ideal for dry skin and can also be applied in the morning. With normal or oily skin, it is better applied in the evening. It does not contain any AHAs, for the reasons outlined earlier. Its qualitative formulation includes the ingredients listed in Table 3.2. Patients over 40–45 Years Old The fight against aging should take into account not only the damage caused by the various sources of cell oxidation but also the drop in hormone levels. For menopausal or postmenopausal women, a standard formula is testosterone propionate 100 mg, estrone 5 mg, estradiol benzoate 5 mg, and water in oil excipient ad 100 g. Extracts of Mexican wild yam (Dioscorea) can also be used, or other estrogen precursors or dehydroepiandrosterone

Table 3.1  Vit. E Anti-oxydant ® Urea and glycerol Enoxolone

Moisturizers Anti-inflammatory

Ceramides

Natural components of the epidermis. One of the major natural skin defenses. Alpha tocopherol acetate

Vitamin E Biosaccharides

Polymers of fucose

Natural moisturizing factor

Natural-like mixture of hexoses and amino acids Avobenzone

Sun protection (UV-A) Sun protection (UV-B)

Ethylhexyl methoxycinnamate

Enoxolone is a natural inflammatory whose structure, similar to cortisol, provides the anti-inflammatory properties, without suffering the antimetabolic properties of cortisol. It has a modulatory effect on neural signaling through gap junction channels. For more information, see Chapter 15. Antiaging, hydrating, and protecting actions. Encourage skin repair after different types of injury. Reinforce the natural lipid barrier of dry and aging skin. Improve long-term moisturizing and protect the skin from external influences. Protects against anti-free-radicals. The tocopheryl acetate used in this cream is one of the most stable derivatives of vitamin E and forms a reservoir in the skin after penetration. Filmogenic properties that induce immediate hydration. Slowly metabolized on the surface of the skin, giving a long-term hydrating effect. Anti-inflammatory effect. One of the major natural skin defenses and hydration systems: it increases the epidermal water content. Physiological moisturizer adapts to the water-binding capacity of human skin. The original global gold standard for UV-A protection: absorbs the full spectrum of UV-A rays. Its ability to absorb ultraviolet light over a wider range of wavelengths than many other sunscreen agents has led to its use as a “broad spectrum” sunscreen. Avobenzone has an absorption maximum of 357 nm. Considered by health agencies as giving a good protection against UV-B and a very low toxicity.

Postpeel care   19 Table 3.2  Nutritive ACE Lipoic Complex ® Thioctic acid = lipoic acid

Ascorbic acid

Retinol

Alpha tocopherol acetate

Urea and glycerol Enoxolone

Ceramides Phytic acid

Antioxidant, chelator, protective Lipoic acid protects the natural enzymatic antioxidant defenses and exists in different racemic forms. Only the R form is active (Figure 3.5). Lipoic acid is absorbed rapidly both orally and topically. Enzymes in cell cytoplasm convert it into dihydrolipoate (DHLA). DHLA penetrates the cell and mitochondrial membranes easily. It is a mitochondrial cofactor that boosts mitochondrial activity while protecting against excess production of free radicals. Lipoic acid has the major advantage of being both fat-soluble and water-soluble, which means that it is active at all levels in the cell. It recycles vitamin C, when it is converted into the ascorbyl radical after acquiring a free electron, thus restoring its antioxidant activity. It also recycles vitamin E indirectly. Lipoic acid protects the natural enzymatic antioxidant defenses, such as catalase, coenzyme Q-10, glutathione, and cysteine. It is an iron, copper, mercury, and aluminum chelator (Figure 3.6). It combats excessive secondary cell apoptosis resulting from various stresses. Pure vitamin C, protected in cyclodextrins. Vitamin C deficiency is linked with a reduced immunity response, an increased risk of infection, reduced collagen synthesis, poor angiogenesis, and higher capillary fragility. Vitamin C is a powerful antioxidant, effective in aqueous solutions, that scavenges free radicals and prevents the breakdown of protein chains. It protects other antioxidants, which is an advantage in situations involving oxidative stress, such as infected or uninfected wounds and in the postpeel healing period. Vitamin C has many roles in wound healing, and vitamin C deficiencies result in impaired healing. Pure vitamin A, protected in cyclodextrins. Retinol induces the expression of retinoic acid-binding protein (RABP) and regulates cell migration in the skin epithelium, which is vital for skin regeneration after a peel. Retinol exerts a strong antioxidant activity. Encapsulating retinol provides better bioavailability of the vitamin and protects the skin against oxidation. Keratinocytes have the enzyme tools required to convert retinol into retinoic acid (the corresponding carboxylic acid), which is the molecule ultimately responsible for the effect of vitamin A. Retinol can be considered as a tretinoin precursor, because when encapsulated in cyclodextrins it enters easily into the skin, and when liberated from the cyclodextrin it is transformed by epidermal enzymes into retynaldehyde and finally retinoic acid. Stable ester of vitamin E. The advantage of the acetate form is that it forms a reservoir that gradually releases the vitamin E inside the skin. Vitamin E scavenges free radicals that could damage neighboring tissue. It blocks oxidative chain reactions by inhibiting the formation of lipoperoxides inside the cell, and in this way protects the nucleic acids and proteins. Vitamin E is an antioxidant, and its lipophilic properties allow it to stabilize cellular membrane integrity. Vitamin E also shows anti-inflammatory properties and decreases the risk of scar formation. Moisturizers Anti-inflammatory Enoxolone is a natural inflammatory whose structure, similar to cortisol, provides anti-inflammatory properties without suffering the antimetabolic properties of cortisol. It has a modulatory effect on neural signaling through gap junction channels. Natural components of the epidermis. Anti-aging, hydrating, and protecting actions. One of the major natural skin defenses. Antioxidant Phytic acid is well known for its anti-tyrosinase and antioxidant action. It is also an iron chelator. This molecule is therefore a good indication for skin-lightening and antiaging treatments. Phytic acid scavenges the free radicals produced by the inflammation that follow any peel and breaks the usual vicious cycle of postpeel inflammation.

Sun protection

O HO

S H S

S

SH

Figure 3.5  Chemical structure of (R)-lipoic acid.

Fe2+

O O

(DHEA). DHEA Phyto® cream contains Dioscorea extracts in a moisturizing cream base that is similar to Vit. E Anti-oxydant cream. Tetra Antiaging System Some newer cosmetics contain peptides. One of them is especially interesting because it allows adipocytes to accumulate more fat. This subcutaneous local fat accumulation acts as a deep filler for the skin. Atrofillin® has multiple actions as outlined in Table 3.3.

O

S

S Fe2+

Figure 3.6  Iron chelation by lipoic acid.

O–

20   Textbook of chemical peels Table 3.3  Atrofillin ® Acetyl hexapeptide 38

DMAE

What it makes Local increase in fat tissue volume, face, or body: fat droplets increase 32.4% in 10 days Local increase of jaw fat: 12% in 14 days Note: No fat, no action (“empty hands” or “empty temporal area” are not good indications) How it works 61% more expression of PGC-1α (coactivator that interacts with PPARy—receptor of peroxysomes proliferation) and modulates adipogenesis. PGC-1α regulates mitochondrial activity. Aging is associated with a lower renewal and activity of mitochondria. “PGC-1α is a master regulator of energy metabolism and mitochondrial biogenesis”1 Maintenance of mitochondrial function is beneficial in the prevention or delay of age-associated diseases. A central molecule seems to be the peroxisome proliferator-activated receptor γ coactivator α (PGC-1α), which is the key regulator of mitochondrial biogenesis. Besides regulating mitochondrial function, PGC-1α targets several other cellular processes and thereby influences cell fate on multiple levels”2 PGC-1α stimulates mitochondrial biogenesis and promotes the remodeling of muscle tissue.3 PGC-1α was investigated as a candidate gene for growth and fatness traits in chickens because of its prominent role in muscle fiber specialization and adipogenesis.4 Progressive effect: • Decreases lipofuscine (lentigos) • Increases collagen fiber thickness and dermal thickness Immediate effect:

Kojic dipalmitate

Alanine-phosphinic acid

Mulberroside, resveratrol

• Increases skin firmness: Increases myofibroblasts tension → better skin tension • Anti-inflammatory • Antioxidant (hydroxyl, ascorbyle, lipids radicals) Kojic acid (KA) is a hydroquinone derivative with antityrosinase action. Known melanogenic inhibitor Ester form more active and less irritant KA esters have lower cytotoxic effect than kojic acid. It works at least as good as hydroquinone. Although hydroquinone is effective and has been available for years, kojic acid has the advantage of being pharmaceutically more stable and, also, a tyrosinase inhibitor. Fifty-one percent of patients responded equally to hydroquinone and kojic acid.1 Twenty-eight percent had a more dramatic reduction in pigment on the kojic acid side; 21% had a more dramatic improvement with the hydroquinone formulation. These results were not statistically different.5–7 How it works Tyrosinase is known as a copper-containing enzyme, thus the capability of KA and KA esters to chelate metal ions may chelate cooper in tyrosinase, changing its three-dimensional conformation to inhibit its enzymatic activity. Efficacy study: KA versus esters (palmitate) of KA Data obtained from control skin, ultraviolet (UV)-stimulated tissue and KA-treated UV-irradiated explants are compared. Moreover, statistical analysis concerning keratinocytes discloses a significant decrease in the mean pigmentation index when explants exposed to UV light were treated with KA. KA monopalmitate gave slightly higher inhibition to melanin formation compared to other inhibitors at doses ranging from 15.63 to 62.5μg/mL. KA and KA esters also show antioxidant activity that will enhance the depigmenting effect. The potency of KA esters to stabilize free radicals and chelate metal ions may help to reduce melanogenesis process and downregulate hyperpigmentation. Safety KA esters derived in this study have very low cytotoxicity, even at very high doses (up to 500 μg/L). KA esters derived from esterification of KA and palm-oil-based fatty acid have been demonstrated as safe and nontoxic depigmenting agents with a satisfactory inhibitory effect on melanin formation and tyrosinase activity as determined on α-MSH induced B16F1 melanoma cells. Thus, it can be suggested that these depigmenting compounds have potential to be used in cosmetic formulations and to treat hyperpigmentation.5–7 Alanine-phosphinic acid is a non-cytotoxic anti-dopachrome tautomerase by inhibition of its spontaneous (oxydative) polymerization or by inhibition of DCT. Stabilizing dopachrome, it is a melanogenesis inhibitor (evidenced on mouse melanocyte and reconstituted human pigmented skin). It is not an antityrosinase. Competitive inhibition and tyrosinase enzyme expression suppression: oxyresveratrol and moracenin D have been extracted and exhibit stronger tyrosinase inhibitory activities than that of kojic acid. These results suggest the Morus root extract as a good source of natural tyrosinase inhibitors with a great potential to be used as a skinwhitening agent.8

Postpeel care   21 Table 3.3 (Continued) Atrofillin ® Twelve compounds with tyrosinase binding activity were found in mulberry leaf extracts. The identities of these compounds were characterized by HPLC-DAD-MS(n). Two compounds, quercetin-3-O-(6-O-malonyl)-β-D-glucopyranoside and kaempferol-3-O-(6-O-malonyl)-β-D-glucopyranoside, were identified as new tyrosinase inhibitors.9 Mulberroside A was isolated from the ethanol extract of Morus alba roots. The enzymatic hydrolysis of mulberroside A with Pectinex produced oxyresveratrol and oxyresveratrol-3-O-glucoside. Histological analysis with FontanaMasson staining confirmed that these compounds significantly reduced the melanin content in the epidermis of UVB-irradiated guinea pig skin compared to the vehicle control. Thus, these compounds effectively reduced pigmentation and may be suitable cosmetic agents for skin whitening.10 How it works Mulberroside and resveratrol (from mulberry extracts) suppressed the expression of melanogenic enzymes tyrosinase, tyrosinase-related protein-1. Mulberroside A is a glycosylated stilbene of oxyresveratrol; thus, the deglycosylation of mulberroside A resulted in enhanced inhibition of melanogenesis.10 In mulberry extracts, the resveratrol is the most efficient part. Mulberroside A and oxyresveratrol showed inhibitory activity against mushroom tyrosinase with an IC(50) of 53.6 and 0.49 micro M, respectively. Inhibition kinetics showed mulberroside A to be a competitive inhibitor of mushroom tyrosinase with L-tyrosine and L-DOPA as substrate. Oxyresveratrol showed mixed inhibition and noncompetitive inhibition against L-tyrosine and L-DOPA, respectively, as substrates. The results indicate that the tyrosinase inhibitory activity of mulberroside A was greatly enhanced by the bioconversion process.11 Mulberry extract acts as an antityrosinase and an antioxidant. Resveratrol: Acts as antioxidant (limits auto-polymerization of dopachrome) Mulberroside F: Acts as antityrosinase. An investigation of the in vitro effects of an 85% methanol extract of dried Morus alba leaves on melanin biosynthesis found that these extracts inhibited the tyrosinase activity that converts dopa to dopachrome in the biosynthetic process of melanin. Mulberroside F showed inhibitory effects on tyrosinase activity and on the melanin formation of melan-a cells. This compound also exhibited superoxide scavenging activity that is involved in the protection against auto-oxidation, but its activity was low and was weaker than of kojic acid. Mulberroside F isolated from mulberry leaves might be used as a skin whitening agent.12–13 Notes:  1. Gomez-Cabrera MC, Sanchis-Gomar F. Mitochondria as sources and targets of damage in cellular aging. Clinical Chemistry and Laboratory Medicine. 2012 Feb 1; 50(8):1287–95.   2. Wenz T. Mitochondria and PGC-1α in aging and age-associated diseases. Journal of Aging Research. 2011; 810619.   3. Ward WF. American Journal of Clinical Nutrition. 2011 April; 93(4):   4. Wu GQ, Deng XM, Li JY, Li N, Yang N. A potential molecular marker for selection against abdominal fatness in chickens. Poultry Science. 2006 Nov; 85(11): 1896–9.   5. Garcia A, Fulton JE Jr. The combination of glycolic acid and hydroquinone or kojic acid for the treatment of melasma and related conditions. Dermatologic Surgery. 1996 May; 22(5): 443–7.   6. Vie K, Fitoussi R, Mathieu E, Benetti LD, Gooris E, Hemmerlé J. Ultrastructural assessments of the melanosome distribution patterns and pigmentation features in human epidermal cells after UV irradiation and kojic acid treatment. International Journal of Cosmetic Science. 2009 Dec; 31(6): 461–73.   7. Lajis AF, Hamid M, Ariff AB. Depigmenting effect of kojic acid esters in hyperpigmented B16F1 melanoma cells. Journal of Biomedicine and Biotechnology. 2012; 952452. Published online 2012 October 2. doi: 10.1155/2012/952452. PMCID: PMC3468271.   8. Zheng ZP, Tan HY, Wang M. Tyrosinase inhibition constituents from the roots of Morus australis. Fitoterapia. 2012 Sep; 83(6): 1008–13.   9. Yang Z, Zhang Y, Sun L, Wang Y, Gao X, Cheng Y. An ultrafiltration high-performance liquid chromatography coupled with diode array detector and mass spectrometry approach for screening and characterising tyrosinase inhibitors from mulberry leaves. Analytica Chimica Acta. 2012 Mar 16; 719: 87–95. doi: 10.1016/j.aca.2012.01.018. Epub 2012 Jan 18. 10. Park KT, Kim JK, Hwang D, Yoo Y, Lim YH. Inhibitory effect of mulberroside A and its derivatives on melanogenesis induced by ultraviolet B irradiation. Food and Chemical Toxicology. 2011 Dec; 49(12): 3038–45. doi: 10.1016/j.fct.2011.09.008. Epub 2011 Sep 16. 11. Kim JK, Kim M, Cho SG, Kim MK, Kim SW, Lim YH. Biotransformation of mulberroside A from Morus alba results in enhancement of tyrosinase inhibition. Journal of Industrial Microbiology and Biotechnology. 2010 Jun; 37(6):631–7. 12. Lee SH, Choi SY, Kim H, Hwang JS, Lee BG, Gao JJ, Kim SY. Mulberroside F isolated from the leaves of Morus alba inhibits melanin biosynthesis. Biological and Pharmaceutical Bulletin. 2002 Aug; 25(8): 1045–8. 13. Department of Herbal Pharmacology, Graduate School of East-West Medical Science, Kyunghee University, Seoul, Korea.

Sagging Skin: DMAE One of the common signs of aging is loss of skin elasticity. The skin appears devitalized and slack. One substance that is of special interest in the treatment of sagging skin is N,Ndimethylaminoethanol (DMAE) (Figure 3.7). DMAE has been used for several years as a topical application to produce a “face-lift” effect. While there is no doubt that it produces a tightening effect on the face, there is no definitive evidence regarding its mode of action. The following

paragraphs describe what type of skin structures respond to DMAE and why it would be difficult to explain this action by an improvement in tension of the striated muscle mass of the face. Actilift® cream contains pure DMAE and helps induce a nice skin tension. Chemistry of DMAE DMAE (also called deanol, dimethylethanolamine, and norcholine) is a small hydrophilic molecule. Its low molecular

22   Textbook of chemical peels

(a)

(b)

(c)

(d)

(e)

Figure 3.7  A tightening effect can be seen after the first application of N,N-dimethylaminoethanol (DMAE) in the form of Skin Tech’s Actilift ®: (a) before; (b) after (photo courtesy of John Jairo Hoyos, Colombia). (c) Before and (d) 30 minutes after application of a thick coat of Actilift ® around the eyes (photo courtesy of Evgeniya Ranneva, Spain). (e) Before (photo courtesy of Evgeniya Ranneva, Spain).

Postpeel care   23

(f)

(g)

Figure 3.7 (Continued)  A tightening effect can be seen after the first application of N,N-dimethylaminoethanol (DMAE) in the form of Skin Tech’s Actilift ®: (f) during, and (g) 30 minutes after application of a thick coat of Actilift® around the eyes. (Photographs courtesy of Evgeniya Ranneva, Spain.)

weight (89.1) allows it to penetrate the skin easily. DMAE is a precursor of acetylcholine (ACh), via choline (Figure 3.8). It is a viscous liquid, as transparent as water, that is often said to smell like ammonia but is in fact more reminiscent of fish long past its sell-by date. Anchovies, sardines, and salmon are important natural sources of DMAE. It is naturally present in the body, and there are traces of it in the brain. DMAE is a very basic molecule (pH 11) that cannot be used in its pure state without the risk of causing chemical skin burns. It must be partially neutralized for use at pH 7. Many derivatives have been used in its place (e.g., DMAE bitartrate or acetamidobenzoate), but these are more suitable for oral rather than topical use. DMAE formulations tend to give only the total dosage of the DMAE derivative used, of which pure DMAE is only part of the weight. For example, 100 mg of DMAE cyclohexylcarboxylate contains only 33 mg of pure DMAE, while 350 mg of DMAE bitartrate contains 130 mg of pure DMAE. The author prefers to use a formulation with DMAE lactate (Skin Tech’s Actilift®) in order to benefit from the properties of an AHA (lactic acid) combined with the DMAE.

(CH3)2NCH2CH2OH DMAE (CH3)3N+CH2CH2OH Choline O (CH3)3N+CH2CH2OCCH3 Acetylcholine

Figure 3.8  Chemical structures of N,N-dimethylaminoethanol (DMAE), choline, and acetylcholine.

Side Effects and Precautions  The high pH of DMAE means that the pure compound should not be brought into contact with strong acids, mucous membranes, or the eyes. Pure DMAE is also incompatible with copper and zinc. DMAE is volatile and should be contained in sealed tubes rather than bottles, to prevent its evaporation. Some cases of allergic dermatitis have been reported after prolonged contact with very high concentrations of DMAE, and it should be applied with extreme caution around the eyelids of atopic subjects. DMAE is not considered to be carcinogenic, cocarcinogenic, or immunosuppressive. Chronic exposure to concentrated fumes of DMAE in the workplace can cause visual problems. Toxicity  DMAE has mostly been used orally. It is most widely available in 100  mg tablets for the treatment of cognitive disorders associated with senile dementia, at a dose of 600 mg/day. The LD50 for oral administration in rats is 2 g/kg. The LD50 in rabbits after application to the skin is 1.370 mg/kg. For subcutaneous injection in mice, the LD50 is 961  mg/kg. In a human clinical study,13 oral administration of 1600  mg/day showed no side effects. The doses used in topical applications are nowhere near the theoretical toxicity limit. It takes a twice-daily application of around 30–50  mg of DMAE on the skin to improve skin tension and achieve the “lifting” effect. It is important to remember that a topical application, even if it is very effective, cannot as yet compete with a surgical procedure. DMAE and N,N-dimethylisopropanolamine (DMIPA) solutions are used in high concentrations (45%–50%) in industry, especially in the printing industry. They are used in sprays, and a study was conducted on their role in the appearance of intermittent corneal opacity in workers in certain types of printing works.14 The corneal opacities caused workers to have blurry vision on their way home from work. These problems were evident only from Mondays to Thursdays and never at the end of the week. Eye tests revealed the appearance of intermittent and reversible corneal opacity, limited to the part of the

24   Textbook of chemical peels

cornea in contact with the droplets of vaporized solution and lasting just a few hours. A complete study was undertaken that put the blame on DMIPA but cleared DMAE of involvement. Lowering the concentrations of DMIPA without changing the concentrations of DMAE solved the problem and produced no visual sequelae. DMAE has also been claimed to be teratogenic. Studies on this subject remain controversial: some have shown that DMAE can be teratogenic in mouse embryos at high doses;15,16 other studies have shown no evidence of toxicity in rodents.17 To the author’s knowledge nothing has been published on teratogenic effects in humans, and no research has shown teratogenicity in humans, despite the wide use of DMAE in industry. Historical and “Usual” Use of DMAE  Procaine, which is used widely in mesotherapy, is one of the active principles of the wellknown (and at times much criticized) Gerovital H3 developed by Dr. Ana Aslan of Romania. Procaine or 2-diethylaminoethyl 4-aminobenzoate hydrochloride (Figure  3.9) was synthesized in 1905 by the German chemist Alfred Einhorn, who called it novocaine (from the Latin novus = new, with the added suffix of cocaine, a gold-standard product up until then). Another German, Dr. Heinrich Braun, introduced the use of novocaine in medicine. In the body, the ester link of procaine is hydrolyzed, yielding p-aminobenzoic acid (PABA) and N,N-diethyl-aminoethanol (DEAE), an analog of DMAE. It is PABA (Figure  3.10) that is responsible for the large majority of allergic reactions to “procaine”; it is excreted rapidly by the kidneys. PABA is most often used as a sunscreen but is sometimes called “vitamin B-x,” although it is not essential for humans and the body cannot synthesize folate from PABA. According to some authors, the “Aslan” method relies solely on the combined action of PABA and DEAE/DMAE. It is assumed that the action of PABA is due to its anti-free-radical properties. Another local anesthetic used in mesotherapy, lidocaine, goes through a different metabolic pathway from procaine, being converted into monoethylglycine, xylididide (MEGX), and acetaldehyde. Its action in this context must therefore have a different basis from that of procaine. As well as having an antioxidant18 and anti-inflammatory effect, DMAE taken orally has been claimed to have many properties: an antiaging effect; improvement of memory and intelligence; increased synthesis of acetylcholine; amelioration

O NH2

CO.CH2CH2N(C2H5)2

Figure 3.9  Chemical ­structure of procaine.

O NH2

of depressive states; improvement in motor coordination; improvement in compulsive, impulsive, hyperactive, or antisocial behavior; reduction of chronic fatigue and improvement in the quality of sleep; aid in giving up alcohol and tobacco; reduction of headaches; improved ability to concentrate; improvement in schizophrenia; improved muscle tone; and overall higher energy levels. DMAE can be incorporated into the membrane structure of cells, where its antioxidant properties improve membrane resistance to the oxidative stress resulting from the release of free radicals from the phospholipid bilayer and the ­production of eicosanoids associated with skin inflammation. The degradation of cell membranes and subsequent inactivation of the transmembrane proteins and receptors are considered to be the main factors responsible for cell aging. Carbachol (Figure  3.11) and the closely related bethanechol are powerful cholinergic agents (used to induce miosis). Carbachol’s structure is similar to that of choline and its precursor, DMAE. Other muscarinic agents (e.g., pilocarpine) have a completely different chemical structure from choline. Topical Skin Application of DMAE  Topical application of DMAE has a visible tightening, firming effect, often called the “lifting effect.” This tightening effect can already be felt 20–30 minutes after the product has been applied to the skin, and when only one side of the face is treated with DMAE, the difference in tension between the two sides is clear. Skin tension continues to improve during the first 6 months of twice-daily application, with individual variations, and remains stable for 4–8 weeks after topical treatment is finished. This would seem to indicate that the product accumulates in the skin and forms a reservoir. Potential Mode(s) of Action of DMAE  DMAE is a precursor of choline; it also inhibits the metabolism of choline in the tissues. As there is more choline available, the biochemical reactions may tip the balance toward an increase in ACh synthesis. DMAE may stimulate macrophage activity and improve the skin’s defenses. The mode of action of DMAE is not yet fully understood, and its action as a local application even less so. We must therefore put forward several hypotheses in an attempt to understand this tightening effect. Action on the Striated Facial Muscles  Botulinum toxin (BTX), which is used to “smooth the skin,” like DMAE, acts on ACh, although its action is the reverse of that of DMAE. BTX relaxes the muscles, whereas DMAE increases muscle tone. Are these two compounds therefore incompatible? It appears not, as they have different targets, and the muscle cells that are deactivated by BTX are not the same as those activated by DMAE. BTX is a large molecule with a high molecular weight, which means that it cannot pass through the skin when applied topically. To achieve a cosmetic result, BTX must be injected directly into the muscle to be paralyzed. BTX has no effect on the epidermis or

O (CH3)3N+CH2CH2CNH2

C OH

Figure 3.10  Chemical structure of p-aminobenzoic acid (PABA).

Figure 3.11  Chemical structure of carbachol. Note the similarity between part of the molecule and DMAE and choline.

Postpeel care   25

dermis, as it blocks cholinergic transmission in the neuromuscular junction of the striated muscles and in this way limits the facial expressions that cause expression lines. BTX is picked up immediately, and there is no chance of it diffusing up through the hypodermal fat layer. DMAE, on the other hand, is a very small hydrophilic molecule with a molecular weight of 89.1 that can easily penetrate the epidermis and the dermis but cannot penetrate the hypodermal fatty layer. DMAE cannot act on the striated muscle groups that produce voluntary facial movements, and so cannot counter the effects of BTX. This physiological hypothesis is confirmed clinically when the two treatments are used together. The physicochemical properties of DMAE give this molecule a great affinity for the dermis and epidermis. As the action kinetics of DMAE lead to the hypothesis of a cutaneous “reservoir,” this could only be located in the deep epidermal layers, as, if it was in the dermis, this small molecule would soon be eliminated by venous or lymphatic resorption because of its concentration gradient. The way in which they are administered, their targets, their characteristics and their different modes of action do not make BTX and DMAE incompatible: administering one will not alter the effectiveness of the other. There is no established link between age-related sagging skin and muscles and a deficiency in ACh in the muscles. Any action of DMAE on striated facial muscles is thus not only unlikely but also pointless. We must therefore look for other more likely modes of action than muscle stimulation, especially as there have been reports of improvements in tone and younger-looking skin around the eyes and lips after only a few days of treatment. Given that it is accepted that paralysis (or hypotonia) of the muscles by BTX “smooths” the skin, it would be illogical to claim that stimulating the same muscle groups (with DMAE) can give similar results. We must therefore look elsewhere: in the skin structures that have cholinergic receptors. Epidermal Action  Human keratinocytes express cholinergic receptors in the cells of the stratum basale, the stratum spinosum, and the stratum granulosum. They use ACh, among other things, to stick together. They also synthesize, store, degrade, and release ACh. ACh synthesis has been shown to occur in the perinuclear regions of human keratinocytes due to the presence of a choline acetyltransferase (this enzyme converts acetyl coenzyme A into ACh). On the other side of the cell, inside or near the cell membranes, an acetylcholinesterase has been identified. This enzyme degrades ACh in order to prevent a toxic buildup. Keratinocytes can move, which is essential during the second phase of healing, thanks to cytoplasmic myosin and actin: the actin moves in relation to the myosin when the two interact,19 in the same way that an oar stroke moves a kayak or an athlete runs on a treadmill (the athlete representing the myosin and the treadmill the actin). It has recently been shown, by immunohistochemistry, that there are free nerve endings in all of the layers of the epidermis, and it is now suspected that keratinocytes have a neurotropic function. The ACh acts locally, in the epidermis, like a hormone that can also be a “messenger” stimulating the dermis. We can then suppose that an epidermal reservoir of DMAE can interact with the dermis via ACh, of which it is a precursor. DMAE is also assumed to inhibit formation and enhance elimination of lipofuchsin, a waste product of the aging cell metabolism of fatty acids. Experiments have shown that lipofuchsin is eliminated from the liver by DMAE. This buildup,

which occurs in all organs, has not been associated with any disorder apart from lentigines. Some authors have reported a gradual reduction in lentigines on the hands with oral DMAE treatment. To date, there have been no studies published on the topical use of DMAE in the treatment of lentigines. Dermal Action  DMAE is used for its antioxidant properties, membrane stabilization, and inhibition or repair of protein cross-links that clearly play a role in the aging process. It could thus help maintain good-quality collagen and elastin and slow down dermal aging. Vasomotor Effect  The dermal blood vessels are innervated by adrenergic fibers, which cause vasoconstriction, and cholinergic fibers, which cause vasodilation. DMAE, as a precursor of ACh, could cause vasodilation that is clinically undetectable but sufficient to produce temporary edema, a buildup of water in the hydrophilic structures of the dermis, and, as a result, a tightening of the skin. This hypothesis only partly explains the particular kinetics of topical DMAE. The fact that treating one side of the face shows improvement on one side only suggests that the DMAE has a purely local action and is not converted into ACh throughout the organism. Local blood flow, which decreases with age, is vital for the nutrition and defense of the dermis and epidermis. Constant slight vasodilation would thus improve skin perfusion—especially in ­smokers— and by diffusion would bring in more of the elements that contribute to the overall rejuvenating effect observed when DMAE is applied topically. Effect on Myofilaments and Smooth Muscle Cells  Myofilaments make up the endoskeleton of a cell (Figure 3.12). They can be found in the smooth muscle cells (SMCs) and in the cytoplasm of “nonmuscle” cells, where they are capable of moving and contracting. SMCs can regulate contraction far more subtly than striated muscle cells. SMCs can shorten to a greater extent than striated muscle cells. Shortening of striated muscle cells is limited to movement within the sarcomere, whereas with SMCs, the myosin filaments can move over a far greater distance, along the network of actin filaments in the

Network tightened with actin microfibrils

Direction of displacement “Stress” contractile fibers + Microtubule

+ Cellular center Nucleus

+

+

Dense bodies

Radial network with actin microfibrils

+

+ +

+ +

+

Loose network with actin microfibrils in all cytosol

Figure 3.12  Different types of organization of actin microfibrils (MF) and microtubules (MT) in a moving cell; organized polarization of the MF and the MT.

26   Textbook of chemical peels

cytosol. The force generated by SMCs is less than that generated by striated muscle cells but can be sustained for much longer. The arrector pili muscle is under adrenergic control and does not respond to a local increase in ACh concentration. The fibroblasts and myofibroblasts (MFBs) are very interesting cells as far as the possibilities of the action of DMAE are concerned. Fibroblasts have cytoplasmic myofilaments that help them move in the dermis when necessary.20 There are different types of fibroblast subpopulations. Some authors maintain that these different subpopulations expand when they are needed through different phenotype expressions, whereas others believe that these subpopulations coexist permanently in the dermis. These two hypotheses are not incompatible. MFBs are phenotypically modified fibroblasts that have the secretory capacity of fibroblasts, which helps them synthesize strong fibronectin fibers. They express the phenotypic characteristics of “nonmuscle” cells, but with the contractile capacities (of SMCs) that make them responsible for most of the phenomena of fibrotic contraction in the body. The fibronectin fibers synthesized by the MFBs serve as a support for them to “pull” on during contraction, which helps the wound to close by as much as 40%. MFBs synthesize far more actin fibers than “standard” fibroblasts and also have myosin fibers that, when interacting with actin, constitute the contractile motor activity of MFBs. MFBs are found in healing tissue, of which they form 40% of the total number of fibroblasts present. A large number of MFBs are also found in the periprosthetic capsule of encapsulated breast implants, while there is no evidence of MFBs if no capsule has formed around the prosthesis. In pathology, abnormal quantities of MFBs are found in diseases such as pulmonary fibrosis and Crohn’s disease. Many SMCs respond to a kind of paracrine stimulation, where the mediator is released into the environment of the target cells and diffuses towards the cell, where it interacts with a membrane receptor. MFBs are not linked to any synapse, which would make it impossible for them to move, but the exposure of MFBs to certain mediators causes significant contraction, comparable to that in SMCs. We can imagine the contractile potential of these SMCs when we recall that the nipples, as well as the scrotum, have many contractile cells of this type that are sensitive to different stimuli. The difference is that the contraction of MFBs during wound healing is irreversible. Fibroblasts and MFBs, like many SMCs, have numerous receptors on their surface for different mediators: ACh, adrenaline (epinephrine), noradrenaline (norepinephrine), oxytocin, vasopressin, histamine, angiotensin II and prostaglandins. As ACh is a small water-soluble molecule, its membrane receptor can be a ligand-gated ion channel receptor or can be coupled with the heterotrimeric G proteins (RCPGs) that control the activity of a target protein, which can be an enzyme or an ion channel. Opening and closing of the ion channels causes polarization or depolarization of the myofilaments, and the SMCs (e.g., endothelial cells) contract or dilate. The G protein acts as a transducer. As ACh is a small ligand, the N-terminus of the G protein in the extracellular environment will be small. The presence of a larger quantity of ACh in the pericellular environment of the MFBs could then stimulate certain membrane receptors more strongly and increase their contractile potential. DMAE, a precursor of ACh, might then stimulate the contraction of MFBs. However, there must be a reactivity threshold for MFBs to ACh, to guard against unnecessary contraction of these cells and the formation of pathological fibroses. The hypothesis put forward here is that a slight

increase in the extracellular concentration of ACh (by conversion from DMAE) could slightly stimulate the contraction of the fibroblasts and do so reversibly, without fibrosis setting in as, clinically, the effect of a topical application of DMAE is reversible 4–8 weeks after treatment has stopped. This improved tone, the reversible contraction of the fibroblasts, could explain the clinical kinetics of DMAE in a topical application. Exocrine Glands  The sweat glands have cholinergic innervation.21 The eccrine sweat glands, which open directly onto the skin, have denser autonomous innervation than the apocrine sweat glands associated with pilosebaceous units. ACh is the active neurotransmitter at this level, and the response of the sweat gland will depend on the dose of ACh that stimulates it. The myoepithelial cells contract in response to the ACh. In strong doses,22 the muscarinic receptors are stimulated and the gland reacts by producing large drops of sweat. At lower concentrations,23 the nicotinic receptor is stimulated and the gland will react by producing tiny droplets of sweat. The possible increase in ACh caused by the application of DMAE cannot, of course, stimulate the muscarinic receptors, and no profuse sweating has been noted after application of DMAE. On the other hand, a slight increase in the concentration of dermal ACh could stimulate the sweat glands’ nicotinic receptors—in a paracrine manner—and increase hydration of the stratum corneum, making the skin more “supple” and resistant. The sweat glands themselves are controlled by circulating hormones and are not under cholinergic control. DMAE will not alter their function. Conclusions  DMAE is a precursor of ACh, a neuromediator that is important to the skin. Keratinocytes, as well as fibroblasts, myofibroblasts, sweat glands, and endothelial cells, have receptors that respond to ACh. They are not stimulated pre- or postsynaptically but by paracrine diffusion, which can activate specific membrane receptors. The hypothesis is that DMAE in a topical application cannot stimulate the striated muscle fibers, to which it has no access. Furthermore, muscle sagging associated with aging is not caused by a deficiency in ACh. The tightening effect of DMAE may result from cholinergic stimulation of the membrane receptors of (myo)fibroblasts and stimulate the gradual contraction of the myofilaments in their cytosol. DMAE also has anti-free-radical and anti-lipofuchsin activities and repairs protein (collagen and elastin) crosslinking. The mode of action of topical DMAE could therefore stem from a combination of effects working together at different levels: tension of the “nonmuscle” dermal cells, keratinocyte cohesion and movement, hydration and suppleness of the stratum corneum, improved skin nourishment and defense, antioxidant, and skin tone evener. As a result, it is very effective at improving skin tone and firmness.

Summary of the Main Cosmeceuticals Used Postpeel See Table 3.4 for a list of postpeel cosmeceuticals according to skin type, together with their times of application.

TROLAMINE Trolamine (triethanolamine salicylate, TEAS) is a salicylate derivative, which is also known as “topical aspirin.” It is an amino alcohol that is used for its topical analgesic and

Postpeel care   27

anti-inflammatory properties. Like the better-known salicylate derivative, methyl salicylate—which has a rubefacient action used to good effect in sports injuries and rheumatism—TEAS is rapidly absorbed through normal skin after topical application. It is used widely for treating sunburn.

Mode of Action and Absorption Various studies show that salicylate derivatives act as much through direct local diffusion as through absorption by the dermal blood vessels and redistribution of salicylates in the whole body. The blood level of salicylates increases in direct proportion to the quantity applied, the resorption surface and the number of topical applications. A large amount of salicylates can be absorbed through the skin. When TEAS is applied unilaterally on one limb, the concentration of salicylates has been found to be identical in the corresponding tissues of the contralateral limb. This supports the theory of action by redistribution through the blood. The use of radiolabeled TEAS also shows renal and fecal elimination. Phonophoresis helps salicylates penetrate further into the skin.

matrix and impairs the barrier function of the stratum corneum. Symptoms of salicylism can appear with chemical peels when large amounts of salicylate derivatives are applied on the skin, on large surface areas or repeatedly, causing a high blood level of salicylates. In cases of toxic levels of salicylate in the blood, an increase in oxygen consumption causes hyperthermia by the uncoupling of oxidative phosphorylation. Trolamine should therefore not be used during the immediate postpeel period.

TIPS FOR THE CARE OF SENSITIVE SKIN • • • •

How to Apply Trolamine Salicylate derivatives, especially trolamine, are applied to firstand second-degree burns. A first-degree burn consists of mild erythema. A superficial second-degree burn consists of painful blisters but does not reach the dermis. Medical advice is essential before applying the product to a second-degree burn.

Precautions Trolamine must not be applied in cases of infection: salicylates can accelerate the penetration of microbes into the skin and aggravate any preexisting infection. It has been shown to cause local skin irritation and scabs to form on the areas to which it has been applied. Skin irritation increases the more it is applied. In smaller quantities, repeated application only induces epidermal hyperplasia. Some authors consider TEAS to be a potential cytotoxic agent. It is a potential skin irritant that makes the skin sensitive and can cause contact allergies. Trolamine is a salicylate derivative, and salicylic acid is a keratolytic agent that dissolves the intercorneocyte amorphous

• •

Prolonged use of creams containing more than 8%–10% of AHAs can make some skins more sensitive by reducing the thickness of the stratum corneum for long periods. Use cleansing milks, lotions, or mineral water sprays to wash. Do not let water dry on the skin; when it evaporates, it soon dries the skin out. Damp skin should be dried with a soft cloth or paper tissues. Avoid exfoliating scrubs, repeated micropeels, and creams containing microcrystals on sensitive skins. Do not use any masks that might dry out the skin. Do not use aggressive soaps. Tretinoin (vitamin A acid) makes the skin more sensitive.

One Easy TCA® peel per week for 4 weeks can restructure the skin and eliminate any abnormal sensitivity. In this indication, the cosmeceuticals that can be combined with it are restricted to Vit. E Anti-oxydant® cream in the morning and the more nourishing Nutritive ACE Lipoic Complex® cream in the evening.

CHARACTERISTICS OF “NORMAL SKIN” Normal skin should be: • • •

Firm: Contain a sufficient quantity of elastin and collagen Soft: Compact stratum corneum protected by skin lipids Hydrated and unwrinkled: Hydrated keratinocytes and dermis

Table 3.4  Main Cosmeceuticals Used Postpeel Skin type

Daily care product

When and how often to apply

Sagging skin

Dimethylaminoethanol (DMEA): Actilift face cream or Actilift body lotion Atrofillin Vit. E Anti-oxydant Atrofillin® Nutritive ACE Lipoic Complex Blending Bleaching Cream DHEA–PHYTO® Nutritive ACE Lipoic Complex Nutritive ACE Lipoic Complex Purifying cream or gel Purifying cream or gel Blending Bleaching Cream Blending Bleaching Cream

Morning and evening

Vit. E Anti-oxydant Atrofillin

Morning, midday, evening Morning, midday, evening

Patients under 40–45: skin aging Lentigines Patients over 40–45: skin aging Lentigines Acne Hyperpigmentation (melasma–lentigines) (Avoid exposure to sun: Melablock® HSP 50+ at 9 a.m., 11 a.m., 2 p.m.; serious cases: 3–4 times a day) Dry skin Thin skin

Morning and evening Morning Morning and evening Evening Morning (all over) Morning Evening Evening Morning (all over) Evening (only on the lesions) Morning (all over) Evening (only on the lesions)

28   Textbook of chemical peels

• • •

High in color: Active microcirculation; pink color visible through the skin Resistant to external aggression: Active protective function Unscarred: No stellate or secondary scars

NOTES 1. Even though this type of sunscreen can protect the skin against free radicals, some sunscreens could also cause postinflammatory hyperpigmentation. 2. SPF 50+ protects the skin against 98% of UV, while SPF 25+ protects against about 96% of UV. 3. A typical example of this is seen when cooking an egg white as it goes from transparent to white as a result of structural modification of the proteins under the effect of heat. 4. By polymerase chain reaction (PCR). 5. Occlusion consists of applying an impermeable plastic film. 6. In the case of sagging skin, Actilift ® face or body can be applied as appropriate. 7. Example of mesolift mixture: 2.5 cm3 non-cross-linked 2% hyaluronic acid + 2.5 cm3 organic silicium + 2 cm3 vitamin C + 2 cc of NA-nocleinate + 1 cm3 lidocaine. 8. Unna’s paste (see Chapter 24). 9. Molecules similar to tyrosine are used, for example, Tyrosilane C®. 10. Summary of Easy TCA “basic protocol”: no prepeel treatment, application of the solution until scattered pinpoint or cloudy white frosting appears, application of the postpeel cream (tyrosinase inhibiting, antioxidant, stimulating). Repeat this process four times at weekly intervals. 11. This paragraph particularly concerns superficial peels or peels to the Grenz zone. Papillary dermal peels are not indicated in cases of active acne.

12. Triclosan can be used as it is or encapsulated in cyclodextrins. 13. Casey DE, Denney D. Dimethylaminoethanol in tardive dyskinesia. New England Journal of Medicine. 1974; 291: 797. 14. NIOSH Publications Office. Health Hazard Evaluation Report 2002–03 79-2901 Superior Label Systems. Cincinnati, OH: May 2003. 15. Fisher MC, Zeisel SH, Mar MH, Sadler TW. Inhibitors of choline uptake and metabolism cause developmental abnormalities in neurulating mouse embryos. Teratology. 2001; 64: 114–24. 16. Fisher MC, Zeisel SH, Mar MH, Sadler TW. Perturbations in choline metabolism cause neural tube defects in mouse embryos in vitro. FASEB Journal. 2002; 12: 619–21. 17. Leung HW, Tyl RW, Ballantyne B, Klonne DR. Developmental toxicity study in Fischer 344 rats by whole-body exposure to N,N-dimethylethanolamine vapor. Journal of Applied Toxicology. 1996; 16: 533–8. 18. The antioxidant effect of DMAE has been shown by electron spin resonance (ESR) for the hydroxyl radical. It does not seem to have any antisuperoxide action. 19. There are different types of myosin for different types of movement; cell movements (myosin II) are not facilitated by the same myosin that permits endocytosis (myosin VI) or the movement of vesicles between cells (Myosin V). 20. For example, movement along the fibrin/fibronectin fibers during the healing process. 21. Catecholamines, vasoactive intestinal peptide and natriuretic peptide have also been detected near the sweat glands. 22. Intradermal injection of 0.1 mg of ACh: postganglionic cholinergic stimulation (The Biology of the Skin: 58). 23. Hurley HJ. The Eccrine Sweat Glands: Structure and Function. In: Freinkel RK, Woodley DT (Eds.). The Biology of the Skin. Lancaster: Parthenon Publishing, 2001: 47–76.

4 Factors influencing the skin’s reactions to chemical peels ALLERGIES These are common when using antibiotic creams or ointments in the postpeel period: between 5% and 10% of allergies should be expected when using antibiotic creams containing neomycin after a peel. The temporary thinning of the stratum corneum allows products applied on the skin after peels to penetrate more easily, which promotes the development of contact allergies.

INFECTIONS These are more common when patients have to undertake complex postpeel care themselves. The basic principles of sterility are not widely known by the public and require special training to be effective. The more patients have to take part in the postpeel care, the higher the risk of infection. For example, patients do not easily understand that it is mandatory to carefully remove leftover skin cream before applying a new layer. They also do not know that touching with nondisinfected hands is the best way to infect skin whose epidermal or stratum corneum protection has been destroyed by the peeling.

SCABS Pulling off scabs often leads to infection, prolonged erythema, and even scarring. The less frequently patients touch their skin, the better.

SUN EXPOSURE It should be remembered that direct exposure to the sun for 10 minutes is enough to trigger pigmentary changes in sensitive individuals during the postpeel period. See the section on effective sun protection in Chapter 3.

DEHYDRATION OF THE SKIN After a peel, drying and flaking skin causes an irresistible urge to scratch and therefore a risk of complications (including secondary infections, inflammation, and scars). Applying white Vaseline immediately improves the pruritus and the feeling of tightness in the skin after a medium or deep peel. Sterile white Vaseline is an excellent topical ointment that can be applied to the treated areas in the first few days after a medium peel or after removing the healing mask (after the eighth day) following a phenol peel. Only a thin layer need be applied to avoid itching caused by the drying out of surface keratinocytes that have not yet differentiated into corneocytes. The Vaseline creates an impermeable layer on the surface of the skin and prevents the water in the epidermis from evaporating. The water accumulates under the layer of Vaseline and provides instant natural hydration that soon relieves the itching caused by the keratinocytes drying out.

INFLUENCE OF AGE Older Patients Intraepidermal and dermal peels are performed as usual even on patients aged 80 or over (see Figure 29.1). With elderly people, there seem to be fewer pigmentary changes, but the theoretical risk of infection is higher. In theory, the weakened capacities of the keratinocytes to regenerate, the presence of numerous cell abnormalities, dormant fibroblasts, and underlying vascular sclerosis should slow down healing after a peel in older people. In practice, the only real problem is increased susceptibility to infection resulting from a weakened immune system. A more important factor seems to be the degree of skin photoaging rather than age itself. Many phenol peels have been performed on patients who are well into their 80s, without any particular problems.

Young Patients At the other end of the scale, what is the minimum age for having a chemical peel? The answer is simple: in the majority of cases, a peel is only necessary for young patients if they have acne. Acne responds extremely well to intraepidermal peels or peels to the basal layer of the epidermis. Deeper peels are not recommended when the skin is infected. Very young patients benefit from relatively superficial techniques with a high safety level (Easy Phytic). The presence of acne means that the young patient’s developing hormone system has created an adult skin—thick and oily and resistant to acids.

USE OF CORTICOSTEROIDS Topical Corticosteroids These are only indicated in cases of serious edema or pruritus during the first few days after an aggressive peel. It is always best to start with a short-acting corticosteroid (hydrocortisone or betamethasone). A cortisone-based cream can be used during the first few days after a peel to reduce excessive edema or pruritus. The deeper the peel, the greater the need for emollients. Hydration after a peel is vital (except after a peel with Unna’s paste); the hydrating cream should contain no alcohol or perfumes. Corticosteroids may be used after peeling in the case where a strong inflammation or a pigment rebound is feared.

Oral Corticosteroids These are rarely indicated in combination with peels, and then only for specific problems (see Chapter 37).

Intravenous Corticosteroids These can be used before a deep peel to limit edema immediately after the peel and avoid any allergic or laryngeal reactions.1 They reduce postpeel inflammation, which is necessary to initiate the skin repair processes. If the degree of inflammation is

30   Textbook of Chemical Peels

reduced, there is a risk of slowing down the first stages of skin regeneration.

UNDERSTANDING THE HEALING PROCESS Understanding the skin healing process after a peel allows evaluation of the risks of scarring, infection, and dyschromia. For more information on how the skin heals in relation to the depth of the peel and on risk evaluation, see the section on scars in Chapter 37. Histologically, the skin healing process follows a precise sequence of stages. The process starts almost immediately: Neutrophils enter the treated area as soon as the peel has been applied, and stay there for 3–5 days. Macrophages are present from the 3rd to the 10th day and lymphocytes from the 6th or 7th day. Reepithelialization starts just 24 hours after the peel and first manifests as a centripetal migration of keratinocytes, followed by rapid cell proliferation. After the reepithelialization phase, dermal collagen is regenerated over a 2- to 3-month period. Assessing the final results of a peel calls for patience. How quickly the skin regenerates after a medium peel depends on the concentration of pilosebaceous units (PSUs) in the treated area: the face has many PSUs, and the nose and forehead have more than the cheeks and temples. Statistically, the cheeks and temples prove more sensitive to scarring. The dermis of the eyelids is thinner but denser than the rest of the face, and the dermoepidermal junction is flatter. The skin on the back of the hand has few PSUs and little subcutaneous fat. Atrophy develops there fairly rapidly. The skin on the back is very thick, and its dermis is dense in collagen. Nevertheless, it has fewer PSUs than the face, and the risk of developing postpeel scars there is higher. The dermis of badly sun-damaged skin has a depleted cell population, and is thin and slower at detoxifying acids. The effect of the acids is therefore increased, and peels on sun-aged skin are more dangerous than on young, well-hydrated skin. Moreover, skin with actinic damage has fewer appendages (PSUs) and tends to regenerate more slowly. Healing is slower when a wound is left to heal in the open air than when the wound is covered. This does not matter much for intraepidermal peels but is more important when dealing with medium or deep peels. One advantage that peels have over laser treatments is that they leave a layer of dead, but protective, skin in place, and this enhances reepithelialization. The strips of skin that remain after a peel should be left alone, as they protect the regenerating skin. Lasers, on the other hand, gradually vaporize the layers of skin to be removed, and the skin is left to heal uncovered. The colloid dressings available on the market (e.g., Convatec, Omniderm, Vigilon) allow better-quality healing, in a moist environment, after laser treatment. The problem with occlusive dressings is that there is an increased risk of infection and they need to be monitored carefully, as bacteria are known to proliferate much more quickly under an occlusive dressing than in the open air. As bacterial proliferation increases under occlusive dressings and as the skin’s immune defenses are reduced after a deep peel, it is often preferable for the skin to heal “under a scab.” To do this, a mask of bismuth subgallate should be used (see Figure 4.1 and Chapter 35).

PREPARING THE SKIN Preparation of this skin is worthwhile when the patient is willing and when it is carried out under medical supervision. Unsupervised or secret use of aggressive products by the patient can sometimes cause problems for the doctor who has

Figure 4.1  After a phenol peel, the crust of bismuth subgallate appears dry but actually helps healing in a moist environment.

not been informed of the patient’s self-administered treatment. The doctor should watch out for unacknowledged use of tretinoin or other retinoids, concentrated glycolic acid, benzoyl peroxide, or any other product that increases penetration of the acids, making them penetrate more quickly and deeply than originally intended. Some patients come to their appointment with their skin thoroughly scrubbed (with an abrasive sponge or creams) to impress the doctor with skin that is clean, but such skin is also hyperpermeable and dangerous.

SKIN COLOR This must be taken into account when choosing a peel: Fitzpatrick skin phototypes I–III can tolerate any kind of peel. Patients of type IV with light-colored eyes have fewer problems with dyschromia after a peel than dark-eyed patients of the same type. Types V and VI patients are at most risk with peels, and it is recommended not to go beyond the papillary dermis with these patients to avoid hypochromia. Type V patients are also quick to develop hyperpigmentation. Special care should be taken with patients who have prolonged hyperpigmentation with mosquito bites or small wounds. Localized phenol peels should only be carried out on patients with a skin phototype lower than IV, so that the area treated with phenol is not left lighter than the surrounding skin, even if it has been treated with a medium peel to even out the color. The same applies to patients with many freckles, which mostly disappear after a peel to the papillary dermis.

CHEMICAL PEELS FOR MEN There is an increasing demand from men for basic treatments. Their skin is thicker, and results are not as good as for women. On the other hand, as men have more PSUs, they heal more quickly and pose fewer risks of scarring. The fact that in most cases they cannot use camouflage makeup makes it difficult to perform a local or full phenol peel. Moreover, phenol peels produce less spectacular results on thick skins than on thin skins. Shaving does not pose a problem, as a peel to the basal layer of the epidermis does not rule out shaving, even with a blade. For a peel to the papillary or reticular dermis, it is best not to shave

Factors influencing the skin’s reactions to chemical peels   31

while the skin is flaking. It is usually possible to shave after the eighth day. Alcohol-based aftershaves should be avoided, and a hydrating, antioxidant, or firming cream should be used instead, followed by effective sun protection.

MAKEUP Patients often ask about makeup. The general principle is that it is possible to wear makeup, even when the skin is flaking, after an epidermal peel or a peel to the basal layer, but it is unlikely to look good. After a peel to the papillary or reticular dermis, makeup is usually allowed, and even recommended, on the eighth day. Patients who do not like wearing makeup should be warned of the likelihood of postpeel erythema, depending on the depth of the treatment. Some patients are thus ruled out, as their professional lives do not allow any visible erythema or they cannot stand the idea of wearing makeup. In these cases, it is recommended to repeat an Easy TCA® peel four times rather than use Unideep®.2

SMOKING AND PEELS It is generally accepted that the free radicals produced each time smoke is inhaled contribute to the overall aging of the body and of the skin in particular. Publications that show the difference in skin quality between two twins, one of whom is a smoker and the other not, speak for themselves, so marked is the deterioration of the smoker’s skin. Smoking causes repeated vasoconstriction and chronic microvascular damage, which contribute to the overall impoverishment and aging of the skin. There are no major problems, however, with heavy smokers who have peels to the papillary dermis. Full-face phenol peels should be performed with caution because of the increased risk of laryngeal edema. A localized phenol peel does not pose this kind of problem, and phenol can, for example, be applied around the edges of the mouth (which is usually very damaged in smokers), while the rest of the face is treated with a trichloroacetic acid peel to the papillary dermis.

MENTAL RETARDATION AND PEELS The more severe the patient’s retardation, the more superficial the peel should be. The same applies to hypersensitive patients.

NUTRITION AND PEELS The patient’s nutritional condition at the time of a peel is an important factor in the treatment. For all the phases of healing to take place correctly, a perfect balance of nutrition and micronutrition is necessary. It is clear that poor nutritional balance will have more impact on healing after a deep peel than after a light peel, which is all the more important to note as deep peels, rather than light peels, are usually intended for older people. Many proteins are synthesized during healing after an intraepidermal peel: many amino acids are needed to

form the provisional matrix as well as to synthesize new collagen. Catabolic patients, or patients who have recently had significant, involuntary weight loss, do not have sufficient protein reserves for the skin to regenerate properly. A dermal peel also induces stress, which causes a hypercatabolic state that is more or less acute depending on the depth of the peel. Patients with insulin-dependent diabetes or patients who have recently undergone significant trauma or surgery, who have liver or kidney deficiencies, or who suffer from chronic inflammation are not the best candidates for dermal peels, as the need for protein increases sharply. The average daily protein requirement is 1.5 g/kg per day. The amino acids considered most essential include arginine and glutamine. However, to date, it has not been proved that supplements improve the quality of wound healing. Arginine is a precursor of proline and collagen, and the recommended dose is 15–25 g/day. It acts as a local stimulant of lymphocytes and a general stimulant of human growth hormone (HGH) and insulin-like growth factor I (IGF-I) production. Glutamine also stimulates the production of HGH, and is an antioxidant and an energy source for fibroblasts, keratinocytes, lymphocytes, and macrophages. A daily intake of 10–30 g/day is recommended. Carbohydrates and fatty acids are also necessary for rapid and good-quality skin regeneration. The extracellular matrix is made up of glycosaminoglycans and proteoglycans, which are polysaccharides linked to proteins. Omega-6 fatty acids are essential for cell membrane formation. Supplements of linoleic and linolenic acid can be recommended when the patient’s blood is not properly balanced.3 Numerous trace elements are necessary for many enzymes to function properly: copper is needed for the formation of the collagen network and the antioxidant action of superoxide dismutase; iron is needed for collagen synthesis; zinc is a cofactor for DNA and RNA polymerases, plays a part in protein synthesis, and stimulates cell division. Vitamins also play a role in the healing process. Vitamin A is involved in angiogenesis and keratinocyte differentiation, stimulates collagen synthesis, and enhances intercellular adhesion and skin immunity. Vitamin E can be used as a lipophilic antioxidant. Vitamin C is necessary for collagen synthesis and for stabilizing the collagen triple helix. Between 500 and 1000 mg/day can be given before and after an intradermal peel.

NOTES 1. Preventing laryngeal edema in smokers undergoing a phenol peel. 2. Unideep (Skin Tech) TCA peel: to the papillary dermis, with a qualitative formulation based on Easy TCA® but with a more concentrated solution and postpeel cream. 3. The Roman Pais laboratory in Nivelles, Belgium, provides— among other nutritional and micronutritional tests—a very precise and scientifically annotated blood count of circulating fatty acids.

5 Selection of the right peel The possibilities for treatment with chemical peels are many and depend on the agent chosen as much as on the way in which it is used. We can take a narrow view of peels as the destruction of damaged tissue with acid.1 From this perspective, a result can be achieved only by “destroying beneath the lesion.” This is, of course, often the case, but we must not forget that chemical peels help to stimulate as much as destroy. Many of their positive effects are largely due to this stimulation. Consider glycolic acid, for example, whose action is mainly intraepidermal2 but which is associated with activation of the papillary dermal fibroblasts. The destructive effect, which removes the stratum corneum and even part of the epidermis (depending on the concentration used), improves the appearance of rough skin, while the effects of remote stimulation improve the extracellular matrix constituents secreted by the fibroblasts. Choosing the right peel is often stressful for a doctor who is starting his or her career in peeling: opting for a technique that is too superficial will satisfy neither patient nor doctor, while using a medium-strength product could cause unexpected side effects that can be hard to cope with, especially if the results are mediocre. Deep peels have their own indications and risks. Sometimes, only a deep peel can solve a cosmetic problem, but the level of complexity and danger of such peels means that they are often rejected by beginners, who will instead attempt to push the limits of a peel and do a medium peel with an agent that is intended to be superficial. They will often pay for the consequences in cash. When choosing a peel, a simple equation should be taken into account: the results expected from the peel must be greater than the sum of the fear of the treatment’s complexity, the risk of complications, and the downtime and financial cost for the patient. The ratio [Results/(complexity + complications + downtime + cost)] must always be positive. During the preliminary consultation, the doctor should first discuss downtime and treatment cost with the patient, who always expects breathtaking results. It is easier to deal with these two factors first before embarking on the complexity of the technique and the potential risks and complications. In this way, the treatment can quickly be oriented to what the patient is prepared to go through. If patients immediately say that they cannot accept any downtime or have limited funds, it is pointless to waste their time, which is as precious as yours, explaining unnecessary technical details about deep peels. A few logical rules make it easier to choose the right peel (see Table  5.1). Nothing speaks louder than pictures when it comes to chemical peels. We will look at different clinical cases to discuss the choice of an appropriate peel.

START OF PHOTOAGING The patient shown in Figure  5.1, who is approaching 40, has a few lentigines and a thick and oily skin with dilated pores.

There are no wrinkles but a slight sagging of the skin that is only noticeable in a standing position. A deep peel would not be the best way to treat this patient, as the ratio of results to complexity + complications + downtime + cost would not be favorable. The possibility of a medium peel to the papillary dermis could be discussed, if the patient wanted fairly quick results or if she did not have enough time for a series of lighter peels. She could also be advised to have a series of peels, either intraepidermal (to remove the epidermis) or down to the basal layer, combined with appropriate daily care. Another possibility would be one alpha hydroxy acid (AHA) peel per week for 6–10 weeks or one Easy TCA® (pinpoint frosting) per week for 4 weeks.3 The daily care routine should include DMAE4 to firm the skin, tyrosinase inhibitors and antioxidants to limit melanin production,5 and, of course, effective sun protection. If the lentigines do not clear quickly, they should be treated locally with a single careful application of Only Touch®, immediately before the last of the four Easy TCA peels.

UNDER-EYE BAGS Many patients want to get rid of or improve under-eye bags (Figure 5.2) that leave them looking permanently tired. This is a purely surgical problem, although it has been suggested that local injections of phosphatidycholine could dissolve the fat, but this treatment can be very risky.6 Peels and cosmetic products cannot improve them. In some circumstances, a phenol peel can improve bluish circles under the eyes if it succeeds in making the thin skin in this area thicker. The best treatment is to remove the weak veins of the inner and outer canthus with a Müller hook, followed by treatment with blue laser light.7

SAGGING SKIN Apart from an improvement in overall skin quality and tone, the patient shown in Figure 5.3 will not benefit from any peeling technique—either repeated superficial peels or a deep phenol peel. Actinic damage is light and there are not many lines or wrinkles. On the other hand, the folds of sagging skin are very marked in this patient, who is a heavy smoker. Examination and palpation show that the dermis has emptied of its ground substance and atrophied. The daily care routine should combine powerful antioxidants,8 DMAE, and possibly DHEA. This patient refused to have any surgical treatment and was treated with a phenol peel in an attempt to get the skin to retract. Unfortunately, on a dermal base totally emptied of ground substance, this treatment resulted in an “accordion effect.”9 This patient would only benefit cosmetically from a surgical facelift, possibly followed by peels to the Grenz zone to improve the quality of the skin.

Selection of the right peel   33 Table 5.1  Choosing an Appropriate Peel Sagging skin

Neck Expression wrinkles Photoaging and free-radical aging from smoking and pollution Active acne Facial acne scars Hyperpigmentation disorders

Solar or senile lentigines Stretch marks Hypertrophic scars Body peels Peels on the backs of the hands

Better treated by surgery. Deep phenol peels are the ones giving the best results in term of skin tension but only if the skin is relatively thin. Peels are not indicated for sagging in thick skins, or for nasolabial folds or for the neck. Chemical peels cannot compete with surgical face-lifts when it comes to sagging skin; they cannot stretch the skin as well as the latter do. Results are often disappointing when we want to act on the oval shape of the face by performing peelings. Responds poorly to chemical peels. Results are positive when we want to act on photoaging signs. Benefit from treatment with botulinum toxin prior to any peel; it allows the skin to regenerate on a nonmoving base. Can be treated with a peel; the speed and quality of the results depend on the depth of the treatment. Should only be treated by a medium peel after it has been treated medically and the infection has cleared up; it can, however, be treated by lighter peels during the active infectious phase. Easy TCA allows a treatment of the active phase of acne, as well as AHA peels (see Chapter 17). Difficult to treat, sometimes even with a deep phenol peel. Acne scars on the back, décolletage, or face can fade or improve with a very deep combined technique of chemical peeling and dermabrasion (anterior chemoabrasion). It is still difficult, however, to eliminate them completely. Results depend entirely on the depth of the problem and the depth of the treatment. They are frequently treated with peels that reach or go beyond the Grenz zone, in conjunction with appropriate daily care. The only way to treat melasma permanently is by completely destroying the cells that produce melanin, by peeling “beneath the lesion” with an agent that is toxic to melanocytes, which is a fairly aggressive treatment. Another option is to treat the skin more superficially to reduce the risk of complications. Only a certain proportion of melanocytes are destroyed to lighten the melasma at the same time as stimulating keratinocyte turnover. The relative increase in the number of keratinocytes compared with the number of melanocytes dilutes the melanin produced in the epidermal cells (the blending effect). Melanogenesis is reduced with tyrosinase inhibitors and antioxidants, which are applied in the long term and combined with effective sun protection (bleaching effect). Respond partially to peels to the Grenz zone and the papillary dermis. They sometimes require a focal peel to the reticular dermis to eliminate them completely. This deep peeling can be local (see Chapter 22). Can only be treated definitively by applying aggressive treatments that can improve the epidermal and dermal atrophy that accompanies them. Peels are not indicated; treatment using corticoids intralesional injections and permanent compression with a silicone sheet give the best results. Some fine facial scars (from a face-lift, for example) improve vastly after local application of some phenol peels; others are improved by a combination of abrasion and peeling. Produce fewer results and more problems than facial peels. Very easy and cause few complications, for example with trichloroacetic acid in the form of Easy TCA, following a specific protocol (see Chapter 19).

Figure 5.2  A peel is not an indication for under-eye bags.

Figure 5.1  Stimulating superficial peels and appropriate daily care are indicated for this patient.

The patient in Figure  5.4, on the other hand, received much benefit from the stimulating and evening effect of Easy Phytic on the epidermis and dermis. The skin tension is better and the yellow discoloration caused by actinic damage has been reduced. The daily care routine also consists of Actilift (DMAE cream) and DHEA-Phyto; see Chapters 2 and 3 for more information on these two products. When retightening is indicated, Easy Phytic can be applied in a single layer every morning for several days, depending on how the skin reacts. The results are surprisingly quick, and the skin soon tightens visibly (see Chapter 11).

34   Textbook of Chemical Peels

Figure 5.3  General sagging of the skin with little actinic damage; this is not a good indication for a peel.

Figure 5.5  Comedonal acne.

(a)

(b)

Figure 5.4  (a, b) A moderate improvement in sagging skin can sometimes be achieved by applying superficial peels: here, after three Easy Phytic peels.

COMEDONAL ACNE Comedonal acne (Figure  5.5) can be treated with an intraepidermal peel or a peel to the basal layer. A trichloroacetic acid (TCA) peel to the papillary or reticular dermis could be considered, but such a deep treatment would be pointless for this type of disorder, which can be treated with a lighter peel and, in any case, requires long-term maintenance treatment. It is essential to “clean” the skin beforehand with a comedone extractor to limit damage to the skin; the skin should be cleaned in this way a week before an alpha hydroxy acid (AHA) peel10 or immediately before each of four Easy TCA peels. Removing the comedones helps produce quicker results and prevents postpeel infections.

Macrocomedones and Large Comedones (1–2 mm in Diameter) These can be treated locally with Only Touch, a solution with a high concentration of saponified and stabilized TCA. Either the applicator provided with the product or the point of a 30G1/2 needle should be used to limit the action precisely to the head of the comedone. In 95% of cases, comedolysis is achieved. Macrocomedones (>2  mm in diameter) can benefit from careful infiltration of Easy TCA or Easy Phytic solution

into the center of the comedone. Postpeel care, which is very important, consists of avoiding comedogenic cosmetics; having the skin cleansed professionally once a month; and applying an anti-acne cream containing AHAs, tretinoin or precursors, disinfectants, anti-inflammatories, tea-tree oil, and so forth11 once or twice a day. For details of this treatment, see Chapter 15.

LENTIGINES, ACNE, AND DYSCHROMIA The patient shown in Figure  5.6(a) has numerous treatments to choose from. She does, however, have an important restriction to take into account: downtime must be minimal and the overall cost low. Resorcinol, TCA to the papillary dermis, and phenol are all automatically ruled out. However, a relatively strong acid is needed to treat the lentigines that can be seen at the top of Figure  5.6(a). For this, Only Touch can be used, applied locally and precisely on the lentigines, with Easy TCA being applied on the rest of the face to treat the dyschromia, superficial lentigines, photoaging, and acne and to even out the result. See Chapter 15 for details on applying this product. Daily postpeel care should consist of an anti-acne cream and a blending and bleaching cream to even skin tone. Figure 5.6(b) shows the lentigines clearing up, an improvement in the overall appearance of the skin, and the dyschromia evening out. This improvement can still be seen 1 year after treatment. Nevertheless, focal application of a deep TCA peel induces 2 weeks of crusting and could induce long-term redness on the facial skin, with potential postinflammatory hyperpigmentation (PIH). Therefore, we actually prefer treating it using a “mosaic” technique: Easy TCA is applied focally, until inducing a focal white frosting. After that, Easy TCA is applied on the full face to obtain a uniform result.

PHOTOAGING The more severe the photoaging, the more important it is to consider the depth of the peel. The patient shown in Figure 5.7

Selection of the right peel   35

(a)

(b)

Figure 5.6  Combination of lentigines, acne, and dyschromia. (b) Results 1 year after combining Easy TCA and Only Touch.

has a light skin type that is sensitive to the sun’s rays. She has developed a number of solar lentigines and fine wrinkles caused by UV rays. The eyelids are very wrinkled and the nasolabial folds and marionette lines are slack. In the long term, this patient’s nasolabial folds and marionette lines will only improve slightly, even with a deep peel. Other techniques12 should be used to treat them. There are many peels to choose from. The wrinkles on the lower eyelids can be softened with a TCA peel to the Grenz zone (Easy TCA) or to the papillary dermis (Unideep), but only phenol can be guaranteed to get rid of them. Many lentigines respond to a TCA peel to the basal layer of the epidermis, the majority to

a TCA to the papillary dermis, while the deepest should be treated to the reticular dermis. Fine wrinkles on the cheeks can improve with TCA,13 but only phenol can really eliminate them and tighten the skin. There are two choices of treatment open to this patient. The first option would be an aggressive treatment, to be done in a single session: a full-face phenol peel that will treat all the symptoms of photoaging at once and tighten the skin. If the patient opts for this treatment, she must accept at least 8 days’ downtime and a high treatment cost. The second option is a less aggressive, more gradual and stimulating treatment that can be combined with a local phenol peel on the lower eyelids. Only Touch is applied locally on the deeper lentigines and Easy TCA on the rest of the face to even out the result and improve the fine wrinkles. A localized phenol peel on the lower eyelids14 is recommended if the patient wants to get rid of her eyelid wrinkles. If this course of action is chosen, the possibility of combining a localized phenol peel with Unideep, a TCA peel to the papillary dermis, should be discussed. With phenol, the downtime is 8 days and it might be more appropriate to combine the local phenol peel with a single session of Unideep® that has a downtime of 5–6 days, instead of having four weekly sessions of Easy TCA. As the results are comparable,15 the decision is often based on cost or the risk of complications, which is higher with a dermal peel. Depending on requirements, daily postpeel care should include a vitamin E antioxidant cream, a blending and bleaching cream, and/or a DMAE cream.16 Some solar and senile lentigines may only respond to peels to the reticular dermis as, histologically, the lentigines may be characterized by deep dermal papillae and elongated rete ridges with golf club–shaped extensions.

POSTINFLAMMATORY HYPERPIGMENTATION AND SCARRING

Figure 5.7  More severe photoaging.

The patient shown in Figure 5.8(a) was in a serious road accident 6 years before the treatment. The surgeon did a perfect job given that the patient’s face had been completely lacerated by the car’s windshield. Severe post-traumatic inflammation quickly turned into PIH that the patient hid for years under camouflage makeup. Given the extent of the problems to be treated, a full-face phenol peel was initially suggested but was then ruled out because of the high cost of the treatment. The glabellar scar

36   Textbook of Chemical Peels

(a)

(b)

(c)

Figure 5.8  (a) Post-traumatic scars and hyperpigmentation. (b) Following treatment with a local phenol peel. (c) Four Easy TCA peels and Blending Bleaching Cream were applied to even out the skin color.

could not be improved by anything but a phenol peel, which was then applied locally, as can be seen in Figure  5.8(b): this photograph shows the pure white frosting resulting from the local application of phenol. The skin color was evened out by applying four Easy TCA peels until a cloudy white frosting was achieved, combined with Blending Bleaching Cream that was applied twice a day from the day after the first peel and continued for at least 6 months (Figure 5.8c). An effective sunscreen (see Chapters 3 and 35) must be applied every day between the four weekly peels and until the end of the maintenance treatment.

SEVERE AGING OF THE SKIN The patient shown in Figure 5.9 has thin skin marked by expression wrinkles, sagging skin, and photoaging. Using a peel that does not reach the dermis is always disappointing in cases like this. Some light peels might tighten the skin temporarily as a result of the edema that occurs afterward. It would be impossible to attempt to correct all of these wrinkles, even by frequent repetitions of an intraepidermal peel or even a peel to the Grenz zone. A peel to the papillary dermis might improve the finer wrinkles and the quality of the skin, but only a full-face phenol peel could tighten the skin definitively through a “threedimensional facelift.”17 The expression wrinkles should be treated first—1 week before the phenol—with botulinum toxin, which will allow the skin to regenerate without the movements that would soon reimprint the wrinkles on a healing dermis.

PERIORAL WRINKLES Perioral wrinkles (around the upper lip and chin) only respond to very deep peels (Figure  5.10). Many different agents have been tried, such as pyruvic acid, which has a high potential for scarring. This particular agent, which is difficult to control in concentrated solutions, is rarely used. Chemical cheiloplasty can only be considered under three conditions: The natural skin color allows treatment without the risk of pigmentary changes. The skin around the area to be treated is in good enough condition that the demarcation line will not be too obvious. Other treatments (i.e., hyaluronic acid, collagen, etc.) would have no effect. Patients with skin phototype above IV are therefore ruled out from this treatment, as are patients with a light skin phototype but a lot of freckles18 and patients whose skin is severely photoaged. Phototype IV patients should make a choice between deep wrinkles and a possible depigmentation. Lip & Eyelid Formula was originally developed to treat only the lips and eyelids before its indications were extended to the full face. It can be applied locally without nerve blocks or any kind of anesthetic (see Chapter 36). A TCA Unideep peel (to the papillary dermis) is applied to the rest of the face immediately after the phenol peel has been applied locally (Figure 5.11).

Selection of the right peel   37

Figure 5.9  Result at 3 months average, after one Lip & Eyelid full face deep phenol peeling.

(a)

(b)

(c)

Figure 5.10  (a) Deep wrinkles on the upper lip and chin. (b) Bismuth subgallate powder mask during the first few days after a phenol peel. (c) Results after treatment of these wrinkles with Lip & Eyelid Formula (phenol peel—chemical cheiloplasty).

38   Textbook of Chemical Peels

(a)

(b)

Figure 5.11  (a, b) Wrinkles on the upper lip treated with a single application of Lip & Eyelid, with the rest of the face being treated with a Unideep peel in the same session. Note the excellent results for facial skin tension with TCA.

The Unideep must not come into contact with the skin that has been treated with phenol. Botulinum toxin often has to be used at the same time as a deep peel on patients with thick skins to limit the contractions of the orbicular muscle of the lips and to improve/maintain results. The horizontal fold between the lower lip and the prominence of the chin does not usually respond well to peels, even deep ones. It can easily be filled in, however, together with the nasolabial folds 1–2 months after the phenol peel.

DERMAL ATROPHY The wrinkles on the cheeks of the patient shown in Figure  5.12(a) have been caused by dermal and hypodermal atrophy. Only a deep peel could improve the cosmetic appearance of this patient. Dermal fillers are, however, another possibility for treatment. Figure  5.12(b) shows the rejuvenating effect of injecting 2.5 cm3 of Bioalcamid®19 in each cheek. The

(a)

deep wrinkles have completely disappeared and the shape of the face has been restored to look like it did in a photograph of the patient when younger. Note the persistent bruising in the injected areas. This bruising can largely be avoided by using a trocar or blunt-tipped needle instead of a conventional needle. This treatment can of course be combined with a peel: Bioalcamid can be used perfectly safely with Easy TCA in the same session. The peel is performed after the liquid implant has been injected. A deeper peel, on the other hand, should only be applied a few weeks after the filling to avoid interference with the necessary process of encapsulation that fixes the filler material in place.

DEEP WRINKLES If the patients in Figures 5.13(a) and 5.14(a) want quick rejuvenation that will last around 15 years, a phenol peel is the only indication (Figures 5.13b and 5.14b). The extent of the problems

(b)

Figure 5.12  (a) This patient’s wrinkles are caused by severe skin atrophy. A peel is not the best indication. (b) Results of treatment with a dermal filler: 2.5 cm3 of Bioalcamid in each cheek.

Selection of the right peel   39

(a)

(b)

Figure 5.13  (a) Deep wrinkles. (b) Results after a session of full-face Exoderm ®.

(a)

(b)

Figure 5.14  (a) Deep wrinkles. (b) Results after a full-face phenol peel; second treatment of the upper lip.

40   Textbook of Chemical Peels

would be beyond dermal fillers, and if these were used, the results would be temporary. Botulinum toxin, used alone, would only partially improve the areas around the eyes, lips, and cheeks. A surgical facelift would tighten the neck and the cheeks, but it would not treat the crow’s feet satisfactorily and would have no effect at all on the wrinkles on the lips and the overall skin quality. A light peel would only improve skin quality and even out skin tone, but would not get rid of the wrinkles. A peel to the papillary dermis would have a similar and more noticeable effect, but would not eliminate the deep and longstanding wrinkles. An experienced doctor could use full-face dermabrasion. Full-face carbon dioxide laser treatment used to be very popular but is gradually being abandoned because of the serious complications faced by both patients and doctors. A phenol peel will treat the sun-damaged skin and tighten these patients’ faces. An inexperienced doctor should not, of course, use this type of peel. Treating the deep wrinkles on the upper lip often calls for a combination of techniques: phenol plus dermabrasion, phenol plus botulinum toxin, second phenol treatment, and so on.

MELASMA Many techniques are now available for treating melasma. Some are more aggressive, some more effective, and others more costly or complex. Only one technique can provide a definitive and effective treatment in one single session: a

(a)

phenol peel. After a phenol peel, melanocytes can no longer produce melanin. If we rule out this treatment, which would be extreme for melasma alone, then the basic principle is relatively clear, if not always 100% effective. The existing melanin reserves must be eliminated by carrying out one or more peels, and melanin must be prevented from building up again by long-term topical postpeel treatment and effective sun protection. How quickly the melanin reserves can be eliminated depends on the strength of the peel: an intraepidermal peel will be extremely slow, a peel to the basal layer will be slow, a peel to the Grenz zone will be quicker, and a peel that destroys most of the papillary dermis will be quicker still. This progression raises the following problems: if the peel acts too slowly, either the patient will tire of the treatment, or the skin, once exposed to the sun’s rays, will resynthesize the melanin as it is being eliminated; if the peel is deeper, to the papillary dermis, and the inflammation is not controlled, the skin might react and develop PIH. In any event, success depends on sun protection/avoidance and long-term topical treatment. Patients who refuse to go through with postpeel care should not be accepted for melasma treatment. The choice of treatment for the patient shown in Figure  5.15(a) was four sessions of Easy TCA (Figure  5.15b). The solution was first applied to the melasma spots until cloudy white frosting appeared; it was then applied to the whole face to even out skin tone.20 One session was done per week. Antityrosinase and antioxidant Blending Bleaching Cream was used

(b)

Figure 5.15  (a) Melasma before treatment. (b) After four Easy TCA peels and Blending Bleaching Cream.

Selection of the right peel   41

twice a day. The cream was first applied the morning after the first peel, on the whole face in the morning, and on the melasma spots in the evening. Any melasma treatment (apart from phenol) must be accompanied by long-term care with antioxidants, tyrosinase inhibitors, and effective sun protection for a minimum of 6 months (although 1 year would be more effective).

COMPLEXITY OF CHOOSING A TCA PEEL TCA peels are doctor-, chemical-, and patient-dependent. Penetration depends on how the skin is prepared, and the doctor’s choice of preparation depends on the patient and the method of application (when prepeel preparation is indicated). It also depends on how rigorously the actual patients, who will only benefit from TCA in simple aqueous solution (TCA–SAS) when the skin has reached the stage of “retinoid dermatitis,” prepare their skin. The results of a TCA peel vary from “inadequate” to “excellent.” As there is no general toxicity, the peel can be applied to all areas of the skin. Pigmentary changes are always a risk with TCA–SAS and should be prevented as much as treated. There is also a risk of scarring when the concentration of TCA is higher than 35% m/m. Treating the neck and décolletage is dangerous, as effective treatment depends on relatively high concentrations of TCA–SAS being applied to an area that is quick to scar because it has few appendages, because of its histological structure, and because of the twisting and stretching movements it is constantly undergoing. For an inexperienced doctor, the choice may seem daunting. What is the best way to deal with general skin aging of “average severity”? Phenol would be too aggressive and glycolic acid not strong enough. A TCA peel would be more appropriate, but how much preparation would the patient accept? What concentration of TCA should be used—25%, 35% or 50%? m/m, m/v or m + v? How much acid solution should be applied and how many coats? What depth should be reached? How much pressure should be applied on the gauze pad? And is it better to use gauze or a cotton swab? Or a brush? What kind of postpeel care should be used? What are the usual developments? What will the results be? What complications could arise? Should the peel be repeated? If so, how many times and how often? The questions posed to an inexperienced doctor are endless. Fortunately, a new concept in TCA peels came into being in the second half of the 1990s: Easy TCA. This peel can be performed in a doctor’s office—without preparation, anesthetics, or close follow-up—on all skin types, on all areas of the skin, and in all seasons.

DIFFERENCES BETWEEN EASY TCA AND TCA–SAS There are many differences between Easy TCA (ETCA) and TCA–SAS applied in the classic manner.

ETCA Logic versus TCA–SAS Logic The logic behind a TCA–SAS peel is different from that behind ETCA. TCA–SAS is used to destroy damaged tissue (removing the papillary dermis) with the skin being left to heal naturally. It is a destructive rather than a stimulating process. The indications for “destructive” peels are different from those for “stimulating” peels. An ETCA peel is stimulating rather than destructive: it does not destroy much skin (the Grenz zone or

basal epidermis is removed; see Chapter 12) but strongly stimulates the regeneration process. All peels induce inflammation (tumor–dolor–rubor– calor), which is responsible for the redness, swelling, and most of the pain21 and heat felt in the treated skin. The swelling and edema come from rapid permeation of the dermal blood vessels, which pour out a large quantity of neutralizing serum, oxygen, and pro-inflammatory components into the dermis and maintain vasodilation. Free radicals are also soon released and damage all the surrounding structures, especially those needed for reepithelialization. Every peel has to take the advantages and disadvantages of inflammation into account: • •

The upside is the stimulation without which regeneration could not take place. The downside is the self-maintained production of free radicals that damage the skin and slow down reepithelialization.

An ETCA peel attempts to make the most of the positive effects of inflammation at the same time as limiting, as far as possible, the negative effects of oxidation with the help of the postpeel cream. TCA–SAS, on the other hand, has to contend with the good and bad sides of inflammation.

ETCA Solution versus TCA–SAS Solution

TCA–SAS TCA–SAS is a simple dilution of TCA in water. Its characteristics are described at length in Chapter 12, together with the various approaches used to counter the difficulties arising in its use. TCA–SAS is usually considered to be effective from 25% m/m. ETCA ETCA consists of a base solution to which the doctor must add a specific quantity of TCA to make up a peel solution that contains 15% m/m TCA. This solution is saponified, stabilized, and adjuvanted. Saponins are natural extracts, glycosides, which have lathering and binding properties for water-soluble products in the skin’s lipids. They help the acids spread and penetrate evenly, on and through the skin. Some studies have shown that saponins have antimicrobial properties that enhance skin regeneration after a peel. ETCA solution also contains the surfactant (Box 5.1) sodium laureth sulfate (SLES).22 SLES degreases the skin, emulsifies fats, and holds skin impurities in suspension. Coconut fatty acid monoethanolamide (cocamide) improves the effectiveness of saponins. Citric acid is a tricarboxylic AHA,

BOX 5.1  Surfactants Emulsifiers are necessary to allow water and lipids to combine. A surfactant is an amphiphilic molecule that has affinities for fats as well as water and that can be incorporated into lamellar lipid structures (e.g., cell walls). Surfactants increase the fluidity of the lipid structures by partitioning into the lipid membranes, as their lateral interactions with the membrane-forming lipids reduce the force of their attractive interaction. The mobility of the membrane lipids increases considerably in a similar manner to when a liquid crystal is converted into a gel. Finally, lipids can be seen to micellize or simply dissolve. Membranes lose their relative impermeability. See Figure 5.16.

42   Textbook of Chemical Peels

Normal membrane structure: active transmembrane protein

ETCA: no antibiotics, no disinfectants. The Langerhans cells (LCs) in the epidermis and papillary dermis are not destroyed, nor are the other antigen-presenting cells, and they continue to prepare the body’s defenses against microscopic predators. The lymphocytes, macrophages, and other defense cells remain present in the dermis. The “postpeel cream,” applied as soon as the first epidermal pinpoint frosting appears, contains tretinoin precursors that boost the LCs and improve their antigenpresenting function.

Immediate Prepeel

Lipid breakdown: inactive transmembrane protein

Figure 5.16  Effect of surfactants on cell membranes.

an antioxidant, chelator, and buffer that helps break down corneodesmosomes and makes it easier for the TCA to penetrate the epidermis. Ascorbic acid has a dual role, acting as a buffer and protecting against free radicals. It protects the solution as well as the skin from oxidation.

Prepeel ETCA versus Prepeel TCA–SAS TCA–SAS should be preceded by several weeks of skin preparation to even out and reduce the thickness of the stratum corneum, reduce melanocyte activity, and enhance reepithelialization. ETCA, on the other hand, is applied on unprepared skin, as the acid and the postpeel cream penetrate evenly; the risk of pigmentary changes (basic protocol) is extremely low and reepithelialization takes place without prestimulation.

Calculating the Solution Mix Preparing a TCA–SAS solution appears easy at first sight, but numerous factors come into play that can change the behavior of a solution, gel, or paste considerably. ETCA provides a standardized solution that always produces the same results when the same protocol is used.

Herpes Prevention Herpes prevention is essential before a TCA–SAS peel, as the dermis of the skin has to be destroyed for the peel to be effective, and the skin’s immune defenses suffer from this destruction. ETCA is more stimulating than destructive; it will not destroy the skin’s immune defenses. On the contrary, repeated peels appear instead to stimulate it. No herpes prevention is necessary before using ETCA in the “basic protocol” (scattered pinpoint or cloudy white frosting).

Bacteria Prevention For the same reasons outlined earlier, the risk of secondary bacterial infection is considerably lower with ETCA than with TCA– SAS. Systematic prevention of infection is not necessary with

With a TCA–SAS peel to the papillary or reticular dermis, the patient’s skin needs to be properly cleansed, cleaned of makeup, disinfected (with alcohol), and degreased (with acetone). The doctor must disinfect his hands properly, and the patient must be kept away from any potentially infectious staff. The TCA– SAS cannot penetrate the skin properly through grease and makeup, and the skin must be disinfected to limit the risk of postpeel secondary infection. ETCA is usually applied without any prior cleansing, makeup removal, degreasing, or disinfection. The peel solution can even be applied on top of makeup, as the emulsifiers in the base solution hold these molecules in suspension and allow the TCA to come into contact with the skin. The endpoint of ETCA treatment is scattered pinpoint frosting or cloudy white frosting, and there is therefore no need to increase penetration of the peel solution artificially. Makeup removal, disinfection, and degreasing are not forbidden before an ETCA peel, but could increase skin permeability and cause the solution to penetrate too deeply and destroy the dermis. A TCA to the dermis is not the same as an ETCA peel.

Depth of Peel TCA–SAS is applied with a view to destroying damaged (usually sun-damaged) skin structures and benefiting from the skin regeneration that naturally follows a peel. It is really effective when it destroys the papillary dermis. With ETCA, the aim is not to destroy the dermis in the hope of its rebuilding later, but rather to stimulate all the phenomena of skin repair repeatedly, in all the different layers of the skin. With frequently repeated ETCA sessions (every 8 days), the sum of the results is comparable to that of a papillary peel without any of the drawbacks. The “basic protocol” for ETCA is intended to reach the basal layer of the epidermis or the Grenz zone. There are (many) other deeper protocols, but they are not as straightforward as ETCA and the risk of complications is relatively much higher. ETCA is not necessarily a light peel; it can be used to reach all depths, from the basal layer of the epidermis to the reticular dermis, depending on the protocol used. The relatively superficial action of the ETCA solution (basic protocol) strongly stimulates the skin regeneration process and increases the permeability of the epidermis. The ETCA postpeel cream penetrates the skin more easily, as it is permeabilized by the peel solution.

Anesthesia, Pain, and Monitoring A TCA–SAS peel to the dermis is painful and requires the use of analgesics. Some resistant patients can tolerate a peel reaching the superficial dermis but are left with such unpleasant memories that they might well refuse further treatment. A peel to the papillary dermis should not be done without facial nerve blocks (FNB) and/or sedation. Performing FNB requires

Selection of the right peel   43

a series of measures, including pulse oximetry at the very least. Any painful intervention can trigger vagal reactions for which the doctor must be prepared. Pain after a peel can be dealt with easily by prescribing oral analgesics (e.g., acetaminophen or codeine/acetaminophen). ETCA does not require any type of anesthetic, sedation, or analgesics. Any mild pain caused by the application of the ETCA solution can be dealt with immediately, as soon as frosting occurs, by applying the postpeel cream.23 No pulse oximetry monitoring is necessary and no vagal reaction has been described, perhaps because it is a short procedure.

Length of Peel It takes 10 minutes to apply ETCA to the basal layer or the Grenz zone, from the time patients lie down to when they get up. Applying a TCA–SAS peel, usually to the papillary dermis, takes a lot longer: at least an hour should be allowed for settling the patient in, disinfection, makeup removal, setting up the monitoring equipment, FNB or sedation, a series of applications, and letting the patient rest after the peel.

Postpeel Care Day 1 to Day 8 Post-ETCA care consists simply of asking patients to protect their skin from the sun (Melablock®-HSP) and to apply the most suitable cosmeceutical for their particular problem (see Chapter 3). They should start the first day after the first of the four peels and continue until the end of the sixth week after the last peel. The posttreatment care after a TCA–SAS peel is more complex and needs much closer monitoring, as the risk of complications is much higher. Follow-up monitoring after a TCA peel to the papillary dermis is described in Chapter 23.

Repeating Peels A TCA–SAS peel can only be repeated after a rest period of usually 6 weeks to allow the skin to regenerate completely. It provides a single strong stimulation that decreases with time. ETCA is repeated four times at weekly intervals to provide ideal stimulation of the skin regeneration processes. The postpeel cream and ETCA application technique allows for this repetition. If the ETCA were repeated less often (once every 2–3 weeks), the effects of stimulation would not be cumulative. Weekly repetition, in contrast, “stimulates the stimulation” resulting from the previous peel.

Combination Treatments TCA–SAS allows few concomitant combinations, and most of the treatments that one might wish to combine it with must be carried out 8–15 days before the peel. For example, nothing can be injected immediately before a TCA–SAS peel. It is, of course, possible to inject botulinum toxin in the upper part of the face just before or after applying a TCA–SAS peel to the area around the lips, but the toxin should not be injected before applying a TCA–SAS peel in the same area. The immediate inflammation induced by the peel could cause the toxin to migrate. ETCA, on the other hand, allows all concomitant combinations. Botulinum Toxin This can be injected immediately before applying ETCA in the same area. The technique is simple: inject the toxin, wait 5 minutes, apply the ETCA until pinpoint frosting appears, and then

apply the postpeel cream. The cream has an immediate and pronounced anti-inflammatory effect, which prevents edema and toxin migration. The restructuring of the skin by the peel improves the results of the toxin, and resting the muscles improves an even collagen deposition. Filling Wrinkles Filling techniques can also be used immediately before ETCA, as the ETCA postpeel cream soon stops inflammation and oxidation. The cream can also absorb the free radicals that are released by the peel and that could damage the three-dimensional structure of dermal fillers, such as hyaluronic acid. In fact, the instructions for most dermal filler products specify not to apply a peel after the filler, but this does not apply to ETCA. Flashlamps ETCA can be used after flashlamp treatment24 when treating pigmentation or photoaging on the face, décolletage, or hands. It is preferable to start with the lamp and to follow up with the peel, for the following reasons: •

•

Epidermal permeability does not seem to change significantly after the lamp, and there is no marked change in the penetration of the ETCA. Caution is, however, advised when applying ETCA solution to make sure that it does not penetrate the skin further than anticipated: the cotton-tipped applicators should be squeezed out properly after the first application and the treatment should not go beyond scattered pinpoint frosting. Applying ETCA and the postpeel cream before the flashlamp would change the refractive and diffractive properties of the epidermis, as well as its water content and color.

Risk of Complications ETCA carries far fewer risks for the patient than TCA–SAS. Infections As described earlier, no herpes or bacteria prevention is necessary with ETCA, unlike TCA–SAS. Risk of Exhausting the Skin’s Resources At the level of the dermis, the fibroblast is a cell of major interest in understanding how peels work. Like Langerhans cells, fibroblasts have dendritic morphology; they are fusiform or stellate but have no antigen-presenting activity. Fibroblasts synthesize all the constituents of the extracellular matrix and play an essential role in the formation and contraction of granulation tissue during wound repair. Peels to the dermis destroy a large number of fibroblasts, and the survivors must multiply in order to reconstitute the fibroblast population. Each time they do this, their telomeres shorten, which gradually exhausts their capacity for future multiplication. Peels to the dermis should therefore not be repeated too often. ETCA, on the other hand, does not destroy dermal fibroblasts (and there is no shortening of telomeres) but stimulates their metabolism and obliges them to produce more and more rapidly. Logically, repeating ETCA (basic protocol) cannot accelerate skin aging, which is not the case with repeated peels to the dermis. Scarring During the healing process, hybrid cells, known as myofibroblasts, appear in the dermis. They have the morphological

44   Textbook of Chemical Peels

characteristics of both fibroblasts and smooth muscle cells. They are responsible for tissue contraction–retraction during healing. Their cytoplasm contains networks of myofilaments that are in contact with specialized zones of the plasma membrane and can interact with the adjacent cells or connective tissue. These myofibroblasts appear to be differentiated fibroblasts that have acquired the properties of smooth muscle cells. Controlled stimulation with DMAE, for example, is a good way to achieve a tightening effect on the skin. Correlating this theoretical data with the clinical data on peels is not without interest, as it allows us to anticipate which peels might potentially cause scarring and which ones will not. Deep peels, which go beyond the upper reticular dermis and practically lay the hypodermis “bare,” are more dangerous as far as retractile scarring is concerned, as they stimulate the conversion of fibroblasts into retractile myofibroblasts that can cause scarring. Not all agents are equally potent; there are more descriptions in the literature of problems with scarring with deep TCA peels than with phenol-based peels. There is no reason why peels that do not go beyond the Grenz zone should stimulate the conversion of fibroblasts into myofibroblasts, as there is no “laying bare” of the internal tissue and hence no need for retraction. Retractile scar reactions are therefore extremely rare with the basic ETCA protocol; they can only occur when the peel has not been applied correctly. Peels that reach the Grenz zone or the papillary dermis stimulate small fibroblasts that are parallel to the epidermis and have dendritic processes that connect with several collagen and elastin bundles. The synthesized collagen is aligned horizontally in the border zone (Grenz zone), and the resulting tension from the activity of any potential myofibroblasts produces a positive cosmetic effect: improved tension in the papillary dermis, which can be called the “lifting effect.” The “lifting effect” achieved with mediumdepth peels in no way compares with the lift achieved when sagging skin and muscle mass are treated surgically. In some cases, doctor and patient can be sent off on the wrong track and delay taking the often dreaded and sometimes formidable decision to go ahead with surgery. Postinflammatory Hyperpigmentation (PIH) It is clear from the medical literature on chemical peels that TCA–SAS is the agent responsible for the majority of postpeel pigmentary problems. Photographs abound in specialist books. A TCA–SAS peel does in fact cause severe inflammation after the peel, and it is therefore not surprising to come across many cases of PIH.25 ETCA in the basic protocol causes almost no PIH. Generally, IV, V, and “light VI” skin phototypes are at greater risk of PIH. Downtime During the postpeel period after a TCA peel to the papillary dermis, the patient has to put up with a week of edema, scabbing, erythema, pain, and other inconveniences. Any form of

social life is out of the question, and the patient can only return to normal social activities, with the help of makeup, after the eighth day. It is several weeks before the skin returns to normal. With ETCA (basic protocol), on the other hand, the patient can lead an almost perfectly normal social life, as the flaking is no more serious than with sunburn and only lasts for 48–72 hours.

NOTES 1. Although some peels with an alkaline formulation do exist. 2. Apart from Easy Phytic Solution, whose acids can penetrate to the papillary dermis. 3. With Easy TCA and Easy Phytic, papulopustular acne can be treated during its active phase. 4. Dimethylaminoethanol, a precursor of acetylcholine. See the section on DMAE in Chapter 3. 5. Blending Bleaching Cream (see www.skintech.info). 6. By injecting phophatidylcholine/deoxycholate into under-eye bags, there is a risk—among other complications—of disrupting the adipocyte cell walls as well as the muscle cells that come into contact with this product. Moreover, it triggers severe and painful edematous erythema that lasts several days and is only effective after several sessions. For the moment, fatty bags under the eyes can only be treated surgically. 7. Source: Dr. Robert Vergereau, Spain. 8. For example, Renutriv ACE Lipoic Complex: vitamins A + C + E and lipoic acid. 9. See the section on the area around the mouth in Chapter 37. 10. The same applies for Easy Phytic Solution. 11. For example, Purifying Cream by Skin Tech. 12. Depending on preliminary examination of the patient and the doctor’s experience: dermal filling, botulinum toxin, cannulation, threading, etc. 13. Either four Easy TCA peels to the basal layer or a Unideep peel to the papillary dermis. 14. See Chapter 34 for application of the Lip & Eyelid Formula. 15. Although it must be taken into account that four peels to the Grenz zone are not necessarily as efficient as one peel to the papillary dermis. The latter can destroy a large number of lesions that peels to the Grenz zone do not always reach. 16. Some studies suggest that DMAE can eliminate the lipofuchsin in lentigines. 17. As the much missed Dr. Yoram Fintsi called it. 18. To avoid leaving an obvious demarcation line. 19. This is a permanent polyalkylimide filler in the form of a removable endoprothesis. Fat transfer is used more often, as there is no risk of rejection and the implant is autologous. 20. See the details of melasma treatment in Chapter 15. 21. The “burning” sensation soon improves on application of a cold pack. 22. SLES is not the same as sodium lauryl sulfate (SLS, also known as sodium dodecyl sulfate [SDS]), a powerful surfactant and very irritating to the skin, with which it is often confused. 23. It is not neutralizing, however, as we shall see later. 24. Provided that this is classic flashlamp treatment and not a device combining pulsed light and radiofrequency, for example. These machines significantly change skin permeability and can cause the acids to penetrate too far, with the risk of scarring. 25. See Chapter 37 for more details.

6 Alpha hydroxy acids Chemistry, pH and pKa, and mechanism of action Alpha hydroxy acids (AHAs) occur naturally in a number of fruits (hence their “eco-friendly” name of fruit acids) and dairy products. This class of acids contains a number of molecules that have in common the presence of a carboxylic acid group (COOH) and a hydroxy group (OH) in the alpha position relative to the acid group (Figure 6.1). As early as 1946, the application of a 3% lactic acid solution at pH 3.8 was already considered a treatment for ichthyosis, although cosmetic dermatologists started using AHAs when in 1974 Van Scott and Yu described how effective they were in the treatment of dry or ichthyotic skin. From then on, the scope of AHAs broadened, and some authors reported their beneficial effects on acne, photoaging, and benign hyperplastic epidermal lesions. It was often suggested that AHAs should be used to treat age-related wrinkles and sagging skin. Although the direct target of AHAs seems to be corneodesmosomes, the indirect action of topically applied AHAs affects not only the whole of the epidermis but also the papillary dermis and the pilosebaceous units. However, while all peels produce similar1 histological effects on the different layers of the skin, clinical results clearly show that AHAs, used as light peels, do not improve the skin’s appearance to the same extent as TCA or phenol. Moreover, indications for glycolic acid peels tend to be restricted to the treatment of sun-damaged or acneic skin, especially in patients who cannot or do not want their skin to flake, often because of their professional activities, which are incompatible with visible peeling. A number of AHAs have been proposed for medical use: glycolic acid, lactic acid, malic acid (with two COOH groups), tartaric acid (with two OH and two COOH groups), citric acid (with three COOH groups), and mandelic acid (which has an aromatic (phenyl) group attached to the alpha carbon atom). See Table 6.1.

GLYCOLIC ACID Glycolic acid (hydroxyethanoic acid, hydroxyacetic acid) is the shortest AHA, with just two carbon atoms (Figure  6.2). It was originally extracted from sugar cane, but the acid used in treatment today is synthesized chemically. AHAs have become popularized as “fruit acids,” and this benign-sounding name has had a great influence on the interest shown by patients. The situation is similar to that when patients talk of lasers, gold threads, or caviar rejuvenating creams. These words evoke dreams of miracle cures in the imaginations of some: odorless, colorless, and painless, permanently effective and, of course, without side-effects. Glycolic acid is extremely hydrophilic, and a pure aqueous solution of glycolic acid, saturated at a concentration of about 80%, has a pH of 0.5. This pH, considerably lower than its pKa of 3.83, shows that the solution consists mostly of pure acid and is effective for performing a peel. The pH of a glycolic acid

solution determines its acidifying power on the skin: a 3% glycolic acid solution at pH 3 can acidify the first five layers of corneocytes, whereas at 10% and pH 3, it causes a deeper and more rapid acidification of the epidermis.2 Note that “acidification of the epidermis” does not mean “peeling effect.” Acidifying several layers of the skin does not necessarily mean destroying the cells. Up to a certain point, cells resist acidification.

LACTIC ACID

Lactic acid (2-hydroxypropanoic acid, α-hydroxypropionic acid) is the next shortest AHA after glycolic acid. A methyl group (CH3) replaces the terminal hydrogen atom on the alpha carbon (Figure  6.3). It has a pKa of 3.86, which is close to that of glycolic acid. Lactic acid occurs naturally in sour milk. After penetrating the skin, lactic acid is converted automatically and reversibly into pyruvic acid, the alpha-keto acid derivative of lactic acid: a keto (= O) function replaces the hydroxy (–OH) function on the alpha carbon. At identical concentrations, lactic acid destroys the epidermis more slowly than glycolic acid. Concentrations of lactic acid of 10%–20% or stronger begin to destroy the stratum corneum and stimulate skin regeneration, the renewal of epidermal cells. However, some studies have shown that cell renewal is not maintained uniformly during long-term treatments with 3% lactic acid at pH 3. In fact, cell renewal gradually falls off during the first 10 weeks of treatment with 3% glycolic or lactic acid at pH 3, decreasing to 29.3% and 28.3%, respectively.3 When applied regularly, lactic and glycolic acids (at 3%, pH 3) lose a significant percentage of their capacity to destroy corneocytes and renew the epidermis around the 12th week. Salicylic acid (a beta-hydroxy acid), on the other hand, retains its ability to destroy corneocytes much longer. At a concentration of 50%–70%, lactic acid produces the same amount of exfoliation as glycolic acid. As early as 1974, it had been shown that lactic acid improved skin hydration and suppleness and that a pH of 3 was more effective than a pH of 5. Lactic acid is also a better hydrator than urea or glycerol. Some studies tend to show that 3 weeks of daily application of 12% lactic acid would allow as much collagen to be deposited in the papillary dermis as applying 25% trichloroacetic acid (TCA) or phenol. We must remember, however, that histological findings, as important as they are, do not always translate into cosmetically visible clinical results and that laying down new collagen is only one of the changes associated with peels.

OTHER HYDROXY AND KETO ACIDS Many other hydroxy acids (and the related keto acids) are used in cosmetic treatments (Table 6.1). Ascorbic acid (vitamin C) is an AHA derivative. It has been shown to stimulate collagen production and reduce

46   Textbook of Chemical Peels

BUFFERS In low concentrations, the pH of a glycolic acid solution varies with the concentration of acid: an unbuffered glycolic acid solution, at less than 1%, has a pH of approximately 2.5.4 At 2%, the pH is 2.1. When the concentration reaches 5%, the pH goes down to 1.9. It is 1.7 for a 10% unbuffered glycolic acid solution. Higher concentrations, 50%–80%, have a pH close to 0.5. At identical pH about 0.5, a solution with a concentration of 80% is more aggressive than a 50% solution (Boxes 6.1 to 6.4).

Hydroxy group OH

O

R — Cα — C H

OH Carboxylic acid group

BOX 6.1  Importance of Buffers in the Body

Figure 6.1  General chemical structure of an alpha hydroxy acid. α indicates the alpha carbon atom; R represents a general organic group.

melanin production. Under identical conditions, classification of the acids described thus far in this chapter in order of strength would give the top three as: 1. Glycolic acid 2. Lactic acid 3. Mandelic acid In the rest of this chapter, it is mainly the use of glycolic acid that will be discussed, and by default this is what the information given applies to. It is clear, however, that as a general rule, and even if some acids have specific properties, most of the hydroxy acids (alpha or beta), carboxylic acids (containing the COOH group), dicarboxylic acids, and alpha-keto acids produce the same positive effects on the skin, depending on the concentration, the pH of the solution (Figure 6.4), and how they are applied.

The body’s—and the skin’s—enzyme reactions are pH-sensitive. It is vital for the body to keep the pH of an organ stable in order to stabilize enzyme reactions. Protection against pH variations—the buffer capacity—must be extremely active and strong, as natural metabolic processes permanently synthesize acids and alkalis that are liable to modify the pH. The blood, for example, is protected by two important buffer systems: the hemoglobin system and the bicarbonate system, which stabilize its pH between 7.37 and 7.43. The bicarbonate system is the most important buffer for plasma and interstitial fluids. Neutralizing the skin with sodium bicarbonate is the most “natural” method.

BOX 6.2  Effect of Dilution on the pH of a Solution Five  ml of the base solution has pH  2.7–3. Adding 20  cm3 of water does not change the pH. The total volume must be brought up to 85  ml for the pH to rise from 3 to 4. See Figure 12.9.

A concentrated glycolic acid solution at pH 0.5 consists of free and active acid, and is aggressive to the skin. It is a thousand

Table 6.1  Hydroxy and Keto Acids Used in Cosmetic Treatments Acida

pKa

Chemical structure and alternative names

Tartaric acid

pKa1 = 3.02 pKa2 = 4.54

Citric acid MW 192.13

pKa1 = 3.06 pKa2 = 4.74 pKa3 = 5.40 pKa = 3.36

HOOC.CH(OH).CH(OH).COOH (+)-2,3-dihydroxybutanedioic acid; d-2,3-dihydroxysuccinic acid (only the dextrorotatory [+, or d] form is active) [dicarboxy dialpha-hydroxy acid] HOOC.CH2.C(OH)(COOH).CH2COOH 2-Hydroxy-1,2,3-propanetricarboxylic acid [Tricarboxy alpha-hydroxy acid] C6H5.CH(OH).COOH (+)-phenylhydroxyethanoic acid; d-α-hydroxyphenylacetic acid; d-phenylglycolic acid; amygdalic acid [alpha-hydroxy acid] CH3.CO.COOH 2-Oxopropanoic acid; acetylformic acid; α-ketopropionic acid; pyroracemic acid [alpha-keto acid] HOOC.CH2.CH(OH).COOH hydroxybutanedioic acid; hydroxysuccinic acid, [dicarboxy alpha-hydroxy acid] HOCH2.(CHOH)4.COOH 2,3,4,5,6-pentahydroxyhexacetic acid α,β,γ,δ,ε-pentahydroxycaproic acid; dextronic acid; glycogenic acid; glyconic acid; maltonic acid [alpha-hydroxy acid] HO.C6H4.COOH o-Hydroxybenzoic acid, [beta-hydroxy acid]

Mandelic acid MW = 122.14 Pyruvic acid MW = 88.06

pKa = 2.50

Malic acid MW = 134.09

pKa1 = 3.40 pKa2 = 5.5

d-Gluconic acid MW = 196.16 Salicylic acid MW = 138.12

pKa = 3.86 pKa = 2.98

ALPHA HYDROXY ACIDS: CHEMISTRY, pH AND pKa, AND MECHANISM OF ACTION   47

BOX 6.3  pH pH is a measure of the acidity or basicity of a water solution. pH = The “p”ower of H+ = pH = proton concentration Solutions with a pH less than 7 are said to be acidic; solutions with a pH greater than 7 are basic or alkaline. Pure water has a pH very close to 7, while tap water is pH +/- 5.5–6. Nonwater solutions have no pH: pH of oleic acid cannot be measured.

BOX 6.4  pOH pOH is a measure of the alkalinity of an aqueous solution. Solutions with a pH greater than 7 are said to be basic or alkaline. pOH ≅ 14 – pH. This measure of alkalinity is rarely used, since the same result can be more easily expressed in pH.

H H

C OH

H

Figure 6.2  Chemical structure of glycolic acid.

HO H3C

C

O C OH

H

Figure 6.3  Chemical structure of lactic acid.

0

pH of Human Skin The pH values on the surface of normal skin vary between 4.5 and 6, and up to a certain point the skin has the ability to defend itself against pH variations and can maintain a stable pH in the face of moderate acid or alkali attacks. When going deeper into the dermis, liquid and nutrients coming out of blood vessels are more and more concentrated and the dermis has the blood pH: 7.2. Liquids and nutrients are frequently replaced; this gives a permanent renewal of the skin buffer capacity. Neutralizing an AHA peel consists in applying a base solution (usually pH  9–10) to the treated area. Rinsing with water only dilutes the acid without neutralizing it (Box 6.2); an acid is neutralized by a base. However, dilution does have the merit of reducing the proton concentration8 and so eventually increases the pH (without changing the pKa, of course) when enough water is added. The high acidity of concentrated and unbuffered AHA solutions, as well as the complications that stem from such treatments, has brought the pH of many glycolic acid solutions to around pH 4–5.5.9 Ammonium salts, sodium bicarbonate, or sodium hydroxide (NaOH) are often used for this. The resulting

O

C

times more acidic than a solution at pH 3.5.5 A solution this strong needs to be properly neutralized by the doctor applying it. Applying a 70% non-neutralized glycolic acid solution to the skin can destroy the epidermis in 2–7 minutes, depending on the skin type, the thickness of the stratum corneum, the degree of photoaging, and the prepeel preparation of the skin. Applying large quantities of pure acid to the skin (during a glycolic acid peel with a non-neutralized solution) saturates its natural buffer capacity, and the excess acid must be neutralized to avoid burning the skin. The contact time for a glycolic acid peel, as well as for other AHAs, is the time between applying the peel6 and neutralizing it. The contact times for partially buffered AHAs, at pH > 2.5, are far longer than for pure unbuffered AHA solutions at pH 0.5,7 which are a hundred times more acidic.

1.5 3 5.5 7 9.5 Milk Easy TCA® Saliva Unideep® Lemon Red Egg white juice wine Seawater

11

12.5

14

Acidic

Basic

70% unbuffered glycolic acid 1 M HCl

Gastric juices

Beer Phenol peel

Coca Cola® Vinegar

EMLA Sodium bicarbonate Human blood Tears

pH 3 is 10 times more acidic than pH 4 pH 3 is 100 times more acidic than pH 5 pH 0.5 is 1000 times more acidic than pH 3.5

Figure 6.4  pH of various substances.

Ammonia

1 M NaOH

48   Textbook of Chemical Peels

chemical reaction produces a salt10 and water—the pH increases and the potency of the acid solution decreases: glycolic acid + NaOH ← sodium glycolate + H2O

Hydronium Hydronium is a synonym of oxonium (trivalent oxygen cation) (Figure  6.5). Hydronium is the cation that forms from water in the presence of hydrogen ions (H+ coming from acids). Hydronium does not exist in a free state: it is extremely reactive and solvated by water, liberating H+. The supplementary H+, stuck on a normal H2O molecule and giving it the form of hydronium, can still build electrical links with another H2O of the neighborhood, forming a “Zundel cation” in which one H+ finally interacts, very transitorily, with 2 water molecules. When an acid liberates a proton in solution, this proton links with one or more water molecules to form hydronium molecules. Hydronium itself is very active and unstable, and immediately exchanges protons with neighboring water molecules or living structures. The activity of oxonium/hydronium cations is not relevant when speaking about peelings because, finally, it is created by the free proton, moving from a water molecule to another one. In fact, when hydronium is in phase of “existence,” the H+ is not able to interact with living structures. Hydronium is not a way of stabilizing an acid, because the structure itself is so quickly transient that it can be considered as not existing.

pKa

The natural pH of an aqueous solution of 60% glycolic acid is 0.5. The gradual addition of a base slowly raises the pH of this solution. When the pH reaches a value of 3.83 as a result of the gradual addition of the base, we know that this solution contains exactly 50% of active free acid and 50% of salt produced by the reaction of the glycolic acid with the base (e.g., sodium glycolate or ammonium glycolate). A pH of 3.83 corresponds to the pKa value of a glycolic acid solution. If we keep on adding a base solution to the glycolic acid solution, the pH will gradually increase, while the proportion of free and active acid and the strength of the solution decrease. A glycolic acid solution whose pH had been brought up to 7 would be completely neutralized or buffered and inactive. A glycolic acid solution at pH 5 is partially neutralized or buffered and partially inactive, as it does not contain much free acid. It is far less aggressive to the skin, of course, but it is also less active. The pKa is therefore an important notion that allows us to understand and anticipate how aggressive an AHA peel solution will be, on condition that we also know the pH of the solution. Knowing the pKa alone, which is a definitive and set parameter for each acid, does not help determine how aggressive a peel solution is. The pKa of glycolic acid is and will always be 3.83, whereas the pH of the solution could vary between

0.5 and 7 or above. The greater the pH than the pKa of an acid solution is, the less aggressive it will be. The lower the pH than the pKa of an acid solution is, the more aggressive it will be. It is therefore not possible to choose the pKa of the solution that we want to use, as this parameter has been determined chemically, once and for all, for each acid, and it gives the exact pH at which 50% of the active molecules remain. We can, on the other hand, change the pH of the solution and make it lower than the pKa to make the solution more aggressive. We can also raise the pH above the pKa to soften the effect. A partially neutralized solution at pH  4 still contains enough free acid to achieve a clinical effect but is far less effective than a solution at a lower pH. Partial neutralization of a glycolic acid solution is therefore a compromise between effect and risk. It is, in fact, surprising that glycolic acid is still partially active at pH levels of around 5. It seems that the alpha position of the hydroxy group in a small molecule like glycolic acid is the reason for this partially maintained effectiveness, even if the pH is relatively high. Other AHAs do not appear to remain active at high pH levels. Using a partially neutralized solution at pH 4.5 achieves the same results in a few months that could be obtained in a few weeks with the same unbuffered concentration. It is therefore true to say that it is possible to achieve the same results using neutralized or non-neutralized peel solutions. But patients would then have to be convinced to have many more peels, which, on top of the inconvenience of repeated visits to the surgery, means more expense—and that is never appreciated. The doctor may think it necessary to sacrifice effectiveness for safety, but the patient usually thinks that the doctor should find a quicker and more effective solution without sacrificing safety. An application of dansyl chloride accumulates in the epidermis and stains the skin. It is possible to measure the rate of disappearance of this coloration after the application of different hydroxy acid solutions at a constant pH. The rate at which the color disappears is correlated with the rate of cell replacement, and therefore provides information on the stimulation of epidermal turnover and on the capacity of the acid to stimulate skin regeneration. Partial neutralization of these solutions, to pH  5, quite clearly reduces the rate of renewal, and neutralizing these same solutions to pH  7 removes all of their clinical effectiveness (Table 6.2). The ultimate goal of treatment with AHAs is to stimulate skin regeneration at the same time as avoiding as far as possible the side effects that stem from their irritant potential. It is not easy to achieve this goal, as a very acid pH is required to ensure optimum clinical effectiveness. The aggressiveness of these acid solutions usually entails a higher risk of complications. It is possible, however, to use a solution made up of different AHAs at a concentration higher than 60% and pH 0.5, at the same time as limiting the risk of complications: Easy Phytic is Table 6.2 Type of acid

Concentration, pH

Skin renewal stimulation, up to:

TCA Lactic acid Acetic acid Pyruvic acid

0.5%, native pH 4%, pH 3 3%, pH 3 4%, pH 3

50% 34% 30% 23%

+

H

Figure 6.5  Hydronium.

O H

H

ALPHA HYDROXY ACIDS: CHEMISTRY, pH AND pKa, AND MECHANISM OF ACTION   49

an unbuffered solution of three AHAs, at pH 0.5. This solution uses a slow-release technology that does not need neutralizing in spite of its very acid pH, which is much lower than its pKa.

MECHANISM OF ACTION AHAs do not coagulate proteins. Applying them in a peel therefore should not produce a “whitening effect.” According to Forestier, the mechanism of action of AHAs is as follows. Even at low concentrations, AHAs can insert themselves between two protein chains. Here, they build a sort of bridge that reduces corneocyte cohesion. As a result of the lytic action of AHAs on corneodesmosomes, corneocytes are shed more easily from the skin, and the thickness of the stratum corneum is reduced. The skin appears more hydrated as the stratum corneum is thinned or disappears temporarily. AHAs, even at low concentrations, acidify the upper layers of the skin. Experimentally, at pH < 5, this acidification causes an increase in the epidermal activity of lipases, phosphatases, and transforming growth factor beta (TGF-β). At higher concentrations, the protein chains are separated from each other, and this causes epidermolysis—more or less visible exfoliation. Because of this corneocyte-shedding activity, AHAs have been used primarily to treat certain hyperkeratinization disorders. Not all corneocytes react in the same way to AHAs: the more superficial, less hydrated corneocytes seem to be less sensitive to the action of AHAs than the corneocytes at the base of the stratum corneum. AHAs may also limit or prevent the cross-linking of proteins in the extracellular matrix. Unlike TCA or phenol, AHAs do not bind with proteins and so are not neutralized by them. The type of action they produce depends on their concentration, the pH of the solution, the pKa of the acids, and the contact time with the skin before neutralization with a base solution. For example, a 70% glycolic acid solution (pH 0.5 for pKa 3.83) in contact with the skin for 5 minutes will be more aggressive than a partially buffered (pH  3.5) 50% solution left in contact with the skin for 2 minutes before neutralization with a base solution (a saturated solution of sodium bicarbonate, for example). The type of AHA molecule used is also of prime importance. Glycolic acid is the most aggressive AHA because it is the smallest. The type of vehicle used, the skin type, and the disorder being treated are also factors to be taken into account when anticipating the action of a peel. The accelerated shedding of corneocytes disrupts the protective barrier function of the epidermis. From there, a cascade of secondary events stimulates growth in the basal layer of the epidermis and accelerates the conversion of keratinocytes into corneocytes11 to restore optimum barrier function as soon

as possible. Stimulation of the mother cells by the keratinocytes of the basal layer can unfortunately go hand in hand with reactional and inflammatory melanocyte stimulation, the cause of potential pigmentary changes.12 The stimulation of keratinocyte growth is also accompanied by positive stimulation of fibroblast proliferation and synthesis of proteins in the dermis (collagen, elastin, and glycosaminoglycans).13 Another indirect effect of AHAs, which also comes from the disruption of the barrier function of the epidermis, is that they enhance the penetration of other topical agents with which they are mixed. AHAs are often used as agents to enhance the penetration of other molecules, in the treatment of acne or melasma, for example. Histological studies show that the injury to the skin and the principles of repair are similar during a peel and during dermabrasion. The extent of repair is directly related to the depth of injury. In the case of glycolic acid peels, scabbing occurs only when the peel has penetrated too deeply. The scab consists of keratin, necrotic keratinocytes, and a protein precipitate. Glycolic acid may be an antioxidant and protect against UV radiation through the same mechanism of action as ascorbic acid, but, given that it reduces the thickness of the stratum corneum, it can also enhance penetration of UV radiation through the epidermis. Even if the thinning of the stratum corneum is only temporary, AHAs are therefore not used to protect the skin against the sun, but can be applied after exposure for their anti-free-radical effects.

NOTES 1. In quality but not quantity. 2. Pons Gimier L, Parra Juez JL. Ciencia Cosmetica. Consejo General de Colegios Oficiales de Farmaceuticos, 1995: 285–6. 3. Pons Gimier L, Parra Juez JL. Ciencia Cosmetica. Consejo General de Colegios Oficiales de Farmaceuticos, 1995: 284–5. 4. A pH similar to that of vinegar or lemon juice. 5. The pH scale is logarithmic rather than linear. 6. Which must be done as quickly as possible so that all areas of the face are at practically the same level of acid attack at the time of neutralizing. 7. Except for Easy Phytic, which is not neutralized. 8. An acid is, by definition, a molecule that can donate a proton. 9. Lidocaine with epinephrine (adrenaline) has a similar acid pH, but it is impossible to do a peel with lidocaine. Acidity is therefore not the only important parameter. 10. A salt is formed by the interaction of an acid and a base; an ester (R–COO–R’ if R’ is not –H) is formed by the interaction of an acid and an alcohol. 11. Via tumor necrosis factor alpha (TNF-α), among other mediators. 12. Known as postinflammatory hyperpigmentation (PIH). 13. Ammonium lactate has been shown to prevent dermal atrophy resulting from the use of topical corticosteroids.

7 Alpha hydroxy acids Histology and factors influencing penetration HISTOLOGICAL CHANGES Epidermis Epidermal regeneration is histologically visible after 2–7 days, and the epidermis is completely replaced 2 weeks after a single light alpha hydroxy acid (AHA) peel. A single application of a glycolic acid peel (20%–30%) reduces corneocyte cohesion, which accelerates the elimination of cells in the stratum corneum and hence reduces the thickness of the epidermis for around 2 weeks (the time it normally takes for the superficial layers of the epidermis to heal). Using 50% concentrations of glycolic acid “unglues” the cells in the stratum granulosum. Higher concentrations (70%) or a more aggressive mode of application causes epidermolysis, or skin necrosis, beneath the stratum corneum. Unlike single applications, daily use of AHAs seems to thicken the epidermis over time because of the constant stimulation it provides.1 However, other authors suggest instead a possible thinning of the epidermis in the long term.

Dermis The histological effects of AHAs also reach the dermis. Moy showed that fibroblast cultures in a glycolic environment produced up to 10 times as much hydroxyproline (a precursor of collagen) than when cultivated in a normal saline environment.1 A practical problem is that AHAs do not normally reach the dermis (because, apart from Easy Phytic Solution, they are neutralized before they can penetrate that far) and therefore cannot directly stimulate fibroblasts as well as they did in this in vitro study.

In the papillary dermis and sometimes even in the upper reticular dermis, mild edema, an inflammatory reaction, and production of new collagen and elastin are observed. Production of these dermal components does not appear to be directly proportional to the extent of the inflammatory reaction. Glycolic acid stimulates fibroblasts to produce collagen, but not in the same way as trichloroacetic acid (TCA) or phenol, which produce a thick horizontal layer of papillary dermal collagen proportional to the dermal injury and hence the repair caused by the acid.2 However, the laying down of a new layer of collagen in the dermis is one of the essential elements of cosmetic improvement and skin rejuvenation. Some studies have presented biopsies showing the presence of new collagen arranged horizontally, with a predominance of fibroblasts 2–3 weeks after a peel.3 This new collagen remains for around 1 year.2 The concentration of glycosaminoglycans increases and gradually stabilizes. This effect could be one of the mechanisms responsible for the positive effect of glycolic acid on fine wrinkles (a filling effect after several peeling sessions). “Chronic” use of AHAs seems to allow the dermis and epidermis to thicken gradually and regenerate after an initial period of flaking that, in contrast, thins the epidermis and requires the daily use of effective sun protection.

FACTORS INFLUENCING AHA PENETRATION Other factors also influence the aggressiveness of a glycolic acid solution (Table 7.1).

Table 7.1  Factors in the Aggressiveness of Glycolic Acid Solution Factor

Fact

Example

pH

The lower the pH is in relation to the pKa, the more aggressive the solution is.

Concentration

The closer the glycolic acid concentration is to 80% (a saturated solution), the more aggressive the solution is. Some components can slow down or accelerate the penetration of AHAs. Bear in mind the esterification reaction: an organic acid (R.COOH) reacts with an alcohol (R’.OH) to form an ester (R.COO.R’) and water: acid + alcohol a ester + water R–COOH + R’–OH a R–COO–R’ + H2O This reaction is slow and reversible. The ester does not produce a peel.

Glycolic acid has a pKa of 3.83. A peeling solution of a given concentration will be more aggressive at pH 1 than at pH 2.5. At pH 3.5, by definition, 50% exactly of the glycolic acid molecules are neutralized, transformed in a salt that is inactive. At constant pH, pH:2 for example, an 80% glycolic acid solution will be more aggressive than a 25% one.

Other components of the solution

An alcoholic solution of AHAs would partially consist of ineffective esters that could be converted back into acid by shifting the balance of the reaction, after the acids in the solution have been medically or naturally neutralized. Applying alcohol to the skin, as a prepeel disinfectant, does not interfere with the peel if the alcohol is given time to evaporate.

Alpha hydroxy acids: HISTOLOGY AND FACTORS INFLUENCING PENETRATION   51 Table 7.1 (Continued)  Factors in the Aggressiveness of Glycolic Acid Solution Factor

Fact

Example

Preparing the skin in the weeks before the peel Preparing the skin just before the peel

Any treatment that thins the stratum corneum increases the permeability of the epidermis4 and the speed of penetration of AHA.

Tretinoin, AHA creams, and benzoyl peroxide are examples of products that allow AHAs to penetrate more deeply.

Before an AHA peel, the skin must be cleansed and degreased, but not aggressively. AHAs are actually hydrophilic, and fats in the skin reduce their clinical effectiveness. Degreasing the skin vigorously, by using an ether swab firmly pressed on the skin for example, would make it difficult to predict how far the AHAs would penetrate. Immediately before an AHA peel, the skin should be cleansed and degreased with alcohol and acetone (although not aggressively), in contrast to what can be done before a TCA peel to the papillary dermis Neutralizing the peel too soon stops its effect. Neutralizing too late can potentially cause serious side effects.

Special attention should be paid to home waxing or scrubbing before the peel.

Contact time

Neutralization versus simple rinsing Frequency of repeated peel sessions Force of application of a peel and type of applicator

Easy Phytic solution, being self-neutralizing, suppresses every neutralization problem. Easy Droxy complex peel is neutralized with a neutralizer that changes color when pH shifts from acidic to basic.

Rinsing with water only dilutes the acid without neutralizing it. Only the application of a base solution can neutralize the acid. Repeating peels too often gradually deepens their action and can cause chemical burns. Repeating peels after too long a delay does not allow gradual stimulation of the dermis—the peel will not be able to achieve its full effects. Up to a logical limit, the more forceful the application, the deeper the penetration.

Skin hydration and health

Young, healthy, and hydrated skin is less permeable than skin treated with tretinoin or skin with seborrheic dermatitis, severe photoaging, or acne.

Volume of acid applied on the skin

At the same pH and concentration, applying a greater volume of acid on the skin induces greater necrosis.

Other factors

The penetration of AHAs through the skin is also increased by prior use of certain products.

NOTES 1. Rubin MG. Manual of Chemical Peels: Superficial and Medium Depth. Philadelphia: Lippincott, 1995. 2. Moy LS, Mene R. Glycolic Acid Chemical Peel. In: Roenigk R, Roenigk H (Eds.). Roenigk & Roenigk’s Dermatoligic Surgery, Principles and Practice. 2nd ed. New York: Dekker, 1996:1103–12.

A less aggressive peel can be repeated more often than a more aggressive one: a 25% glycolic acid peel could be repeated 1 or 2 times/week, while a phenol peel can’t be repeated before several months (6 weeks in the case of Lip & Eyelid Formula or Easy Phen light). At constant acid quantity applied on the skin, a brush simply spreads the acid solution on the stratum corneum, whereas using gauze causes some abrasion at the moment of applying the acid solution and makes it penetrate more deeply. Cotton buds appear to be a safe and reproducible way to apply peelings, since the pressure can’t vary too much: a too strong pressure binds the cotton buds. Note that a brush could apply more product to the skin compared to cotton buds, which would induce a more aggressive peeling. Aging induces a thickening of the stratum corneum, skin dryness, and impermeability. Active acne lesions allow a faster acid penetration, by stratum corneum disruption. Applying just a few drops of 70% unbuffered glycolic acid solution on the face will be far less aggressive than applying 5 ml of the same solution. Adding coat after coat of a peeling solution progressively deepens its action. Such products include: • • • • •

Hair-removal products (watch out for the upper lip area) Exfoliants (some creams contain fruit acids) Preparatory masks and vinyl masks Retinoids Hair perms (increased penetration on the hairline)

3. For this reason, it pays to inject botulinum toxin before starting the peel. Immobilizing the muscle mass will allow the smooth synthesis of new collagen. 4. Epidermal permeability in descending order: genital organs > facial skin > skin on torso > skin on upper and lower limbs.

8 Alpha hydroxy acids Indications and results The results following daily topical application of low concentrations of glycolic acid in a simple aqueous solution start to show after 2–3 months of continuous treatment, if the concentration is higher than 8%. Alpha hydroxy acids (AHAs) produce almost no results after a single application;1 the application has to be repeated several times to produce clinical results. Whatever the number of AHA peels, the results for wrinkles, dyschromia, or photoaging will never compare with the results of a medium or deep peel (cf. the indications for phenol), except in rare cases where the dermatological problem being treated is very superficial in origin. The results are not permanent, and biological analysis shows a return to the original condition 1–2 years after AHA peels. We must accept these limitations of superficial peels. AHAs are not toxic to melanocytes, and can therefore be applied on dark skin and in all seasons, on condition that effective sun protection is used.2 Contact time (Table  8.1) depends on skin type, peel concentration and formulation, peel pH, the method of application, preliminary skin preparation, and other factors. At an identical pH, a 50% concentration of glycolic acid will penetrate half as deep as a 70% concentration, and will take twice as long to do so.

ACNE The use of AHAs (especially glycolic or lactic acid) in treating acne has often given good or even excellent results. Easy Phytic Solution (see Chapter 11) is especially safe, effective, and comfortable for this indication. Keratinocyte cohesion in the follicles is also reduced, and this prevents the follicle canals from closing. AHAs are excellent comedolytics: glycolic acid eliminates the hyperkeratosis responsible for the clogged pores. After a glycolic acid peel, the top of the lesion will sometimes whiten to a certain degree as a result of the increase in epidermal permeability around the edge of the inflamed lesion. The whitened areas will disappear in a few days, allowing the sebaceous glands to open and drain. When treating facial acne, concentrations of 50% or more seem to be the most effective, with contact times of 1–3 minutes. Higher concentrations or prolonged contact times cause unexpected frosting (areas of epidermolysis) and slow down postpeel healing. When treating the back, a concentration of 50% is not enough, and concentrations of 70% should be used for 4–10 minutes. If frosting occurs on the back, it is a sign of greater effectiveness, in contrast to facial treatment. Maximum effectiveness is achieved when treating active inflammatory acne. Superficial scars are only rarely and very slightly improved by repeated AHA peels. Ice-pick acne scars are not an indication for superficial peels, and deep scars only respond to a combination of other treatments: dermabrasion, punch elevation, deep peels, filling, dermal stimulation, or laser. Treatment

of active acne (comedonal, papular, or papulopustular) involves a combination of skin preparation, weekly sessions of glycolic acid peels, and appropriate and effective daily cosmetic care (see Chapter 3). AHAs produce only a cosmetic result and do not alter the particular genetic traits that lead to acne in some patients: a peel does not change the blood testosterone level, the activity of 5α-reductase, receptor sensitivity, or the tendency of the corneocytes to stick together and block the pilosebaceous units. AHA peels must be accompanied by appropriate long-term anti-acne daily cosmetic care (Skin Tech’s Purifying Cream or gel).

AGING OF THE SKIN AHAs were first used to treat dry skin (hyperkeratinization and xerosis) before the positive effects on photoaging skin gradually came to light. Photoaging causes the stratum corneum to thicken (the skin becomes dry and rough), local proliferation of melanocytes (lentigines and pigmented hyperkeratosis), and dermal elastosis (wrinkles, fine lines, and sagging skin). AHAs can partially help to fight these three types of involution that progressively and inexorably make the quality of the skin deteriorate. AHAs can only provide superficial treatments, whose direct action is limited to the epidermis. However, for the careful observer equipped with good photographs, long-term repetition of AHA peels shows a gradual improvement in the quality and tone of the skin, which becomes softer and more even in tone, as well as partial correction of the appearance of fine lines.3 Contact times can be relatively short when AHAs are being used to prevent aging, but when the photodamage is more severe, the length of contact time between the glycolic acid peel and the skin before neutralization should be increased to help improve penetration, as sun-damaged skin is more resistant.4 When using glycolic acid creams, the photodamaged skin soon becomes less dry and rough: results start to show after 3–4 weeks of daily treatment, but obvious clinical results can be seen more clearly after several months of treatment. Patients should never be led to expect too much too soon. Even though patients soon feel an improvement in the “feel” and quality of their skin, it is pointless to exaggerate and promise that wrinkles, folds, or fine lines will disappear altogether: a long series of 50%–70% unbuffered glycolic acid peels (for 6–12 months) only moderately improves fine lines. Wrinkles and skin folds are not indications for AHAs. A histological study did not show any significant change after four monthly AHA peels.5 The long rest period between peels could be to blame for the lack of histological results, as the peels must be repeated in relatively close succession to be effective and benefit from the gradual cumulative effect of the stimulation

Alpha hydroxy acids: INDICATIONS AND RESULTS   53 Table 8.1  Suggested Contact Times for Glycolic Acid Condition

Glycolic acid concentration (%)

Contact time (min)

Acne Keratoses Fine wrinkles Back

50–70 70 50–70 70

1–3 4–8 4–8 4–10

produced by the different peels. Once a month is too infrequent and, clinically, weekly repetition is far more effective. Weekly sessions should be kept up for the first 4–6 weeks of treatment, if the patient’s skin can tolerate it. Thereafter, peels should be repeated twice monthly, and eventually once a month as maintenance treatment. Treatment for aging skin should, of course, be accompanied by active daily cosmetic care: DHEA-Phyto, Actilift, or Renutriv ACE Lipoic Complex.6 Treatment of photoaging is the second preferred indication for Easy Phytic Solution, and results (tightening effect) appear rapidly, after the first few sessions.

DYSCHROMIA: MELASMA Combining glycolic acid in a 50% peel and daily creams of 8%–12% helps moderately improve dyschromia of a purely epidermal origin. There is relatively little risk of postpeel pigmentary changes if the peel is applied correctly, but this risk cannot be ruled out, even when the glycolic acid peel has been kept in technically perfect conditions (see Figure  37.28). When treating hyperpigmentation, the skin must be cleansed and degreased with the utmost care before the peel, because if the skin is handled too roughly, too much glycolic acid could penetrate too quickly locally and cause postinflammatory hyperpigmentation.

Use of an AHA Cream Alone More often than not, it takes 3–4 months of daily applications of AHA creams alone to get a clinical result. AHAs are not renowned for their anti-tyrosinase action; they limit melanin synthesis mainly through their antioxidant power and increase the turnover and renewal of cells laden with pigment. Using AHA creams as the only form of treatment for melasma is disappointing.

antioxidants. It has been proved that applying a depigmenting cream between peeling sessions is more effective than applying a glycolic acid cream. It has also been proved that a treatment combining peels and a depigmenting cream is more effective than a treatment with depigmenting cream alone. AHA peels are not, of course, the first choice of treatment for melasma.

XEROSIS, ICHTHYOSIS, AND WARTS AHAs have been prescribed for a long time in the treatment of xerosis, ichthyosis, and sometimes warts. Dry and rough skin is an excellent indication for AHA creams and peels. Easy Phytic (see Chapter 11) solution is particularly well tolerated by patients with ichthyosis, who soon feel an improvement in the elasticity of the superficial layers of the skin, which pulls less after the first applications.

HYPERKERATOTIC ECZEMA Glycolic or lactic acid 15%–20% has been used in the treatment of hyperkeratotic eczema and hyperkeratosis of the palms and soles.

GLYCOLIC ACID AS A PREPEEL TREATMENT Glycolic acid helps to increase penetration and enhances the action of the active molecules in the cosmeceuticals or medication applied between peeling sessions. It may act as an antioxidant and chelate iron ions (reducing the production of free radicals). Applying a 12% glycolic acid cream after exposure to the sun helps reduce the duration of the erythema. Glycolic acid has also been used as a preparation for a medium-depth peel, to enhance the penetration of trichloroacetic acid (TCA) to the papillary dermis (i.e., before a 35% m/v TCA), for example. However, in the author’s opinion, the uneven penetration of the glycolic acid peel is not ideal for enhancing TCA penetration. The TCA will penetrate more deeply where the glycolic acid penetrated most, and the overall result could be uneven. AHA peels have been used unsuccessfully in the treatment of stretch marks, both as monotherapy and in combination with corundum crystal microdermabrasion before the peel. Treating the stretch marks with microdermabrasion beforehand enhances AHA penetration but does so linearly, in the form of claw marks (Figure 8.1). The results are poor, even on fine, white, superficial stretch marks.

AHA Cream and Peel Combining regularly applied glycolic acid peels with AHA daily care creams increases the effectiveness of both. One of the mechanisms of action of AHAs is to facilitate penetration of the components of cosmeceutical creams used between the different peel sessions. AHA peels help rid the superficial layers of the epidermis of an excess of melanin, and AHA creams applied daily increase keratinocyte turnover, with the melanin produced being diluted in the increased number of keratinocytes. Combined use of effective sun protection reduces melanocyte production and improves the results.

AHA Peels and Non-AHA Cosmetics Combining regular peels with Blending Bleaching Cream and effective sun protection (see Chapters 2 and 3) is the most effective option for treating melasma. Tretinoin can be combined with other cosmetics, as can hydroquinone, tyrosinase inhibitors, and

Figure 8.1  Alpha hydroxy acid peel after microdermabrasion.

54   Textbook of Chemical Peels

EFFECTIVENESS OF AHA PEELS The effectiveness, in cosmetic terms, of a glycolic acid peel can sometimes be miraculous, sometimes non-existent. Some patients are delighted and others are deeply disappointed, but more often than not the result of a series of peels with glycolic acid in an aqueous solution is considered “average.” However, long repetition of the peels can maintain the appearance of the skin or even visibly improve it. One clear advantage of glycolic acid lies in the fact that patients can carry on with their professional and social lives immediately after the peel, without any visible signs of flaking7 in the days following the treatment. Cosmetic improvement is very gradual, and often, if there is no good-quality pretreatment photographic record, the patient as well as the practitioner may wonder if the treatment has really been effective. Although the patient’s immediate entourage might not really notice any difference, the people the patient meets less often will notice some change and might comment on how rested or youthful the patient looks. Repeating peels over a long period of time ensures the progressive effectiveness of peels with glycolic acid in an aqueous solution.

Effectiveness Is Doctor-Dependent The application technique used by the doctor, how carefully he applies the peel, and his experience are all factors that influence the outcome of treatment.

Effectiveness Depends on the Galenical Form Not all glycolic acid peels are the same as far as the skin is concerned. The peels that are the most difficult to use are glycolic acid in simple aqueous solution and glycolic acid masks (because it is difficult to monitor how the skin is reacting). The most effective peel would be one that does not need neutralizing, in spite of having a pH of 0.5 for a solution with a pKa between 3 and 4.

Effectiveness Is Doubly Time-Dependent The effectiveness of a peel with glycolic acid in aqueous solution depends on the amount of time for which the acid is contact with the skin and therefore on how soon it is neutralized.8 Neutralizing too soon only allows a small proportion of the acid to act. Effectiveness also depends on the number of sessions. The greater the number of sessions, the more visible the results. The effectiveness of glycolic acid is therefore entirely dependent on time in both the short and long term. In the short term, the same concentration will reach the deeper layers if it is left on longer before being neutralized. In the long term, for the results to be visible, a number of repeated peels are necessary, even with 70% unbuffered glycolic acid on a well-prepared skin. A single application of partially buffered 50% glycolic acid only allows exfoliation just beneath the surface—plainly subclinical.

Effectiveness is Patient-Dependent Preparing the skin properly during the weeks before the peel helps the glycolic acid penetrate more evenly and deeply.

The quality of the results will be better if the patient follows the doctor’s recommendations to the letter. Some patients underestimate the importance of preparation and do not put on the creams they have been prescribed. The result is inadequate and uneven penetration, which leads to inadequate results and an increased risk of complications. Some overenthusiastic patients, on the other hand, think they can get into the doctor’s good books by applying the prepeel treatment more often or more liberally than prescribed. This results in an unexpected increase in skin permeability that deepens the effect of the glycolic acid and increases the risk of complications, without the advantage of a better outcome. With Easy Phytic, there should be no prepeel preparation, as the stratum corneum must be intact to allow it to act progressively. Creams likely to facilitate AHA penetration should be stopped 2 weeks before the first Easy Phytic treatment.

A Glycolic Acid Peel Is Not an End in Itself A glycolic acid peel should never be considered as an end in itself but as part of an overall care plan for the past and future of a patient’s skin. Pre- and postpeel care plays a large part in the final outcome. For the follow-up, there should be a specially detailed file recording the various events of the peel and the treatments accompanying it.

Effectiveness on Wrinkles, Fine Lines, and Folds A glycolic acid peel is not an effective treatment for folds and wrinkles. Fine lines can improve gradually over the course of repeated glycolic acid peels. New collagen synthesis has been noted in the papillary dermis, but what seems to be responsible for a large part of the results of a glycolic acid peel on fine lines is the edema that is caused and maintained by the repeated application of the acid. The tautening and filling effect on the skin is sadly only temporary. Whatever the case may be, it is interesting to note that it is possible to improve fine lines, if only slightly, without causing skin necrosis. The treatment plan must be rigorous, and care between and after peels is of vital importance.

NOTES 1. Except that the skin’s texture may feel smoother. 2. Peyronnet B. Acide trichloracétique ou acide glycolique? Journal de Médecine Esthétique et de Chirurgie Dermatologique. 1994; XXI (84): 257–60. 3. Wrinkles can only be improved by using deep peels; folds usually only respond to surgery, support threads, or fillers. An improvement in the appearance of fine lines can be seen after 4–6 months of daily application of 10%–12% glycolic acid cream. 4. The stratum corneum is thicker and so more impermeable in photoaged skin. 5. Piacquadio D, Grove MJ, Dobry M. Efficacy of glycolic acid peels questioned for photodamaged skin: A pilot study. Dermatology Times. 1992; May: 52. 6. Skin Tech (www.skintech.info). 7. If the glycotic acid is neutralized as soon as erythema appears and before any frosting appears. 8. In other words, it depends on the “contact time.”

9 Alpha hydroxy acids Application as cosmetics and as peels COSMETIC APPLICATION OF GLYCOLIC ACID Because the application of glycolic acid at first reduces the thickness of the epidermis, the skin can no longer provide the same protection against light, and it is essential to use effective sun protection to avoid the risk of accelerated photoaging. A glycolic acid cream or gel can easily be prepared in a pharmacy dispensary, at concentrations of 8%–15%. There are many commercial preparations of glycolic acid that have the combined advantage of spreading evenly and a galenical form that allows better penetration of the acid. These low-concentration, daily topical treatments are mainly indicated for preparing the skin for other techniques, for follow-up treatment between peels, or for maintenance treatment afterward. In general, patients who use glycolic acid as a cosmetic do not expect or will not accept any flaking. If the skin does flake, treatment should be stopped and started again a few days later at a lower concentration (or warm water can be sprayed on the face before applying the glycotic acid cream to dilute it). As monotherapy, 8%–15% gels (which can be buffered to the physiological pH to 4.55)1 are applied twice a day, after washing the face with a mild soap (e.g., Avène®) if the skin is “normal.” If the skin is dry, care should be taken not to degrease the skin, so that the gel does not penetrate too deeply. If the skin is oily and/or acneic, it should be degreased with a glycolic acid–based cleanser before applying the gel. It is essential to use effective sun protection. As a precaution, the initial concentration of glycolic acid should not be more than 8% and the gel should be applied every other day at first. The concentration and frequency of application can be increased, depending on the skin’s response and tolerance. When treating severe photoaging, the concentration of the glycolic acid should be gradually increased from 8% to 12%, 15%, or possibly 20%. Alpha hydroxy acids (AHAs) can be applied on the face as well as the neck, décolletage, hands, forearms, and other parts of the body. It must be remembered that the skin on the face is far more permeable than the skin on the limbs or torso.

Combination of AHAs and Tretinoin

Shared Effects Tretinoin and AHAs act on the epidermis and the dermis. When used over a long period of time, they both have the following effects: • •

An increase in the overall thickness of the epidermis at the same time as a decrease in the thickness of the stratum corneum: the skin appears smoother and more hydrated. Increased dermal thickness and new synthesis of collagen and elastin fibers.

Specific Effects Retinoids induce neoangiogenesis, whereas AHAs act on the dermis without necessarily going through a phase of inflammatory reaction. We can therefore assume that their combined effects can produce better results while reducing the incidence of side effects thanks to the use of lower doses of each of these two potential irritants. For example, if there is resistance to (daily or twice daily) monotherapy with tretinoin 2 at 0.1%, applying an 8%–10% glycolic acid gel beforehand helps the retinoid to penetrate more efficiently. Tretinoin and AHAs can be applied separately, but they can also be mixed in the same gel. If, on the other hand, a patient cannot tolerate a concentration of tretinoin at 0.05%, applying an 8%–10% glycolic acid cream in the morning will make a tretinoin cream at 0.015% applied in the evening more effective, while reducing the irritation caused by the retinoid. These combinations must always be used under close medical supervision, however, as in dual therapy, skin reactions can be highly unpredictable and severe in some patients. More sensitive skins can be treated as follows: • • •

Days 1–15: 8%–10% glycolic acid cream in the morning. Days 15–30: 10%–12% glycolic acid in the morning. Days 30–60: 8%–10% glycolic acid in the morning plus 0.015% tretinoin in the evening.

The doses of each product should be increased gradually thereafter. If the patient has a tendency to erythema, photosensitivity, or telangiectasias, the glycolic acid should be increased and the concentration of the tretinoin decreased. If the patient has thin skin, the tretinoin should be increased more quickly than the glycolic acid.

Combination of AHAs and Hydroquinone There is no point in combining hydroquinone and AHAs in a peel solution, as hydroquinone has a tyrosinase-inhibiting action that can only establish itself gradually and act on the first biochemical stages of melanin synthesis. On the other hand, it is worthwhile combining the two in the daily treatment of melasma between or after peels. The pharmacist should be asked to add 3%–8% hydroquinone to a water-in-oil cream with an 8%–10% glycolic acid concentration. Gels are more active and better tolerated by oily skins, while the most suitable galenical form for dry skins is cream. Kojic acid (2%–5%) can also be added gradually to the combined glycolic acid plus hydroquinone formulation to enhance its action.

56      Textbook of Chemical Peels

Combination of AHAs and Other Topical Pharmaceuticals The reduction in corneocyte cohesion caused by AHAs allows topical preparations containing cortisone, antifungal and antimitotic agents, and so forth to penetrate more easily. 5-Fluorouracil (5-FU) has been widely combined with glycolic acid in the treatment of severe photoaging. Application should be “pulsed” to limit the inflammatory reaction caused by daily application of 5-FU. Glycolic acid 10% should be applied once or twice a day, while the 5-FU (as a cream with a concentration of 1%–5%) should only be applied on two consecutive days per week, every other week. Actinic keratoses on the scalp can tolerate a weekly application of 5-FU combined with glycolic acid. David R. Harris3 reports treating actinic cheilitis by applying a Vaseline or silicone ointment containing 5% glycolic acid and paraffin. This treatment can be deepened by periodic applications of 5-FU and/or light trichloroacetic acid (TCA) peels. AHA peels can be used to treat patients of all skin phototypes who cannot accept any downtime. Results are, however, difficult to predict: some patients show a rapid improvement in the quality and color of the skin, while others do not notice any cosmetically visible change. The unexpected, though rare, occurrence of complications always poses a major problem when a treatment has been guaranteed “not to be noticed by a third party.”

APPLICATION OF GLYCOLIC ACID PEELS Prepeel Preparation Table 9.1 lists steps for preparing for glycolic acid peels.

Desquamation Buffered solutions of glycolic acid, when applied correctly, only produce virtual desquamation. Water-based glycolic acid does not penetrate evenly, and the risk of localized

overpeeling, scabbing, or postinflammatory hyperpigmentation is not insignificant. The destruction of the epidermis that causes visible flaking depends on how the peel is applied, as well as on the type of peel used. A short contact time with a 50% glycolic acid peel at pH 3.5 produces almost no visible flaking, while a longer contact time with 70% glycolic acid at pH 0.5 induces epidermolysis and the appearance of small scabs and visible flaking. The correct contact time with a water-based 70% glycolic acid at pH 0.54 causes little or no flaking, but repeating it too soon could trigger visible flaking. Applying a water-based 70% glycolic acid peel at pH 0.5 with a flat brush will cause less flaking than if it is applied with a gauze pad (which is slightly abrasive) after the skin has been disinfected with alcohol or degreased with acetone or ether, or after the skin has been prepared for several weeks with tretinoin cream. All other conditions being equal, applying a greater quantity of AHA causes more of the epidermis to be destroyed and more visible flaking. Easy Phytic Solution, in spite of its pH of 0.5, causes almost no flaking and penetrates more evenly than other AHAs because of its formulation and application procedure.

Treating the Face or Body AHA peels primarily have been used to treat the face but can also be used to treat other areas of the body. Facial skin is more permeable to AHA peels than the skin on the rest of the body. The neck, décolletage, hands, and forearms can be treated with a combination of AHA peels and effective postpeel care (see Chapter 3). With these body treatments, we can expect an improvement in the quality of the structure of the skin, improved hydration, and some temporary lightening of the complexion. Lentigines and keratoses should be treated by another method in parallel with AHA peels. There are other, more efficient, techniques to treat these problems: liquid nitrogen, dry ice, Only Touch peel, intense pulsed light (IPL), laser,

Table 9.1  Preparation for Glycolic Acid Peels Long-term preparation starts 4–6 weeks before a water-based AHA peel. Nonspecific preparation to make a water-based AHA peel deeper and more even Specific preparation: to give patients a focused care plan

It can be nonspecific or specific. It is not essential, but noticeably improves results by ensuring deeper and more even penetration of the glycolic acid peel. Greater vigilance is required when applying the peel, however, as it must be neutralized more quickly. In the evening, a 0.05% tretinoin cream should be applied (see Chapter 2). This cream reduces the thickness of the stratum corneum and provides a deeper peel with the same concentration. A 10% (nonphotosensitizing) glycolic acid gel could be applied on younger women in the morning. Preparing a patient who has acne is not the same as preparing a patient with photoaging or melasma. Hyperpigmentation of all sorts responds extremely well to prepeel treatments. Menopausal or postmenopausal women can benefit from a hormone cream as part of antiaging treatment. The following formulation can be prescribed: • • • • •

Medium-term preparation starts 2–4 weeks before a peel.

Short-term preparation

Testosterone propionate 100 mg Estrone 5 mg Estradiol benzoate 5 mg Eucerin O/W 45 g or Neribase 45 g

See Chapter 2 for more details. This concerns combined treatments used before the peels as well as the cosmeceuticals or pharmaceutical products used by the patient (see above). Folds, wrinkles, and fine lines should be treated beforehand with dermal fillers, thread lifts, mesotherapy, stimulation, or other treatment chosen by the doctor. Benign tumors can be excised or treated by shave biopsy or lasers. Rosacea and seborrheic dermatitis should be treated before the peel during this same period. Botulinum toxin ideally should be injected 8 days before the first water-based glycolic acid peel. It is preferable not to put on any cream that could permeabilize the skin nor use any technique likely to damage the stratum corneum during the few days before an AHA peel. Small retention cysts can be removed with a needle or number 11 scalpel blade 1 week before applying the water-based glycolic acid.

Alpha hydroxy acids: APPLICATION AS COSMETICS AND AS PEELS      57

and others. Dr. Robert Vergereau (France) compared the use of dry ice, Erbium laser, Q-switched laser, coagulation, and Only Touch peel. He concluded that “If all these methods are satisfactory, in my opinion, the technique using trichloroacetic acid5 is the most beneficial.” Treatment of other areas of the body with AHAs is not often described because of the poor penetration of these acids through the skin of the body. A technique combining abrasion and an application of Easy Phytic solution (see Chapter 11) is more successful on the legs, arms, and torso.

Buffered or Unbuffered AHAs? The results produced by buffered AHA peels can, in a way, be compared to those produced by unbuffered peels, but only when applied over a longer period of time and more frequently. From a histological point of view, all peels produce comparable results depending on the strength of the peel. The action of an AHA peel with a pH higher than its pKa and close to the skin’s physiological pH (4.5–6) is very slow. A buffered solution will often only be applied for the first “reconnaissance” peels or on sensitive skins. Thereafter, the peels will be performed with 70% unbuffered glycolic acid solution in a gel or Easy Phytic solution.

How Many Sessions Should Be Anticipated? AHA peels should be considered a long-term treatment. No noticeably visible improvement, except for softer skin, should be expected until after many sessions. Sometimes, the results do not become obvious until after 8–10 sessions of water-based unbuffered 70% glycolic acid peels. How frequently the sessions should be repeated depends on how the skin reacts or how sensitive it is. Some thin and sensitive skins will not tolerate more than one session every 2 weeks, whereas thicker or oilier skins will easily tolerate a weekly session or even more. It is clearly difficult for people who can only tolerate one session a month to achieve visible results. Even the most willing patients can be worn down by the boredom of repeated sessions that can sometimes be unpleasant and have a limited effect. Patients who cannot be treated more than once a month often give up treatment long before it has finished.

Classic Application Technique for Glycolic Acid A glycolic acid peel can be applied in an aqueous solution or in a gel, with a gauze pad, a brush, presoaked cotton swabs or pads, gloved fingers, and so on. Compact and opaque AHA masks have been used, but monitoring the skin while the mask is on is neither easy nor certain. The glycolic acid solution is applied quickly (in 15–20 seconds maximum) so that the contact time is the same for the whole face. The solution should be applied to the most resistant areas first (the forehead) and to the more sensitive areas last (the eyelids). It is important to develop application habits and always use the same system, both for applying and neutralizing the peel. Partially squeezing out the applicator before using it guards against the product forming “pools” on the skin. Massaging the skin with a gloved finger allows more even penetration or deeper local penetration if the doctor considers it necessary. By closely monitoring changes in skin color, the AHA solution can be neutralized before any frosting occurs. To a certain degree, the contact time is more important than the total quantity of AHAs applied to the skin: a low overall quantity of glycolic acid left to act for a longer time can penetrate

the skin more deeply than a larger quantity that is neutralized immediately. As well as the choice of peel, monitoring the contact time is an essential part of any glycolic acid peel. This is why the glycolic acid peel has been called “time-dependent,” prompting the purchase of many completely redundant timers. Glycolic acid can be applied up to a few millimeters from the eyelashes, no matter what its concentration. If any glycolic acid comes into contact with the eyes, they should be rinsed immediately with plenty of water, and drops of artificial tears or physiological solution should be applied. Glycolic acid is not a protein coagulant like TCA or phenol, and the risk of damage to the eye after contact is not high. In fact, dilution from teardrops appears to be enough to avert most of the danger. The author has never come across any objective ocular damage, even in the extremely rare case of contact between glycolic acid and the eyes. Sometimes, a very small quantity of glycolic acid can be drawn up into the eye by capillarity if the peel is applied too close to the conjunctivae. This immediately causes the formation of tears, which dilute the acid and reduce its aggressiveness. Patients should be asked to keep their eyes shut while waiting to have eye drops put in that will bring immediate relief.

CONTACT TIME The contact time is the time during which the AHA is left to act before being neutralized and stopping its effect. It depends more on the appearance of erythema than on the concentration, the pH, the total volume applied, the number of applications, and other factors. AHAs in aqueous solution do not penetrate the epidermis evenly, and the erythema, which is the first sign of the skin reacting to a peel (Table 9.2), does not appear evenly either, but rather in spots or patches. It is therefore essential for the doctor to stay beside the patient during this phase of the peel and not to take his eyes off the treated area. The safety limits are not very flexible when using AHA in aqueous solution, and a peel can go from “too superficial” to “too deep”6 very quickly. Contact time should end as soon as erythema begins. The problem is that it is not long before erythema turns to frosting, and the doctor is often faced with the following dilemma: neutralize too soon and have limited results, or try to neutralize a bit later and risk complications. It was to avoid this dilemma that the author developed Easy Phytic solution.

Contact Time for a Glycolic Acid Peel Each patient’s skin reactivity should be tested by an initial application of a less concentrated and/or a partially neutralized peel (e.g., 50% at pH 3.5). As a precaution, the initial contact times should be short, to test the skin’s reactivity. When we say that an AHA peel is “time-dependent,” we mean that the contact time depends on examining the skin directly and not on the clock. We do not need to know exactly how long the product should be left to act: the right contact time is enough time for erythema to occur, but no frosting. Table 9.3 shows, as an approximate guide, the depths reached by unbuffered 70% Table 9.2  Correlation between Skin Appearance and Depth of AHA Peel No erythema Spots of erythema Patches of erythema Widespread erythema Frosting

Virtual peeling effect Very, very superficial Very superficial Superficial peel, suitable depth for AHAs Too deep for an AHA peel

58      Textbook of Chemical Peels Table 9.3  Depths Reached by Unbuffered 70% Glycotic Acid (pH 0.5) as a Function of Contact Time Contact time (min) Depth of effect 1–5 5 10 15

Gradually deepening epidermolysis, depending on contact time and skin sensitivity The acid reaches the dermoepidermal junction The acid reaches the dermis, which is not desirable, as its effect, locally, will be similar to that of 30–35% TCA m/v The depth of skin necrosis, locally, is histologically comparable to or greater than that reached with 35–40% TCA m/v

glycolic acid (pH 0.5) with different contact times on the face. Doctors must remember, however, that AHAs should never be used to do anything other an epidermal peel. Each patient has his or her own particular level of sensitivity and contact time. It is therefore important to take precise notes on the treatment given: the type of solution, the concentration used, the contact time (except in the case of Easy Phytic solution, which does not need neutralizing; Figure  9.1), the places where erythema first appears,7 the number of coats, the type of neutralizing solution applied, and so forth. These notes will be useful for determining any potential change in contact time for subsequent peels. A cautious contact time of 2 minutes for a first peel with 70% glycolic acid, pH 0.5, on a patient with healthy skin of normal thickness can gradually be prolonged by 30–60 seconds in subsequent peels, if the skin can tolerate it—that is to say as long as there is no frosting.

NEUTRALIZATION An AHA peel should be neutralized as soon as erythema appears and before (or, at the very latest, just as) the first pinpoints of protein coagulation (frosting) appear. The peel can be neutralized with a solution saturated with sodium bicarbonate, for example. (Sodium bicarbonate is readily available at pharmacies.) The “bicarbonate system” is a natural and powerful

system for neutralizing organic acids. Neutralizing an AHA peel with a bicarbonate solution immediately stops its action. The reaction of an acid with a base produces a salt that has no peeling activity. The question is then what proportion of acid was effective during the AHA peel. If unbuffered 70% glycolic acid is applied and neutralized after a few minutes’ contact time, what is the proportion of free acid that will have been effective: 30% or 50%? If a solution is applied with a concentration of 70% but buffered at exactly pH 3.83 (which is the pKa of any glycolic acid solution), it contains only 50% free and active glycolic acid; the other 50% consists of an inactive salt. In reality, this solution corresponds to only 50% of the 70%, that is, 35% of pure glycolic acid. Rapid neutralization of this solution reduces its effectiveness even further (Figure 9.2). The problem with AHA peels clearly lies in the neutralization. Easy Phytic provides a solution to this difficult problem because in spite of its pH of 0.5, this peel does not need to be neutralized and therefore benefits from the effectiveness of 100% of the molecules applied to the skin. It should be remembered that rinsing with pure water dilutes an acid (lowers its concentration), whereas a base solution neutralizes it (raises its pH). The neutralizing solution should be prepared before the peel so that it is instantly available when neutralization is necessary (Box 9.1). Skin burns as a result of neutralizing too late because of lack of preliminary preparation of the neutralizer are always considered as professional misconduct by an expert. The doctor and assistant should carefully monitor all the areas treated with acid. Surfaces that develop any local erythema should be neutralized there and then with the tip of a sponge soaked in saturated bicarbonate solution. It is possible to apply corticosteroid cream to the localized erythema. When several areas have become erythematous and been neutralized, the whole face should be neutralized by applying strips of paper, for example,8 soaked in the neutralizing bicarbonate solution (Figure  9.4). If the glycolic acid is

Easy Phytic Solution: Self Neutralizing

pH 7,5–8

pH 5.5 Physiologic pH

Physiologic pH

Peeling pH

pH 3.5 0.5–3.5

Rinse with water Neutralize, then rinse with warm water

Table 9.5  Acids in Hybrid Peeling Solution Type of acid

Name

Acidity potential

Alpha hydroxy acids Beta hydroxy acid Tricarboxylic acid

Glycolic acid Lactic acid Salicylic acid Citric acid

Pyrone derivative

Kojic acid

pKa: 3.83 pKa: 3.86 pKa 2.97 pKa1: 3.14 pKa2: 4.75 pKa3: 6.39 pKa: 9.40

The Neutralizer Versicolor cream is naturally blue and turns yellow when the skin is acid, turns green when the skin is at pH:7, and returns to blue when the skin has been totally neutralized, presenting a pH higher than 7 (Figures 9.5 and 9.6).

POSTPEEL CARE Further information on care following a peel is available in Chapter 3.

Immediate Postpeel Care The appearance of uniform erythema indicates that the glycolic acid has penetrated properly and is the signal for neutralization. After neutralization, spraying with warm water cleans the skin of any residual chemicals. Immediately after the glycolic acid peel, the skin is very permeable, and products applied to it during this period will penetrate more deeply and thoroughly. This is an ideal time to apply the classic postpeel care treatments; see Table  3.1 in Chapter 3.

Care between Peels Glycolic acid peels help cosmetic or medical treatments applied between peeling sessions to penetrate more easily. Tretinoin should be used carefully during the days immediately following a peel, especially when the skin is thin and dry. The choice of vehicle should be discussed with patients: a patient with oily skin will not always like using creams and might prefer a gel; the same gel would be unpleasant for a patient with thin, dry skin.

Alpha hydroxy acids: APPLICATION AS COSMETICS AND AS PEELS      61

Easy Droxy Complex Peel: Neutralizer Versicolor

Neutralization pH

pH 7.5–8

pH 5.5

Neutralizer blue Neutralizer green

Physiologic pH

Physiologic pH

Neutralizer yellow Peeling pH

pH 60%] Slow release Self-neutralizing

HO

P

HO

OH

HO

O

O

HO

P

OH

O

OH

O O O

O P

O O

P HO

Figure 11.3  Phytic acid.

O OH

OH P O

OH

Alpha hydroxy acids: A NEW SLOW-RELEASE AHA COMPLEX WITH NO NEUTRALIZATION REQUIRED   67

produced by the inflammation that follows any peel and breaks the usual vicious cycle of postpeel inflammation: peel → inflammation7 → vasodilation → O2 intake + pro-inflammatory components → free-radical production → cell damage → self-perpetuating inflammation → more free radicals ⇒ vicious cycle established There are two sides to inflammation. The first is positive, as it is an essential trigger for postpeel regeneration and the synthesis of new dermal components—no inflammation, no repair. The other side is negative, as the combination of vasodilation (which, among other things, helps improve tissue oxygenation) and pro-inflammatory components increases the generation of free radicals that damage the cell structures upon which the body relies to repair the skin. The presence of phytic acid, an excellent antioxidant thanks to its 12 hydroxy groups, could reduce the incidence of postpeel inflammatory reactions.

INDICATIONS AHAs thicken the epidermis and papillary dermis, increase the production of mucopolysaccharides, improve the quality of the elastin produced, and increase collagen density.8 Patients treated with EPS also describe an appreciable tightening effect. Although EPS can be used for the same indications as other AHAs, its two areas of choice are aging and acne. EPS can be used as a combined treatment or as a maintenance peel with other deeper treatments; it can also be used alongside other techniques such as mesotherapy and pulsed light.9 EPS is more of a stimulating and regenerating treatment than an actual peel, as there is almost no visible flaking. The epidermis flakes almost cell by cell and not in “cell plates.” Patients who are reluctant to have a “peel” for fear of downtime seem to prefer EPS being presented as a “stimulating solution.” The term superficial peel conjures up images of something relatively ineffective that causes unsightly flaking. EPS can be combined with “mesolift” mesotherapy to particularly good effect: alternating a mesolift and EPS every other week would seem to be the best way to proceed.

Aging Skin Aging skin is an excellent indication for EPS. Note, however, that it is still a relatively superficial peel and cannot claim to eliminate folds or wrinkles, which have to be treated by surgery and deep peels or laser treatments. EPS could be called a “lunchtime peel,” as it can be performed during the lunch hour and the patient can go back to work immediately.

(a)

EPS as a Classic Antiaging Treatment The classic treatment consists of weekly applications of EPS together with use of a suitable cosmeceutical cream (see Chapters 2 and 3,10 and also the section later in this chapter on application protocol). The total number of peels will vary between 6 and 10, depending on the skin and how it reacts. At the end of the active phase of the treatment, a maintenance peel can be applied once every 2 weeks and eventually once every month.

EPS Combined with Mesotherapy A mesolift is a mesotherapy technique that involves injecting stimulating, relaxing, tensing, or filling agents such as hyaluronic acid, polymerized DNA, vitamins, trace elements, dimethylaminoethanol (DMAE), eligopeptides, and others into the dermis. Facial mesotherapy can be rather painful, however, and may require the use of topical anesthetics such as EMLA. The side effects are not always invisible; redness, swelling, and minor bruising may occur. EPS is therefore ideal for use with a mesolift: mesolift one week, EPS the week after. It is wiser not to apply EPS immediately after a mesolift, because the multiple needle perforations in the dermis and epidermis would enhance local penetration of the peel solution. Similarly, a mesolift performed immediately after an EPS peel would be extremely painful for the patient, and the acids in the EPS solution would penetrate through to the deep dermis. Nevertheless, many European, American, and Asian doctors have reported using a combination of EPS + mesolift or mesolift + EPS at the same time, with excellent results.

EPS Combined with Botulinum Toxin Ideally, the botulinum toxin should be injected a few days before the first EPS session. In this way, the two products can work together to good effect (Figure 11.4). If preferred, the botulinum toxin can of course be used after the EPS. If the botulinum toxin is injected immediately after the EPS, the needle will have to go through the nonneutralized acid solution on the skin and will take a few acid molecules into the dermis, which will make the injection more painful. It is not known how botulinum toxin and the AHAs in EPS interact in the body. The injection could be given, say, a quarter of an hour before the EPS. Another potential problem is that the postpeel inflammatory reaction—even if minor—could move the toxin. Allowing a few days between the EPS session and the botulinum toxin injection would seem to be a wise choice.

(b)

Figure 11.4  (a) Before treatment with botulinum toxin and EPS. (b) After botulinum toxin and two sessions of EPS.

68   Textbook of Chemical Peels

Figure 11.6  Day 4 after EPS preceded by superficial abrasion with 3M Wetordry sandpaper P220.

Figure 11.5  Sun aging, thinning skin, yellowish color.

Handling the skin during the peels and postpeel vasodilation11 does not seem to have much effect on the outcome of the botulinum toxin injection. In 10 years of experience in injecting botulinum toxin immediately before applying the trichloroacetic acid peel Easy TCA, the author has seen no evidence of any direct interaction between these two procedures.

Combining EPS and Flashlamp in Antiaging Treatments Intense pulsed light (IPL) is a widely used technique for treating aging skin (Figure 11.5). However, many doctors are disappointed with the results obtained with IPL as a monotherapy and are looking for a combination of treatments that will benefit their patients. Phototherapy should not be used immediately after EPS, as the light rays will have a much greater depth of action, and may cause photochemical reactions. The presence of EPS on the skin could also refract the pulsed light. EPS can be used after flashlamp treatment, but it is best to be cautious, as the energy from the lamp might breach the stratum corneum and the acids in the EPS might penetrate more quickly. The doctor should be ready to neutralize the peel at the least sign of protein coagulation (frosting). It is a good idea to alternate flashlamp treatment and EPS, as with the mesolift: EPS one week and flashlamp the following week.

Antiaging Treatment for the Body EPS does not penetrate body skin as easily as it does facial skin. Several coats are needed to trigger erythema and large amounts of solution have to be used. Treating the body with EPS takes a long time and large quantities of the product. A combination of sandpaper abrasion and EPS (Figure  11.6) can be used to treat photoaging on the back and the upper or lower limbs. Light abrasion12 can thin the stratum corneum enough to allow the EPS solution to penetrate the skin more easily and more quickly. The sandpaper should be used gently and evenly, without causing any unpleasant sensation, pain, or bleeding. Only the most superficial layer of the stratum corneum should be removed. Any deeper abrasion that destroys the stratum corneum is to be avoided, as the active components of the EPS would penetrate the skin too quickly and soon saturate its

defenses, its buffer capacity. When using this abrasive technique, it is essential to have the necessary equipment at hand to neutralize the peel (see the section on neutralizing glycolic acid in Chapter 9) in case it penetrates more deeply than desired. This technique can be repeated at a minimum of 2-weekly intervals only.

More Frequent Application Another application technique for EPS can be considered, especially for patients with resistant skin who would benefit from a more intense tightening effect. EPS is applied following the usual protocol as described later in this chapter, but it is repeated more frequently. Applying the solution more frequently requires great care and experience. Daily applications of EPS allow the peel to gradually penetrate more deeply. After a few days, small scabs will start to appear, signaling that the maximum depth has been reached and must not be passed. Within about 2 weeks, the scabs will have healed, and daily applications can be started again. Appropriate cosmeceuticals should be used between the two series of daily peels. For quicker results, the EPS can also be applied two or three times a week (e.g., on Saturday, Monday, and Wednesday), especially on thick and oily male skin or in cases of acne.

Antiaging Maintenance Treatment EPS can be used to maintain the results of other peels when the patient wants a maintenance treatment without visible flaking. It should then be applied once a month.

Acne EPS is an excellent treatment for mild comedonal, papular, or papulopustular acne. Peels are obviously not indicated in more severe cases of acne, for which only dermatological treatments will do. Comedones, microcysts, and “whiteheads” should be removed13 during the week before the first EPS to avoid handling the skin immediately before the peel at the risk of the EPS penetrating too deeply. Some doctors report removal of comedones or microcysts immediately before EPS, with good results. EPS can improve the appearance of acneic skin in just a few sessions when it is combined with Skin Tech’s Purifying Cream, which consists of glycolic acid, retinol, vitamin E,

Alpha hydroxy acids: A NEW SLOW-RELEASE AHA COMPLEX WITH NO NEUTRALIZATION REQUIRED   69

(a)

(b)

(c)

Figure 11.7  (a) Active papulopustular acne and postacne pigmentation. (b) After four sessions of EPS and Purifying Cream, the acne has almost disappeared. (c) Substitution of Purifying Cream with Blending Bleaching Cream for PIH treatment.

triclosan, glycyrrhetinic acid, and tea-tree oil. As can be seen in Figure  11.7(a, b) (see also Figure  11.8), four EPS peels used in conjunction with Purifying Cream can vastly improve a patient’s pustular acne. After four sessions, the acne is almost inactive. The oldest postacne pigmentation persisted, however, and in this case we continued to apply EPS once a week (four extra sessions), combining it with Blending Bleaching Cream (containing tyrosinase inhibitors and antioxidants) to treat the persistent pigmentation. After eight sessions of EPS, of which the first four were combined with Purifying Cream and the last four with Blending Bleaching Cream, the patient’s skin started to look healthier (Figure 11.7c).

Pigmentation Disorders and Other Indications EPS acts similarly to other AHAs.

UNWANTED EFFECTS: PRECAUTIONS EPS is a very particular peel and has its own particular side effect. The day after application, an average of 2% of patients develop an allergic-type reaction consisting of small, slightly pruritic pinkish nodules (Figure 11.9). This reaction is only seen with this peel. It can often result from using products before

a peel that enhance penetration of the acids or from postpeel treatments that are unnecessarily aggressive or incompatible. Questioning patients closely about their cosmetic routine may provide an answer. In most cases, however, it seems to be for the following reason: in classic AHA peels14 the AHAs have to be neutralized, but with EPS they are not; as they are not neutralized, the acids may penetrate as far as the dermis and cause a local inflammatory reaction (a source of fibroblast stimulation and new collagen production as well) in the “highest” dermal papillae. This inflammatory reaction subsides by itself within 1–2 days at most. An allergic reaction is also theoretically possible and should be treated accordingly. That will also disappear within a few days (Box 11.2). This type of reaction should be seen as purely ­inflammatory—a positive reaction if the inflammation is controlled by antioxidants and does not last more than 2 days. If it does go on any longer, it could be considered an allergy. EPS contact with the eyes should be avoided. In the case of contact, the eyes should be rinsed with artificial tears or physiological saline solution. EPS may also, in some cases, penetrate too deeply or too quickly if the patient has been using skincare products that thin or remove the stratum corneum. Patients using topical

70   Textbook of Chemical Peels

(a)

(b)

(c)

Figure 11.8  (a, b) Papulopustular acne before treatment. (c) After four sessions of EPS and Purifying Cream, the acne is no longer active. After cleaning active acne, the Purifying Cream should be replaced with Blending Bleaching Cream to get rid of the pigmentation.

BOX 11.2  Excessive Penetration Appearance of an “acne-like” or “allergy-like” reaction some hours—or the day—after Easy Phytic Solution (EPS) usually means that for some reason, EPS penetrated the papillary dermis.

Figure 11.9  A complication that is specific to EPS: an acne-like reaction that lasts 24–48 hours and subsides by itself, occurring in an average 2% of patients.

1. Check if prepeel conditioning did not increase acid penetration. a. Medical prepeel. b. Home cosmetics or waxing, scrubbing, and so on. 2. Check if too much acid has been applied on the specific skin of this single patient.

Retrospective studies during nearly 20 years of use show clusters of this side effect, limited to a specific user and not related with a lot number, season of the year, or skin type. Surprisingly, the next peeling usually does not produce the same side effect. This might be the result of a skin structure normalization after peeling. If the side effect has a tendency to increase and not to decrease during the next hours, the possibility of an allergic reaction should be studied.

Alpha hydroxy acids: A NEW SLOW-RELEASE AHA COMPLEX WITH NO NEUTRALIZATION REQUIRED   71

BOX 11.3  Simple Application Protocol 1. Cleanse Wash

Dry

2. Apply Apply the last coat when the patient expresses a tingling sensation

3. Specific cream after peeling Ex: acne: Purifying Cream

Ex: skin tension: Actilift

Cleaning the Skin

Figure 11.10  Abnormally deep penetration in a young patient who had been applying benzoyl peroxide locally for acne.

Any makeup should be removed and the skin cleansed twice with Skin Tech Cleanser (foam without glycolic acid [Figure  11.11]); the skin should then be rinsed with warm water and dried with a swab. Alcohol or acetone should not be used before EPS because these products remove surface lipids and increase skin permeability (which is not necessary with EPS).

retinoids, AHA creams, or benzoyl peroxide should stop using them 2 weeks before EPS to ensure that the stratum corneum regains its normal thickness and function. Figure 11.10 shows the results of overpeeling in a young patient who had been using a benzoyl peroxide cream. Benzoyl peroxide is a powerful pro-oxidant used in the antibacterial treatment of acne, and it reduces the stratum corneum’s impermeability properties. The EPS can then penetrate more deeply into the skin. In this case, a fluorocortisone cream was applied immediately. Between the second and sixth day, the patient was showing areas of local erythema that were treated with topical cortisone. On the 10th day, there were no visible sequelae. Other complications caused by AHAs are extremely rare with EPS. Infection or pigmentation problems are often caused by errors made when neutralizing AHA peels. EPS is automatically neutralized by the skin’s buffer capacity, and postpeel complications are far rarer than with conventional AHA peels. See Box 11.3.

Prepeel Preparation This is likely to increase the penetration of the acids unnecessarily. EPS was designed to avoid any prepeel treatment. Application of EPS should be delayed for 2 weeks if there has been any prepeel preparation: EPS uses the stratum corneum as a reservoir for the slow release of the acids, and if it has been damaged, it can no longer fulfill this role and the acids will penetrate too rapidly through the thinned layer of skin. Body skin is much less permeable than face skin. This is why an abrasive technique has been described earlier in this chapter.

Figure 11.11  Prepeel skin cleansing using the prepeel cleanser foam.

72   Textbook of Chemical Peels

BOX 11.4  Average Number of EPS Coats Thin skin: 2 Normal skin: 2–3 Thick skin: 3–4

Skin Tech Cleanser has a physiological pH of 5. It allows the skin to return to a normal pH before applying peeling solutions.

Application Small cotton wool balls seem to be the best method of application. A syringe is used to draw out 2–2.5 cm3 of the EPS. The cotton wool ball is soaked (not too much), and the solution is applied evenly and quickly over the whole face. Two coats are usually enough to produce a tingling sensation on the skin. When the patient can feel some tingling, one last coat is applied with the same applicator. There should be no frosting. In the case of inadvertent frosting,15 a neutralizing solution of sodium bicarbonate should be applied immediately. If there is no frosting, a neutralizing solution should not be applied—the skin neutralizes EPS automatically. Patients with very permeable skin may feel some tingling as soon as the first coat is applied. They should be given a total of two coats only: the first triggers the tingling and the second finishes off the peel. Patients with thick skin may not feel anything before the third coat. They should be given a total of four coats (Box 11.4). The treated area should be massaged with a gloved hand to ensure even penetration until the tingling sensation subsides. Slight tingling is normal and can last from 30–60 minutes after the application of this slow-release solution.

Immediate Postpeel Period As soon as the patient says that the tingling has subsided, the skincare cream best suited to the patient’s skin should be rubbed in: Purifying Cream in the case of acne, Blending Bleaching Cream in the case of pigmented marks, DHEA-Phyto cream for antiaging for patients over 40, and Renutriv ACE with lipoic acid to prevent aging in patients under 40. Actilift cream with DMAE can be used to increase skin firmness. These creams penetrate much more easily immediately after the AHAs have been applied, but using a plastic occlusive film (Figure  11.12) for 20–30 minutes further enhances penetration of the skincare creams. In vivo, the natural water content of the stratum corneum is relatively low. When the surface of the skin is occluded with an impermeable plastic film, the water that normally evaporates through the epidermis (TEWL16) can no longer do so, and water of endogenous origin gradually soaks the stratum corneum, which can absorb up to 5–6 times its dry weight. The thickness of the stratum corneum increases in proportion to the amount of endogenous water absorbed and can become up to four times thicker.17 It is then far more permeable to the watersoluble ingredients, and this improved permeability lasts for several hours after the occlusive film has been removed. Occlusion raises the temperature of the hyperhydrated epidermis and makes the various hydrophilic ingredients in the creams more soluble. Finally, occlusion prevents the active components in the creams from evaporating too quickly. The plastic film is then removed and any excess cream is rubbed in

Figure 11.12  Postpeel occlusion with a suitable cosmeceutical for a duration of 15–30 minutes.

to enhance penetration one last time. All of the products—EPS and cream—are left on the skin until the following morning, when the patient can wash his or her face.

Postpeel Period (3–4 Days) The skin flakes only very slightly, usually unseen by the naked eye, because it practically flakes “cell by cell.” The skin should be kept fully hydrated with a cream containing vitamin E but without fruit acids (Vit. E Anti-oxydant), and the cream most appropriate for the problem under treatment should continue to be used. This will often be the same cream applied to the skin immediately after the peel (see Table 3.1 in Chapter 3).

Period between Peels (between Two EPS Sessions) The appropriate cream should continue to be used between peels. Exposure to the sun’s rays must be avoided; this means staying out of the sun and using an effective sun protection cream for 2 weeks after the last peel.

Repeating the Peel When EPS is the main treatment, it can be repeated once or several times a week (see earlier discussion). When EPS is used as a maintenance treatment with other peels, it can be repeated once or twice a month. In standard treatment, EPS can be applied once a week for 6–8 weeks. Thereafter, it is applied as a maintenance treatment: four extra EPS peels, once every 2 weeks. Finally, in the long term, EPS can be applied once every 4–6 weeks (Figure 11.13).

CONTRAINDICATIONS • • • • •

Women who are pregnant or breast-feeding (as a precaution). Presence of herpes or other active lesions. Lesions of unknown origin. Allergy to one of the components. Unrealistic hopes.

Alpha hydroxy acids: A NEW SLOW-RELEASE AHA COMPLEX WITH NO NEUTRALIZATION REQUIRED   73 Table 11.1  Differences between Obsolete Glycolic Acid Solutions and Easy Phytic Solution Obsolete glycolic acid peeling solutions

Easy Phytic Solution

Prepeel preparation Exclusively hydrophilic solution Complexity of protocols (avoid upper eyelid, nostrils, etc.) Random neutralization at time x Neutralization stops the activity of acids Neutralization too early: inefficient Neutralization too late: danger Uncontrolled activity, strong mobility of protons Uncontrolled and massive penetration pH : often = +/– 3 No reservoir effect — Uncontrolled inflammatory reaction Random social life Possibly numerous complications

Without prepeel preparation Solution hydro + lipophilic Very simple protocol Autoneutralization by skin No neutralization, 100% of active acids Autoneutralization Autoneutralization Partial inactivity of protons Controlled and sequential progressive penetration pH: +/– 1 Reservoir effect Reactivation of the acids in the skin Controlled inflammatory reaction Social life preserved One unique transitory complication described

8 days

8 days

8 days

8 days

15 days

4–6 weeks

7

7

7

7

7

7 Time line

1st EPS

2nd

3rd

4th

5th

6th

7th

Figure 11.13  Diagram of repeated EPS peels.

CONCLUSIONS EPS is the first slow-release AHA peel that does not need neutralizing, in spite of its pH of 0.5–1. This makes it extremely safe to use. It combines the known superficial peeling effects of three AHAs with the antioxidant, chelating, and tyrosinaseinhibiting action of phytic acid (Table 11.1). It is a new type of peel that overcomes all the problems associated with neutralizing conventional AHAs. EPS allows each of the molecules in the solution to act to full effect, without being neutralized. The best indications for EPS are the treatment of adolescent acne and aging skin, on which it has a tightening effect.

NOTES 1. Glycolic acid has a pKa of 3.83, lactic acid a pKa of 3.86, and mandelic acid a pKa of 3.36. 2. See Chapter 6 for a discussion of pKa. 3. Saponification allows the acids to act more evenly. 4. As is the case when unbuffered peel solutions are applied to the skin. 5. It is therefore essential for the stratum corneum to be complete when using EPS. If any preliminary treatments reduce its thickness, the solution may penetrate too quickly and saturate the skin’s buffer capacity. 6. AHAs are water-soluble.

7. Dolor–Rubor–Tumor–Calor. 8. Ditre CM, Griffin TD, Murphy GF, Sucki H, et al. Effects of alpha-hydroxy acids on photoaged skin: A pilot clinical, histologic, and ultrastructural study. Journal of the American Academy of Dermatology. 1996; 34(2 pt 1): 187–95. 9. EPS can be applied after pulsed light treatment, unless the skin has been made excessively permeable. See the discussion later in this chapter. 10. Although EPS does not require any specific prepeel care. 11. It should be noted that EPS and Easy TCA are both used in conjunction with anti-free-radicals that control the postpeel inflammatory reaction. This is not the case with the majority of other peels. The author’s experience is based only on the combination of botulinum toxin and EPS or Easy TCA. Combinations with other peels have not been tested. 12. For example, with 3M Wetordry sandpaper P220. 13. Comedone remover, No. 11 scalpel blade, point of a needle. 14. For example, a 70% unbuffered glycolic acid peel. 15. Frosting has rarely been described; the author has never come across it. 16. Transepidermal water loss: 5–20 g of water/m 2 of skin under normal physiological conditions. 17. The increase in permeability is also due to a reduction in corneocyte cohesion related to the unusual hyperhydration of the stratum corneum.

12 Trichloroacetic acid General information, toxicity, formulations, and histology HALOACETIC ACIDS Haloacetic acids are derivatives of acetic acid in which one or more hydrogen atoms on the alpha carbon1 are replaced by halogens (fluorine, chlorine, bromine, or iodine) (Figure 12.1). The haloacetic acid most commonly used in peels is trichloroacetic acid, and we will therefore look at the chlorine derivatives of acetic acid.

Acetic Acid Acetic acid (Figure  12.2), also known as echanoic acid, has a low molecular weight of 60.05 and a pKa of 4.76.2 It is obtained by distilling vinegar (the acetic acid that comes from the action of certain aerobic bacteria on dilute alcohol) or through the Monsanto process by the reaction of carbon monoxide with methanol at high temperature and pressure. It is a strong irritant to the eyes, mucous membranes, and skin. Prolonged contact between the skin and “glacial” acetic acid3 can cause skin necrosis. Acetic acid has disinfectant and fungicidal properties. It is not carcinogenic, mutagenic, or teratogenic to animals or humans. The oral LD50 in rats is 3.310 mg/kg.

Monochloroacetic Acid Monochloroacetic acid (MCA; Figure 12.3), also known as chloroacetic acid and chloroethanoic acid, has a molecular weight of 94.5 and can be obtained from the reaction between acetic acid and chlorine under high pressure. The pH of an 80% MCA solution is lower than 1 and its pKa is 2.82. In both its acid form and its salt forms (e.g., sodium monochloroacetate), MCA is highly toxic to the skeletal muscles, the renal system, and cardiovascular system and is rapidly absorbed through the skin and mucous membranes. MCA poisoning by ingestion, inhalation, or exposure of more than 5% of the body surface area is frequently lethal. The symptoms of poisoning are not immediate; they can appear between 1 and 4 hours after exposure. The noncorrosive sodium salt does not penetrate the skin and is not toxic by skin contact (unlike MCA, which passes through the skin very easily). It is, on the other hand, highly toxic by the oral route. There are no data available on the parenteral administration of MCA in humans. In laboratory animals, however, an injection is rapidly lethal. MCA accumulates in the liver and kidneys before it accumulates in the brain. Elimination of MCA is renal in humans: most of it is eliminated in its free form, with a small part being eliminated in conjugated form with glutathione. The mechanism of MCA toxicity seems to be via inhibition of the enzyme pyruvate dehydrogenase; this inhibition blocks the Krebs (tricarboxylic acid) cycle and disrupts the cell’s energy supply. Almost immediately, the cell finds itself without energy. Ketoglutarate dehydrogenase activity is also reduced,

which causes lactic acidosis. The MCA also damages the blood– brain barrier, probably through the formation of vascular endothelial microlesions. Symptoms of poisoning begin with nausea and vomiting, diarrhea, and central nervous system (CNS) excitation with disorientation. The effects observed later on or with higher doses include CNS depression, cerebral edema, severe myocardial depression, coma, and cardiogenic shock resulting from nonspecific myocardial lesions and significant arrhythmias. Within the first few hours, severe metabolic acidosis4 with hypokalemia occurs. The severity of the rhabdomolysis causes myoglobinuria severe enough to cause kidney failure5 in those who survive it. One treatment involves administering dichloroacetate by slow (in 10 minutes) intravenous injection (50 mg/ kg), if possible before metabolic acidosis begins. The dichloroacetate is only active as long as all the pyruvate and ketoglutarate dehydrogenase molecules have not been deactivated by the MCA. The severity of poisoning due to skin contact depends on the surface area of skin exposed: applying an 80% MCA solution on less than 5% of the body surface area can cause severe poisoning, while exposing 6%–10% of the body surface to MCA is often lethal. MCA has nevertheless been suggested as a dermatological treatment for mosaic warts or periungual warts at a concentration of 80% or 60 g of MCA + 10 ml of water. Treating warts involves MCA coming into contact with a very limited area of skin, which explains the absence of poisoning when the treatment is performed carefully. MCA has also been combined with salicylic acid and is considered more effective than dichloro- or trichloroacetic acid in the treatment of warts. Because of this product’s very high and potentially fatal toxicity, its use and indications should be strictly limited. Monofluoroacetic acid is even more toxic than MCA, being fatal after ingested doses of 2  mg/kg, whereas MCA is fatal after doses of 50 mg/kg.6

Dichloroacetic Acid

Chemistry and Toxicity of DCA Dichloroacetic acid (DCA; Figure 12.4), also known as bichloroacetic acid and dichloroethanoic acid, has a molecular weight of 128.94 and a pKa of 1.3. It is soluble in water, alcohol, and ether. DCA has been used in the treatment of severe lactic acidosis. No clinical side effects have been observed after parenteral administration. On the contrary, intravenous administration of DCA during experimental poisoning of rodents with MCA increased the survival rate, raising it from 8% to 83% after an injection of 50 mg/kg and from 8% to 100% after an injection of 100 mg/kg. There are strict protocols for the injection of DCA in the case of MCA poisoning.

Trichloroacetic acid: GENERAL INFORMATION, TOXICITY, FORMULATIONS, AND HISTOLOGY   75

X

O

Y — Cα — C

—

OH

Z

Carboxylic acid group

Figure 12.1  General chemical structure of a haloacetic acid. α indicates the alpha carbon atom. X, Y, and Z represent hydrogen (H) or a halogen (F, Cl, Br or I)—at least one of these must be a halogen.

H H

C

OH C O

H

Figure 12.2  Chemical structure of acetic acid.

H H

C

OH C O

Cl

Figure 12.3  Chemical structure of monochloroacetic acid (MCA).

H Cl

C Cl

OH C O

Figure 12.4  Chemical structure of dichloroacetic acid (DCA).

When ingested, DCA is rapidly absorbed by the digestive tract. In animals, only 1%–2% of the quantity ingested is found in the feces, which means that the acid is almost completely absorbed. Only 1% is found, in free form, in the urine. In humans, up to 5% of DCA can be found in the urine, very soon after DCA has been absorbed. Peak plasma levels are reached within 15–20 minutes in humans. Intoxication by inhalation is rare, as DCA is not a very volatile substance. DCA causes the liver to increase in volume as a result of a buildup of glycogen. Increases in aminotransferase (transaminase) levels have been observed during treatment with high doses of DCA, in both rodents and humans. DCA can cause focal, or even widespread, hepatocellular necrosis in mice, but no cases have been described in rats, dogs, or humans, even when administered in high doses. Neurological toxicity in humans is limited to sedation and potential peripheral neuropathy that is reversible. DCA undergoes oxidative dechlorination that converts it into glyoxylate,7 which is in turn oxidized into oxalate,8 reduced

into glycolate,9 and eventually transaminated into glycine.10 However, in certain individuals, the DCA can be partially converted into MCA. This has been described in a child suffering from congenital lactic acidosis. It appears that the DCA may enhance the development of hepatocellular carcinoma in animals, although not in humans.11 DCA is genotoxic in vitro and in vivo and induces DNA hypomethylation in vivo. The oral LD50 in rats is 2.820  mg/kg. The human toxicity of DCA is mainly local, through chemical burns, but DCA could be considered to be potentially carcinogenic in humans. To date, there is no convincing data on this subject. Application Protocol for DCA DCA has been shown to stimulate keratinocyte growth and differentiation in vitro.12 It has been used in the treatment of human papillomas, without much success,13 as well as in the treatment of epistaxis. DCA is used as a cauterizing agent in the treatment of all types of warts, calluses, corns, xanthelasma, seborrheic keratoses, ingrown toenails, and similar conditions. It is just as effective as other methods such as electrodessication or dry ice. DCA is a powerful keratolytic, and it is important to apply it only to the lesion being treated. Before any treatment, Vaseline should be applied around the lesion to prevent any contact with healthy skin. The doctor should also have some water at hand to wash the skin in case of inadvertent contact. A neutralizing solution of sodium bicarbonate can also be used immediately in case of accidental contact with the skin. The quantity of DCA required largely depends on the type of lesion being treated. Very thick and horny lesions are treated using a cotton bud. A wooden toothpick soaked in DCA solution can also be used; it should be pushed inside the callus or wart. Three to five applications are necessary to get results on very thick lesions, whereas only one or sometimes two applications are enough on relatively flat lesions. The depth of application is monitored by watching for the appearance of protein coagulation, which turns the skin a whitish-gray color. A combination of shave excision and chemical coagulation can also be used. The top of the wart is first removed with an electrosurgical or radiofrequency knife. The DCA is applied after the edges of the wart have been protected with a thin layer of Vaseline. Foot calluses should be pared surgically before the acid is applied. Posttreatment care consists of covering the skin with Vaseline to help it flake more quickly. Large calluses often have to be treated several times. Treating xanthelasma with DCA is fairly common.14 The skin around the xanthelasma must be protected with Vaseline and the DCA applied carefully and not to excess. The scars are mostly invisible. Treating xanthelasma with phenol, however, leaves no scarring (see Chapter 36). The potential toxicity of DCA means that it cannot be used on a large absorbent surface area. The author has found no significant references to the use of DCA in full-face or body peels.

Trichloroacetic Acid (TCA)

Chemistry and Toxicity of TCA Trichloroacetic acid (Figure 12.5), also known as trichloroethanoic acid and trichloromethane carboxylic acid, comes in the form of colorless or white crystals and has a distinctive sharp, pungent odor. As far as its toxicity is concerned, industrial accidents have been reported in which individuals were subjected to high doses of TCA, either by being splashed with the solution over large areas of the body or by accidental ingestion or

76   Textbook of Chemical Peels

Cl Cl

C Cl

OH C O

Figure 12.5  Chemical structure of trichloroacetic acid.

inhalation of concentrated vapors. However, such toxicity has never been described when TCA has been used as a chemical peel. It is nevertheless worthwhile to become acquainted with the potential symptoms of industrial poisoning. TCA is readily absorbed through the respiratory and digestive tracts. Acute accidental exposure to TCA has caused skin necrosis. Contact with the eyes causes burns or irritation, depending on the concentration of the acid. Exposure of the eye to small amounts of solution with a concentration equal to or lower than 15% m/m does not appear to cause any irreversible damage to the cornea. Immediate dilution with physiological saline solution instantly stops the burning and any risk of damage to the eye. However, the proteins in the cornea could coagulate with larger amounts of low-concentration TCA or smaller amounts of high-concentration TCA. Inhaling concentrated vapors of TCA can irritate the respiratory tract. Poisoning through inhaling high doses of TCA can cause headache accompanied by nausea, vomiting, and coughing. Higher concentrations cause weakness, dizziness, bronchitis, and/or pneumonia. Acute poisoning with TCA vapor can lead to chest pains, breathing difficulties, low blood pressure, edema of the respiratory tract, suffocation, and death. Accidental ingestion of TCA causes irritation and burns in the digestive tract, vomiting, diarrhea, and low blood pressure. Accidental ingestion of high concentrations can erode the teeth and cause necrosis of the jaw. Controlled ingestion of 3  mg/kg of TCA in three male volunteers showed a half-life of 50 hours. Liver toxicity has been studied in mice: hepatomegaly (30% enlargement) was observed in male mice given water containing 1 g/l of TCA for 52 weeks. In a group given water with a concentration of 2 g/l of TCA, the liver enlarged by 63%. The incidence of liver carcinoma did not increase, irrespective of the administered dose. In another study, it was proved that TCA does not cause adenomas or liver cell carcinoma, even in rodents pretreated with ethylnitrosourea, conventionally used to induce carcinomas. No in vitro studies using human cells have shown any chromosomal abnormalities after contact with TCA. To the best of the author’s knowledge, no studies have shown any link between chronic exposure to TCA15 and cancer in humans. When TCA is applied to the skin, it is not absorbed, and it is therefore not toxic in this application.

AQUEOUS SOLUTIONS OF TCA Hydrophilicity of TCA Crystals TCA crystals are very hydrophilic and therefore unstable in the presence of water. They readily dissolve on exposure to atmospheric humidity. This extreme hydrophilicity can cause problems when TCA solutions are made up in a pharmacy. In fact, the packaging of pure TCA crystals usually allows for the preparation of far more peel solution than the doctor actually needs. The pharmacist does not usually dissolve all the crystals

at one time, as this would produce a large quantity of solution that is difficult to store. He or she will usually measure out the quantity of crystals needed for each order of peel solution. Every time the bottle is opened and every time the pure TCA crystals are taken out, they come into contact with atmospheric water, which gradually hydrates them. The larger the bottle, the more likely it is that the remaining crystals will be hydrated every time the bottle is opened. The longer it takes to weigh the crystals, the more hydrated they will become. Peel solutions are therefore prepared by diluting crystals that are gradually becoming more and more hydrated: at the same weight, the pharmacist is in fact weighing TCA crystals that are slowly swelling with water. The solutions that he prepares are more and more diluted and therefore less and less effective. The doctor, for his part, gets into the habit of applying increasingly weaker TCA peels with increasing firmness, in spite of the fact that the same labels show the same concentration. The doctor therefore gets used to applying ever increasing volumes of peel solution to achieve the same results—until the day when the pharmacist starts using a new bottle of pure TCA crystals and makes up a peel solution with fresh, anhydrous crystals that are more aggressive than the “old” hydrated crystals. Applying this new and more concentrated solution of course results in a peel that is deeper than the doctor expected, and the risk of complications is increased, even though there is no apparent difference in the application procedure. Unlike pure crystals, TCA solutions do not hydrate by themselves. It is therefore safer not to keep TCA in crystal form and instead to use reconstituted solutions whose concentration is more stable than crystals.

Inhomogeneity of TCA Solutions A solution is said to be homogeneous when the different elements of which it is made are evenly distributed in the container that holds it. The homogeneity of peel solutions is one of the essential elements of their safety. Simple Aqueous Solutions of TCA Unfortunately, TCA simple aqueous solutions (TCA–SAS)16 are neither homogeneous nor stable. The TCA molecule is very mobile in the solution, and its motion has both a random element and a component determined by its chemical structure. When an aqueous solution of TCA is left in an unmoving container, the concentration of the solution does not remain uniform. The TCA temporarily becomes more concentrated in some parts of the container and more dilute in others. For example, if a TCA solution of 33% m/m is prepared and left at room temperature, some regions of the solution will have a concentration of 35% for a certain length of time while neighboring regions will have concentrations of 30% or 40% (Figure  12.6). As this process continues, the region that just had a concentration of 35% will now have a concentration of 37%, while other areas of the solution will have different concentrations again, for example 25% and 29%, and so on.17 Depending on the position of the tip of the needle used for taking the acid out of the bottle, the solution will be more concentrated or more dilute. A solution that is too dilute or too concentrated could be applied to different parts of the face. Simple aqueous solutions of TCA have to be mixed continuously, both when they are being taken out of the bottle and while they are being used. Certain complications that arise unexpectedly after a TCA–SAS peel can be explained—at least partially—by this phenomenon of inhomogeneity.

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30%

29% 37% 25%

(a)

15% 40%

(b)

Figure 12.6  Inhomogeneity of simple aqueous solutions of TCA. (a) A solution with a presumed concentration of 33% contains mobile regions of different concentrations. (b) At a later time, the same TCA solution with a presumed concentration of 33% contains mobile areas of concentrations that are different.

Unfortunately, this type of calculation (weight by volume, w/v) is widely used in some countries: a volume of 100  ml of TCA solution contains x grams of TCA. If we know the concentration in w + v only, it is difficult to calculate the exact amount of TCA in the solution. To get the correct answer, one has to calculate mass with mass, and volume with volume, and not volume with mass.20 Examples of calculations of concentration using the w/w, m/v, and w + v methods are given in Boxes 12.1–12.3. Methods of calculation based on volume lead to values of concentrations that can be as high as 140%. Because a “0% solution” is pure water and a “100% solution” pure TCA, values greater than 100% are essentially meaningless. Ideally, therefore, these methods should not be employed for the calculation of concentrations—only the m/m method should be used. Nevertheless, for the sake of simplicity, pharmacists often prefer to use dilutions in volume whenever possible, as they can buy “standardized” TCA solutions at 20%, 50%, and so on. Then, in theory, all the pharmacist has to do is add 100 ml of water to 100 ml of TCA solution at “50%” to get a “25%” solution. It is not easy for a doctor to calculate how much TCA these solutions contain. Examples of calculations of dilutions using the m/m, m/v, and m + v methods are given in Boxes 12.4–12.6 and Tables 12.1 and 12.2.

Publications Can Be Misleading Awareness of this problem led to the rapid development of new TCA peel formulas between 1990 and 2000. One of the first solutions developed was the New Peel combination of TCA and Mikuda complex. The Soft Peel formulation used asiaticosides and ginsenoids, glycerol, urea (carbamide), sorbitan monolaurate, and methyldibromo-glutaronitrile, among other ingredients. Easy TCA, Unideep, and Only Touch peel (OTP) provided another answer to the problem: these stabilized solutions consist of a base solution to which a determined quantity of 50% m/m TCA is added. There are no complicated calculations to be performed; the directions for use state precisely what volume of 50% m/m TCA solution should be added to the base solution to make up the Easy TCA, Unideep and OTP solutions, which provide peels to the basal layer, the papillary dermis, and the reticular dermis, respectively.

Calculating the Concentration of TCA Since TCA peels first came into use, practitioners have suffered from a lack of standardization regarding how a solution’s concentration is to be calculated. The calculation can be done in different ways: by mass per mass (m/m), mass per volume (m/v), or mass plus volume (m + v, e.g., m + 100 ml). There are also different formulas for diluting these solutions using approximate curves. Therefore, “50%” TCA has little meaning if we do not know whether the calculation is m/m, m/v, or m + 100 ml. In 1995 and 1996, Trauchessec and Pissot18,19 suggested standardizing the calculation of the concentration of a TCA solution by expressing it in m/m, which is the only logical way of calculating a percentage. It should be possible to make a strict comparison of the terms of a percentage. For example, the carbohydrate content of a meal is given as a percentage: a content of 20% carbohydrate means that 100 g contains 20 g of carbohydrate and 80 g of something else. Unless it is clearly indicated on the packaging, there is no way of knowing that a volume of 100 ml of this meal would contain 20 g of carbohydrate. It would be impossible to understand exactly how much carbohydrate is in the food.

A major problem arises when reading publications from different sources. Suppose that an American doctor wants to use a peeling technique described by a European author who gives concentrations in m/m but does not mention this in the publication, as is too often the case. The American doctor gets his pharmacist to make up the solution as described by the European doctor. The American pharmacist, however, prepares a solution in m/v or m+v, or even dilutes it as described in the

BOX 12.1  TCA Solution at 50% Mass per Mass (m/m)1 100  g of TCA solution at 50% m/m contains 50  g of pure, unhydrated TCA crystals and 50  g of water. 100  g of this solution is not, however, 100 ml, but only 79 ml. In fact, 1 g of TCA displaces 0.6 ml and not 1 ml of water.2 Scientifically, this is the most rigorous method of calculation, as 100 ml of a solution at 50% m/m would contain (50/79) × 100 = 63.3 g of TCA.

%

Mass of TCA (g)

Volume of water (ml)

Final mass (g)

Final volume (ml)

10 20 30 40 50 60 70

10 20 30 40 50 60 70

90 80 70 60 50 40 30

100 100 100 100 100 100 100

96 92 88 83 79 75 71

Taken from Trauchessec JM, Pissot F. Solutions d’acide trichloroacétique masse pour masse pour peelings dermatologiques. Les Nouvelles Dermatologiques. 1996; 15: 252–55, with the authors’ permission. 2. According to Trauchessec, the exact value is 0.59 ± 0.01. The value of the constant 0.60 used here is an acceptable approximation. It means that 1 g of TCA displaces 0.6 ml of pure water, whatever the concentration of the solution. 1.

78   Textbook of Chemical Peels

BOX 12.2  TCA Solution at 50% Mass per Volume (m/v)1 This solution is prepared in the following manner: 50 g of TCA is diluted in a small amount of distilled water to get a small amount of solution, then the volume is made up by adding distilled water until the final volume reaches 100 ml. To get 100 ml of solution and an end mass of 121 g, 50 g of TCA will be dissolved in 71 ml of water. This method of calculation is easy for the pharmacist, as 100 ml of solution contains 50 g of TCA (100 g of this solution would contain 41.32 g of TCA).

%

Mass of TCA (g)

Volume of water (ml)

Final mass (g)

Final volume (ml)

10 20 30 40 50 60 70

10 20 30 40 50 60 70

94 88 82 77 71 65 59

104 108 112 117 121 125 129

100 100 100 100 100 100 100

1.

Taken from Trauchessec JM, Pissot F. Solutions d’acide trichloroacétique masse pour masee pour peelings dermatologiques. Les Nouvelles Dermatologiques. 1996; 15: 252–55, with the authors’ permission.

100 g of a solution of TCA at 50% m/m contains 50 g of TCA and 50 g of water (50 g of water is in fact equivalent to 50 ml of water) and has a volume of 79 ml. If 79 ml of solution contains 50 g of TCA, then 1 ml contains 0.633 g of TCA, therefore 100 ml of TCA solution at 50% m/m contains 63.3 g of TCA. If this solution is diluted with the same volume of water (i.e., 100 ml), it produces 200 ml (but not 200 g) of TCA solution, in which there is still 63.3 g of TCA. Therefore, 100 ml of the new diluted solution contains 31.65 g of pure TCA.

BOX 12.5  Dilution of a Base Solution at 50% Mass per Volume (m/v) 100  ml of TCA solution at 50% m/v contains 50  g of TCA diluted in 71 ml of water, to give a solution with a volume of 100 ml for a mass of 121 g. If 100 ml of pure water is added to 100 ml of solution at 50% m/v, it produces 200 ml of solution, which weighs 221 g and contains 50 g of TCA. 100 g of this solution contains 22.6 g of TCA, while 100 ml of the same solution contains 25 g.

BOX 12.6  Dilution of a Base Solution at 50% Mass + Volume (m + 100 ml)

BOX 12.3  100 ml1 This method of preparation involves adding 100 ml of water to 50 g of pure TCA crystals. The final volume of this solution is 129 ml for a mass of 150 g. 100 ml of this solution contains 38.75 g of TCA, while 100 g of this solution m + 100 ml contains 33.33 g of TCA. This is the easiest but also the worst method of calculation, as it is extremely difficult to work out the exact amount of TCA.

%

Mass of TCA (g)

Volume of water (ml)

Final mass (g)

Final volume (ml)

10 20 30 40 50 60 70

10 20 30 40 50 60 70

100 100 100 100 100 100 100

110 120 130 140 150 160 170

106 112 117 123 129 135 141

1.

BOX 12.4  Dilution of a Base Solution at 50% Mass per Mass (m/m)

Taken from Trauchessec JM, Pissot F. Solutions d’acide trichloroacétique masse pour masse pour peelings dermatologiques. Les Nouvelles Dermatologiques. 1996; 15: 252–55, with the authors’ permission.

100 ml of TCA solution at 50% m + 100 ml contains 38.75 g of pure TCA for a mass of 116.27 g. Adding 100 ml of water with the aim of converting the theoretical concentration into 25% therefore gives a solution of volume 200 ml, whose mass is 226.27 g and which still contains the same 38.75 g of TCA. 100 g of the new solution therefore contains 17.12 g of TCA. 100 ml of the new solution contains half of the 38.75 g, which is 19.38 g of TCA.

Table 12.1  Calculation of a TCA Solution at 50% in Mass or in Volume Method of calculation

Grams of TCA in 100 ml Grams of TCA in 100 g

m/m

m/v

m + 100 ml

63.3 50

50 41.32

38.75 33.33

Table 12.2  Obtaining a Solution at “25%” by Adding 100 ml of Water to a Solution at “50%” Method of calculation

previous section. The European technique may well be based on an aggressive TCA, with a concentration of 45% m/m. The American doctor orders a solution at 45% from his pharmacy but is in fact using a concentration of 38.1% m/m when the calculation has been made at 45% in m + 100 ml. A solution with a concentration of 31% m/m will clearly not produce the same results as a concentration of 45% m/m. The American doctor cannot achieve the same results as the European author, whose results might therefore easily be considered exaggerated or even rigged.

Grams of TCA in 100 ml Grams of TCA in 100 g

m/m

m/v

m + 100 ml

31.65 25

25 22.6

19.38 17.12

The situation is more serious when a European doctor wants to use an American application technique with a TCA solution at 50% m + 100 ml. This solution contains 50 g of pure TCA to which 100 g of water is added. The final volume of the solution will be 129  ml for a mass of 150  g, and 100  g of this

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solution is actually equivalent to 33% m/m. The American author who applies a TCA solution at 50% m/v—which is in fact a European 33% m/m solution—to a patient’s face can achieve excellent results. The European doctor, who wants to achieve the same results by applying a solution at 50% m/m provided by the pharmacist, is running a huge risk of burning the patient’s skin and causing hypo- or hyperpigmentation, scarring,21 and other problems. It is therefore essential to stipulate the type of concentration to use, and this is one of the first pitfalls awaiting any doctor who is new to peeling. The technique for applying TCA, which is actually very easy, has for a long time been made difficult because of the different methods for calculating concentrations (see earlier discussion) and the approximate explanations given in many publications.22 There are many inconsistencies: some publications consider a TCA peel at 50% to be a “superficial peel.” Yet we know that a peel at 50% reaches the reticular dermis easily and quickly, and can sometimes even go beyond it: this is a deep peel—in most cases too deep. This solution penetrates the whole of the papillary dermis immediately, achieving a “medium” or “deep” peel, but certainly not a superficial one. The same solution at 50%, but calculated in m + 100 ml, would be equivalent to a 33.3% m/m solution, and the first coat of TCA at 33% m/m would soon reach the papillary dermis. It is then difficult to understand how anyone can say that a “TCA peel at 50% produces a superficial peel”: in whatever way the calculation is made, it is wrong and a TCA solution at 50% will produce, at the very least, a medium-depth peel even if it is calibrated in m + 100 ml. The type of applicator used, the number of coats, and the total quantity of TCA applied to the skin, as well as any prepeel preparation and other considerations, must also be taken into account. Histological studies have compared the depths reached by different concentrations of TCA used in conjunction with different techniques such as dry ice or prior application of Jessner’s solution. A histological study by Brody and Stegman, at 3, 30, and 90 days,23 showed that the deeper the injury, the more necrosis and regeneration are histologically visible. It has thus been shown that three successive applications of TCA cause deeper necrosis than one application.24 The technique used in this study involved the application of TCA at a concentration of 35%—presumably calculated in mass per volume, although it was not stated whether this was a w/v calculation, m + 100 ml calculation, or a dilution of TCA solution. The Jessner’s solution in the study was supposed to be prepared from lactic acid crystals rather than from an 80% (w/w, w/v?) lactic acid solution. This solution was applied with a cotton bud: the volume, form, and texture of the cotton bud have an influence on the quantity of solution that comes into contact with the skin. The dry ice was applied firmly (how firmly was not stated) in acetone (exactly how much and at exactly what temperature were also not stated) for 15 seconds. The importance of studies such as this should not be underestimated, but it is necessary to draw attention to the number and importance of the variables that have to be taken into account when evaluating results.

A Good Method of Calculation A consistent method of calculating concentrations must be adopted. It would of course be preferable to use pharmacological concepts such as molar mass, but practitioners are not used to handling such data. From a practical point of view, there are two units of measurement that are easily accessible: mass and volume. As we have just seen, the only acceptable values

are calculations in m/m (if we are referring to mass) or in m/v (if we are referring to volume). Measurements in m + 100  ml are too approximate, as is using dilutions of preexisting solutions. Anyone is capable of measuring an approximate volume, although not an exact one, and this introduces another margin of error. With the help of precision scales, it is possible to measure a mass precisely—more precisely, in any case, than by judging gradients on a measuring glass with the naked eye. This confusion over concentrations is extremely dangerous, and a standardized concentration should be used to avoid disappointment as well as complications. McCullough25 has drawn attention to the discrepancies between calculations of TCA concentrations but prefers to use the m/v method. We have chosen to calculate the concentration in m/m for the following reasons, as expressed by Trauchessec:19 1. Measuring mass is more precise than measuring volume. 2. A real percentage can only be calculated using m/m or v/v. 3. The use of approximate dilution curves is avoided with m/m calculations. 4. With m/m calculations, there is no potential for errors caused by the existence of three types of mass per volume concentrations: m/v in QS, adding 100  ml of water to a mass of TCA, or diluting preexisting TCA solutions. 5. The m/m calculation does not produce values of TCA “concentrations” reaching 140%—which make no sense. 6. Finally, the size of TCA crystals, the compactness of the mass of crystals, and the temperature of the solution are elements that have to be taken into account when making m/v or m + v calculations. The m/m calculation does not depend on these parameters.

Easy TCA, Unideep, and Only Touch Solutions Easy TCA is a stabilized,26 homogeneous and adjuvanted solution with a final TCA concentration of 15% m/m, combined with alpha hydroxy acids (AHAs), antioxidants, vitamins, and saponins. Unideep is a TCA peel based on the same principles as Easy TCA and reaches the papillary dermis readily and evenly; it has a TCA concentration of 23% m/m. The application protocols for these two peels allow all depths to be reached. There is no point using higher concentrations that could cause complications (see Chapter 37).

TCA IN SIMPLE AQUEOUS SOLUTION Simply diluting TCA crystals in water produces an unstable solution whose characteristics have been discussed earlier in this chapter. TCA-SAS solutions are the cheapest a doctor can buy. They are also the most dangerous.27,28 It is clear from the literature on chemical peels how dangerous these solutions are; most photographs of serious complications show patients treated with TCA–SAS. It is clear that an experienced doctor can avoid most of the serious complications, but an inexperienced one can easily fall into every trap that these cheap solutions set. To paraphrase: While it is cheaper to spend the night on a park bench in a big city than to rent a room in a decent hotel, it is nonetheless true that you would get a much better and safer night’s sleep in a hotel room than you would in the park. Even though some of the world’s best peelers can use TCA–SAS with complete safety, it is still true that the vast majority of complications occur after the application of these cheap solutions. Some ill-informed doctors have ended up claiming that TCA simply cannot be used to treat melasma, for example.

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Reading the textbooks on chemical peels is very instructive, and the pictures of complications often reflect the complexity of using TCA–SAS correctly. Today’s new TCA peel solutions have been developed with a view to convenience and safety. The author can already hear reproaches from those who claim the contrary and are perfectly able to use TCA–SAS safely, but he can also hear the sobs and regrets of practitioners who listened to them and whose patients have suffered for it. The simple aqueous solution of TCA was born in the 19th century. It had its day; now practitioners should move on.

“ADJUVANTED” TCA Applying TCA–SAS to the skin causes frosting that is rarely even,28 especially when using intermediate concentrations. Applying TCA–SAS at 10% m/m does not usually cause any frosting and is almost risk-free; applying TCA–SAS at 50% m/m causes very rapid frosting whose depth is difficult to evaluate and control.29 Intermediate aqueous concentrations (e.g., at 25% or 30% m/m) do not penetrate evenly and produce intraepidermal peel zones next to peel zones to the papillary or reticular dermis. It is difficult to get even frosting, and the results of the peel are not homogeneous: undertreated areas are next to overtreated areas that could easily create problems with postinflammatory hyperpigmentation (PIH), hypopigmentation, or even scarring (Figure 12.7). Various adjuvants have been added to TCA to even out its effect. The term adjuvanted is used to describe a TCA solution to which something has been added to enhance or even out its action. Many different products have been added to TCA.

Glycerol Glycerol (Figure  12.8), also known as glycerine, glycerin, 1,2,3-propanetriol, or 1,2,3-trihydroxypropane, has a molecular weight of 92.09. It is often used as an antimicrobial preservative (in concentrations >20%), a humectant (≤ 30%), an emollient (≤ 30%), or a solvent. It is used in cosmetic products as well as in parenteral or oral preparations. Adding glycerol to a solution increases its viscosity. Glycerol, being an alcohol, potentially induces formation of esters components in the solution; esters have no peeling potential. Glycerol does not oxidize easily on contact with air. It is not toxic: after absorption by the digestive tract, it is metabolized into carbon dioxide and glycogen or is used for lipid synthesis. High doses of glycerol taken orally have a laxative effect and can cause headaches, hyperglycemia, thirst, and nausea. Glycerol is also used in the laboratory as a protein stabilizer (which seems paradoxical, considering that the effect sought by applying TCA is the destruction of proteins). Soft Peel was presented as a solution for improving the tolerance and effectiveness of TCA. Nevertheless, adding glycerol did not eliminate the need to prepare the skin beforehand, 3 weeks before the peel:30

Figure 12.7  Technical error during the treatment of stretch marks using an abrasive procedure (see Chapter 21). Typically, a halo of hyperpigmentation surrounds the depigmented area, which in turn surrounds a scar response. Hyperpigmentation develops where the peel solution goes slightly deeper than it should, and scars form where the peel is much too deep.

H

•

With a depigmenting formula to prevent pigmentary changes in patients with a high skin phototype (over Fitzpatrick IV); it was also necessary to wear a total sunblock before this peel, which suggests that pigmentary changes are common after this type of peel. With retinoids or benzoyl peroxide in cases of acne: treatment with isotretinoin was not given as a strict contraindication to Soft Peel on condition that the daily prescribed dose 2 or 3 weeks earlier did not exceed 0.3 mg/kg per day.

C

OH

H

C

OH

H

C

OH

H

Figure 12.8  Chemical structure of glycerol.

• •

H

With tretinoin at 0.05% once a day in the evening combined or not with glycolic acid to increase and even out penetration of the TCA and accelerate regeneration of the epidermis after the peel, which suggests that the solution did not penetrate evenly and readily and that healing was slow.

The total number of “soft peels” required was 5–10, with an interval of 8–21 days in between, depending on the depth reached by each peel. The peel solution had to be “neutralized” with water as soon as frosting occurred.31 It should be

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H H

C

H

H

C

OH

H

C

OH

H

Figure 12.11  Chemical structure of propylene glycol.

Propylene Glycol Figure 12.9  Effect of dilution on the pH of 5 ml of an organic acid solution at pH 2.7: 80 ml of water must be added before the pH rises a little more than 1 point.

remembered, however, that adding water to an acid solution does not neutralize it but simply dilutes it. The pH increases very slowly when the solution is diluted, and large quantities of water are needed (Figure 12.9). Rinsing with water was necessary, however, to remove the excess solution that was no longer needed after the appearance of frosting on the skin. It would be more accurate to say remove any surplus solution with water as soon as frosting appears instead of neutralize the acid. Without rinsing, the TCA in the TCA–glycerol solution would continue to destroy the skin proteins and deepen the effect of the peel. Choosing the right moment to rinse is therefore essential and has to be timed very carefully, which is not easy for an inexperienced doctor. Some formulations (called “composite” or “compositum”) still use solutions with glycerol and the postpeel rinsing technique, which is both restrictive and the source of errors. It is also important to make sure that the water does not carry the TCA into the eyes or onto the neck and décolletage, where it will cause an accidental peel.

Glyceryl Monooleate Some glycerol derivatives can be used as adjuvants. Glyceryl monooleate (Figure 12.10), for example, is a nonionic surfactant and polar lipid with a molecular weight of 356.55. It is a monoester of glycerol in which one of the hydroxy groups is replaced by a long side-chain derived from oleic acid (CH3(CH2)7CH = CH(CH2)7COOH).32

Propylene glycol (Figure 12.11), also known as 1,2-propanediol and 1,2-dihydroxypropane, has a molecular weight of 76.1. It is used as an antimicrobial preservative (at 15%–30%), a disinfectant, a humectant (at 15%), a solvent or co-solvent, and a stabilizer for vitamins, both in cosmetics and in parenteral pharmaceuticals (10%–60%). Although propylene glycol is considered to be nontoxic, parenteral administration of high doses can cause problems, especially in patients with renal insufficiency. Propylene glycol, being an alcohol, potentially induces formation of esters components in the solution; esters have no peeling potential. Its disinfecting power is slightly lower than that of ethanol. Propylene glycol is stable at low temperatures. At high temperatures, it tends to oxidize and form lactic acid, acetic acid, pyruvic acid, and propionaldehyde. Locally, propylene glycol is more of an irritant than glycerol, especially if it comes into contact with the mucous membranes or is used under occlusion. It is neither mutagenic nor teratogenic.

Stability of TCA Solutions with Glycerol or Propylene Glycol Attempts to stabilize TCA solutions by adding glycerol (“soft peeling”31) or propylene glycol improved the safety of TCA peels, although it did not necessarily make them completely stable. Moreover, the addition of glycerol or its derivatives was still empirical and varied from one doctor to another—more of a do-it-yourself approach than a professional one. It is difficult to compare the different solutions because the exact concentrations of these adjuvants were neither uniform nor even known for certain. Soft Peel involved the ad hoc combination of TCA at variable concentrations with the same quantity (volume) of glycerol.

Other Adjuvants Other attempts to stabilize and even out TCA were made in the 1990s.

H

O

H

C

O

H

C

OH

H

C

OH

C

C17H33

H

Figure 12.10  Chemical structure of glyceryl monooleate.

“Enzymatic” TCA An enzyme is, by definition, a protein. TCA coagulates proteins. It is therefore difficult to include active proteins and TCA in the same solution, because even if some enzymes are acid resistant (e.g., in the stomach), the conditions for acid resistance are strict and not reproducible in a TCA solution. To the author’s knowledge, there is no preparative approach that would allow proteins to be encapsulated in nanosomes, liposomes, cyclodextrins, and so on, to protect them from the coagulating action of concentrated TCA.

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Sorbitan Monolaurate Sorbitan monoesters are partial esters of sorbitol with fatty acids (monolaurate in this case). They have a molecular weight of between 346 and 964. Sorbitan monolaurate is widely used in cosmetics, the food industry, and pharmaceutical preparations. Sorbitan monoesters are non-ionic surfactants, and dissolving and dispersing agents. One of the problems of using sorbitan monoesters is that in the presence of strong acids (like TCA) they tend to form soaps that have no power to attack the skin. This is partly why TCA “adjuvanted” with sorbitan monolaurate is less aggressive for the skin. Phenoxyethanol Phenoxyethanol, C6H5OCH2CH2OH, also known as ethylene glycol monophenyl ether, 2-hydroxyethyl phenyl ether, 1-hydroxy2-phenoxyethane, 2-phenoxy-ethyl alcohol, and 2-phenoxyethanol, has a molecular weight of 138.16. Phenoxyethanol, being an alcohol, potentially induces formation of esters components in the solution; esters have no peeling potential. It is a simple disinfectant in the adjuvant solution, an antimicrobial agent that seems not to have a real adjuvant effect on the peel. Chelation of TCA Some TCA masks33 have been presented as “chelated” TCA. Chelation34 is a medical therapy that aims to detoxify the body of harmful minerals and metals. Chemically, chelation is the process by which an organic substance (the chelator) binds metal ions (iron, copper, lead, calcium, etc.) into inactive, nontoxic, and water-soluble complexes that are easily eliminated in the urine. Intravenous chelation therapy (e.g., with ethylenediamine tetra acetic acid, EDTA) is often used to treat poisoning with heavy metals, including lead. The use of the term chelation therefore seems inappropriate as far as TCA is concerned, and has no chemical basis because TCA is not a metal. The little information available states that chelation reduces the speed of penetration of TCA and therefore its depth of action.35 Might what we call chelation be partial inactivation of the TCA? The directions of use for Accu Peel state that a “process called chelation allows the TCA to reach an even depth at the same time as using lower concentrations of TCA.” Might chelation, on the contrary, be a process that activates the TCA? But how can TCA be activated? The directions for use of TCA Cream Peel tell us that, thanks to chelation, not only is this peel as deep and smooth (sic) as regular TCA but also that it uses much milder concentrations (the stakes are being raised) so there is less pain and stinging and healing is faster. Is chelation the ultimate answer for TCA? The Holy Grail of the peeler? The Plastic Surgery Group states that “chelation” of Accu Peel, on the contrary, provides a superficial peel that heals more quickly—which at least seems logical. Chelation is therefore presented as the ultimate solution to all the problems posed by TCA. The most scientific-sounding explanation seems to be of a specific technique where the TCA binds to metallic ions in bentonite clay. It is not therefore strictly chelation, which would imply the binding of metallic poisons and their elimination through urine. But it is partly true insofar as an organic substance (the TCA) binds with silicon and metal ions (aluminum and magnesium). Even if the process is the opposite of chelation—because in this case it is the TCA itself that is the chelating agent—this explanation merits closer examination to understand the possible interactions between the TCA and the structure of the clay.

TCA in Clay Masks TCA sometimes comes in the form of a clay paste. Generally, clays consist of two types of compounds: aluminum silicates (bentonites) and magnesium silicates (hectorites). Clays36 are made up of stacked three-layer platelets (Figure 12.12): a middle layer of magnesium oxide (in the case of hectorites) or aluminum oxide (in the case of bentonites) surrounded by two layers of silicon dioxide (silica). The lateral surfaces of each platelet are positively charged,37 and the lower and upper surfaces are negatively charged.38 The clay platelet therefore reacts like a dipole, and the different particles rearrange themselves depending on the electrical charges that encourage contact between the lateral surface and the upper surface. Clay has a “house of cards” structure, and macroscopically forms a coarse gel with a grainy texture in the aqueous phase. The TCA molecule is itself electrically neutral. When it is in an unbuffered solution, it more or less completely breaks up, releasing its proton (H+) into the solution, which then becomes acidic. The TCA, without its proton (i.e., trichloroacetate anion), has an overall negative charge that can therefore combine electrically with the positively charged lateral surfaces of the clay, while the positively charged protons will combine more readily with the lower and upper surfaces of the negatively charged clay particles (Figure 12.13). The protons therefore combine with the oxygen atoms of the silica molecules on the lower and upper surfaces, whereas the negatively charged trichloro-acetate anion will combine with the metallic cations on the other surfaces of the clay particles. This then explains how the TCA binds with metallic ions. It is easy to understand how this might stabilize the TCA, as once it has broken up, it binds electrically with the different parts of the clay particles. It is, however, difficult to understand the real clinical advantage of this combination, as the protons that produce the peeling effect are still attached to the part of the TCA that has not broken up or else they have to break away from the clay to be effective. It could then be argued that the protons (and the trichloroacetate) and the clay are relatively united and that the TCA in a clay mask will act more slowly and be less aggressive. It is difficult to reconcile this with the statement that a low-concentration TCA clay mask produces the same effect as a more concentrated water-based TCA in which all the molecules exert their peeling effect at the same time. It cannot seriously be claimed that a clay paste of “chelated” TCA at 20% is equivalent to any other TCA liquid at 45%–50%. Even then, it would be necessary to know whether the concentration is m/m, m/v, or m + v. It cannot possibly be m/m, as a TCA at 50% m/m is extremely aggressive and causes

+ + +

+ + +

– – – – – – – – – – – – – – – – – – – – + ++ + ++ ++ + ++ +

Silicon dioxide Aluminum or magnesium oxide Silicon dioxide

++++ ++++ ++++

Figure 12.12  Clays consist of a stack of platelets that are electrically linked. This diagram shows the typical structure of a clay platelet and its electrical charge.

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O O

O O

C

CL3

H+

++++

++++

+

+

++++

++++ Silicon dioxide

– – – – – – – – – – – – – – – – – – – –

+ + + + Aluminum or magnesium oxide ++++

++++

– – – – – – – – – – – – – – – – – –

Silicon dioxide

Silicon dioxide

++++

Silicon dioxide

++++

++++

++++

+

+

+ + + + Aluminum or magnesium oxide + + + +

+ + + + Aluminum or magnesium oxide ++++ +

+

+

++++

Silicon dioxide

+

+

+

++++

++++

– – – – – – – – – – – – – – – – – – – –

+

Silicon dioxide

++++

+

H+

++++

– – – – – – – – – – – – – – – – –

Silicon dioxide

Silicon dioxide

+

++++

++++

+ + + + Aluminum or magnesium oxide + + + + ++++

CL3

+

++++ Aluminum or magnesium oxide + + + +

Silicon dioxide

++++

++++

Silicon dioxide

O

– – – – – – – – – – – – – – – – –

+

++++

H+ H +

H+

+

+ +

H+ +

C

O C

CL3

Figure 12.13  A possible arrangement of TCA in a solution with clay in the gel phase, on the basis of electrical charges.

more complications than effective results. Besides, 20% TCA masks are marketed as superficial peels, which is incompatible with the gratuitous claim that “20% in mask form is equivalent to 50% in liquid form” but completely compatible with the scientific explanation given earlier. Another major problem comes from the fact that the clay mask forms a coarse and opaque layer: it is impossible to observe the effect of the TCA directly and continuously through the clay mask (Figure 12.14). One common method of monitoring the peel consists of using a tongue depressor to remove the clay from a small area to see if, or how much, frosting has occurred. If there is no frosting, the acidified clay is replaced. This examination is repeated after a few minutes or if the patient makes any comment. It should be noted that removing the clay with a spatula creates an abrasion on the skin where the acid can penetrate more deeply. The next time, therefore, the same area must be checked again as well as a different area. When a TCA paste is called “homogeneous,” it should not automatically be assumed that the TCA is distributed evenly, although it may well be. One should assume that the paste itself has a homogeneous consistency and is not grainy. It is possible—though not easy—to spread TCA homogeneously in a clay paste. However, the even distribution of TCA in a paste does not in itself guarantee that the acid will penetrate the skin evenly.

Figure 12.14  TCA green clay mask (TCArcil mask). The hands and forearms are covered in a clay paste layer that spreads easily.

Another argument that counters the claim that lower concentrations are more effective is that the application technique for a TCA mask involves degreasing the skin and applying glycolic acid or tretinoin beforehand.35 This makes the skin far more permeable and enhances the penetration of the TCA,39 which means being very careful about how long the paste remains in contact with the skin. Some TCA clay pastes are presented as causing simple erythema with no protein coagulation, but they nevertheless have a downtime of 6–8 days.35 The absence of frosting is compatible with a superficial peel but not with an improvement in the appearance of

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deep wrinkles, which can only be treated with a deep peel. Then again, a downtime of 6–8 days is not compatible with a superficial peel, as it is the same as the downtime following a “medium” TCA peel to the papillary dermis. The TCA mask is not the easiest40 or safest of peels, as it is not possible to check in real time whether the TCA is penetrating too deeply under the mask. It does, however, make application a little easier for doctors who doubt their ability to apply a superficial TCA peel evenly. We can therefore conclude by saying that TCA masks are easy to apply but difficult to monitor. Even if “chelation” makes the clay mask less aggressive, it is on the whole not as safe as an “open” TCA peel, which can be monitored at all times. The author’s experience with a TCA mask preceded by a glycolic acid mask is in the context of a regular medium-depth TCA peel to the papillary dermis.

HISTOLOGY Even though histological sections taken 30 minutes after the application of a medium-depth TCA peel on the skin have not revealed any skin necrosis, and even though histologically everything appears normal, it is certain that necrosis is taking place both clinically and chemically. The epidermis is functionally dead, although it appears to be histologically normal. Maybe this can be explained by the protein-coagulating action of the TCA: with conventional histology, it is not possible to see membrane proteins (essential to cell life) coagulating. It is only later on that necrosis can be detected histologically when the normal cell structure has radically changed as a result of its protein membranes becoming devitalized. The overall histological effect of a TCA peel consists of the destruction of the living cells of the epidermis and possibly the dermis (the depth of destruction depends on the concentration used). Abnormal keratinocytes are replaced by healthy cells from deep surviving islets of keratinocytes, the pilosebaceous units, and the sweat glands.41 As the skin reepithelializes, new collagen is formed. The depth of skin necrosis is directly proportional to the concentration of the TCA. Necrosis should not be the only endpoint of a TCA peel—stimulation also plays an important role. Repeated application of less concentrated TCA helps rebuild the papillary dermis directly and/or indirectly as a result of the repeated dermal irritation of the peel-induced inflammation. It is possible to reach the dermis using a low-concentration solution applied to an epidermis that has been made temporarily more permeable by a prior peel or “robust” preparation. TCA peels allow different depths of penetration to be reached (Table 12.3). A study by Roenigk41 shows that regeneration of dermal collagen starts within 2–3 weeks. The increase in papillary dermal collagen and the production of elastic fibers continues for

6 months. Another study42 on mice artificially photoaged by exposure to UV rays compared the histological effects of four different types of peels against a control group: • • • •

50% glycolic acid. 30% TCA (m/v or m + v not specified). 50% TCA (m/v or m + v not specified). Phenol peel (Baker Gordon’s formula).

In all of the peel groups, the concentration of collagen increased from the 3rd day, fell around the 7th day, and reached a positive peak around the 28th day. There was more of an increase with the TCA and phenol peels than with the glycolic acid. There was a significant increase in the concentration of glycosaminoglycans with the 50% TCA and phenol at 14 and 28 days. On the 60th day, the dermal concentrations both of collagen and glycosaminoglycans had returned to their original values in all of the groups. These findings cannot be considered as proof that these peels are not clinically effective, as the structure of the epidermis and dermis improved histologically, the collagen fibers were significantly rearranged in the papillary and reticular dermis, and elastotic material disappeared in the deep TCA and phenol groups. At the same time, it was noticed that the elastic fibers rearranged themselves. These positive histological changes are more marked in the deep TCA and phenol groups than in the other peel groups. As for the global effect, the study shows an overall increase in dermal thickness with the deeper peels. In the long term, the histological changes brought about by TCA are temporary when the TCA penetrates superficially and long lasting when the TCA penetrates to the papillary dermis at least. Dermal fibroplasia causes hypertrophic scarring, scar adhesions, and keloids. Black or dark skins are more likely to develop this type of reaction. The shoulder girdle and the lower thorax are both high-risk areas, as is the jaw area on the face. This type of scarring does not occur when necrosis goes no further than the upper reticular dermis. Apart from a few exceptional cases (e.g., Ehlers–Danlos syndrome), the destruction of the papillary dermis does not cause hypertrophic scarring. There is a risk of skin atrophy when all of the appendages of a treated area undergo necrosis. The skin does not have any source of supply to regenerate cells quickly. The keratinocyte clones can only come from the (distant) edges of the necrotic areas; they cannot be produced in sufficient numbers for rapid skin regeneration if the lesion is more than a few centimeters in diameter. Lesions smaller than 1 cm in diameter, even in the deep reticular dermis, do not pose a high risk of scarring unless there is a secondary infection or the patient scratches the scabs.

Table 12.3  The Depths of Peelings, Type of Action, and Duration of Change Level of destruction

Type of action

Duration of change

Upper stratum corneum Intraepidermal Basal layer Grenz zone Papillary dermis Upper reticular dermis (with vertical fibers) Deep reticular dermis (with horizontal fibers) Hypodermis

Exfoliation Partial destruction of the epidermis Destruction of the basal layer Destruction of the Grenz zone Destruction of the papillary dermis Destruction of the upper reticular dermis Destruction of the deep reticular dermis Scarring

Very temporary Very temporary Temporary Medium duration Long lasting Permanent Permanent; risk of scarring Permanent

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When all of the appendages have undergone necrosis, the melanocyte reserve as well as the keratinocyte reserve suffers, and scarring will be hypopigmented or unpigmented.

SELECTION OF THE RIGHT TCA CONCENTRATION Many books have been written about TCA in water application techniques, and this book does not attempt to rewrite them. Nevertheless, the author would like to point out a few important details. The main questions posed by new practitioners are: What is the best TCA concentration? How many coats should be applied? How often? How and when should I neutralize? These are not simple questions, and providing simple answers would give the appearance that selecting the right TCA concentration is similar to inflexibly following an easy recipe. The easiest of these questions to answer is about when to neutralize. TCA action cannot be neutralized (see Chapter 3). The best TCA concentration is, simply, the one we selected. The point is to know how to select a TCA concentration and how to calculate it. In short, we are using chemical products, and we should keep our calculations scientifically reproducible and accurate. Only the w/w calculation makes sense for this point of view, even if the w/v or the v/v is more common in the United States. Doctors must select the right concentration for each patient. Remember two points: First, a patient with thick skin will need more acid than one with thin skin. Second, the most important factor is the total quantity of acid that is able to interact with proteins. A highly concentrated acid applied to thin skin might burn it immediately, but the same concentration will do a great job on thick, oily skin. Looking at the thickness of the skin fold in the area of the malar bone gives us a simple clinical appreciation of skin thickness: if the fold is 1 cm thick, the skin is considered “normal”; if it is less than 1 cm, the skin is thin; and if it is more than 1 cm, the skin is thick. Thin skin is more sensitive to acids than thick skin, and remembering this fact can help in selecting the TCA concentration. However, transepidermal acid penetration does not depend only on skin thickness; it also depends on the type of acid. A “big” acid will penetrate faster than a “small” one—for example, long fatty acids penetrate more slowly through the skin than lactic acid. Transepidermal penetration also depends on skin permeability and prepeel skin conditioning. Thick oily skin,43 after skin conditioning44 and acetone45 degreasing, can become as permeable as thin skin. Skin dermabrasion (preferably using 3M wet or dry sandpaper 200) easily removes the stratum corneum and largely deepens the action of the acids. The author uses a complex technique called “anterior chemabrasion” together with Easy TCA to treat acne scars and old atrophic and deep stretch marks, with excellent results. Another technique, that the author calls a “pixel peel,” consists of multiperforating the stratum corneum using a microneedling device (needles range from 0.25 to 2 mm), immediately before applying a TCA peel. This technique is described in Chapter 38. Many actions can affect skin permeability. If the patient scrubbed his or her face before the appointment, it will be more permeable. Waxing the skin before the peel results in more permeability. On the other hand, applying an oily moisturizer,

sunscreen, or a gel containing hyaluronic acid can reduce skin permeability. How many coats of TCA should be applied? Every practitioner would like to have a clear, simple answer to this question. Unfortunately, the number of coats depends on the permeability of each patient’s skin and the TCA concentration of the solution. Focusing solely on the concentration is risky because there are so many other variables to consider in determining how many coats of the solution should be applied. Two methods can be used to determine the number of coats. The first one consists of guessing the right concentration for a patient’s skin and hoping that the acid’s action will stop at the right depth. The second one, which the author prefers, is to use very few (three) different concentrations and apply several coats until you see the desired frosting. This method results in a peel to the desired level without the possibility of error. Consider the following scenario. A phototype 2 patient has skin of normal thickness and permeability and has undergone classic prepeel conditioning. The doctor would like to reach the Grenz zone. He or she can decide to apply a 30% TCA (w/w? w/v? etc.). What the doctor cannot decide is how deep this acid will penetrate by itself. The doctor can rub the product on the patient’s skin and see the result at the end, knowing that more than one coat of a 30% w/w TCA solution on such skin can be dangerous, or on the contrary can be insufficient. The action of the acid solution can be seen, but only when the damage is done and irreversible. This is why there are so many reports of skin damage after TCA peels and why some authors erroneously claim that TCA is not adapted to melasma treatment. However, the results depend on the application technique and prepeel decisions. A 30% w/w TCA solution rubbed once on normal thickness skin after prepeel conditioning usually results in a pink-white uniform frosting, showing a papillary dermis penetration. The doctor surpassed the target of the Grenz zone. Another possibility for the same patient is to use a lower concentration TCA solution, such as a 15% w/w solution. A first coat induced only erythema. The doctor realizes that the skin was less permeable than guessed and that he reached the epidermal level only. When the patient’s skin has dried by evaporation, the doctor will apply another coat of the same acid solution. The skin will show small “frosting points,” and he will deduce that the solution reached the basal layer depth. The next coat will induce a cloudy frosting, a sign of the penetration of the acids into the Grenz zone. When the doctor sees the cloudy frosting, he stops the TCA solution application and knows that the peel reached exactly the desired depth. Easy, isn’t it? Usually, doctors focus on good prepeel conditioning for better, more even penetration and faster regeneration. Nevertheless, more attention should be paid to the immediate postpeel event—the inflammatory reaction that begins immediately after the first drop of acid contacts the skin. This inflammatory reaction is necessary but also dangerous. A peel that induces no inflammatory reaction is not efficient, because inflammation is the real skin rebuilding source. At the same time, if this inflammation is uncontrolled, or selfmaintained, it begins a vicious cycle in which the free radicals and the pro-inflammatory components liberated from cell destruction induce more cell damage and more inflammation. This inflammatory cycle is responsible for a lengthy stimulation of melanocytes that will respond by synthesizing more melanin and inducing PIH.

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Performing a peel can present a booby trap. You might think that the pharmacist prepared a 30% mass by volume (w/v) solution, but he prepared it w/w (which is stronger). Your patient might have practiced virtual mesotherapy46 or a depilation face wax the day before the peel; if so, the patient’s skin will be permeabilized, acids will penetrate faster and deeper, and an overpeel and side effects will result. The author avoids these problems by using a safer and easier formula: Easy TCA peel.47 This formula allows me to avoid the long and uncomfortable prepeel conditioning phase in the majority of cases48 because it can be applied using the progressive technique explained above; it uses a specific postpeel mask, so I am able to control the postpeel inflammatory reaction; and it will be repeated once a week for 4 weeks. Each peel, performed up to frosting points or maximum local frosting clouds, treats an eventual pigment rebound induced by the preceding peel. The Easy TCA postpeel mask is a complex formula containing vitamins, trace elements, strong antioxidants, tretinoin precursors, selenio-methionin, antityrosinases, and more. This cream is applied once by the practitioner, immediately after the desired frosting has been seen. It immediately scavenges free radicals, stopping the excess inflammatory reaction and the burning sensation induced by the Easy TCA peel solution. It introduces into the skin elements that can help the skin regenerate faster and lowers the tyrosinase activity. Postpeel penetration of ingredients is dramatically modified by the previous application of the peeling solution. The postpeel rate of penetration is much higher than the normal skin rate. The skin is much more permeable during the postpeel period: sebum and corneocytes no longer act as a barrier, and water soluble ingredients can rapidly pass through this modified epidermis. Large quantities of stimulating factors and antioxidants can reach the dermis. It is clinically evident that the residual inflammatory reaction is strong enough to stimulate the skin’s rebuilding but not strong and long enough to stimulate melanocytes or to slow down the basal layer regenerative sequences. Some practitioners have wondered how this cream can immediately stop the burning sensation if it is not a neutralizer (this cream is not basic) and if the frosting signs continue to appear normally, even after the postpeel mask has been applied. Unfortunately, I cannot provide a scientific answer, but I have a theory: the postpeel mask’s antioxidant properties are such that they break the pro-inflammatory immediate postpeel reaction. It is well known that inflammatory reaction typically is a major component of pain. To summarize, the Easy TCA formula offers many benefits. It is easy to perform (10 minutes is the maximum time needed for the face and neck), it is inexpensive, it is not painful (no anesthesia or painkiller is needed), it requires no skin conditioning (the peeling solution and postpeel mask do the work), it does not interrupt the patient’s social life (desquamation looks like a sunburn), there is no phototype limitation (phototypes 1–6 are allowed), and it presents few side effects (an average 1.7% of transitory side effects, with duration less than 8 days49). This peel, applied according to different protocols, allows for a wide spectrum of depths of action and therapeutic indications, from active acne to pigmentations and acne scars, photoaging, and old and deep stretch marks.50 It can be applied to both the face and the body. Moreover, it can be performed during the same session as other treatments, including laser, intense pulsed light (IPL), mesotherapy, radiofrequencies, depilation, botulinic toxin,51 surgery, and telangiectasies

treatment. Hyaluronic acid injections for wrinkle treatment are even allowed, immediately before the Easy TCA peel.52 As mentioned earlier in this chapter, the author uses three different concentrations of Easy TCA. The primary concentration, used on approximately 80%–85% of patients, is Easy TCA solution containing vitamins, antioxidants, AHAs and saponines, together with 15% w/w TCA. Advantages include the postpeel mask’s protection against postpeel inflammatory reactions and the ability to immediately stop postpeel burning. Depending on the number of coats applied, the peel can reach into the epidermis, basal layer, Grenz zone, or even the papillary dermis. Papillary dermis peels require many coats of Easy TCA, which may be uncomfortable for the patient. The author prefers to use a derivative of Easy TCA to reach the papillary dermis: Unideep.53 It has the same structure as Easy TCA; it consists of a 23% w/w TCA and an adapted postpeel mask with the same function as the Easy TCA. To go very deep into the skin to treat focal old lentigine or solar keratoses, successive focal coats of Easy TCA or Unideep can be applied, but the work is easier using the Only Touch peel (OTP). It has the same qualitative base solution as Unideep but contains 45% w/w TCA. Only Touch has no postpeel mask and has to be used in combination with Easy TCA to avoid postpeel inflammation. Using OTP without Easy TCA induces PIH in more than 60% of patients. When Only Touch is done immediately before Easy TCA, the percentage of PIH is lower: a maximum of 10% if the protocol is respected, even lower if the patient does not scratch the scabs. OTP can be used on small surfaces only; it is a focal peeling for treating lesions whose diameter is than 1 cm. OTP is applied, avoiding excess product, with a fine cotton bud or a wooden toothpick or skewer. The practitioner should touch the lesion to be treated quickly, precisely, and once only with the chosen applicator and wait until the acid solution has dried completely. A significant frosting will appear quickly on the face, and slowly on the body. If no such frosting occurs, however, the practitioner can repeat the application cautiously a few minutes after the solution has dried. Immediately after the frosting occurs, apply the first of the four basic protocols of Easy TCA on the entire treated area, including the area where OTP has just been applied, to obtain an even result and limit the risk of side effects.

OCCLUSION OF TCA Following the example of phenol, it has been suggested that occluding TCA could potentially enhance penetration. A histological study by Stegman54 in 1980 revealed that occlusion does in fact increase the depth of action of phenol but actually reduces that of TCA. An occlusive dressing applied quickly after a phenol peel helps it macerate and deepens its action. An occlusive dressing applied immediately after TCA creates a barrier to epidermal water evaporation and to the water in the solution itself. Under occlusion, this water accumulates in the uppermost layers of the skin, where it dilutes the TCA fairly rapidly. With phenol, this slight dilution enhances its penetration. An occlusive dressing applied 30 minutes after TCA does not dilute the acid, as it has had enough time to coagulate the proteins in the skin and neutralize itself by combining with the proteins before occlusion could dilute it. Applying a greasy substance, such as Vaseline or an antibiotic ointment, immediately after a TCA peel is equivalent to occlusion and can reduce the depth of necrosis caused by the TCA.

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INCREASING THE PERMEABILITY OF THE STRATUM CORNEUM The thicker the stratum corneum, the less the TCA penetrates, and any method used to make the stratum corneum thinner before applying TCA deepens its action. Applying tretinoin for 2 weeks before a TCA peel thins the skin and causes the keratinocytes and corneocytes to dedifferentiate. Acetone degreases the skin and causes chemical changes in the membrane lipids, which increase the skin’s permeability and the depth of action of the peels. Applying a given concentration of TCA to thin and permeable skin will cause deeper necrosis than application to thick and impermeable skin. Another way of increasing the depth of skin necrosis is to use higher concentrations of TCA, but this method produces variable results because of the wide variation in penetration of TCA in an aqueous solution. The risk of scarring increases with the concentration of the TCA.

NOTES 1. The alpha carbon atom is that adjacent to the COOH group (as with alpha hydroxy acids; see Chapter 6). 2. Which means that at a pH of 4.76, 50% acetic acid in an aqueous solution is in the form of acetate. 3. “Glacial” acetic acid is 100% acetic acid. It is so called because of its tendency to solidify near room temperature (its melting point is 16.7°C). 4. Through the accumulation of lactic and/or glycolic acid. Tubular necrosis develops rapidly. 5. Due to precipitation of myoglobin and oxalate crystals in the renal tubules. 6. Bismuth Ch. Toxicologie Clinique. 5th ed. Paris: Editions Médecine–Sciences, Flammarion, 2000. 7. Ketoacetic acid, oxoethanoic acid. 8. Oxalic acid (ethandioic acid) is HOOC.COOH, with pKa1 = 1.23 and pKa2 = 4.19. 9. Glycolic acid is HO.CH2.COOH, with pKa = 3.83 (see Chapter 6). Glyoxylate is converted into glycolate by glyoxylate reductase. 10. Glycine (aminoacetic acid, aminoethanoic acid) is H2N.CH2. COOH, with pKa = 2.4. It is transaminated by an alanine–glyoxylate aminotransferase. The glycine can then be incorporated into proteins and used for serine synthesis or simply be degraded. 11. DCA was administered orally in the drinking water of rodents. No specific data have been reported in humans. 12. Kitamura N, Ota Y, Mimura K. Effects of diisopropylamine dichloroacetate on proliferation and differentiation of normal keratinocytes in vitro. Skin Pharmacology and Applied Skin Physiology. 1999; 12: 317–325. 13. Johnson K, with the Canadian Task Force on the Periodic Health Examination. Periodic Health Examination, 1995 update: 1. Screening for human papillomavirus infection in asymptotic women. CMAJ. 1995; 152: 483–93. 14. Although using the new phenol formulas seems to be safer (see Chapter 36). 15. TCA is often found in drinking water as a by-product of disinfection. 16. Obtained by simple dilution of TCA crystals in water. 17. The author begs any chemist reading this to forgive this explanatory shortcut. 18. Trauchessec JM, Pissot F. Solution d’acide trichloracétique masse par masse pour peelings dermatologiques, nécessité d’une formulation explicite pour les solutions d’acide trichloracétique. 18th réunion du GRCD, Perpignan, 9 Septembre 1995: 28–38.

19. Trauchessec JM, Pissot F. Solutions d’acide trichloracétique masse par masse pour peelings dermatologique. Les Nouvelles Dermatologiques. 1996; 15: 252–55. 20. One apple plus one apple equals two apples, whereas one apple plus one pineapple equals two pieces of fruit. 21. According to Roenigk, applying TCA at 70% m/v on the face usually causes scarring, while in gynecology, treating vaginal or cervical condylomas does not produce any scarring. McCollough EG, Langsdon PR, Maloney BP. Chemical Peel with Phenol. Roenigk RK, Roenigk HH (Eds.). Dermatologic Surgery, Principles and Practice. 2nd ed. Oxford: Marcel Dekker, 1996: 1147–60. 22. Rereading the textbooks that I used at the beginning of my career as a “peeler” makes me realize why it was so difficult to get an overall grasp of the field and to understand the consistency of the technique. 23. Brody H, Stegman S. Histological study by Harold Brody and Samuel Stegman, at 3, 30, and 90 days. 24. TCA therefore does not have an “all or nothing” action. 25. McCollough EG, Langsdon PR, Maloney BP. Chemical Peel with Phenol. In: Roenigk RK, Roenigk HH (Eds.). Dermatologic Surgery, Principles and Practice. 2nd ed. Oxford: Marcel Dekker, 1996: 1147–60. 26. Easy TCA and Unideep consist of peel solutions as well as a postpeel cream whose ingredients help achieve better results and avoid complications. Only Touch consists of a solution alone but has to be combined with Easy TCA or Unideep, and thus benefits from the application of the postpeel cream of these peels as well. 27. Chiarello SE, Resnik BI, Resnik SS. The TCA masque. A new cream formulation used alone and in combination with Jessner’s solution. Dermatological Surgery. 1996; 22: 687–90. 28. Vergereau R, Trauchessec JM, Peyronnet B. Le new peel. Le Journal de Médecine Esthétique et de Chirurgie Dermatologique. 1990; XXII (68): 243–55. 29. See the many previously published works on the semiology of TCA–SAS peels. 30. See Chapter 2. 31. Peyronnet B, Trauchessec JM, Vergereau R. Le peeling doux. Le Journal de Médecine Esthétique et de Chirurgie Dermatologique. 1991; XXIII (69); 33–37. 32. In fact, the commercially available “glyceryl monooleate” is a mixture of esters of glycerol with a number of fatty acids (longchain carboxylic acids), the major component of which is the monoester with oleic acid. 33. TCA Masque, Accu Peel cream, and TCA cream peel. 34. From the Greek chele, meaning “claw.” 35. Cabaní I. Nuestra experiencia en la aplicación de la nueva máscara de TCA. Medicina Estética (SEME). 1995; 39: 25–29. 36. A clay is a friable sedimentary rock that can be molded when soaked in water. 37. Thanks to the metallic cations of the crystalline lattice. 38. Thanks to the oxygen atoms of the silica molecules. 39. Which would be pointless—even dangerous—if the TCA mask at 20% had the same effect as 50% TCA. 40. Prior application of a glycolic acid mask, and close and difficult monitoring of the contact time and downtime are necessary. 41. McCollough EG, Langsdon PR, Maloney BP. Chemical Peel with Phenol. In: Roenigk RK, Roenigk HH (Eds.). Dermatologic Surgery, Principles and Practice. 2nd ed. Oxford: Marcel Dekker, 1996: 1147–60. 42. Butler P, Gonzales S, Randolp M, et al. Quantitative and qualitative effects of chemical peeling on photo aged skin: An experimental study. Plastic and Reconstructive Surgery. 2001; 107: 222–28. 43. Skin fold = more than 1 cm. 44. Glycolic acid to reduce stratum corneum thickness + tretinoin for stimulating basal layer turnover and regeneration and for reducing the stratum corneum permeability: this kind of prepeel conditioning makes the skin much more permeable.

88   Textbook of Chemical Peels 45. Note that acetone not only degreases the skin but also begins a protein denaturation that makes the skin more permeable. 46. Virtual mesotherapy: slight abrasion using sandpaper, application of specific vitamins and other elements to the skin, use of Excellderm (nonthermogenic radiofrequencies for inducing an intracellular penetration). See www.aestheticdermal.com. 47. See this book or www.skintech.info. 48. I would use a prepeel conditioning only in specific cases, such as for a phototype 4 or 5 patient with a long history of familial melasma. 49. Unpublished statistic established from a total amount of 5,000 peeling sessions in Clinica Hera, Empuriabrava, Spain: 28 transitory, easy-to-treat side effects. No definitive side effect. 50. See: www.estetik.com, left column, treatment tips, peelings, for a complete description of active acne, stretch mark, and melasma treatments, along with the protocol for local phenol peels around the eyes and lips.

51. Ten minutes after botulinic toxin injection, Easy TCA (as a basal layer peel) can be performed. The author has never seen migration or shorter results after this association. 52. The author also read the HA notice for injection, which stated not to perform peelings after HA injections. Nevertheless, this recommendation is valid only because of the huge release of free radicals after usual peelings. Free radicals rapidly damage the HA polymer, breaking it and shortening its life. The Easy TCA postpeel mask scavenges free radicals at the same time they are produced, which can stop self-maintained free radical reactions that may damage the HA polymer. 53. Easy TCA, Unideep, and Only Touch are peels developed by Skin Tech, based on the author’s formulas. 54. Stegman SJ. A study of dermabrasion and chemical peels in an animal model. Journal of Dermatologic Surgery and Oncology. 1980; 6(6): 490–97.

13 Trichloroacetic acid Indications and contraindications MAIN INDICATIONS FOR TRICHLOROACETIC ACID Trichloroacetic acid (TCA) is an extremely versatile peel that can reach all depths and can be applied to all skin types, on all parts of the body and in many indications. Using solutions that are properly prepared and following strict protocols ensures a safe and effective peel. Repeating several easy peels, such as Easy TCA, can boost collagen and elastin production to the same degree as a deeper peel; repetition may even be preferable to using a more aggressive peel when the aim is to stimulate the skin and renew the epidermis, as is the case in the treatment of photoaging. On the other hand, when the desired effect is destruction of deeper layers of the dermis and epidermis to eliminate certain lesions, a single deeper peel may be a better indication than repeating several peels to the Grenz zone, as is the case when treating lentigines and mixed or dermal melasma.

Folds and Wrinkles Deep wrinkles and folds are not a good indication for TCA peels: • •

• •

Folds cannot be treated by peels and require surgery, dermal fillers, or thread lifts. Deep nasolabial folds and marionette lines do not always respond to phenol. Dynamic wrinkles respond well to a combination of botulinum toxin and peels: the peels restructure the epidermis and the dermis on an unmoving base and the clinical results are better when these two treatments are combined than when used alone. Fine sun-related wrinkles respond well to TCA, but deeper ones respond better to phenol. Wrinkles around the mouth and eyes are very poor indications for TCA, even in high concentrations; phenol is far more effective (see Chapter 36).

Photoaging Early photoaging (Figure  13.1) is one of the best indications for a TCA peel. In short, it improves and evens out the complexion, reduces or eliminates lentigines, improves elastosis and fine lines, improves skin tone, and generally brightens the skin. TCA peels have often been combined with tretinoin in this indication (see Chapter 2). Photoaging on the hands is an excellent and easy indication for TCA (see the next section and Figure 13.3). Solar Elastosis The papillary dermis is sometimes so atrophic that the epidermis appears to be lying directly on the middle dermis, without the intervening Grenz zone. The epidermis then becomes

“too big” for the underlying dermis, and wrinkles appear—like baggy clothes that crease on a body that has grown too thin. In theory, only a very deep peel can treat solar elastosis, by producing enough good-quality collagen and elastin in the papillary dermis to fill the atrophied dermis and bury the sun-damaged fibers deep down (see Chapter 26). Repeating certain types of peel to the Grenz zone1 once a week may be effective enough to improve the appearance of the skin without the downtime that inevitably follows medium or deep peels. Of course, the deeper peels will be more effective; there is no comparison between the results of a phenol peel and those of an alpha hydroxy acid (AHA), resorcinol, or TCA peel! On the other hand, dermatologically and toxicologically, phenol is a risky option for treating anything but facial skin. Body skin only benefits from other agents. Solar elastosis appears in several forms. It starts with the appearance of limited areas of elastosis that as yet have no or little clinical expression. Its maximum expression is seen when the skin has a cobblestone appearance (Figure 13.2). The type of treatment depends on whether the elastosis is in its very early stages or if it is more advanced (Figure  13.2). Early elastosis, which is characterized by very fine lines and an uneven complexion, can be treated successfully with four Easy TCA peels or one Unideep peel, while advanced elastosis can only benefit from a deep reticular peel (full-face Lip & Eyelid Formula) and a major restructuring of the skin. TCA would have no effect on the deep wrinkles in Figure  13.2, no matter which concentration, adjuvants, or other combined treatments were used. Solar elastosis often affects the legs if they are frequently exposed to the sun, which is the case with women who wear skirts. The skin between the knee and the malleolus is sometimes affected by visible elastosis that can be improved by combining abrasion and Easy Phytic solution (see Chapter 11). The hands and forearms respond extremely well to Easy TCA, with no side effects (Figure 13.3). Lentiginosis2 TCA is effective in treating solar lentigines. The concentration of the TCA is chosen depending on the assumed depth of the lentigo. Relatively superficial lentigines are easily treated with Easy TCA (Figure 13.4). Lentigines of medium depth respond to Unideep. Lentigines originating from the deepest dermal papillae and embedded deep in the dermis only respond to very concentrated TCA (Only Touch), or even phenol (Lip & Eyelid Formula), applied locally and combined with Easy TCA (or Unideep) to even out the results and treat the smaller subclinical lesions (Figure 13.5). It should be noted that a TCA peel, even to the papillary dermis, does not always treat lentigines definitively and that several peels to the papillary dermis may be necessary for long-term results.

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Figure 13.1  Early photoaging: a good indication for TCA.

Figure 13.3  Overall rejuvenation of the hands after four sessions of Easy TCA at a rate of one session every 2 weeks.

Figure 13.2  Solar elastosis (skin with a cobblestone appearance): this is not the best indication for TCA.

Perioral Wrinkles Very fine lines around the mouth can be improved by a combination of filling techniques (e.g., hyaluronic acid) and one or more TCA peels to the papillary dermis, but the results achieved with TCA never equal or even come anywhere near those achieved with phenol, which is preferred in chemical labioplasty or cheiloplasty (see Chapter 36) in combination with botulinum toxin, if possible. Prevention of Skin Aging The wisest patients go to see their doctor before the clinical signs of aging appear and seek advice on how to prevent skin aging. The preventive treatments that might be suggested to

(a)

(b)

Figure 13.4  Lentiginosis and photoaging. (a) Before treatment, there are about 40 lentigines and/or actinic keratoses. (b) After four sessions of Easy TCA peels to the Grenz zone, there are only about 10 lentigines/keratoses left. The signs of photoaging are visibly reduced: fine lines, quality of the skin, improved eyelid tension, etc.

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(a)

(c)

(b)

(d)

Figure 13.5  Photoaging, actinic keratosis, and lentigines. (a) Before and (b) after a peel to the papillary dermis with TCA (Unideep) and phenol (Lip & Eyelid Formula) around the mouth and on the large lentigo on the left temple only. (c) Before and (d) on the 6th day after the peel. For more details, see Chapter 23.

these patients are straightforward and superficial procedures that do not disrupt their social lives too much. They may simply be prescribed cosmeceuticals: DHEA-Phyto, Actilift (dimethylaminoethanol (DMAE) cream), Renutriv ACE Lipoic Complex (an antioxidant), or Vit. E Anti-oxydant (a hydrating antioxidant). These cosmeceuticals should be combined with sun protection against UVA and UVB. A series of AHA peels or TCA peels to the basal layer of the epidermis can be repeated on a yearly basis. If the signs of aging are beginning to show clinically, Easy Phytic solution can be extremely beneficial. When the signs are more obvious, Easy TCA is the best choice of peel (Figure 13.6). Very obvious photoaging can benefit from Unideep, a papillary intraepidermal peel. An excellent treatment for preventing photoaging is a combination of a mesolift3 and a peel, sometimes called a “mesopeel”: a peel and a mesolift are used alternatively every other week or sometimes even in the same session when mesotherapy is combined with Easy TCA. The need for a surgical facelift or a deep phenol peel can be put off for several years.

Melasma and Chloasma Melasma (Figure 13.7) is a common acquired hyperpigmentation disorder of the face, neck, and forearms. It is usually symmetrical. The density of color in the hyperpigmented area can vary but is clearly delimited. Patients with a dark skin phototype are more prone and can get melasma earlier in life than those with light skin phototypes.4 Melasma appears almost exclusively on areas of skin that have been exposed to the sun. It can be of the types listed in Table 13.1. The cause of melasma is still widely debated, and potential pathogenic factors include the influence of UVs, the hyperpigmenting effect of some cosmetics,6 genetic predisposition, hormone therapy, and pregnancy.7 Estrogens and possibly progestogens can trigger melasma. Topical treatments for melasma usually include tyrosinase inhibitors, with or without tretinoin or one of its precursors. Azelaic acid is also a viable treatment option. A corticosteroid can be combined with it to counter any potential

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Figure 13.6  Early photoaging: treatment of rosacea on the cheeks with a radiofrequency device (Ellman) and four applications of Easy TCA (basic protocol). Daily care: Vit. E Anti-oxydant cream.

Figure 13.7  Melasma on the forehead: centrofacial. Other kinds of melasma include malar and mandibular.

Table 13.1  Types of Melasma Purely epidermal

Dermal

Mixed epidermal–dermal

There is a lot of melanin in the basal and suprabasal layers of the epidermis. It is occasionally found throughout the epidermis. A Wood’s light5 increases the contrast between the melasma and normal skin. This is the most common type of melasma. Melanin accumulates in the macrophages of the papillary and/or reticular dermis. A Wood’s light does not increase the contrast. Wood’s light accentuates the contrast in some areas and not in others, but an “epidermal” area can hide an “underlying dermal” area.

active inflammation. Lasers, intense pulsed light (IPL), dermabrasion, and microdermabrasion also have been suggested but often cause postinflammatory hyperpigmentation (PIH). TCA can be an excellent treatment for melasma as it eliminates the melanin stored in the papillary dermis and epidermis (Figure 13.8). Mesotherapy has been recently reputed as an effective treatment of melasma.8 If the melanin responsible for the melasma is too deep, TCA will only be effective after many repeated sessions. In any event, the TCA peel must be combined with effective sun protection and appropriate postpeel care in the long term. Simple aqueous solutions of TCA also require the skin to be prepared, to even out penetration and prevent common pigmentary changes. See Chapter 16 for the protocol for treating melasma.

Postinflammatory Hyperpigmentation and Berloque Dermatitis PIH (Figure 13.9) and berloque dermatitis9 usually respond well to TCA; they can be treated in the same way as melasma but have a better prognosis as the original trauma disappears after treatment, unlike melasma, which often persists or recurs.

Freckles Freckles (Figure 13.10) are small, clearly delimited, benign pigmented macules that appear on areas of sun-exposed skin in patients with a light skin phototype. They are never present at birth but can start to appear from the age of 3 years, and there is an autosomal dominant pattern of genetic transmission. They result from melanocyte hypertrophy, although not from an increase in melanocyte numbers. In the basal and suprabasal layers, more melanin is synthesized and transferred between the melanocytes and keratinocytes. This increased melanin synthesis could result from melanocyte clones that have mutated following UV exposure. The structure of the epidermis remains normal, apart from the parabasal keratinocytes,

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(a)

(b)

(c)

(d)

Figure 13.8  Melasma on the forehead in a patient with skin phototype VI: (a) The condition before peeling. (b) Results of the following treatment: two sessions of Easy TCA to the Grenz zone, combined with Blending Bleaching Cream. As the results were unsatisfactory, the practitioner decided to use a deeper treatment. After two Easy TCA peels, the patient was given two Unideep peels to the papillary dermis, (c) still combined with Blending Bleaching Cream and Melablock 50+. The peel to the papillary dermis was applied locally to the most resistant parts of the melasma. (d) End result.

Figure 13.10  Freckles.

Figure 13.9  Postinflammatory hyperpigmentation after a road accident (see Chapter 5).

which contain more melanin in relation to the neighboring unpigmented cells. A peel to the basal layer lightens the freckles, sometimes only temporarily. A peel to the Grenz zone removes many freckles and lightens others. A peel to the papillary or reticular dermis eliminates freckles altogether (Figure 13.11). Easy TCA, Easy TCA PC, Unideep (TCA), and Lip & Eyelid (phenol) can all be used as treatments for freckles, although phenol will generally not be used as the TCA can eliminate them by itself. Other treatments have been suggested. As freckles

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(40%–50% m/m) often produce only temporary or incomplete results. Figure  13.12 shows how flat warts on the back of the hand reacted to a combined treatment of Only Touch and Easy TCA. Smaller flat warts can disappear completely, as can subclinical flat warts. Medium-size warts will come back, and they will sometimes need shaving with a radiofrequency scalpel (Ellman), for example. Not only are larger warts impermeable to TCA, but also their very size prevents the TCA from getting around them to “undermine” and treat them from underneath (Figure 13.13). They should be treated by shave excision at the same time as the others are being treated with a peel. (a)

(b)

Figure 13.11  Freckles before (a) and after (b) a peel to the papillary dermis (Unideep). A peel to the papillary dermis improves the quality of the skin, removes the freckles, and improves the fine lines, but does not treat wrinkles.

grow darker on exposure to UV rays, using a sunscreen helps to lighten them. Tyrosinase inhibitors, antioxidants, and tretinoin and its precursors can be used in conjunction with the peels to improve or prolong results.

Postacne Scarring TCA has some effect on shallow scars but can only improve the general condition of the skin and cannot eliminate scars altogether. TCA can be combined with sandpaper abrasion (see the discussion of abrasive peels in Chapter 15) or scar subcision before the acid is applied. Even a phenol peel cannot always guarantee to heal acne scars. High concentrations of TCA can be directly applied on acne scars, levelly, with good results.

Sensitive Skin Abnormal skin sensitivity is a clear sign of dysfunction of the skin’s protective properties against a hostile environment. Sensitive skin should be treated until its tolerance to external aggression returns to normal. Many products cause skin allergies that are not always easy to identify because they may manifest as “overreactive” or “oversensitive skin.” In the case of allergy, it is best to avoid using too many cosmetic products and stick to a few well-tolerated creams.

Actinic Keratoses The treatment of actinic keratoses, like photoaging, is a common indication for chemical peels (Figure  13.14). The chemical elimination of actinic keratoses reduces the incidence of basocellular and/or spinocellular cancers.10 Other localized treatments (e.g., cryotherapy or laser) could also be suggested, but they are only applied to  visible  lesions

Dilated Pores Although it has been claimed that TCA has a circular contraction effect that narrows the follicle opening, it appears that it has a limited effect on dilated pores, or, at best, the results are difficult to predict. Patients should never be promised visible results for dilated pores. Any results should be considered a bonus and not taken for granted. Using an abrasive technique before applying Easy TCA may give promising results, but this remains to be confirmed with more experience. Highconcentration TCA can successfully treat dilated pores or pike acne scars.

Seborrheic Dermatitis Seborrheic dermatitis is a chronic dermatologic problem, often needing lifelong treatment. Flares of seborrheic dermatitis can be treated by corticoids cream that will soften the immunologic inflammatory reaction. A long-term treatment should be applied; the illness needs a permanent care. Seborrheic dermatitis could improve after chemical peels but also could risk local infection. Recommendations are to pretreat seborrheic dermatitis before applying a chemical peeling.

Widespread Flat Warts Flat warts are localized skin-colored papules that primarily appear on the back of the hands, the forearms, and the face. Clinically visible flat warts do not respond to moderate concentrations of TCA (10%–30%), and higher concentrations

Figure 13.12  Appearance of the hand after two sessions of Only Touch and three sessions of Easy TCA (for further details, see Chapter 15). The flat warts have disappeared. Note that the flat wart treated with radiofrequency is still healing. The fine visible flaking all over the hand comes from an Easy TCA peel applied to even out the Only Touch and treat the subclinical lesions.

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(a)

(b)

Figure 13.13  (a) Multiple flat warts. (b) Localized frosting of the flat warts after multiple applications of Only Touch. Note that the thicker dome of the flat warts is impermeable even to concentrated TCA. The wart in the middle is too thick, and should be shaved with (Ellman) radiofrequency.

Figure 13.14  Keratoses: peel solutions penetrate the keratoses slowly. This photograph shows the slow penetration of phenol through keratoses during a full-face peel.

and  leave clinically undetectable microlesions to develop. A chemical peel, on the other hand, will treat all lesions, both visible and subclinical ones, and will improve long-term prognosis. In comparisons between TCA peels to the papillary dermis and the application of a 5-fluorouracil (5-FU) cream, the peels fare better, as applying 5-FU gradually causes severe and rather nasty-looking dermatitis (Figure 13.15). Patients and friends can find the long, drawn-out treatment difficult to bear. A mediumdepth TCA peel, on the other hand, is generally a one-time treatment (or a few sessions at most).

Figure 13.15  Appearance of keratoses during treatment with 5-FU.

Oncological Indications As Vergereau and colleagues11 remind us, after a biopsy to confirm the diagnosis and depth of a lesion, TCA is indicated in the treatment of primitive malignant intraepidermal and intradermal tumors (depending on the depth of action of the TCA: TCA has to act deep enough). Keratoses that have developed into

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microinvasive spinocellular or basocellular carcinomas can be treated with deep TCA peel without leaving any scars: Only Touch easily reaches the reticular dermis. Nondegenerated lentigo maligna (Hutchinson’s freckle or Dubreuilh’s melanosis) is also given as a potential indication for TCA, although phenol is no doubt more effective.

Acne All common types of acne can be treated with TCA. Severe acne, such as acne necrotica, acne conglobata, or acne fulminans, should first be treated medically and the inflammation eliminated before the cosmetic use of peels. Oral isotretinoin (13-cis-retinoic acid) is the gold-standard treatment for severe acne (Box 13.1), but new retinoids come to light regularly. A combination of techniques proves worthwhile. Acne responds well to a TCA peel to the basal layer or the Grenz zone, whether it is comedonal, microcystic (Figure  13.16), papular, or papulopustular. Deeper peels, to the papillary

BOX 13.1  Isotretinoin for Acne • Tablets dosed at 10 mg or 20 mg • Total cumulative dose 120 mg/kg • Daily dose 0.3–0.5 mg/kg For example, for a patient whose weight is 70 kg, the total cumulative dose is 8400 mg. • Daily dose of 0.3 mg/kg = 21 mg/day • Accumulated dose for a month: 600 mg • Total duration of treatment • 8400/600 = 14 months • Daily dose of 0.5 mg/kg = 35 mg/day • Accumulated dose for a month: 1050 mg • Total duration of treatment • 8400/1050 = 8 months

Figure 13.16  TCA will reduce the number of lesions and the inflammation of this type of microcystic acne. Opening the microcysts with a No. 11 scalpel blade or a needle and removing the blackheads with a comedone extractor immediately before applying Easy TCA will produce faster and better results.

dermis, should not be used when acne is still active, because of the increased risk of infection (see Chapter 37). The number of open or closed comedones can be expected to decrease after several TCA peels. The Easy TCA technique allows comedones and microcysts to be opened immediately before the peel, which gives faster and better results. Seborrhea is often reduced after TCA peels, and seborrheic dermatitis improves significantly (although only temporarily). Acne improves more quickly when treated with Easy TCA than it does when treated with tretinoin, benzoyl peroxide11 creams, glycolic or azelaic acid creams, or “purifying” creams used alone. These creams do, however, play an important part in the postpeel treatment of acne. Pigmented acne scars usually respond well to TCA. Shallow scars gradually soften. Ice-pick scars do not respond at all to TCA. A combination of sandpaper abrasion followed by Easy TCA—a technique similar to the one described later in this chapter for the treatment of stretch marks—can significantly improve postacne scarring, even on the back.

Xanthelasma Eyelid xanthelasma has been presented as a good indication for TCA and dichloroacetic acid. Nevertheless, the high concentrations required make it relatively dangerous compared with the “chemical blepharoplasty” technique using phenol, which is more effective and easier to control than highly concentrated TCA. It must be remembered that xanthelasma is associated with dyslipidemia in 50% of cases. It can also be symptomatic of hepatobiliary disorders (biliary atresia and biliary cirrhosis) when associated with cholesterol deposits that start to build up in the hands and feet before spreading. Monoclonal gammapathies have also been described in association with xanthelasma. A local deep phenol peel (Lip & Eyelid Formula) is, on the contrary, a good treatment for xanthelasma.

Stretch Marks Countless suggestions have been made for the treatment of stretch marks, but none of them have been truly effective. Some techniques are not deep enough and others not extensive enough. Superficial, intraepidermal, basal, Grenz zone, and papillary techniques can only improve the appearance of stretch marks temporarily but cannot reduce their size or depth. Some peels have been developed to give the atrophic base of the stretch marks a similar color to that of the surrounding skin; they contain resorcinol, which is oxidized to match the normal skin color. The results of these peels are good, but only temporary. Deep techniques, limited to the deepest part of the stretch marks, can do no more than tighten the little collagen that is left and slightly stimulate the few surviving fibroblasts. In spite of the fact that these localized treatments reach the deepest part of the stretch marks, the results are always disappointing. That is why the author developed a technique for treating stretch marks consisting of sandpaper abrasion followed by Easy TCA peel solution and postpeel cream. The excellent results achieved with this method are due to the fact that the atrophic base of the stretch marks contracts at the same time that the cells on the edge of the stretch marks are being stimulated. The results seem to be permanent. See the description of this technique in Chapter 15. Even if the results are less dramatic compared to the chemoabrasive technique, the “pixel peel” technique also can be

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used for stretch mark treatment (see Chapter 38 for details). Some advantages of this techniques are that it is much less aggressive than chemoabrasion and can be used for darker phototypes: A microneedling is used for multiperforating the skin immediately before applying an Easy TCA peel. Needles should be 1–2.5 mm long and induce bleeding. The author uses AD Roll TD, a CE-certified sterile medical device produced by Aesthetic Dermal SL (Spain). The patented device includes a 600-needle roller and a 12-needle stamp that is embedded in the handpiece.

Other Indications These include alopecia areata, liposuction scars, neurogenic excoriations, and rosacea. TCA has often been used to treat vitiligo but without success.

GENERAL CONTRAINDICATIONS FOR TCA • • • • • • • • • • •

•

General rundown condition. Epidermolysis or dermolysis bullosa. Active bacterial, mycotic, or viral skin infections. Depression or personality disorder. Tendency to scratch. IQ insufficient to understand the events surrounding the application of the peel solution. Expectations of miraculous and life-changing results. Refusal to make follow-up visits. Severe progressive neoplasic disorders. Immunodeficiency. Insulin-dependent diabetes, depending on the depth of the peel and the risk of infection. Type 2 diabetes is not a contraindication for peels. Patients with stable insulindependent diabetes can be given a peel to the Grenz zone. Prior treatment with isotretinoin, if the peel is to the Grenz zone.

• •

Ehlers–Danlos syndrome, keloid scars, if the peel is to the papillary dermis. Extensive telangiectasias; these should be treated before peeling.

NOTES 1. Easy TCA in the basic protocol. 2. For more details, see Chapter 1. 3. A mesolift is a mesotherapy technique that involves injecting various products into the dermis: hyaluronic acid, vitamins, trace elements, DMAE, polylactic acid, etc. 4. In South Asian, Southeast Asian, or Middle Eastern patients, melasma can appear before the age of 10, while it is rarely seen in Caucasian patients before puberty. 5. It is not possible to do a Wood’s light examination on very dark skin types. 6. To date, however, it has not been possible to reproduce the melasma by applying these cosmetics intentionally. 7. The mask of pregnancy tends to lighten naturally and even disappear in patients with a light phototype unless they are taking estrogens and progestogens, which can cause the mask of pregnancy to persist. 8. See www.astheticdermal.com. 9. Berloque dermatitis is an acquired hypermelanosis resulting from contact photodermatitis caused by a sensitizing agent (perfume or metal in jewelry). Berloque, or berlock, dermatitis gets its (misspelled) name from the French word breloque, meaning a trinket or charm that is attached to a bracelet. These charms are often of poor quality and cause contact allergies in the shape of the trinket itself. 10. McCollough EG, Langsdon PR, Maloney BP. Chemical Peel with Phenol. In: Roenigk RK, Roenigk HH (Eds.). Dermatologic Surgery, Principles and Practice. 2nd ed. Oxford: Marcel Dekker, 1996: 1147–60. 11. Vergereau R, Trauchessec JM, Peyronnet B. Le new peel. Journal de Médecine Esthétique et de Chirurgie Dermatologique. 1990, XXII (68): 243–55.

14 Trichloroacetic acid Classic semiology PREPARING THE SKIN Prepeel care is discussed in Chapter 2, and additional information can be found in Chapter 12. The safety of peels employing trichloroacetic acid in simple aqueous solution (TCA-SAS) has been greatly improved by systematic preparation of the skin before peeling. Preparing the skin helps improve microcirculation, increase glycosaminoglycan synthesis, increase the number of mitoses in the basal layer keratinocytes, stimulate production of epidermal growth factors, deactivate melanocytes, and even out and deepen the effect of the TCA. One month before a peel with TCA-SAS (Soft Peel), the patient should apply a cream consisting of hydroquinone (4 g), micronized hydrocortisone acetate (0.5 g), paraffin oil (16 g) or emulsifier based on polyglycol stearate (21.5  g), and excipient qs 100 g, twice a day. Tretinoin is then mixed into this cream in gradually increasing quantities. The concentration of tretinoin is increased every week to reach a final concentration of 0.3%.1 Dermatitis develops due to the tretinoin: irritation with flaking and redness signals that the skin has been properly prepared and guarantees a successful peel. However, the need to use a technique to enhance and even out penetration of the TCA–SAS proves that the action of TCA–SAS is uneven and inadequate. The need to apply hydroquinone twice a day at a concentration of 4% as a preventive shows how aggressive the peel is to the skin and how it triggers postinflammatory pigmentary changes. In short, the introduction of skin preparation before a TCA–SAS peel and adding adjuvants greatly improves safety and is still essential to compensate for the inadequate and uneven penetration of this type of peel, as well as to reduce the risk of complications, especially pigmentary changes. It is interesting to note that the first time the author presented Easy TCA at a congress of the Belgian Society of Cosmetic Medicine in Brussels in 1997, there was an outcry. The peel was shouted down, demonized, and criticized even before it was presented, as it flew in the face of the all too recent dogma of aggressive skin preparation that then held sway. Anyone tempted to use it was told that their worst nightmares would come true if they did not prepare the skin beforehand. It was soon proved that the Easy TCA2 technique is valid and that, apart from specific cases such as the treatment of stretch marks or resistant melasma, this peel does not require any skin preparation. The doomsayers gradually fell silent, and the sworn enemies of Easy TCA started to talk about the relative merits of preparation and eventually the pointlessness of preparing the skin in many cases. Preparing the skin is now considered as an additional tool for many peels. It is an optional step in some cases but remains essential when using TCA–SAS. Treatment with oral isotretinoin is essential in some cases of severe acne but is contraindicated before a peel to the papillary dermis. An Easy TCA peel to the basal layer,3 on the other hand, can be performed without any risk of complications

and can produce excellent results for severe acne that has been treated beforehand with oral isotretinoin.

APPLICATION OF TCA–SAS It is easy to summarize the application of TCA-SAS.

Day –30 to Day 0 Prepeel preparation (see also Chapter 2) involves the following: • • • • •

Deactivation of melanocytes. Thinning and evening out of the stratum corneum. Stimulation of keratinocyte regeneration. Botulinum toxin, coagulation of telangiectasias, excision of benign tumors, cleaning the skin, and so forth. Obtaining photographs, informed consent, and other legal documents.

Day 0 This day involves the taking of photographs, settling in, disinfection, and degreasing. The patient is photographed from five angles, with and without flash (see Chapter 34). The patient is placed in the dorsal supine position; good lighting is needed to monitor the skin and any changes in skin tone. The skin is disinfected with a sterile swab soaked in alcohol, and degreased with a sterile swab soaked in acetone. Good ventilation must be ensured so that the patient does not inhale the alcohol or acetone fumes. Local Anesthetic Local anesthetic is never needed when TCA is used to treat the epidermis to the Grenz zone. It may be necessary when the TCA reaches the papillary or reticular dermis.

Applying the TCA–SAS TCA–SAS can be applied with any type of applicator. Effect of the Type of Applicator A rough-textured applicator (sterile gauze) abrades the skin, causing surface injury as it deposits the acid on the skin. This helps the TCA penetrate more deeply. Effect of Pressure of Application The pressure of application also plays a role in determining the depth of action of the TCA. The harder the solution is applied, the more deeply the TCA will penetrate. A swab held in the hand has less abrasive force than a swab held with Kocher forceps. A smooth applicator does not abrade the skin while depositing the acid, and the action of the TCA remains more superficial. Using a brush to apply the same number of coats of the same TCA solution with the same concentration produces a

Trichloroacetic acid: Classic Semiology   99 Table 14.1  Symptoms Following TCA Application Symptom

Depth of peel

Type of flaking

Erythema Scattered pinpoint frosting Cloudy-white frosting Even pink-white frosting (Figure 14.5) and “epidermal sliding”

Intraepidermal Near the basal layer (Figure 14.1) Peel has reached the Grenz zone (Figure 14.3) TCA is in the papillary dermis (Figure 14.6) Sliding (wrinkling) can be seen when skin is pinched and corresponds to coagulation of anchoring fibers between dermis and epidermis TCA has reached reticular dermis

No or little risk of visible flaking Sunburn-type flaking (Figure 14.2) Flaking: light, thin skin (Figure 14.4) Flaking: more or less brownish skin, depending on phototype and photodamage (Figures 14.7 and 14.8)

Pure white frosting (Figure 14.9), gradual disappearance of epidermal sliding Gray-white frosting, epidermal sliding has gone Gray frosting and/or yellowish patches (phenol)

TCA is in reticular dermis Deep reticular dermis

TCA should no longer be used for peels to deep reticular dermis

more superficial peel than using a swab. The depth of action of the same peel solution can therefore be varied simply by changing the applicator or the pressure of application. Effect of Speed of Application The speed of application of TCA is not in itself important, because: • •

Unlike alpha-hydroxy acid (AHA) solutions, TCA does not have to be neutralized. Unlike phenol solutions, TCA is not toxic. The speed of application depends on:

•

•

•

The patient’s sensitivity: A very sensitive patient will find it difficult to stand the burning sensation of the TCA on the whole face and will be better off if the TCA is applied zone by zone. The surface area being treated: Only Touch can be applied quickly on lentigines, as only small areas are affected by the burning from the acid. Large areas (e.g., the back) should be treated by TCA zone by zone for the patient’s comfort. The depth of the peel: Applying TCA is painful, but an intradermal peel is far more painful than an intraepidermal peel. An intradermal peel should be applied zone by zone for the patient’s comfort, while an intraepidermal peel can be applied in one pass.

Symptomatology of TCA Application

Figure 14.1  Scattered pinpoint frosting.

Applying TCA causes protein coagulation more or less rapidly, depending on the formulation of the peel, its concentration, prior preparation of the skin, the pressure of application, the skin type, etc. A 35% m/m TCA coagulates proteins. Different symptoms appear gradually: see Table 14.1 and Figures 14.1–14.9. A low-concentration formula is applied in several coats; the doctor can progressively see each of the symptoms described in Table 14.1, and can stop whenever he wants. A high-concentration formula penetrates very rapidly, and the symptoms come in such quick succession that it is impossible to see them clearly. The technique is much quicker but the doctor cannot choose when to stop. Two endpoints are worthy of more attention: • •

Scattered pinpoint and cloudy-white frosting signal the most superficial peel to the dermis: this is the limit of effectiveness (see Chapter 15). Even pink–white frosting signals a peel to the papillary dermis: this is the safety limit (see Chapter 23).

Figure 14.2  Flaking after scattered pinpoint frosting.

100   Textbook of Chemical Peels

Figure 14.6  The skin wrinkles when pinched between the fingers. Figure 14.3  Cloudy-white frosting.

Figure 14.4  Flaking after cloudy-white frosting.

Figure 14.5  Even pink-white frosting (the differences in color come from the presence of melasma). The contours of the eyes have been chemically resurfaced locally.

Figure 14.7  Flaking after a papillary peel on a light skin phototype with little photodamage.

Figure 14.8  Flaking after a papillary peel on a light skin phototype that has been badly damaged by the sun.

Trichloroacetic acid: Classic Semiology   101

POSTPEEL CARE Postpeel care is also discussed in Chapter 3. In short, postpeel care is extremely important and depends on the skin type, the depth of the peel, and the dermatological problem being treated. It is more important than preparation when using Easy TCA or Unideep. “Peelers” quickly learn that applying a peel solution is extremely easy; one does not need a university degree to take a cotton bud and get skin to frost gradually. The choice of indications and managing postpeel care are different matters, and a thorough knowledge of medicine is essential to do them properly.

NOTES

Figure 14.9  Pure white frosting from a peel to the reticular dermis.

1. Preparing the skin with tretinoin before the peel accelerates postpeel healing. 2. Easy TCA was called “Easy Peel” at the time. The name was changed when Easy Phytic peel was released, to avoid any confusion between the two “Easy” peels: Easy TCA, a combination of a TCA peel and Easy Phytic, uses alpha hydroxy acids (AHAs) and phytic acid. See Chapter 11 for more information on this peel. 3. The peel produces scattered pinpoint frosting only.

15 Easy TCA and Easy TCA Pain Control Description and basic protocols INTRODUCTION: IMPORTANCE OF LANGERHANS CELLS IN RELATION TO PEELING SIDE EFFECTS In 1968, Paul Langerhans discovered the presence of a particular type of epidermal cell in humans, which is now named after him. The Langerhans cell (LC) is a mobile dendritic cell that has no desmosomes and is found in most multilayered malpighian epithelia. LCs make up 2%–5% of epidermal cells. They come from the medulla, migrate toward and within the skin, and stay within the epidermis for 2 weeks at the most. LCs have three functions: 1. Constant monitoring of the antigenic environment. 2. Inspection of foreign molecules. 3. Custody of the foreign invaders while the lymphocyte system reacts with an appropriate immune response. It is easy to understand how important LCs are when one imagines the impressive number of potential antigen contacts over the entire epithelial surface of the body. When the entire epidermis is destroyed by certain peels, this affects not only the keratinocytes and the LCs, but also other dermal dendritic cells (DDCs) that are potentially antigen-presenting cells. New generations of sentinel cells migrate rapidly from the bone marrow to the epidermis, which is being rebuilt after the peel, but this process is not effective immediately. Moreover, the first LCs to arrive as reinforcements on the battlefield of the skin are “overwhelmed” as soon as they reach the dermis by the different types of antigen stimulation that they have to face on skin that has lost its impermeability and physical defenses. The stratum corneum can be compared to the ramparts of a medieval city and the Langerhans cells to the soldiers who have to defend it. The likelihood of unexpected bacterial and viral complications occurring will be even higher, as there are fewer cells in the skin capable of an immune response. It is important to consider these basic notions of biology to better understand what happens and anticipate which type of peel might be associated with a higher incidence of complications in the form of bacterial or viral infections. It then seems obvious why applying peel solutions capable of destroying the epidermis and part of the dermis on a skin with active herpes, acne, or other infectious disorders is strongly contraindicated. Any medical staff suffering from respiratory or nose-and-throat infections should be kept well away from the patient, and the doctor’s hands should always be surgically disinfected before applying medium or deep peel solutions. Superficial peels with alpha hydroxy acids (AHAs), on the other hand, are known to cause very few bacterial or viral complications after peeling, as their direct action is limited to

breaking up the spaces between corneocytes.1 Even if the peel penetrates too deeply in places, it is, quite logically, exceedingly rare for an AHA peel to cause complications in the form of infection, when the endpoint is focal or localized frosting. With AHAs, the stratum disjunctum (SD), the outermost layer of the epidermis that makes the skin feel rough, flakes immediately. The skin, having lost its topmost layer, immediately feels softer to the touch. The risk of bacterial or viral complications with medium or deep peels could lead doctors to think that, in order to avoid these problems, only superficial peels should be performed and patients with active acne or herpes should not be treated. With a medium or deep peel, herpes prevention consists of a sandwich treatment with aciclovir, which is not well tolerated by patients with sensitive stomachs. For patients with acne, caution limits the range of treatment choices to careful superficial peels (which have limited effectiveness even after repeated sessions). We are forced to put off, sometimes indefinitely, performing “medium-depth” peels on patients with acne or herpes who have not responded to preliminary medical treatment. The development of Easy TCA (ETCA), however, has introduced another possibility for treatment. In many indications, ETCA can produce the results of a medium peel with only the complication risks—usually nonexistent—of a superficial peel. ETCA can be applied quite successfully to active acne lesions, and the presence of herpes lesions on the lips is only a formal contraindication to the peel applied following the basic protocol. It is still advisable to avoid treating patients with active herpes, however. Then again, if herpes were to develop in the course of an ETCA peel, it would be reasonable to think that it was fortuitous and not directly related to the treatment. To date, there has been no reported incidence of herpes spreading after the application of ETCA (basic protocol). With regard to acne, in 80% of cases, the first application of ETCA to active papulopustular facial lesions improves their number and severity by 50%, and the lesions seem to heal without scarring. ETCA is applied on the basis of one peel per week for 4 weeks that clear the lesions almost completely without having to resort to antibiotics. Deep wrinkles and acne scars do not disappear: they lie deep under the skin and even phenol or carbon dioxide laser resurfacing cannot always treat them. A combination of several different techniques is clearly needed in these indications. Although the face can be treated separately, the neck should always be treated at the same time—to at least the seventh cervical vertebra—to ensure a better “tightening effect.” Ideally, all visible areas should be treated: face, neck, décolletage, forearms, and hands (Table 15.1).

Easy TCA and Easy TCA Pain Control: Description and basic protocols   103 Table 15.1  Volume of ETCA Solution for One Peel (As a Rough Guide; See the Different Protocols for Details) Procedure

Approximate volumes (ml)

Face only Face and neck Face, neck, and décolletage Face, neck, décolletage, hands, and forearms

1.2–1.5 1.5–2 2.5–3 3–4

GENERAL DESCRIPTION A growing number of doctors consider ETCA to be the safest and easiest trichloroacetic acid peel, and it is used in more than 70 countries worldwide. ETCA comes in two main presentations: Easy TCA Classic and Easy TCA Pain Control. Both are certified as Class II medical devices. Easy TCA Classic is the most popular form of Easy TCA; it has been used since 1996. Easy TCA Pain Control represents the most recent evolution of the peel. The peeling solution is a patented formula, containing nontoxic amounts of phenol. The clinical difference between the peels is that Easy TCA Pain Control tends to be 80% less painful and 25% more efficient than Easy TCA Classic. Frosting appears more quickly and is stronger when Easy TCA Pain Control is used; a deeper frosting induces a much milder burning sensation. Nevertheless, Easy TCA Pain Control is not intended for use after microneedling and is contraindicated after abrasion.

Easy TCA Classic

Presentations • Easy TCA Starter 4: Kit for 4 peelings. • Easy TCA Classic 12: Kit for 12 peelings. • Easy TCA Classic 24: Kit for 24 peelings. Kit Contents The number of items varies and is adapted to the number of planned peels. •

Base solution: Solution containing four AHAs, antioxidants, trace elements, and saponins. • Starter 4: 4 ampoules of base solution. • Classic 12: 12 ampoules of base solution. • Classic 24: 2 vials of base solution.

•

Aktivator  TCA 50%: Solution TCA concentrated at 50% w/w. • Each kit contains a vial of Aktivator TCA 50% adapted to it.

•

Postpeel mask: Cosmetic cream to be applied immediately after the peel. • Each kit contains one or several tube(s) of postpeel mask, depending on needs. • The application of the postpeel mask, once, immediately after obtaining the desired skin frosting, immediately alleviates the burning sensation.

•

Various: One or more dosing cards for dosing the postpeel mask, small container for mixing the TCA with the base solution, protective plastic tube to prevent cut fingers when breaking open an ampule, cotton swabs, and instructions for use.

Easy TCA Pain Control

Presentations • Easy TCA Pain Control: Kit for 4 peelings. • Easy TCA Pain Control 12: Kit for 12 peelings. Kit Contents The number of items varies and is adapted to the number of peels provided. •

Pain Control base solution: Solution containing four AHAs, antioxidants, trace elements, saponines, and phenol. • Kit for 4 peelings: One 8 ml vial. • Kit for 12 peelings: One 25 ml vial.

•

Aktivator  TCA 50%: Vial containing a 50% w/w TCA solution. • 4 peelings: One 3.4 ml vial. • 12 peelings: One 10 ml vial.

•

Postpeel mask: Cream designed to control inflammation and burning after the peel. • 4 peelings: One 10 ml tube. • 12 peelings: Three 10 ml tubes.

•

Various: One or more dosing cards for dosing the postpeel mask, a small container for mixing the TCA with Pain Control base solution, cotton buds, and instructions for use.

Base Solution to Be Mixed with TCA The base solution itself does not contain trichloroacetic acid; it is intended to be mixed with a specific volume of Aktivator TCA at 50% w/w. The base solutions for the Easy TCA Classic and the Easy TCA Pain Control are very similar. The Easy TCA Pain Control base solution contains a specific phenol concentration that makes the peel 25% more efficient and 85% less painful than the Easy TCA Classic. The phenol in the Easy TCA Pain Control base solution does not reach a potentially toxic concentration. The Easy TCA Classic and Pain Control peeling solutions, reconstituted by the addition of Aktivator TCA, have an acid pH of +/–1. This pH, which is much lower than the solution’s pKa, means that the base solution is composed primarily of free and potentially active acids and contains no partially neutralized acids.2 The TCA concentration of both the Easy TCA Classic and Easy TCA Pain Control peels is 15% m/m. Figure 15.1 compares the formulations of a TCA in simple aqueous solution (TCA-SAS) and the Easy TCA Classic, base solution.

THE LEGAL POINT OF VIEW A TCA-SAS is a simple mixture of trichloroacetic acid crystals and water (see Chapter 12). Such a simple solution is less expensive than a more complex solution but, as explained in Chapter 12, it has its limitations. TCA-SAS is legally produced by pharmacies only, and for medical use. In European countries, at least, a physician is not legally allowed to mix TCA crystals and water to prepare a solution that he will apply on a patient; this is usually considered as an illegal practice of pharmacy. However, a physician is legally allowed to mix a TCA solution (Aktivator TCA) with the base solution of a kit that is CE Class II certified because the components of the kit are largely controlled, validated, and legal for medical use.

104   Textbook of Chemical Peels

TCA in water solution

Easy TCA 4 alpha hydroxy acids: 2- Monocarboxylic AHAs 1- Dicarboxylic AHA 1- Tricarboxylic AHA Saponines

Water

Antioxidants Phytic acid, ascorbic acid SOD Trace elements

+ TCA

+ TCA

Figure 15.1  TCA compared to Easy TCA.

Easy TCA Pain Control has the advantage of being the only (as far as the author knows) phenol-containing peel that is CE certified and legal for utilization. Note that unlike a CE Class II medical device, a Class I medical device needs no external control. Class I represents a self-certification only. When the single logo CE appears on a box, without four numbers after it, it means that the CE is a self-certification, without external control. For example, for TCA or phenol-containing peels, CE 1234 indicates a medical device duly certified by an external controlled “notified body”; CE alone, without four numbers, indicates a self-certified medical device. Evidently, CE 1234 presents a stronger guarantee of security and efficacy than the self-certified CE.

THE EFFICACY POINT OF VIEW While water itself has no clinically visible efficacy, the components of the Easy TCA base solution have a specific efficacy. • •

• • •

•

The four AHAs of the formula allow a faster and deeper penetration of the other actives. They have an anti-freeradical action. Saponins are natural extracts known as glycosides that have special foaming and soapy properties. As a glycoside, a saponin may have binding properties for water in the skin. Some studies show that saponins have an antimicrobial effect and enhance skin healing. They are mainly used in peelings to even out the penetration of the TCA through the skin. Ascorbic acid has an anti-free-radical action and protects the solution itself as well as the skin it is applied on. It is also an acidifying agent and a buffer. Phytic acid is a good antioxidant and tyrosinase inhibitor. It protects against the risk of hyperpigmentation and postpeel inflammation. Super oxide dismutase (SOD) is a metalloproteinase with a strong, natural antioxidant feature that protects cells against peroxidation. It is an important molecule that can, for example, prevent the superoxide radical (O2–) from reacting with the NO radical to produce peroxinitrile, which is extremely toxic to cells. Trace elements are necessary to the activity of many enzymes and skin metabolism.

When comparing a TCA-SAS solution to the base solution, it is clear that the Easy TCA base solution helps the penetration and the activity of the TCA; it protects the skin against the negative action of the free radicals that are immediately produced when the acids react with skin components. As a consequence, application of Easy TCA is less painful than application of TCA-SAS solutions.

POSTPEEL MASK CREAM The postpeel mask cream, which is highly antioxidant, contains many ingredients. The doctor applies it only once, immediately after the required level of frosting has been achieved. The cream’s formulation is responsible for a significant proportion3 of the beneficial results of ETCA. It stops the burning sensation almost immediately and greatly reduces the risk of postpeel complications (see Chapter 5). Its components are discussed later in this chapter. While postpeel care is discussed in detail in Chapter 3, it is important to mention that after TCA-SAS application, medications are needed to control side effects. Side effects occur quite frequently and are often the reason doctors prefer using methods other than TCA peels. The postpeel mask used immediately after an Easy TCA peel controls, in minutes, the inflammation produced by the peel. It quickly stops the cycle of self-maintained oxidative reactions, burning sensation, and erythema. Often, the patient leaves the clinic without any visible sign of the Easy TCA peel. After the Easy TCA Pain Control peel, the postpeel mask is mainly intended to control postpeel inflammation rather than burning or pain, because Easy TCA Pain Control produces much less discomfort than other peels. Immediate control of postpeel inflammation limits the risk of side effects. Figure 15.2 compares the Easy TCA (and Easy TCA Pain Control) postpeel mask with the medications used after a TCASAS peel.

TCA IN WATER SOLUTION, POSTPEEL CARE Hydroquinone After a TCA-SAS peel, hydroquinone is used to combat postinflammatory hyperpigmentation (PIH). See Chapter 37 for examples of PIH and more information about hydroquinone.

Easy TCA and Easy TCA Pain Control: Description and basic protocols   105

TCA in water solution

Medications usually used during the postpeel period for limiting or curing side effects. Duration of use, up to 30–90 days Hydroquinone Tretinoin Corticoids N.S. ANTI-INFLAMMATORIES

Easy TCA postpeel mask

Main components of postpeel mask used once only after peel. Anti-oxidant Vitamins (A, C, E, H...) Antityrosinases Phytic acid Tretinoin precursors Growth factor (bFbF) Fatty acids Organic silicium Seleniomethionine Trace elements Enoxolone SOD

Figure 15.2  TCA compared to Easy TCA postpeel.

Tretinoin Tretinoin is used to stimulate the skin basal layer turnover and speed up the healing process. However, it also limits the transformation of keratinocytes into corneocytes. A new horny layer will not quickly appear, and full skin protection will not be restored. The consequence is potential long-term sensitivity of the skin after the peel. When used in the postpeel period, tretinoin seems to slow down the building of the skin architecture and extend the duration of erythema.

Corticoids Corticoids are used to control postpeel inflammation because of their antimetabolic effect on melanocytes. Nevertheless, they present a catabolic effect that also could slow down skin regeneration and induce skin thinning and telangiectasies if used for an excessive amount of time.

Nonsteroidal Anti-Inflammatories Indomethacin 2% is sometimes used as part of a more complex formula for controlling postpeel inflammation. Tranexamic acid should be used before the melanin is synthesized, very soon after a chemical peel. The effectiveness of nonsteroidal antiinflammatories (NSAIDs) is lower than that of corticoids.

COMPONENTS OF THE EASY TCA AND EASY TCA PAIN CONTROL POSTPEEL MASK The Easy TCA Classic and Easy TCA Pain Control peels use the same postpeel mask formula.

Antioxidants PIH often occurs after chemical peels as a direct result of melanocyte to oxidative reactions or to complex chain reaction mechanisms. The mechanism of PIH is well understood, but it is clear that many inflammatory mediators and reactive oxygen species are liberated by the interaction of the chemical peeling agent and the skin. For example, TCA breaks cell

membranes and liberates cell components that are not proinflammatory as long as they are enclosed in the cell. When cells walls are broken, the plasma content is liberated and many potentially pro-inflammatory components reach extracellular spaces where they induce inflammation. After a peel, long lasting and progressive liberation of these pro-inflammatory components induces long-term stimulation of melanocytes and, finally, PIH. Antioxidants can block the cycle of postpeel inflammation, avoiding long-term melanocyte stimulation and therefore reducing the risk of PIH after an Easy TCA peel.

Vitamins A, C, E, and H Vitamins A, C, E, and H have potent antioxidant, regenerative, and anti-inflammatory effects. Vitamin A The postpeel mask cream contains retinol microencapsulated in cyclodextrin. Vitamin A is involved in the processes of cell division and differentiation that helps the epidermis regenerate after the peel from the cells of the basal layer (Figure 15.3). Retinol induces the expression of retinoic acid-binding protein (RABP) and regulates cell migration in the skin epithelium, which is vital for skin regeneration after a peel. Retinol exerts a strong antioxidant activity; encapsulating retinol provides better bioavailability of the vitamin and protects the skin against oxidation. Keratinocytes have the enzyme tools required to convert retinol into retinoic acid (the corresponding carboxylic acid), which is the molecule ultimately responsible for the effect of vitamin A. Retinol can be considered as a tretinoin precursor because, when encapsulated in cyclodextrins, it enters easily into the skin, and when liberated from the cyclodextrin, it is transformed by epidermal enzymes into retynaldehyde and finally retinoic acid. This kind of natural tretinoin production seems not to induce the slowdown of keratinocytes–corneocytes transformation and not interact with the postpeel skin permeability. Vitamin A modulates cellular proliferation and

106   Textbook of Chemical Peels

Intrakeratinocytic production Enzyme ROL Retinol

Enzyme RAL Retinaldehyde

RA

RAR

RA Retinoic acid

ARNm

Retinyl esters Protein synthesis

Stockage

 

(a)

(b)

Figure 15.3  (a) Retinol encapsulated in cyclodextrin. (b) From retinol to retinoic acid.

differentiation. At the level of the dermal matrix, it increases collagen and hyaluronic acid synthesis, and decreases metalloproteinases-mediated extracellular matrix damage. Vitamin A deficiency makes the skin at risk of impaired wound healing. Vitamin A increases fibroblast proliferation. Vitamin C Magnesium ascorbyl phosphate (MAP) is more effective than ascorbyl palmitate (AP), as its active function by esterification protects the MAP against oxidation and provides an antioxidant effect that is of higher quality and longer lasting than that of ascorbyl palmitate, a molecule in which the enediol function of the “2” carbon atom is not protected by esterification. Vitamin C deficiency is linked with a reduced immunity response, an increased risk of infection, reduced collagen synthesis, poor angiogenesis, and higher capillary fragility. Vitamin C is a powerful antioxidant, effective in aqueous solutions, that scavenges free radicals and prevents the breakdown of protein chains. It protects other antioxidants, which is an advantage in situations involving oxidative stress, such as infected or uninfected wounds and in the postpeel healing period. Vitamin C has many roles in wound healing, and vitamin C deficiencies result in impaired healing. Vitamin E Tocopheryl acetate is the most stable ester of vitamin E. It is readily hydrolyzed by esterases into pure vitamin E after it has been absorbed by the skin. The advantage of the acetate form is that it forms a reservoir that gradually releases the vitamin E inside the skin. Vitamin E scavenges free radicals that could damage neighboring tissue. It blocks oxidative chain reactions by inhibiting the formation of lipoperoxides inside the cell, and in this way protects the nucleic acids and proteins. Vitamin E is an antioxidant, and its lipophilic properties allow it to stabilize cellular membrane integrity. Vitamin E also has anti-inflammatory properties and decreases the risk of scar formation. Topical Vitamin E is widely used as an antiscarring agent, even if it seems not to be able to speed up skin regeneration.

Vitamin H (Coenzyme R, Biotin, Vitamin B8) The metabolic action of vitamin H is mediated through biotindependent enzymes that actively synthesize purines. It is a stable monocarboxylic acid, soluble in water and alcohol, and acts as a coenzyme as well as a growth factor, even in very small quantities. Biotin deficiencies cause scaly dermatitis, hyperkeratosis, and alopecia. Topical application of biotin reduces the secretion of sebum.

Antityrosinases Antityrosinases block the synthesis of melanin from tyrosine. They act at several levels of the chemical pathway. When applied immediately after a peel, they penetrate the basal layer more quickly and greatly reduce melanin production. However, they are not able to remove the melanin already in the keratinocytes. Their action allows the melanocytes to produce less melanin and transfer less melanin to the keratinocytes. When used on an existing melasma or PIH, after inducing a lower melanin synthesis, the epidermal turnover still has to bring to the surface these keratinocytes containing less melanin to obtain a clinical result. When topical antityrosinases in a cream are used alone, clinical result can last up to 8 to 10 weeks.

Phytic Acid Phytic acid is an antioxidant and tyrosinase inhibitor that protects against the risk of hyperpigmentation and postpeel inflammation.

Epidermal Growth Factor Epidermal growth factor (CG-bFGF) stimulates epidermal cell growth and has an antiscarring effect, which aids wound healing.

Fatty Acids Polyunsaturated fatty acids (PUFA) limit the destructive effects of wound inflammation. The mechanism is not yet well understood, but it appears that omega-3 and omega-6 fatty acids

Easy TCA and Easy TCA Pain Control: Description and basic protocols   107

control some cytokines liberation and limit their activity. PUFA are therefore indicated after peels to reduce the risk of scarring and speed up skin healing.

Organic Silicium (Trimethylsilanol Monomannuronate) Organic silicium is strongly linked to proteoglycans and mucopolysaccharides, hyaluronic acid, and chondroitin sulfate. It plays an important role in skin healing and is essential in antiaging treatments.

Organic Selenium and Selenio-Methionine

Allantoine Allantoine stimulates the skin renewal process. Soothing and anti-irritant, it regulates the inflammatory process. It also helps the skin retain water and helps eliminate dead cells.

Rhamnosoft Rhamnosoft is a biosaccharides mixture. Its anti-inflammatory action includes biologic attenuation of inflammation, which inhibits PGE2 liberation. Rhamnosoft also inhibits intercellular proinflammatory message transfer between cells, blocking postpeel inflammation. In addition, its antiseptic properties limit bacterial adhesion on surfaces.

Selenium is a trace element that accelerates skin healing; it penetrates more easily when combined with methionine. The postpeel mask contains a combination of selenium and methionine, which improves healing after laser resurfacing or a peel, and prevents seborrheic dermatitis. Selenium is a component of glutathione peroxidase (GPX), an antioxidant enzyme that helps fight peroxidation. Selenium helps reduce inflammation by lowering the number of hydroperoxide intermediates in cyclooxygenase and lipoxygenase reactions. It prevents the production of inflammatory and immunosuppressive cytokines and stimulates cellular immunity and humoral immunity. Combining it with vitamin E reinforces its protective action. Selenium and methionine have a tretinoin-like effect without causing irritation.

Note:  The fact that the peel solution has been applied on the skin beforehand has a significant effect on the rate of penetration of the postpeel cream’s ingredients. The cream penetrates much more deeply after a peel than on untreated skin: the skin is far more permeable immediately after a peel, sebum and corneocytes no longer function as a barrier, and the purely water-soluble ingredients can penetrate the altered epidermis  rapidly. In this way, large quantities of antityrosinases, healing stimulants, protectors, and antioxidants can reach the dermis. The postpeel mask has a pH of 6.5; it is not a neutralizing cream.

Trace Elements

INDICATIONS

Optimal skin repair requires a balanced concentration of several micronutrients. Zinc is a co-factor for RNA and DNA polymerase and can impair wound healing. Magnesium is a co-factor for many enzymes (protein and collagen synthesis). Copper is a required co-factor for cytochrome oxidase, SOD, and natural collagen cross-linking.

Easy TCA Classic and Easy TCA Pain Control have a wide range of indications and depths of action (Table 15.2). Easy TCA Classic can be used on both the face and the body, regardless of previous microneedling or dermabrasion. Easy TCA Pain Control is only indicated for facial treatment, and the notice for use warns against its use after microneedling or dermabrasion to avoid a too fast penetration of phenol. Easy TCA can be applied to the face, hands, neck, décolletage, and body. Easy TCA Pain Control can be applied to a maximum of 4% of the body (e.g., the face). The décolletage can be treated separately.

Superoxide Dismuthase SOD blocks O2 free radicals. It is the only enzyme that can detoxify the extremely toxic superoxide free radical.

Enoxolone Enoxolone is a natural inflammatory whose structure provides anti-inflammatory properties without the antimetabolic properties of cortisol. It has a modulatory effect on neural signaling through gap junction channels (Figure 15.4).

Urea and Glycerol Urea and glycerol both have well-known moisturizing properties.

HO OH O

O

OH

HO

H

H

H H

These protocols include stretch marks, acne scars on the face and body, keratosis pilaris, and badly damaged décolletage. Easy TCA Classic can be used after dermabrasion or microneedling (see Chapters 21 and 29). Easy TCA Pain Control is not recommended after microneedling and is prohibited after dermabrasion.

Deeper Protocols

O

HO

Abrasive or Microneedling Protocols

O (a)

Figure 15.4  (a) Enoxolene and (b) cortisol.

H (b)

H

Easy TCA or Easy TCA Pain Control can be applied as a peel to the papillary dermis, when a sufficient number of coats are gradually applied to produce even pink-white frosting and “epidermal sliding.” The protocol developed to treat stretch marks also has been used successfully for facial rejuvenation, in combination with Easy TCA Classic.

Combined Protocols Easy TCA Classic or Easy TCA Pain Control can be combined with other treatments, including the following (see Table 15.3): • •

A peel to the papillary dermis: Unideep A localized peel to the reticular dermis: Only Touch

108   Textbook of Chemical Peels Table 15.2  Indications for Easy TCA or Easy TCA Pain Control Type

Subtype

Easy TCA or Easy TCA Pain Control basic protocol

Acne

Comedonal Microcystic Papular Papulo pustular Pustular Other types of acne (conglobata, necrotica, etc.) Pigmentary postacne scars Hypertrophic postacne scars Deep scarring (pike, scars, etc.) postacne

Frosting points Frosting points Frosting points Frosting points Frosting points (-) Peelings not indicated

Scars

Stretch marks Pigment Aging

Melasma-chloasma PIH Photoaging Chronoaging Smoker’s skin Keratosis—solar lentigine

Frosting point or clouds (-) Simple peel not active (-) Simple peel not active After dermabrasion or microneedling (not Easy TCA Pain Control) (-) Simple peel not active After dermabrasion or microneedling (not Easy TCA Pain Control) Frosting points or clouds Frosting points or clouds Frosting points up to papillary dermis Deep phenol peel associated with surgery Easy TCA/Easy TCA Pain Control frosting points up to papillary dermis Easy TCA/Easy TCA Pain Control in touch on facial keratosis Hands–décolletage–scalp: use Only Touch + Easy TCA

Table 15.3  Combined Protocols

Reticular dermis application Papillary dermis application Unideep together with Only Touch together with Local Lip & Eyelid together with Hair removal Skin mechanical cleaning Skin abrasion Botulinum toxin immediately before Skin microneedling Wrinkle filling (hyaluronic acid) Telangiectasies coagulation before Mesotherapy before Fractional laser

Easy TCA

Easy TCA Pain Control

Easy Phen Light

– x x x x

– x x x x

x x – – x

Depth of a Peel

x x x x

(x) – – x

– – – –

PREPARING THE EASY TCA CLASSIC SOLUTION

x x

(x) x

– –

x

(x)

(x)

x x

x (x)

– –

1. As a cosmetic product: In this case, the kit contains no TCA and the pharmacist should be asked to prepare the following TCA–SAS solution at 50% m/m. TCA crystals    10 g Distilled water  10 g pf 20 g of TCA aqueous solution 2. As a Class II medical device class: In this case, the kit contains Aktivator TCA 50%.

Can be combined Not recommended; depends on the medical decision —: Can’t be combined x:

(x):

•

• • •

penetrates the tiny holes created by the laser and induces a pixelized deeper peel that boosts results and help the skin recover very quickly.

Localized phenol for lip and eyelid wrinkles: Lip & Eyelid Formula. A combination of local Lip & Eyelid Formula and Easy TCA Pain Control is effective for wrinkles around the eyes or mouth that are not strongly associated with photoaging. If they are strongly associated with photoaging, combination with easy phen light is better. Electric hair removal, skin cleaning, botulinum toxin, wrinkle filling, minor surgery, coagulation of telangiectasias, mesotherapy, slimming diets (to stop face sagging), etc. Lasers and flashlamps. These are not strictly contraindicated but should be judged on a case-by-case basis, depending on the type of equipment used. Pixelized laser treatment (fractional laser). Easy TCA Classic is very effective immediately after skin laser pixelization. This combination allows using a reduced laser fluence, which limits potential side effects. Easy TCA Classic

The depth of a peel must be chosen before the peel is performed, taking into account the indications and the patient’s skin type. The examples in Table 15.4 are not binding or limiting.

The base solution must be activated by adding TCA at 50% m/m. Easy TCA Classic is presented in two main forms:

To activate the peel,4 a precise quantity of the base solution has to be injected into: • • •

Each ampoule of the Easy TCA starter (four peels) or the Easy TCA Classic kit (12 peels), or Each of the two bottles of base solution for Easy TCA Classic 24 peels, or The vial of base solution for Easy TCA Pain Control.

This solution, prepared in advance, ideally should be kept in the refrigerator if stored for long-term use. In normal-use conditions, the solution can be stored at room temperature (20–22ºC). Table 15.5 shows the presentations available.

PREPARING THE EASY TCA KITS Details for preparing the kits are written on the inside cover of the box. Every peel should be carefully prepared, following the instructions, to avoid complications.

Easy TCA and Easy TCA Pain Control: Description and basic protocols   109 Table 15.4  Indications vs Depth of Peels Indications

Type of peel

Suitable phototype

Depth of peel

Active acne, dry skin, anti-aging

Intra epidermal peel Or basal layer peel ETCA to the basal layer ETCA to the Grenz Zone FACE: Focal touch with ETCA or ETCA PC - Hands, forearms, décolletage: focal touch Only Touch peel Anterior chemoabrasion

All phototypes Phototypes 4-6 Phototypes 1-3 Phototypes 1-4 Phototypes 1-4

Depth 2/7 Depth 3/7 Depth 3/7 Depth 4/7 Depth 5/7 Depth 6/7

Phototypes 1-3

Depth 5/7 to 6/7

Melasma, chloasma, photoaging Lentigines Stretch marks, acne scars, deep wrinkles

Table 15.5  Differences between CE and No CE Easy TCA Kits Cosmetic

Easy TCA Classic

Medical device

Easy TCA Classic Easy TCA Pain Control

4 peels (starter kit) 12 peels (classic kit) 24 peels (large kit) 4 peels (starter kit) 12 peels (classic kit) 24 peels (large kit) 4 peels 12 peels

Kit contains no TCA Kit contains TCA

PREPARING THE PATIENT As a general rule, when a basal layer depth or Grenz zone depth is chosen, no skin preparation is necessary in the weeks preceding the peel or even immediately before the procedure. It is not necessary to clean or degrease the skin, or to remove makeup5 (except for impermeable makeup with a silicone base). If the doctor wants the skin to be cleaned, it should be cleaned carefully, without irritating it or increasing its permeability. Skin Tech’s prepeel cleansing foam is recommended, as it does not increase skin permeability and has a physiologic pH of 4.5 that brings the skin back to its natural acidity before the peel.

Exceptions Skin preparation is optional before Easy TCA (depths 3/7— basal layer to 4/7—Grenz zone). Antipigment preparation is recommended for deeper protocols or higher phototypes (FZ– Fitzpatrick, 5/7): apply Skin Tech Blending Bleaching Cream twice daily for 3–4 weeks prior to a peeling depth 4/7 or 5/7. For a peeling depth of 5/7, prevention of herpes simplex is mandatory for patients with a history of classical herpes.

Figure 15.5  A single cotton bud cannot withstand sufficient pressure.

SUITABLE APPLICATOR Different types of applicator can be used, but experience shows that the best results are achieved using a double cotton bud (Figure 15.5). A single cotton bud cannot withstand “­scratching” pressure6 and bends. Two cotton buds, on the other hand, can stand the right amount of pressure, and allow easy, quick, and precise application.

BASIC PROTOCOL Cotton Buds Two cotton buds should be soaked in the ETCA solution that has been made in the glass container (Figure 15.6). Any excess solution should be removed by squeezing out the cotton buds on the rim of the glass container (Figure 15.7).

Peeling Application Easy TCA Classic or Easy TCA Pain Control is usually applied with circular movements, using the cotton buds (called “applicators”) included in the kit.

Figure 15.6  Soaking the cotton buds.

Application of the First Layer Divide the face into seven different areas (see Figure 15.8). Soak the applicators in the peeling solution, squeeze them dry on the edge of the glass container to eliminate the excess solution, and

110   Textbook of Chemical Peels

Figure 15.7  Squeezing out the cotton buds. Figure 15.9  The frontal and lateral areas of the face.

“result” (see previous section). Repeat the application if necessary (dividing the face into three different areas) and allow each layer to dry until the required frosting is obtained. The “clinical sign” corresponds to the depth achieved (rash, spots, or clouds); that is considered the “end of the peel.” At this time, apply the correct amount of the Skin Tech postpeel mask (see dosage card). Application of the Postpeel Mask Apply the Skin Tech postpeel mask cream in the amount determined by the kit’s dosing card. The postpeel mask stops skin pain, erythema, swelling, and heat in a few seconds, and drastically reduces the risk of side effects.

Figure 15.8  The seven areas of the face.

apply them to the first area using regular circular movements. Let this first layer dry completely and check the “result.” Repeat this process for each area. The “result” is not a volumetric notion (milliliters) or a temporal concept (minutes) but rather a clinical sign: • • •

Erythema: Sign of peeling depth 2/7 (intraepidermal) Frosting points: Sign of peeling depth 3/7 (basal layer) Frosting clouds: Sign of peeling depth 4/7 (Grenz zone)

Immediate Postpeel The postpeel mask should remain in place for at least 8 hours before being washed with Skin Tech cleansing foam. The cleanser will bring the skin’s pH back to its natural level (pH 5.5). Predictable Effects during the First Week Postpeel Dry skin begins to peel on the third day (sometimes later in the case of a first peel) and finishes by the sixth day. The desquamation intensity depends on the depth of the peel. •

Depth 2/7 (intra-epidermal): Desquamation is almost invisible. Depth 3/7 (basal layer): Desquamation lasts for 3 days, similar to a sunburn. Depth 4/7 (Grenz zone): The skin may darken in peeling zone 4/7 and results in a more visible peeling.

If the desired frosting was obtained with the first layer, immediately apply the correct amount of the Skin Tech postpeel mask on the treated skin (see the dosing card in the kit). If the desired frosting has not been obtained with the first layer, reapply the Easy TCA solution to the face as described below.

•

Application of Subsequent Layers Divide the face into three different areas (frontal and lateral areas; see Figure  15.9) and apply the peeling solution using circular movements. Let this second layer dry and check the

Application Sequence for Each Coat The first coat of ETCA is applied in sequence on the face (Figure 15.10), area after area. This coat should be left to dry. If the application is even, following the recommendations

•

Table 15.6 summarizes the process.

Table 15.6  Basic Peeling Process Peeling

Application

First coat

Second and subsequent coats

Easy TCA Classic

2 cotton buds, circular motion

Divide the face into 7 areas

Divide the face into 3 areas

Easy TCA Pain Control

End point

Immediate postpeel care

Frosting points

Postpeel mask

Frosting clouds

Easy TCA and Easy TCA Pain Control: Description and basic protocols   111

2

1

2

3

5

6

7

1

3 4

6 7 5

4

Cotton Buds Movements: No

No

Figure 15.11  Pinpoint frosting.

Figure 15.10  The sequence for application on the face. For the first coat of peeling: The double cotton buds are moistened before applying the solution to each area (1 to 7); the solution is applied using a circular motion. For the second coat, if necessary, the face is divided into three areas only: first area = forehead area limited by a line from the tragus up to the external canthus. The lower part of the face is divided into two areas by a central vertical line. For the second and subsequent coat(s), the double cotton buds are moistened three times only, for applying the peel solution on each of the three areas.

described earlier, this first coat should not cause any problems. It must be allowed to dry completely before the second coat is applied. The doctor applies the number of coats needed to produce the first pinpoint frosting or, at the most, cloudywhite frosting.

End of Application of ETCA Peel Solution (Basic Protocol) The postpeel mask cream should be applied as soon as pinpoint frosting occurs (Figure 15.11).8 After the appearance of pinpoint frosting, applying another coat of ETCA solution produces cloudy-white frosting (Figure 15.12). If the pinpoint frosting occurs quickly (which can occur with very permeable skin), the postpeel mask can be applied even if the acid has not completely dried. If the pinpoint frosting appears slowly (which can occur with less permeable skin), the postpeel mask should be applied after the skin has completely dried.

Potential Depths of Action The potential depths of action of Easy TCA Classic and Easy TCA Pain Control are summarized in Table 15.9.

Thin Skin versus Normal or Thick Skin The number of coats necessary to produce the first pinpoint frosting depends on the patient’s skin type (Table  15.7).7 An easy way to determine the thickness of the patient’s skin is by simply “pinching” the cheek where the cheekbone is most prominent (Table 15.8). Table 15.7  Number of Coats Needed to Achieve Pinpoint Frosting (A Rough Guide) Skin type

Number of coats

Thin skin Skin treated with AHA, benzoyl peroxide, etc. Skin treated with retinoic acid Normal skin Thick and oily skin

1 only 1 only 1 only 1–2 2–4

Table 15.8  Thickness of Pinched Skin Thickness (cm)

Skin type

1

Thin Normal Thick

Figure 15.12  Cloudy-white frosting.

112   Textbook of Chemical Peels Table 15.9  Potential Depths of Action of ETCA Depth of ETCA peel

Clinical signs

Repetition of ETCA

Superficial: partial removal of the epidermis Basic protocol: removal of the epidermis. The peel reaches the basal layer. Basic protocol: removal of the Grenz zone. The peel reaches the Grenz zone. Medium protocol: removal of the papillary dermis Abrasive protocol: removal of the reticular dermis

Erythema without frosting Pinpoint frosting

4 peels: 1 per week 4 peels: 1 per week

Cloudy-white frosting

4 peels: 1 per week

Even pink-white frosting Skin liquefaction after 24 hours

After 1 month After 1 month

SKIN

SKIN

TECH

TECH

0.5 g 2g

1g

0.5 g 2×0.5g

3g

0.5 g 0.5 g

Post Peel Mask

Post Peel Mask

(a)

(b)

Figure 15.13  (a) Dosage card from the ETCA kit. One side of this card shows icons; beside each one is the quantity of cream needed for each zone. To treat the face, 2 g are needed, while to treat the face and neck, 3 g are needed. (b) The lines on the other side of the card help to correctly dose the postpeel cream: 1 line is equivalent to 0.5 g of postpeel cream (2 lines = 1 g and 4 lines = 2 g).

End of Application The peeling session is over after the postpeel mask cream has been applied (Figure  15.13a and b). The inflammatory reaction is beginning; therefore, the production of oxidants must be stopped quickly and the free radicals must be scavenged to break the cycle of self-perpetuating inflammation. The postpeel mask cream reduces the risk of complications. The Easy TCA or Easy TCA Pain Control solution has permeabilized the skin: the components of the postpeel cream are rapidly absorbed and ready to act precisely where the free radicals have been produced. It scavenges the free radicals to reap the advantages of inflammation (stimulation of the regeneration processes) but not the disadvantages (uncontrolled and self-perpetuating inflammation), which are the cause of most postpeel complications. The patient should be warned not to wash the treated area until the next morning and to leave the postpeel mask to work for at least 6 hours. The next morning, the treated area should be washed with a mild soap or cleansing lotion and rinsed with water. No metal jewelry should be worn next to the skin on the treated areas for 48 hours.

progressively become gray, which is a sign of a focal deep reticular penetration. 2. Small lentigines also need to be treated because they will become large. Easy TCA Classic is used. Typically, two or three coats are applied until frosting clouds appear (Figure 15.14). At the end of peel application, the postpeel mask was selectively applied on the left part of the patient’s décolletage, and the anti-inflammatory effect could be seen a few minutes after application. Pain dissipated on the left side, and redness also began to dissipate (Figure 15.15).

Postpeel Mask Efficacy A patient underwent a first peeling session on her décolletage to treat small and large lentigines. A combined treatment was used: 1. Focally touch the large lentigines with one cotton bud soaked with 0.15 ml of Only Touch peel. Do not press the product on the skin and do not allow a long contact time. Several successive touches are allowed until a white frosting appears. After white frosting appears, do not apply more product, because the white frosting will

Figure 15.14  Application of Only Touch peel.

Easy TCA and Easy TCA Pain Control: Description and basic protocols   113

Figure 15.17  Postpeel mask on décolletage after 20 minutes. Figure 15.15  Postpeel mask on décolletage.

Five Minutes after Postpeel Mask Application The anti-inflammatory effect is clearly visible on the left side, compared to the right side. Edema and burning sensation disappeared; the area was notably less hot compared to the other side. Erythema is in phase of disappearing. Note the sharp difference between the area treated with postpeel mask and the untreated side. Ten Minutes after Postpeel Mask Application The postpeel mask’s anti-inflammatory effect is nearly complete on the areas treated with Easy TCA Classic up to the Grenz zone. A large surface of skin has already returned to a normal color, without any sign of inflammation. The areas treated with focal application of the Only Touch peel are reacting more slowly; the cream needs more time to reach the deep reticular dermis and is partially diluted into the huge edema created by the application of the focal deep TCA peel. Nevertheless, it is apparent that many of the lentigines treated with Only Touch show reduced redness and swelling (Figure 15.16). Twenty Minutes after Postpeel Mask Application Nearly all of the left side inflammation has disappeared. The area located on the border of the nontreated area seems to have resisted the action of the postpeel mask. This could result from

its proximity to a large area of inflammation that could “contaminate” the border area with persisting pro-inflammatory components (Figure 15.17). In summary, the postpeel mask suppresses a majority of the signs of inflammation in less than 30 minutes. Even through it suppresses the burning pain induced by acid application, it is not a neutralizing cream. The postpeel mask has a quick and strong anti-inflammatory action that can break the cycle of selfmaintained inflammation, which is potentially responsible for many side effects.

DAILY CARE ROUTINE Starting the day after any peeling, sun protection (Skin Tech Melablock-HSP SPF 30 or 50+) is required and must be applied until the end of the second week after the last peeling (applications at 9 a.m., 1 p.m., and 3 p.m.). On the day after the first peeling, the patient should begin applying, once or twice a day, the appropriate Skin Tech creams described in Table 15.10, until the problem disappears. The ETCA sessions are just the start of the skin treatment. The peels should be combined with appropriate daily care to effectively combat the signs of aging. Skin Tech’s care creams have been specially designed to be applied not only in combination with the peels but also in the long term (at least 6 months) to maintain results.

Precautions The patient should avoid aggressive scratching or picking at the flaking areas of skin, and should call the doctor with any questions or concerns, no matter how minor.

WEEKLY REPETITION OF EASY TCA OR EASY TCA PAIN CONTROL

Figure 15.16  Postpeel mask on décolletage after 10 minutes.

The ETCA basic protocol (basic protocol to achieve scattered pinpoint frosting) is repeated four times,9 at weekly intervals for a facial peel and at twice-weekly intervals for a body peel. This repetition is one of the peel’s built-in safety features; applying just one ETCA peel may not be enough and may cause complications (Figure 15.18). Easy TCA Pain Control could be applied in a slightly different way. It is more efficient than Easy TCA classic, and

114   Textbook of Chemical Peels Table 15.10  Skin Tech Postpeel Creams For acne

Purifying Cream: very hydrating cream suitable between peeling sessions or Purigel gel: suitable for long-term treatment, after the end of the peeling sessions Blending Bleaching Cream 2 or 3 times/day Vit. E Anti-oxydant cream as many times as necessary or Nutritive Cream Vit. A-C-E Lipoic Complex as many times as necessary DHEA-Phyto Cream, mainly for patients over 40 years old or ATROFILLIN cream for patients suffering from subcutaneous fat atrophy ACTILIF cream 2 times/day: tensing effect due to DMAE IPLase Mask; also suitable after lasers, radiofrequencies, radiotherapy, etc. Melablock-HSP 30 for cloudy-rainy weather, phototypes 1–3 Melablock-HSP 50+ for sunny areas, phototypes 4–6

For pigmentation For dry skin Aging skin For skin laxity For postpeel erythema Sun protection

Generally, if any cream produces a sensation of intense heat, suspend the application for a few days.

8 days 8 days 8 days

1st ETCA

2nd ETCA

3rd ETCA

8 days 8 days 8 days

4th ETCA

1st ETCA

2nd ETCA

3rd ETCA

8 days 8 days 8 days

4th ETCA

1st ETCA

2nd ETCA

3rd ETCA

4th ETCA

Daily care

Figure 15.18  Diagram showing repeated cycles of skin regeneration. A maximum of three cycles is possible. More than 90% of cases are treated in one cycle. It is extremely rare to have to apply a third cycle.

two or three sessions might be sufficient for the patient. If the peeling was deep (to the ­papillary dermis), the next peeling can be performed only when all the signs of the first peel have disappeared.

Repetition of Facial Peels A schematic illustration of the repetition of ETCA treatment for facial peels is shown in Figure 15.19. Eight days is the average frequency; the outside limits are a minimum of 5 days (if the condition of the skin allows) and a maximum of 15 days.

Repetition of Body Peels

DAILY CARE

NO SEASON LIMITATION

PROFESSIONAL ADVICE

Body skin is not as permeable nor does it have the same capacity for regeneration as facial skin. For this reason, body peels can be repeated only once every 2 weeks on average. The outside limits are a minimum of 10 days (if the skin allows) and a maximum of 30 days.

Abrasive protocols are repeated once a month. After four sessions,9 a rest period of 4–6 weeks allows the skin to regenerate fully and the results to be improved or maintained through the use of appropriate cosmeceuticals. Abrasive protocols alter the reticular dermis and cause a definitive and irreversible skin reaction. The results achieved in each session can therefore be considered definitive, and the rest period of 4–6 weeks is a minimum. The subsequent peel can, however, be planned well ahead of the last one: 3 months, 6 months, 1 year, and so on.

SKIN REGENERATION CYCLE This chapter has described how to induce a cycle of skin regeneration: four successive peels followed by (at least) 6 weeks of applying suitable care creams represents a cycle of skin regeneration.

NUTRATITIVE CREAM VIT. A-C-E LIPOIC COMPLEX morning/evening(moisturizer) CLEANSER twice a day Sun protection: MELABLOCK-HSP® SPF 50+

8 days 1st

Repetition of Abrasive Protocols

8 days 2nd

8 days 3rd

8 days 4th

EASY TCA CLASSIC sessions EASY DROXY COMPLEX PEEL sessions

Figure 15.19  Repetition of Easy TCA on the face.

6-week period

5th

REPEAT if necessary

Easy TCA and Easy TCA Pain Control: Description and basic protocols   115

What to Do after the First Skin Regeneration Cycle

NOTES

A single cycle of regeneration is enough to achieve the desired results in the vast majority of cases, but when the results of the first cycle are deemed inadequate, another regeneration cycle can be repeated after 6 weeks of applying cosmeceuticals at home, if the doctor believes that applying more peels will help improve the patient’s skin (see Figure 15.18). Up to three regeneration cycles can be repeated in some cases.

1. The breakdown of the corneodesmosomes has deeper repercussions in the skin (see Chapter 6). 2. See Chapter 6 for more information on the relationship between pKa and peels. 3. Which some doctors judge to be more than 75%. 4. The amount of TCA at 50% m/m that should be injected into each bottle of base solution is usually 4.8 ml. There are different types of presentation kits (Classic kit for 12 peels, Classic kit for 24 peels, and Starter’s kit for 4 peels), and it is preferable to refer to the information contained in each kit. 5. See the discussion at the start of Chapter 14 regarding differences between ETCA and TCA–SAS peels. 6. Recall that the penetration depth of TCA also depends on the pressure with which it is applied: it is recommended to apply the same amount of pressure as when scratching. 7. This is why there is usually a lot of solution left when pinpoint frosting appears. The volume of solution allowed for is to treat oily, thick, and resistant skin. 8. With some protocols, it is recommended to produce cloudywhite frosting locally (see Chapters 16 and 22 on the treatment of melasma and lentigines). 9. Four times is, of course, an average. If the results are obvious, the treatment can be stopped after three sessions. If results are slow to appear and the skin is thick, up to six peels might be necessary.

MAINTAINING RESULTS IN THE LONG TERM Easy TCA or Easy TCA Pain Control, in base protocol, is more of a stimulating peel than a destructive one, and there is no risk of repeated peels making the skin less capable of regenerating in the future. One regeneration cycle per year (four peels plus 6 weeks of postpeel care), combined with daily care creams, helps the skin stay healthy in the long term. This technique is commonly known as SYFE, or “Stay Young Forever.”

TREATING PHOTOAGING AND SMOKERS’ SKIN Applying the Peel The Easy TCA or Easy TCA Pain Control basic protocol can be used to treat the visible signs of aging: dull, dry, wrinkled skin and uneven skin tone. To combat the signs of photoaging, the basic protocol should be followed as described above. Four (sometimes five) peels should be applied in all, at weekly intervals.

16 Treating melasma, chloasma, and postinflammatory hyperpigmentation The histological features of melasma and chloasma are discussed elsewhere in this book. The standard recommendations for treatment often mention only the topical applications tretinoin, hydroquinone, fluorinated corticosteroids, sun protection, and tyrosinase inhibitors; chemical peels are considered as a last resort because of their potential to turn melasma into postinflammatory hyperpigmentation (PIH). Conventional peels require conscientious prepeel preparation to avoid this danger. Easy TCA (ETCA), in combination with appropriate postpeel care, can be used to treat melasma without the constraints of prepeel preparation (Figures  16.1–16.5). Laser therapy is not recommended for treating melasma because lasers are difficult to use and have been linked to many common side effects. The numerous evolutions and promises of laser therapy have not solved these problems. Before performing an Easy TCA Classic or Easy TCA Pain Control peel, it is not usually necessary to prepare the skin, but for patients with long-standing or resistant melasma or with a skin phototype higher than Fitzpatrick III, preparing the skin can be worthwhile and improve results:

2. A focal, deeper application only on the melasma area can be used. A first coat of ETCA solution is applied to the melasma and left to dry completely (Figure 16.6). The desired endpoint is cloudy pink-white frosting that is the same shape as the melasma plus 1 cm. If there is no frosting after the first coat, additional coats of ETCA solution must be applied until cloudy pink-white frosting occurs. There is no set number of coats required, and there is no way of knowing in advance how many to apply. Each coat of ETCA solution must be left to dry completely before applying the next coat if the skin has not frosted sufficiently. More resistant skin shows cloudy pink-white frosting only after three or four coats. Once localized cloudy frosting has been achieved on the melasma, the ETCA solution is applied to the whole face, following the instructions for the basic protocol. It is up to the doctor whether this last coat should go over the frosting on the melasma as well: •

PREPARING THE SKIN The following are recommended to prepare the skin before the peel: • •

Blending Bleaching Cream (see Chapter 3): Applied twice a day on the melasma itself and once a day on the rest of the face. Melablock-HSP 50+ (see Chapter 3): Applied all over the face in the morning and then reapplied every 3 hours on the melasma itself.

Practitioners should understand that while a peel eliminates the constituted stock of melanin, it does not act on melanin synthesis. Blocking melanin synthesis or melanosomes transfer is needed to insure a long-term result (see Table 16.1). In other words, Easy TCA can eliminate the melanin responsible for the melasma but will not act on melanin synthesis, which means it will not prevent melanin neo-synthesis. Preventing the melasma from recurring requires long-term daily care with products that block the chemical and enzyme pathway from tyrosine to the large polymer melanin.

APPLYING THE EASY TCA PEEL SOLUTION Refer to Chapter 15 for details about the correct application of Easy TCA. Melasma can be treated in two different ways: 1. The basic protocol can be used, as in cases of diffuse, epidermal pigmentation.

•

If the frosting on the melasma is pink and even, with some epidermal sliding,1 the ETCA solution should not be applied there again. If the frosting is uneven, the ETCA solution can be applied to the melasma again at the same time it is being applied to the whole face.

The previous coat must be completely dry before another coat can be applied.

APPLYING THE POSTPEEL MASK The ETCA postpeel mask cream is applied to the whole face, starting from the melasma. A little more of the postpeel mask is applied to the melasma itself.2 The components of the ETCA postpeel mask cream work directly and specifically on pigmentation. If possible, after the mask has been applied, the face should not be washed until the following morning.

POSTPEEL DEVELOPMENTS The acids dehydrate the keratinocytes and make the melasma appear darker the day after the peel and for several days afterward (Figure 16.6). This is not a pigmentary change. The darkening of the melasma in the first few days after the first ETCA peel is, on the contrary, a positive prognostic factor, a sign that the acid is working.

REPEATING THE PEEL The ETCA peel is repeated four times at weekly intervals (see Chapter 15). The doctor can change the total number of peels as

Treating melasma, chloasma, and postinflammatory hyperpigmentation   117

Figure 16.1  Melasma on the neck. The position might suggest poikiloderma of Civatte, but there is neither telangiectasias nor any atrophy of the skin around the follicle.

Figure 16.4  Treatment of melasma with ETCA and Blending Bleaching Cream. Patient with light skin phototype.

Figure 16.5  Treatment of melasma with ETCA and Blending Bleaching Cream. Patient with dark skin phototype. Figure 16.2  On the third day after ETCA treatment, epidermal melanin has been eliminated.

Table 16.1  Active Products against Melanin Products that can

Figure 16.3  Results after four ETCA peels and Blending Bleaching Cream.

Nonlimitative list

Remarks

Prevent melanin synthesis

Tretinoin, tranexamic acid, or other anti-inflammatory molecules

They typically have little effect on melasma after the melanin has been transmitted to keratinocytes.

Lower melanin synthesis

Azelaic acid, arbutine, hydroquinone, kojic acid, licorice extracts, resveratrol and oxyresveratrol, polyphenols, vitamin C, phytic acid Arbutin, glabridin, niacinamide, retinoids, and linoleic and linolenic acids

Accelerate epidermal turnover, to limit the transfer of melanin through melanosomes, to reduce melanin, etc.

Chemical peels, especially, allow the destruction of the cells containing melanin, to eliminate the actual epidermal (or dermal, depending on the peeling depth) stock of it.

118   Textbook of Chemical Peels

(a)

(b)

(c)

(d)

Figure 16.6  (a) Melasma before treatment. (b) Cloudy-white frosting after application of ETCA solution. (c) Flaking on third and fourth day. (d) Results after day five with the second ETCA combined with Blending Bleaching Cream.

well as the intervals between them, depending on the condition of the patient’s skin. The minimum recommended interval is 5 days and the maximum 15 days.

MELANIN SYNTHESIS AND HOW BLENDING BLEACHING CREAM WORKS Figures 16.7 through 16.15 illustrate the process of melanin synthesis from the amino acid tyrosine up to effective melanin.

DAILY POSTPEEL CARE Postpeel care is essential to achieve optimum results and avoid complications (Table 16.2). Lightening creams (Blending Bleaching Cream) and sun protection (SPF 50+) should be applied beginning on the morning after the first ETCA peel.

COMBINATION OF EASY TCA AND BLENDING BLEACHING CREAM The complex formulation of Blending Bleaching Cream makes it highly effective. This effectiveness is the reason Blending Bleaching Cream is a required element in treatments for pigment problems.

Table 16.2  Postpeel Care Boost the results

Blending Bleaching Cream during the regeneration cycle • On the whole face in the morning • On the melasma only at midday and in the evening

Protect against stimulation from the sun’s rays

Melablock-HSP 50+

Maintain the results (6 months–1 year daily care maintenance)

Blending Bleaching Cream: 3 days per week

• Every 3 hours (during the cycle) • Sun avoidance (6 months–1 year) • Melablock-HSP 30: morning and midday • Four ETCA or ETCA Pain Control sessions repeated once or twice a year as necessary

Treating melasma, chloasma, and postinflammatory hyperpigmentation   119

Keratinocyte Melanin transport Melanosome Golgi apparatus Tyrosinase + transport vesicle Ribosomes on ENDOPLASTIC RETICULUM

Nucleus

Cell membrane

Figure 16.7  Melanin synthesis (courtesy of Skin Tech).

Active products of Blending Bleaching have to reach quickly the basal layer: Ethylene diglycol concentrates active products around the basal layer

Tyrosinase is synthesized by ribsomes or E.R. then transferred to Golgi where it works on tyrosine (transport proteins with clip-clap system) to build melanin polymer

Keratinocyte Melanin transport Melanin granule (no tyrosinase activity)

Melanin synthesis pathway Melanosome Golgi apparatus

Melanosome III (tyrosinase + melanin)

Golgi

Melanosome II (tyrosinase + melanin)

Tyrosinase transport vesicle

Nucleus

Tyrosinase synthesis

Tyrosine

Rough endoplasmic reticulum

Basolateral plasma membrane

Tyrosinase Tyrosine

Figure 16.8  The tyrosinase pathway.

Tyrosinase DOPA

Oxidation

Membrane-bound polyribosomes on ER

Dopaquinone Oxidation

120   Textbook of Chemical Peels

Morus extracts:

Arbutin:

Contain OXYRESVERATROL 30 × more active compared to kojic acid Contains MULBERROSIDE (A, B, F); MULBERROFURANE; MORACIN (N, O, C)

Direct derivative of hydroquinone The glycosidic bond is hydrolyzed in vivo by the normal skin microflora leading to the controlled release of hydroquinone Arbutin acts by tyrosinase activity inhibition

NON competitive inhibition of tyrosinase Inhibit oxidation of tyrosine by tyrosinase

Arbutine Morus extracts Aspergillus (Kojic) Licorice - glabridin

ASPERGILLUS extracts contains natural kojic acid (KA)

Licorice contains i.e. glabridin

KA acts by inhibiting the production of free tyrosinase Potent antioxidant

Tyrosinase inhibitory properties Anti-inflammatory properties

Tyrosinase

Tyrosinase DOPA

Tyrosine Oxidation

Dopaquinone Oxidation

Figure 16.9  Interrupting the tyrosinase pathway.

Phaeomelanin

Oxidative polymerization of HBTA

(Cysteinyldopa oxidized in -> HBTA 5-hydroxy 1,4-benzothia-zinylalanine

Aspergillus extracts and kojic acid Tyrosinase Tyrosine

Tyrosinase Dopaquinone

DOPA Oxidation

Oxidation

Back reduction Vit C (ascorbyl phosphate Mg) ANTIOXIDANT is able to reduce back dopaquinone into DOPA, avoiding dopachrome and melanin formation

Figure 16.10  Two additional methods to avoid dopaquinone converting into the next subproduct (dopachrome).

Treating melasma, chloasma, and postinflammatory hyperpigmentation   121

14 active molecules acting at these levels

Phaeomelanin 2 active molecules acting at this level

DOPA

Tyrosine

Dopaquinone Back reduction

11 active molecules acting as antityrosinase

2 active molecules (ALA-P and kojic acid) act as anti dopachrome tautomerase and therefore limit polymerization

Leucodopachrome

Dopachrome Tyrosinase

DCT

5-6 Indolequinone

5-6 Dihydroxyindole

Polymerization

Melanin

Figure 16.11  The melanin pathway.

As mentioned earlier, Blending Bleaching Cream inhibits melanin synthesis at the melanocyte level and also inhibits the transfer of melanosomes to keratinocytes, but it does not remove the actual skin stock of melanin. • •

The cream’s latency of action when used as a unique treatment is 8 weeks. Using it in combination with alpha hydroxy acid (AHA) or trichloroacetic  (TCA) peels is ideal because the skin’s higher postpeel permeability allows the cream to penetrate deeper and faster, increasing and speeding up the results.

Potential Problems Persistent Dark Ring on the Edge of the Melasma In this case the pink-white frosting has not gone beyond the edge of the melasma; it should go 1 cm beyond. The peel could not work on the melanin around the edges (Figure 16.16).

Recurrence To prevent the melasma from recurring: •

It is important to check that the patient has kept up with postpeel care.

• • • •

The four ETCA peels should be repeated once or twice a year. The need for the following should be stressed: • Sun protection with Melablock-HSP 50+. • Blending Bleaching Cream. A strong corticosteroid can be applied to the melasma immediately after the postpeel mask cream, after every peel, to reduce any inflammation. The use of 5% hydroquinone (and 0.05% tretinoin) in combination with the Blending Bleaching Cream should be evaluated.

Melasma Chart Figure  16.17 gives general advice about decisions to be made during a full course of melasma treatment. Note that the advice represents a personal point of view only. Medical treatments depend on the diagnosis and the treatment decision of the practitioner, who has full responsibility for treatment decisions and possible side effects resulting from them.3

POSTINFLAMMATORY HYPERPIGMENTATION With topical treatment alone, PIH usually has a good prognosis. Blending Bleaching Cream or a prescription cream

122   Textbook of Chemical Peels

ALA - P (albatin) Stabilizes DOPACHROME Inhibits dopachrome tautomerase Opposes further spontaneous polymerization

1-aminoethyl phosphinic acid (ALA-P) kojic acid

DCT 5-6 Dihydroxyindole

Polymerization

Melanin

Figure 16.12  The ALA-P pathway to melanin (courtesy of Skin Tech).

Back reduction Tyrosine

DOPA

Dopaquinone

Leucodopachrome

Phaeomelanin

Dopachrome

5-6 Indolequinone

5-6 Dihydroxyindole

Polymerization

Eumelanin

Licorice extracts Ascorbyle Phosph.Na

Melanin reduction

Figure 16.13  Eumelanin + phaeomelanin + reduced melanin = mixed melanin (courtesy of Skin Tech).

Treating melasma, chloasma, and postinflammatory hyperpigmentation   123

Kojic acid Inhibits dendritization

Phaeomelanosome Eumelanosome

Dendrite Keratinocytes Premelanosome

Melanosomes

Nucleus

Melanin grains

Melanocyte

??

Melanocyte Basal membrane

Figure 16.14  The influence of kojic acid (courtesy of Skin Tech).

Kojic acid inhibits dendritization

Basal layer Receptors triggered by free radicals initiate production of tyrosinase enzyme

Basal layer Tyrosinase activates melanocyte to start producing melanin

Epidermis layer Melanin is transfered from melanocyte to skin’s surface

Figure 16.15  The effect of the sun on the skin. Left: Free radicals produced by sun exposure switch on melanin production. Retinol, tocopherol, vitamin C, kojic acid, and licorice oppose oxidative processes are induced by UV and responsible for inflammatory response. Right: Melanin accumulates in the epidermal cells. Retinol stimulates epidermal turnover; allantoin is a keratolytic and a moisturizer.

with hydroquinone 2%–4% and effective sun protection (Melablock-HSP 50+) should be used. PIH tends to improve gradually and naturally, and disappears completely if it is not too severe and the melanocytes are not stimulated by UV photons.

PIH, whether caused by trauma (e.g., a mosquito bite, scratch, or wound), laser or intense pulsed light (IPL) treatment, or another peel, usually responds to four sessions of  ETCA following the same guidelines as for melasma treatment.

124   Textbook of Chemical Peels

Figure 16.16  Persistence of a dark ring on the edge of the melasma.

Melasma Phototypes 1-3

Phototypes 4-6

1st Peel

1st Peel

ETCA* GZ* on melasma + BL* rest of face +DC*

ETCA* BL* Full face 1 week

1 week

2nd Peel Before peel, check if Worse

Stable

Better/Cured

ETCA* BL* Full face + DC* + Hq*

ETCA* GZ* on melasma + BL* rest of face +DC* + Hq*

ETCA* BL* Full face + DC*

Daily Care (DC*) Blending Bleaching Cream (morning & evening)

2nd Peel Before peel, check if Better/Cured

1 week

Suspend Peels

ETCA* GZ* on melasma + BL* rest of face +DC* + Hq*

1 week

3rd Peel Before peel, check if

Better/Cured ETCA* BL* Full face + DC*

1 week

4th Peel Before peel, check if Worse

Stable Suspend peels

Worse ETCA* BL* Full face +DC* +Hq*

+

Before peel, check if Stable

Stable

ETCA* BL* Full face + DC*

Melablock-HSP SPF 50+ or 30 (9am 12pm 3pm)

3rd Peel

Worse

PREPEEL CONDITIONING 3-4 weeks Blending Bleaching Cream 2 times a day + Hydroquinone 3% 2 times a day + Melablock HSP SPF 50+ 9am - 12pm - 3pm

Better/Cured Last ETCA* BL* Full face +DC*: 3-12 months

Better/Cured

Stable

Worse

ETCA* BL* Full face

ETCA*1 BL* Full face

Suspend peels

+ Daily care

Suspend Peels Blending Bleaching 2x/day + Hydroquinone 3% + Melablock-HSP SPF 50+ 6-8 weeks then peel again according to phototype

Hq*+DC*

1 week

4th Peel Before peel, check if Better/Cured Last ETCA* BL* Full face +DC*: 6-12 months

Stable

Worse Suspend peels

*ETCA: Easy TCA - *BL : Basal layer - Frosting points - *GZ: Grenz Zone - Frosting Clouds exactly on melasma - *Hq: Hydroquinone 6% 2x/Day to be mixed 50/50 with Blending Bleaching immediately before applying - *DC : Daily Care

Figure 16.17  The melasma chart.

Treating melasma, chloasma, and postinflammatory hyperpigmentation   125

NOTES 1. Fine wrinkling of the skin when pinched: the acid coagulates proteins that ensure cohesion between the dermis and epidermis, and the epidermis slides on the dermis to which it is no longer firmly attached.

2. The quantities of postpeel mask cream have been overestimated to allow for more cream to be applied in certain areas. Each small tube contains 10 g of postpeel mask, and 8 g is enough to do four basic facial protocols. 3. Also see: http://www.skintech.info/melasmachart.

17 Treating acne Classic recommendations for treating acne with peels are the following: 1. Treat acne to stop infection and stop inflammation, using antibiotics, retinoids, hormonal treatments, and so forth. Eventually, clean the skin, opening comedones, papules, and pustules. 2. Only when acne is no longer active, begin peels for a better cosmetic appearance. Clinical experience has shown that there is a much faster—yet largely unknown—method to eliminate acne, without using antibiotics or retinoids. It is very simple to physically extract from the skin the cause of infectious acne, and at the same time regenerate good skin architecture. The treatment that will be described in this chapter consists of extracting open or closed comedones and pustules, and applying an Easy TCA or Easy TCA Pain Control peel immediately after extraction.

EXTRACTION OF COMEDONES, ELIMINATION OF MICROCYSTS AND PUSTULES After disinfecting the skin, the comedones are extracted using a comedone extractor. Pustules and microcysts (closed comedones) are extracted by cutting the thin epidermal layer that covers them and gently pressing the skin to push them out. Epidermal cutting can be done with a No. 11 scalpel blade or, more simply, a needle (18-gauge). The doctor will judge whether he or she prefers to extract all the comedones before the first of the four Easy TCA (ETCA) peels or to extract only some of the comedones before each peel. Patients usually prefer the second option as it is less aggressive. The choice depends on the number of comedones to be extracted: if there are only a few lesions, they all can be extracted at the same time; numerous lesions should be extracted progressively before each of the four ECTA sessions (Table 17.1).

cotton buds should be squeezed out properly before applying the ETCA/Easy TCA PC solution. Whether all acne lesions will be opened at the same time before the first peeling session or progressively before each session is a decision the doctor must make. Note that opening many acne lesions could cause a strong inflammatory reaction and be painful for the patient. A better option seems to progressively open acne lesions before each peeling session. Figure 17.5 shows how to progressively eliminate physically acne lesions before every peeling session.

CARE BETWEEN AND AFTER PEELS Care creams (Table  17.2) should be used beginning on the morning after the first peel. The skin should be cleaned in the morning and evening with a cleanser.

Between Peel Sessions • •

Long-Term Maintenance Treatment Oil-free Purigel should be applied once or twice a day according to medical advice. The four ETCA peeling sessions are repeated once or twice a year.

Combined Antibiotic Treatment The doctor will decide if it is necessary to perform a combined medical treatment. For example, if papular acne does not improve after the first two sessions, the peel should be combined with 100 mg/day of minocycline.

Treating Acne Side Effects •

EXAMPLES OF INDICATIONS Indications include comedonian acne (Figure 17.1), microcystic acne (Figure 17.2), typical juvenile acne (Figure 17.3), and papulo pustulous acne (Figure 17.4).

APPLYING THE PEEL SOLUTION As soon as the comedones have been removed, the ETCA or Easy TCA Pain Control (PC) solution is applied following the basic protocol (Chapter 15). The solution penetrates and disinfects the openings left by the comedones. This localized penetration has not been reported to have any negative effect. The irritation caused by extracting the comedones can, however, cause the ETCA/Easy TCA PC solution to penetrate more deeply and produce “cloudy” rather than “pinpoint” frosting. To reduce the risk of cloudy frosting developing, the

In the morning, Purifying Cream should be applied to the whole face. In the evening, Purifying Cream should be applied only to the areas with acne.

•

•

•

Postacne pigmentation on the face (Figure  17.6) can be treated in the same way as melasma, combining ETCA (basic protocol), Blending Bleaching Cream, and sun protection (Melablock-HSP 25+ is sufficient). Postacne pigmentation on the décolletage can be treated in the same way, but there is also an abrasive protocol designed especially for the décolletage: abrasion plus occlusion of the postpeel mask without the application of acid (see Chapters 20 and 21). Postacne pigmentation on the back does not respond readily to ETCA alone. The protocol developed for treating stretch marks produces excellent results—not only on the residual pigmentation but also on the depth of the acne scars. Facial acne scars can be treated by dermabrasion followed by peeling (see Chapter 21).

Figures 17.7–17.9 show more results for acne treated with ETCA peels. ETCA can treat the activity of acne, but acne scars

Treating acne    127 Table 17.1  Protocol for Extraction Action

Material needed

Skin disinfection Extract the “acne lesions”

Alcohol or chlorexidine Comedone extractor 18-gauge needle No. 11 scalpel blade

Apply peeling solution

Easy TCA or Easy TCA Pain Control

Apply the postpeel mask cream

Postpeel mask

Repeat the peel four times at weekly intervals

Eventually extract comedones and open other acne lesions before each peeling

Maintenance treatment

Skin Tech Cleanser Skin Tech Purifying Cream Skin Tech Purigel

(a)

Details Extract blackheads (comedone extractor) (Figure 17.1). Open microcysts and pustules (needle, blade) (Figures 17.2, 17.3, and 17.4). Do not touch papules. If there are only a few lesions, all lesions can be extracted together, just before the first of the four ETCA peels; if there are many lesions, some can be extracted before each of the ETCA sessions. Immediately after extracting the acne lesions, apply the ETCA (or ETCA PC) solution on the whole face and allow it to dry completely before applying more coats. End point: Pinpoints of frosting appear or, at the most, localized cloudy-white frosting. The ingredients of the ETCA or ETCA PC postpeel mask stimulate skin regeneration and reduce the risk of side effects, thanks to their antiinflammatory and antioxidant action. Do not wash the skin for at least 6 hours after application of the mask to allow the active ingredients in the postpeel mask and the peel solution to work. Repeating the peels in the proper manner ensures good results and reduces the risk of side effects. The doctor decides on the interval between peeling sessions, depending on the condition of the patient’s skin. Minimum interval between two peels: 5 days (if less than 5 days, the peel might be too deep). Maximum interval between two peels: 15 days (if more than 15 days, results will be less satisfactory). Cleanse the skin every morning and evening with Skin Tech Cleanser (balances skin pH at 5). Extract blackheads/whiteheads and microcysts once a month. Repeat one session of four ETCA peels, once a year. As long as peelings are done, apply Purifying Cream twice a day. Two weeks after the last peeling, stop using Purifying Cream and substitute it with Purigel once a day for a long-term maintenance program.

(b)

Figure 17.1  (a) Comedones before treatment. (b) Immediately after comedone extraction and ETCA peels.

128    Textbook of Chemical Peels

(a)

(b)

Figure 17.3  (a, b) Detail of the temple area of a young patient with papulopustular acne treated with ETCA and Purifying Cream.

suitable treatment: antibiotics, hormone therapy (cyproterone acetate), or a combination of treatments (Table 17.4).

GENERAL REMARKS ON TREATING ACNE WITH PEELS Speed of Results

Figure 17.2  Microcystic acne.

that remain after ETCA should be treated using the anterior abrasion technique described in Chapter 21. Additional tips are listed in Table 17.3.

Normal Evolution and Problem Solving Results should be evident after the first few peels. If this is not the case, the doctor should develop an etiological diagnosis and

(a)

When treating acne, as with melasma, obtaining results quickly is a positive sign that could indicate excellent end results. If the acne or melasma improves after the first session, the patient can usually be guaranteed satisfactory and rapid results. If, on the other hand, the situation has not started to change after the second ETCA session, it is likely that results will be slow and only partial, and other treatments should be combined with the peels (antibiotics with acne and hydroquinone with melasma). It is best to notify patients of these possibilities before starting treatment.

(b)

 

Figure 17.4  (a) A patient with acne that did not respond to a 3-month course of tetracycline. The antibiotics were stopped and four ETCA peels were applied at weekly intervals combined with Purifying Cream. (b) The results at the end of the first regeneration cycle—there is no scarring.

Treating acne    129

= Open comedones, subcutaneous cysts, pustules, IMMEDIATELY before peels

8 days

8 days

6 weeks regeneration

8 days

Time line

1st ETCA session

2nd

3rd

4th ETCA session

Purifying Cream

Purigel Sun protection: Melablock HSP 30

Figure 17.5  Treatment plan for acne.

Table 17.2  Comparison between Purifying and Purigel Creams

Treatment Must Remain Multifocal

Purifying Cream

Purigel

•

Antiacne moisturizing cream for daily care between peeling sessions Glycolic acid (8%): softens the skin, prevents pores from clogging, stimulates epidermal turnover (pH 4) Retinol: tretinoin precursor, helps drain the pilosebaceous units

Non-oily gel for long-term maintenance daily care Thiosome: lowers sebum production

•

Vitamin E (tocopheryl acetate) anti-free-radical, breaks the vicious circle of oxidation–inflammation Triclosan: antiseptic, antiinflammatory, antimycotic Glycyrrhetinic acid: hydrates, antipruritic, anti-allergic Tea tree oil: extract of an Australian shrub, as active as benzoyl peroxide but without the pro-oxidant effect—antibacterial, antiviral, antimycotic, anti-inflammatory

Burdock extracts: anti-inflammatory, antibacterial Keratolytic Triclosan: antiseptic, anti-inflammatory, antimycotic Salicylic acid: unclogs pores, keratolytic Menthol/camphor: fresh skin sensation

• • •

Normalize the rate of exfoliation/hyperkeratinization by enhancing elimination of dead cells and hydrating the skin properly: retinyl palmitate, glycolic acid, and glycyrrhetinic acid. Eliminate or reduce infection: disinfectants, tea tree oil, and azelaic acid. Help the pilosebaceous units drain: glycolic acid, lactic acid, retinyl palmitate, glycyrrhetinic acid, and azelaic acid. Eliminate or reduce inflammation: tea tree oil, glycyrrhetinic acid, and azelaic acid. Reduce sebum production: thiosome.

The protocols established for treating acne with ETCA in no way prevent the doctor from choosing the treatment that is best for the patient based on his or her knowledge and personal experience. ETCA helps combat acne lesions by exfoliating the skin chemically and through use of the postpeel mask cream. Daily care helps maintain the results of dermatological or systemic acne treatments. No peel can change the genetic makeup of a

Figure 17.6  Active acne and acne pigmentary sequellae on a phototype 5 patient. Result of treatment with ETCA, 4 peels, 1 peel/week, in combination with Blending Bleaching Cream and sun protection.

130    Textbook of Chemical Peels

Figure 17.7  Acne, before and after ETCA peel.

Figure 17.8  Acne, before and after ETCA peel.

Figure 17.9  Acne, before and after ETCA peel.

Treating acne    131 Table 17.3  Frequent Questions and Answers about Acne Treatment What happens when the acid penetrates through the openings left by the extracted lesions?

ETCA solution disinfects everything. There have been no reported adverse effects from this focal deeper penetration. On the contrary, it provides “deep pixelized stimulation.”

When should I begin applying daily care?

Purifying Cream daily care starts the next day after the first peeling session, or even before it. Purifying Cream should be applied until the end of the second week after the last peeling. Sun protection and sun avoidance are mandatory after any peeling. Melablock-HSP, SPF 30 or 50+

Should I use a sun protection?

The irritation resulting from handling the lesions can cause the ETCA solution to penetrate more deeply and cause cloudy-white frosting instead of pinpoint frosting. Purigel should be initiated 2 weeks after the end of the peeling sessions; continue until the acne is stabilized. For acne, Melablock-HSP SPF 30 is usually sufficient.

Table 17.4  Frequent Problems in Acne Treatment and How to Solve Them Difficulty extracting comedones The patient is on isotretinoin (Roaccutane). The patient is using AHAs, tretinoin, or topical benzoyl peroxide. Aggravation of the acne after the first session Aggravation of acne, and the patient already is using antibiotics Acne recurrence after few weeks of improvement How long is daily maintenance needed?

The patient does not want any flaking.

Folliculitis barbae

Place hot water compresses on the skin and try again, or try again after having done one ETCA. Suction devices can be used to help extract comedones. It is better to delay the treatment for a few months; if you cannot delay, treat the patient very carefully; do not go beyond pinpoint frosting. No peel beyond the basal layer should be performed on patients who are taking oral retinoic acid. These products reduce skin permeability to different degrees. There is a risk of increased penetration, so be careful how much ETCA you use. Do not go beyond pinpoint frosting. Give the patient oral antibiotics and continue with the ETCA. Antibiotics commonly used: oxytetracycline (500 mg/d), doxycycline or minocycline (100–200 mg/d); erythromycin (500 mg 2x/d). Check the patient’s hormonal status and use of contraceptive pill, continue treating the patient with antibiotics (eventually shift to another kind of antibiotherapy), and continue doing ETCA. Continue the maintenance treatment, repeat another four ETCA peels, or switch to Roaccutane. Peelings can reorganize the skin architecture and eliminate the visible signs of acne. They cannot treat the cause of acne (i.e., peelings do not affect 5-alpha reductase activity). Maintenance treatment should be employed as long as the skin needs it—as long as the body produces acne. Use Easy Phytic Solution or Easy Droxy Complex peel: these AHA peels offer good results in cases of acne, without flaking. They are the best choice for teenagers and people with active social lives. Use a nonpeeling technique: daily application of Dermasebex foam until acne inflammation disappearance, then two or three times/week for maintenance. Unless it requires treatment with oral antibiotics, folliculitis of the beard can be treated in the following manner: Open the “whiteheads” with the tip of the No. 11 scalpel. Drain the infection by squeezing gently and disinfect the skin. Apply ETCA to the whole face until pinpoint frosting occurs. Apply the postpeel mask. Daily care: Apply Purigel after showering. Using Dermasebex foam for shaving (mechanical) or after shaving (electrical) prevents folliculitis barbae from developing.

particular individual or his or her skin. For example, applying an acid does not reduce androgen production or change the sensitivity of sebocyte membrane receptors or the strength of 5-alpha reductase. The peel works on other parameters, such as intercorneocyte cohesion or unclogging the openings of the pilosebaceous units. Maintaining the results in the long

term depends on prolonged treatment with Purifying Cream, which should be applied twice a day, starting on the day after the first peel and continuing to at least 6 weeks after the last peel. Long-term maintenance of the results sometimes requires continued use of Purifying Cream or Purigel for several months.

18 Treating multiple keratoses on the scalp A balding scalp often shows signs of accelerated photoaging, with scattered lentigines and/or keratoses. Many peeling treatments are available (Table 18.1).

PREPARING FOR THE PEEL A peel for treating keratoses or lentigines of the scalp should be quite deep—the average depth is 5/7 or 6/7. This depth of peel applied on a large, low-permeability surface can be quite painful for the patient, because several coats usually are needed to reach the correct depth. The first coats are not too painful, but as the acids make their way to the deep dermis, inflammatory pain develops and the passes of cotton buds begin to feel like cuts with razor blades to the patient. Analgesics or nerve blocks are therefore recommended for the patient (Table 18.2). This chapter describes the application of Easy TCA, Easy TCA Pain Control, or Unideep to treat scalp keratoses. The use of Lip & Eyelid Formula and Easy Phen Light is described in Chapters 34, 35, and 36.

APPLYING THE EASY TCA (OR EASY TCA PAIN CONTROL) SOLUTION The first coat of the peeling solution is applied to the whole scalp and left to dry. Additional coats are then applied as necessary to achieve an even white-gray frosting of the skin. The keratoses are relatively impermeable to acids. If a focal application of peeling solution has not been done, the frosting typically is uneven (Figure  18.1). As soon as there are signs of epidermal sliding, the frosting is sufficient (Figure 18.2) (see Chapter 14). The acid works by “undermining,” or going underneath, the keratosis. Each coat is left to dry before applying the next one. Up to five coats of Easy TCA are sometimes required. Other peels listed in Table 18.3 require fewer coats.

POSTPEEL DEVELOPMENTS AND CARE Flaking occurs after at least 1 week and lasts 4–5 days. On days 1–6, IPLase cream should be applied to combat the formation of free radicals and reduce erythema; vitamin E ­a ntioxidant should be applied many times a day to achieve good ­ hydration. Vaseline could then be applied to help the flaking as soon as it starts. Effective sun protection (Melablock-HSP 50+ or 30) and avoiding sun exposure are essential. The treatment is repeated two to four times, every 2 weeks, intervals if flaking has stopped.

Results can be maintained in the long term with a combination of topical treatment (tretinoin, DHEA-Phyto, Renutriv ACE, etc.) and a series of several ETCA peels a year, with eventual local applications of Only Touch. Figure 18.3 outlines scalp postpeel care.

TIPS How to Accelerate Penetration of the Acid Solution Gentle abrasion with sandpaper, microneedling, or intraepidermal erbium laser treatment (fractional laser) can help accelerate penetration of the ETCA solution. These combined techniques are not suitable when a phenol-containing peeling solution is used, for evident toxicity reasons. When ­sandpaper abrasion is used, a topical anesthetic should be applied (a swab with 2% lidocaine with adrenaline [epinephrine]) after the abrasion, before applying the acid. With an erbium laser (not fractional), a nerve block or ring block is necessary.

Relative Impermeability of Keratoses Keratoses are relatively impermeable, and the acid needs more time to get through them. Patience is required, and frosting takes much longer to appear. Enough ETCA solution has been applied when the skin immediately surrounding the keratosis has frosted. Take care not to apply too much acid, because the skin around the keratosis/lentigines could be completely burned before the keratosis shows any frosting.

How to Determine the Total Number of Coats Required When the skin around the keratosis turns pink-white, it means that a sufficient number of coats has been applied. When the skin on the scalp is pinched between two fingers and epidermal sliding occurs (Figure  18.2), the papillary dermis has been reached. As soon as an even frosting occurs, the postpeel mask cream should be applied and rubbed in. The peel is then complete.

POSTPEEL PAIN While the pain felt after a peel is bearable, the doctor can make the patient more comfortable by prescribing a mediumstrength analgesic to be taken after the procedure and in the evening before going to bed. Figure  18.4 shows an example of a scalp treated with ETCA peels.

Treating multiple keratoses on the scalp    133 Table 18.1  Peels for Scalp Keratoses Type of peel

Depth

Details Superficial peels are not efficient for this indication. The scalp skin is very resistant, usually quite oily, and thick. Superficial acids (glycolic, lactic, mandelic, salicylic, etc.) have a low potential for treating scalp keratoses or lentigines. ETCA and ETCA PC can treat lentigines and not-too-large keratoses using a papillary dermis protocol.

Superficial peels

AHA, BHA

1/7 to 3/7

Easy TCA (ETCA) Easy TCA Pain Control (ETCA PC) Unideep

TCA TCA + Phenol

5/7

TCA

5/7

Easy Phen Light (EPL)

Phenol + TCA

6/7

Only Touch (OTP)

TCA

Focal 7/7 depth Mosaic technique

Lip & Eyelid Formula

Oil of phenol

7/7

This is a trichloroacetic acid papillary dermis peeling whose result is similar to that of ETCA, but faster acting (see Chapter 23). EPL is a new light phenol peeling that works at the level of the interface between the deep papillary dermis and the superficial part of reticulary dermis. OTP is a high TCA concentration (average 45% w/w mixed in a promoting base solution) peel that often is used with focal application on keratoses up to the reticular dermis. It is always used in association with a more superficial peeling applied on the rest of the skin, at a depth of 3/7 to 5/7. This is called the “mosaic technique.” One of the advantages of a mosaic treatment (focal deep peeling associated with a more superficial peel) is a deeper local action that offers fewer side effects and a faster recovery. Lip & Eyelid Formula is a deep phenol peel, up to the deep reticulary dermis. It is a perfect option for patients with numerous thick lesions. This formula can completely clean a scalp in only one session. As a precaution, the scalp will be treated with a deep phenol peel in a separate session, never together with the face, for toxicity reasons.

Table 18.2  Prepeel Conditioning and Anesthesia 30 minutes before peel

Analgesics

10 minutes before peel

Cleansing, balancing pH Disinfecting, degreasing

Just before peel

Nerve blocks

During application

Ventilation or cooling (3M Cold Pack) can help ease the pain of the acid.

The patient is given an acetaminophen plus codeine tablet or other relatively strong analgesic. Anxiolytics can help very anxious patients. The skin is cleansed using Skin Tech pre-peel cleanser, a foam that balances skin pH to a physiological ph:5 average. Then the skin is rinsed and dried. The skin is then disinfected with alcohol and degreased with acetone, which are left to evaporate.1 Anesthetic creams are not indicated for these treatments because they are inefficient and modify skin pH, hydration, and permeability. The anterior half of the scalp is innervated by the frontal nerve. In its intraorbital journey, this nerve divides into the internal and external frontal nerves. The nerve branches emerge from the supraorbital foramen and innervate the front of the skull after traveling vertically upward. Blocking these nerve branches anesthetizes the forehead as well as the first 6–10 cm of the area normally covered in hair. For more details, see Chapter 33. The lateral regions of the scalp are not innervated by the frontal nerve, but by branches of the lower cervical plexus or the auriculotemporal nerve. The posterior region of the scalp is innervated by the occipital nerve of Arnold, which is easily blocked by an injection of 2% lidocaine with adrenaline (epinephrine). The vertex of the scalp is innervated by all the nerve endings that sensitize the skull. This region is therefore sometimes difficult to anesthetize completely without doing a full circular nerve block of the scalp. Ring block: If the doctor does not want to or is not prepared to perform nerve blocks, or if they are inadequate for more sensitive patients, he can also do a tracer injection, 1 cm beyond the outside edge of the zone to be treated, and a ring block on the whole area to be peeled. Some patients claim that the breeze or the cold induce more pain.

134    Textbook of Chemical Peels

Figure 18.2  Epidermal sliding: this appears when the skin is pinched after a peel to the papillary dermis.

Figure 18.1  Frosting—considered to be even because of the large number of keratoses.

Table 18.3  Application of Easy TCA and Easy TCA Pain Control Action

Needed for

Type of peel

Remarks

Focal application on lentigines/keratoses, using one cotton bud soaked in the product

Large lentigines or thick keratoses

Focal white frosting. One touch of Lip & Eyelid can be sufficient to induce the white frosting, while three to five touches with Easy TCA will be necessary to reach the same result, depending on the skin permeability.

Full area application

Small lentigines or keratoses

Easy TCA Easy TCA Pain Control Unideep Only Touch Easy Phen Light Lip & Eyelid Formula Easy TCA Easy TCA Pain Control Unideep Easy Phen Light

Postpeel mask

Stopping immediate postpeel inflammation and pain

Day 0: Afternoon and evening Apply postpeel mask

When using phenol peels, about always consider potential phenol toxicity (see Chapters 25–36). No penetration promotion is allowed (abrasion, microneedling, fractional laser, etc.). End point is white or white-gray frosting.

All peels

Day 6 Apply vaseline

S

= Scalp treatment

Day 3 and 6 Check if infection

– 2 Weeks

S 0

Protective home care 1–2

3

4–5

6

7–8

9–14

15 to 30

IPLASE (reduces erythema) 3x/d Vit E antioxidant (moisturizing) every time the patient feels the skin tensed Skin Tech cleanser (cleanse skin) Blending Bleaching (pigment control) 2x/d

Melablock HSP, SFP 50+

09 am, 12 pm, 03 pm

if PIH risk, give the patient Blending Bleaching 3 x/day 2 weeks before peeling

Figure 18.3  Scalp postpeel care.

Specific home care After day 30 Smokers, polluted cities: Pigment control: Moisturizing: Dry skin, + 40 years old: Refill dermis: Dermal tensor: Melablock HSP, SFP 30

Nutritive ACE lipoic complex Blending bleaching Vit E antioxidant DHEA Phyto Atrofillin Actilift 09 am, 12 pm, 03 pm

Treating multiple keratoses on the scalp    135

(a)

(c)

(b)

(d)

Figure 18.4  (a) Scalp before treatment. (b) After two ETCA peels to the papillary dermis. (c) After three ETCA peels to the papillary dermis. (d) A year after treatment: maintenance with topical 0.05% tretinoin.

NOTE 1. This is an exception to the normal ETCA procedure. The skin on the scalp has to be disinfected and degreased because it is much thicker and oilier than the skin on the face; the treatment has to reach the papillary dermis.

19 Treating aging skin of the hands and forearms SIMPLE AGING, LENTIGINES, KERATOSES, FLAT WARTS Arms, forearms, and hands receive exactly the same treatment protocol.

AGING OF THE HANDS Over the last decade, facial rejuvenation treatments have been developed and refined. Major technical advances have changed the face of surgery as well as peeling and dermal filling techniques. The results of these treatments are more and more natural. Surgical scars, less visible now than they were in the past, can be softened even more by using peels or laser treatment after surgery. The blade has more respect for the architecture of the face, peels can maintain it perfectly well, and dermal filling techniques can even improve it. Cosmetic medicine helps to hide imperfections that cannot be corrected by other means. The use of gentler or less aggressive techniques has drastically reduced the risk of permanent complications. In short, nowadays, a person’s age is not written on his or her face, and patients who are properly treated can easily claim to be 15 years younger than they really are. The risk of this little white lie being found out is minimal—as long as the individual trying to guess the treated person’s age only looks at that person’s face. The quality of the skin on the neck and décolletage is often a sure sign of time spent in the sun or on a tanning bed. Surgery can, of course, improve the tension of the skin on the neck, but only certain peels can improve the quality of the skin or make a telltale décolletage look younger. Even if the right combination of techniques has been used to excellent effect and a patient’s face, neck, and décolletage do not show their real age, there is still a body area that can give away one’s age: the hands. They are often the weakest link in the treatment chain, a telltale sign of a patient’s real age and the fact that she or he has had other treatments. There are always mittens, of course, but who wears those year-round? If you look at a patient’s hands, you notice that they start aging fairly soon, often between the ages of 30 and 40. Small, almost colorless, sessile tumors may start to appear, along with small patches of hyperpigmentation; the skin dehydrates and starts to wither. Between the ages of 40 and 50, the patches of hyperpigmentation grow and solar keratoses may start appearing. Between 50 and 70, in parallel with a decline in sex hormone production (more gradual in men than in women), signs of atrophy in the epidermis, subcutaneous fatty tissue, muscle, and bone start to appear. Rheumatic disorders often develop that deform the joints. The veins, which have become more sinuous, stand out through the thinned epidermis. Very old hands are typically arthritic, atrophic (especially in women), dehydrated, and covered in hyperchromic patches and hyperkeratoses. The often fragile capillaries easily cause bruising. Friction wounds are more frequent and more spectacular, as the dermal papillae are no longer as deep and the epidermis is not held as tightly to the dermis. Our calendar age is

not the only thing responsible for the aging process; our actions are directly responsible for several contributing factors: smoking, for example, either through vasoconstriction immediately after smoke has been inhaled or through excessive production of free radicals in the body, is one of the major causes of aging that might well be termed autogenous as it is directly linked to an individual’s behavior. Avoiding repeated traumas; eating a balanced diet of vitamins, antioxidants, and fatty acids; keeping out of the sun; and good hormone levels all play an important preventive role in keeping the hands looking young. But what can one do when the damage is done, when the signs of aging are obvious and a patient wants to have younger-looking hands? What can be done to slow down the aging process once it has started? There is a 10-year age difference between the hands of the patients shown in Figure 19.1: the patient in (a) started menopause and estrogen–progesterone hormone replacement therapy (HRT) 2 years previously; the patient in (b) has been in menopause on estrogen-only HRT1 for 13 years. The signs of aging due to dermal, epidermal, fat, and muscle atrophy are clearly visible, and 10 years of (southern) sun have also left their mark on the skin.

Treatment of Simple Hand Aging Figure 19.1 shows simple skin aging. Usually, all that is needed to rejuvenate the skin on the hands is to regenerate the architecture of the dermis and epidermis. This type of skin regeneration is perfectly suited to Easy TCA (ETCA). Examples of this treatment are shown in Figures 19.2, 19.3, and 19.4.

Applying the Easy TCA Peel The process for applying the Easy TCA peel for a simple aging treatment is outlined in Figure 19.5 and Table 19.1.

Treatment of Sun Lentigines on the Hands Solar lentigines on the hands and overall photoaging usually appear together and share the same etiology. Large lentigines are treated with a local application of Only Touch solution (Figure  19.6). Small lentigines and overall photoaging can be treated with ETCA or Easy TCA Pain Control. The Easy TCA solution is applied to the entire hand, including the areas treated with Only Touch. This is why the Only Touch application should be stopped at the level of white frosting and not gray frosting as we would need to see in case of a deep reticulary dermis application. Easy TCA applied after Only Touch will add more acids to the treated areas and deepen the effects (Figure 19.7). Only Touch Peel Presentation The Only Touch kit contains a vial of base solution and a vial of Aktivator TCA 80%, which contains trichloroacetic acid (TCA) concentrated to 80% w/w. After mixing, the final concentration of TCA is 43% w/w.

Treating aging skin of the hands and forearms    137

(a)

(b)

Figure 19.1  (a) Hand of a 50-year-old patient. (b) Hand of a 60-year-old patient.

(a)

(b)

Figure 19.2  (a, b) The dermis and epidermis restructuring after four ETCA sessions, at a rate of one peel every 2 weeks.

(a)

(b)

Figure 19.3  (a, b) The dermis and epidermis restructuring after four ETCA sessions, at a rate of one peel every 2 weeks.

138    Textbook of Chemical Peels

(a)

(b)

Figure 19.4  Simple aging treated by four ETCA sessions, (a) before and (b) after. Daily care consisted of Skin Tech DHEA-Phyto twice a day and Melablock-HSP 50+ at 9 a.m., 12 p.m., and 3 p.m.

Only Touch Kit Contents • Base solution: One 5 ml vial containing a solution of four alpha hydroxy acids (AHAs), antioxidants, trace elements, and saponines. • Aktivator TCA 80%: One 3.8 ml vial containing a 80% w/w TCA solution. • Various: A small container for mixing the TCA with the base solution, cotton buds, and instructions for use.

Table 19.1  Application of Easy TCA Prepeel preparation

Easy TCA application Softly touch every lentigo with a cotton bud soaked in Only Touch peel. Several touches are needed up to end point: white frosting.

1st coat Easy TCA Let it dry

Postpeel mask application Flaking Postpeel care

2nd coat Easy TCA Let it dry

If 1st frosting points

No disinfection or degreasing of the skin is needed, except if moisturizers or sun protection have been applied. Two or three successive coats of ETCA solution are applied to the hands. Do not try to achieve frosting. Each coat should be left to dry completely before applying the next. If cloudy frosting appears after the first or second coat, no more coats should be applied. When the last coat of solution has dried, the postpeel mask cream is applied using the quantities indicated on the dosage card, and is left to work for at least 8 hours. Flaking often occurs after at least 1 week and lasts around 4–5 days. Start the day after the first peel and continue for at least 6 weeks after the last peel. Three daily care creams are recommended for simple hand aging treatment: • DHEA-Phyto, containing DHAE phytoprecursors to boost the anabolic potential of the skin. • Nutritive Cream Vit. A-C-E Lipoic Complex to fight free radicals produced by exposure to the sun or to chemical irritants. • Melablock-HSP 30 or 50+ as a strong sun protection.

If NO frosting points 3rd coat Easy TCA

ETCA postpeel mask

Figure 19.5  Application algorithm.

Remove all jewelry.

Repeat Easy TCA

Easy TCA is repeated four times, at 2-week intervals, unless the skin has not finished flaking.

Treating aging skin of the hands and forearms    139

Large and deep lentigo

Subcutaneous tissue

Dermis

Epidermis

Small and superficial lentigo

(a)

(b) Small and superficial lentigo

Only Touch

Subcutaneous tissue

Dermis

Epidermis

Large and deep lentigo

Only Touch Peel: focal deep tower technique

(d)

(c) Small and superficial lentigo

Easy TCA Only Touch

Subcutaneous tissue

Dermis

Epidermis

Large and deep lentigo

(e)

(f )

Figure 19.6  (a) Large lentigines typically have a deep structure; small lentigines typically are superficial. (b) Solar lentigines before treatment. (c) Large lentigines are treated by a focal deep tower technique: Only Touch peel. (d) Frosting induced by local applications of Only Touch. (e) Superficial lentigines are treated with full-area application of Easy TCA as for simple aging. (f) Clinical results after treatment.

140    Textbook of Chemical Peels

1st coat Easy TCA Let it dry

2nd coat Easy TCA Let it dry

If 1st frosting points

If NO frosting points 3rd coat Easy TCA

in the case of postinflammatory hyperpigmentation (PIH). See the “General Notice Peelings” section in the kit instructions. In particular, do not apply Only Touch to patients who have had or are undergoing treatments that might increase skin permeability. Do not apply Aktivator TCA 80% without diluting it to the recommended concentration, as this could cause permanent scarring. Only Touch, used alone, can be associated with hyperpigmentation changes, while ETCA prevents or treats them. Therefore, both peels are used together in the treatment of solar lentigines (Figure 19.8). Only Touch should be carefully applied and never over the white “elastic” frosting, without the skin becoming hard when pinching. When the Only Touch application results in gray or yellowish frosting, side effects (infection, delayed healing, scarring, or pigment problems) often occur (Table 19.2).

Combined Treatment for the Hands: Peels and Fat Transfer ETCA postpeel mask

Figure 19.7  Application algorithm for the hands.

Indications Only Touch is indicated for the treatment of keratoses and lentigines of the hands, forearms, and neck with a maximum diameter of 1 cm, in phototypes FZ 1–4. Only Touch is only for local application and never for large areas. For lentigines or facial keratoses, local or focal application of Only Touch to the Grenz zone (depth 4/7) should be followed immediately by an application of Easy TCA 15% to the basal layer (depth 3/7) for the whole zone, treated previously by Only Touch. This gives the desired result with minimal residual erythema. Contraindications Only Touch should not be used in patients with phototypes 4–6. Avoid applying Only Touch on facial skin because it could leave persistent red spots on the skin for months, combined and

(a)

Solar lentigines are combined with atrophy of the integuments, subcutaneous tissue, muscles, and bones. While peels can correct photoaging, they cannot correct hormone-induced atrophy. Often the only option is a fat transfer combined with chemical peels (Figures 19.9, 19.10, and 19.11). A fat transfer, however, cannot prevent photoaging and the development of lentigines. For this reason, Easy TCA should be resumed yearly, even after a fat transfer.

Flat Warts The hands of premenopausal patients often do not show evident signs of atrophic aging, but too much sun produces a range of spots, sessile tumors, flat warts, and solar keratoses. Small, flat warts can be treated successfully with Only Touch combined with ETCA (Figure 19.12). Only small, flat warts respond to Only Touch. Thicker, and therefore more impermeable, lesions do not respond and should be treated by shave excision with high-frequency shaving or lasers.

MAINTAINING RESULTS IN THE LONG TERM Results can be maintained in the long term by using appropriate daily care and repeating the peels once a year.

(b)

Figure 19.8  (a) Appearance of the skin on the 8th day after Only Touch combined with ETCA; the scabs should not be pulled off. (b) Appearance of the same hand on the 15th day: the scabs are gone.

Treating aging skin of the hands and forearms    141 Table 19.2  Combined Application of Only Touch and Easy TCA on Hands, Forearms, or Arms Prepeel preparation Only Touch preparation Only Touch application

Easy TCA application

Postpeel mask application Flaking Postpeel care

Remove all jewelry. No disinfection or degreasing of the skin is needed, except if moisturizers or sun protection have been applied. Using a 1 ml syringe and an 18-gauge needle, draw out 0.3 ml of Only Touch peel solution. Drop 0.15 ml of the solution on a cotton bud; it should be moist but not dripping. Softly touch the visible lentigines once. The touch should be quick and not deep; use the same force as for dialing a number on a smartphone screen. The lentigines should be shiny afterward. When the cotton bud becomes dry, add just 3 drops of Only Touch solution directly from the syringe. Let the peeling solution dry, allowing as much time as necessary. Touch the lentigines again as many times as necessary to get to the end point: white frosting. The skin should never be hard as if frozen; it should always stay elastic, even after frosting. Two or three successive coats of ETCA solution are applied to the hands. Do not try to achieve more frosting. Each coat should be left to dry completely before applying the next. If cloudy frosting appears after the first or second coat, no more coats should be applied. When the last coat of solution has dried, the postpeel mask cream is applied using the quantities indicated on the dosage card, and is left to work for at least 8 hours. Flaking often occurs after at least 1 week and lasts around 1 week more. The areas treated with Only Touch will scab; the scabs should never be removed. See Figure 19.8. Removal of the scabs might cause scars. The patient should avoid working with the hands in water. Care should start the day after the first peel and continue for at least 6 weeks after the last peel. Three daily care creams are recommended for simple hand aging treatment (note 2): • DHEA-phyto, containing DHAE phyto-precursors to boost the anabolic potential of the skin • Nutritive Cream Vit. A-C-E Lipoic Complex to fight free radicals produced by exposure to the sun or to chemical irritants • Melablock HSP-30 or 50+ as a strong sun protection

Repeat treatment

Only Touch is usually applied immediately before the first Easy TCA and eventually repeated, if needed, before the fourth Easy TCA. Easy TCA is repeated four times, at 2-week intervals, unless the skin has not finished flaking. See Chapter 22 for more information.

(a)

(b)

Figure 19.9  (a) Before treatment. (b) 12 months after fat transfer. (c) 3 years and 6 months after fat transfer.

(c)

142    Textbook of Chemical Peels

(a)

(b)

(c)

Figure 19.10  Figure 19.10  (a) A hyperkeratotic lesion less than 1 cm in diameter, with a dry and atrophic epidermis. (b) After one local application of Only Touch combined with two ETCA sessions. (c) Dramatic improvement after two applications of Only Touch and three of ETCA. An extra session of Only Touch would be necessary to treat the problem completely.

Treating aging skin of the hands and forearms    143

(a)

(b)

(c)

(d)

Figure 19.11  (a) Before application of Only Touch and Easy TCA. (b) Day 8 after application of Only Touch and Easy TCA: scabs are visible; the patient should not scratch them. (c) Day 30 after Only Touch and Easy TCA treatment, just before fat graft. (d) Day 30 after fat graft.

(a)

(b)

Figure 19.12  (a) Flat warts after treatment with Only Touch. (b) Uneven but sufficient frosting achieved after local applications of Only Touch.

NOTES 1. I shall make no comment on the validity of this type of replacement therapy.

2. See Chapter 3. DHEA-Phyto cream (in the morning) and Renutriv ACE Lipoic Complex (in the evening) are particularly effective on the hands. Please see on page 141, “note 2.”

20 Treating the neck and décolletage CONSIDERATIONS IN TREATMENT Peeling or Surgery The neck is a difficult area to treat, and results vary widely. Essentially, the sagging neck remains a surgical indication. Peelings can improve the neck skin quality, but they cannot tense sagging skin. It is dangerous to think that applying a larger quantity of acids on the neck will tense the skin. If enough acid is applied on the neck to tense the skin, it will be because of the scars that the acid induced. Décolletage usually is not an indication for surgery; ­peelings are superior to surgical methods for improving décolletage skin quality.

Specific Risks of Peeling Neck/Décolletage Even if this area presents a low appendage density, the skin on the décolletage remains a good candidate for careful chemical peelings. Nevertheless, it responds all too readily to serious injury (peeling procedures that are too deep) by forming scars that are often hypertrophic. Décolletage peeling should never be too deep; it should never surpass the low capacity of this skin to regenerate.

Peeling Selection Trichloroacetic acid (TCA) is a good choice as long as its concentration does not surpass 25%. The author prefers using Easy TCA (ETCA), Easy TCA Pain Control, or Unideep peels for the neck and décolletage. Deep focal application is possible, as long as the diameter of focal application is less than 1 cm. For small areas, a soft touch with Only Touch peel is safe, even if the concentration surpasses 45% w/w.

Peeling Application When applying the peeling solution, the doctor must be patient Do not apply quickly the successive layers; carefully wait for each layer to dry completely before applying solution to the next one. If the solution is applied to many layers without waiting for it to dry, too much acid will interact with skin and an overpeeling could result. The details of treatments are outlined in Table 20.1. Figure  20.6(a) shows the presence of numerous, large lentigines on the décolletage. The average diameter of the ­lentigines is larger than 1 cm, and many lesions are confluent. This ­contraindicates the use of Only Touch peel. The selected alternative is a focal touch with Easy Phen Light on a cotton bud (30% oil of phenol + 15% TCA + 4 alpha hydroxy acids) combined with a full area application of ETCA after obtaining the end point frosting with Easy Phen Light. An immediate ­erythema appears; it will be controlled in 5–10 minutes by applying the Skin Tech postpeel mask (Figure 20.6[b]).

After the postpeel mask has been applied, a protective layer of Yellskreen powder is applied to the treated area. Yellskreen contains bismuth subgallate powder, which forms a protective crust (Figure 20.6[c]). This crust is not water soluble, but natural moisture is present under the crust, which helps achieve perfect healing. Moreover, the powder is antiseptic. Because of the Yellskreen application, no special care is needed for the next 8 days, which makes the postpeel period as simple as possible. There will be no chance of self-infection by the patient’s hands. On postpeel day 8, white petrolatum jelly is applied on the Yellskreen. It will form an impermeable coating over the yellow crust, which will block the natural transepidermal water loss into the crust and make the scab unstuck, because it is not water soluble (Figure 20.6[d]). On day 10, focal erythema is visible on the points that had been the most deeply touched by the phenol. The rest of the skin is no longer red. The most important step is to apply IPLase to block further inflammation and free radical production, and sun protection 50+ to prevent melanocyte stimulation by UVs. Blending Bleaching Cream also should be used to prevent PIH development. On postpeel day 30, some erythema is still visible, but it will progressively fade when following the same postpeel care regimen (Figure 20.6[e]).

Acne Scars Acne scars may be visible (Figure  20.7[a]); the presternal area is known for its capacity of developing hypertrophic scarring. The patient illustrated also presented facial vitiligo and vitiligo spots on the area to be treated. The aim of the treatment was to improve the appearance of the acne scars without inducing hypertrophic scars and limiting the risk of the Koebner phenomenon that could “import” vitiligo to the treated area. The treatment plan was as follows: •

• •

After careful disinfection, perform a superficial abrasion: very first pinpoints of blood (Figure  20.7[b]). Sand paper P220 wet or dry, gamma ray sterilized, has been used for abrasion. Do not apply acid after the abrasion. Apply the Skin Tech postpeel mask under occlusion for 24 hours. The treatment team came to this decision after discovering the postpeel mask under occlusion deepens a peeling.

The postpeel mask is applied to the skin after sandpaper abrasion; the mask is then covered by an alcohol disinfected

Treating the neck and décolletage    145 Table 20.1  Treatments for Décolletage and Neck Indications

Protocol and repetition

Remarks

Slightly sun-damaged neck and/ or décolletage (Figure 20.1)

The basic protocol for Easy TCA (ETCA) should be used on décolletage. End point: Frosting points Depth: 3/7 Postpeel mask applied at the end of peel Then face is treated to the desired depth. To be repeated: 1

• Four times at weekly intervals on the face • Four times once every 2 weeks on the neck and décolletage, which take twice as long to flake as the face. Moderately sun-damaged neck and/or décolletage (Figure 20.2; also see Chapter 15)

Deeper protocol of application is used. End point: Cloudy-white frosting Depth: 4/7 Postpeel mask applied at the end of peel Then face is treated to the desired depth. To be repeated:

The décolletage could be treated as a separate area but is usually treated at the same time as the face and neck. The order in which these areas are treated does not matter. Nevertheless, for the patient’s comfort, take into consideration that treating the décolletage is usually less painful than treating the face. A moderately damaged décolletage presents deeper damage and should be treated more aggressively than a slightly damaged décolletage.

• Four times at weekly intervals on the face • Two times once every 2 weeks on the neck and décolletage, which take twice as long to flake as the face. Lentiginosis of the décolletage (Figure 20.3; also see Chapters 19, 22, and 38)

“Mosaic peel” technique is recommended. Only Touch peel is applied focally on easily visible lentigines. End point: White frosting. Easy TCA is applied after Only Touch, up to the desired depth: 3/7 or 4/7. Postpeel mask is applied immediately at the end of the procedure. To be repeated: • Only Touch to be applied immediately before the first and eventually before the fourth ETCA. • ETCA to be repeated an average two times once every 2 to 3 weeks on the neck and décolletage, which take twice as long to flake as the face.

Moderate photoaging and acne scars on the décolletage (Figure 20.4; also see Chapter 21)

Severe photoaging of the décolletage (Figure 20.5; also see Chapter 23)

If photoaging is widespread, a specific ETCA abrasive protocol can be used: the décolletage is abraded with sandpaper abrasion up to the very first bleeding pinpoints. No acid is applied in this protocol, to prevent the acid from penetrating too deeply and potentially causing scars, but the area is covered with postpeel mask cream and left under occlusion for 24 hours. Such abrasive protocol, without acid, can be repeated after 1 month’s rest. Deeper procedures could be considered: 1. Unideep, a papillary dermis TCA peel, can peel the décolletage area more deeply. Depth: 5/7 Unideep can be repeated 1 month after the first procedure. 2. Easy TCA Pain Control can induce a deeper peeling than ETCA and could be used for the décolletage area. Depth: 5/7 Easy TCA Pain Control can be repeated 1 month after the first procedure. 3. Easy Phen Light also can be used as a touch procedure for treating numerous large décolletage lentigines. Depth: focal 6/7 ETCA is applied after Easy Phen Light to the entire area.

This is treated with a combination of Only Touch and ETCA. Regular maintenance treatment and sun protection are essential to avoid recurrence or the appearance of new lentigines. Note: For more information on face lentigines, see Chapter 22. Only Touch is not intended for a facial application because it could induce scarring and long-term redness/pigment problems.

For more information about Unideep, see Chapter 23. Easy TCA Pain Control contains phenol, but no toxicity is to be feared as long as one dose only (2.7 ml of reconstituted solution) is used.

146    Textbook of Chemical Peels

(a)

(b)

Figure 20.1  (a, b) Improvement only in the quality of the skin on the neck after two series of four ETCA peels according to the basic protocol (frosting points).

Figure 20.2  Only the top part of the décolletage has been treated with two sessions of four ETCA peels: there is a noticeable improvement in the texture of the skin in the treated area.

(a)

Figure 20.3  Treatment of lentigines on the hands and décolletage with Only Touch plus ETCA.

(b)

Figure 20.4  (a) Postpeel mask cream (only postpeel mask, without application of acid solution) under occlusion after sandpaper abrasion. (b) Appearance of the skin on the third day, just before flaking begins.

Treating the neck and décolletage    147

(c)

(a)

(d)

(b)

(e)

(f)

(g)

Figure 20.5  (a) Typical photoaging of the décolletage. (b) Treatment of décolletage photoaging with Unideep (TCA peel to the papillary dermis). There is pink-white even frosting and “sliding” sign. (c) Cold packs (3M) can alleviate the burning sensation of acids. (d) Treatment of décolletage photoaging with Unideep (TCA peel to the papillary dermis). Endpoint of the treatment and application of the postpeel mask. (e) Skin desquamation of décolletage at day 3 after papillary dermis peeling with Unideep. (f) Daily care is as follows: on days 1–6, Nutritive Cream Vit. A-C-E Lipoic Complex; on days 6 and 7, sterile white Vaseline. The photograph shows the results after 8 days. (g) Unideep: results after 12 days. Sun protection of SPF 50+ and daily care are essential to maintain the results in the long term.

148    Textbook of Chemical Peels

(a)

(b)

(d)

(c)

(e)

Figure 20.6  (a) Numerous large lentigines on décolletage. (b) Erythema appears immediately after focal treatment with Easy Phen light. (c) A protective layer of Yellskreen powder is applied. (d) White petrolatum jelly forms an impermeable coat over the yellow crust. (e) Result at day 30.

cling film for 24 hours. Figure  20.7(c) shows a few bleeding points. After 24 hours, the cling film is removed. The skin appears uniformly red and without epidermis (Figure 20.7[d]); some focal infection points are visible, and the patient will be given antibiotic therapy for 5 days.

Yellskreen powder is applied to the desepidermized skin, to protect the skin, and allow a natural healing under the crust (Figure 20.7[e]). An appreciable result typically is obtained after only one session (Figure 20.8[a,b]).

Treating the neck and décolletage    149

(a)

(b)

(c)

(d)

(e)

Figure 20.7  (a) Acne scars on presternal area. (b) Appearance after superficial abrasion. (c) Postpeel mask and alcohol-disinfected cling film. (d) Appearance after 24 hours. (e) Yellskreen powder is applied on the desepidermized skin.

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(a)

(b)

Figure 20.8  Acne scars (a) before and (b) after one session.

(a)

(b)

(c)

Figure 20.9  (a) Neck aging. (b) Result after one Easy TCA Pain Control (papillary dermis level). (c) Result after 2nd Easy TCA Pain Control (papillary dermis level).

Treating the neck and décolletage    151

Neck Rejuvenation after One Application of Easy TCA Pain Control, Depth 5/7 (Papillary Dermis) Neck aging (Figure 20.9[a]) is treated separately with Easy TCA pain control. • • •

Depth 5/7: white frosting. One session. Postpeel care: Atrofillin cream and DHEA-Phyto cream.

After 3 months, a good result is obtained for the skin structure of the neck (Figure 20.9[b]).

CARE AFTER PEELS Usually, the postpeel period after neck/décolletage TCA peels is characterized by redness and an inflammatory reaction that appears quite soon after the peel and lasts for 2–3 days. Fortunately, the postpeel mask stops this reaction immediately. The immediate postpeel period, after a peeling depth of 4/7, followed by the Skin Tech postpeel mask, is usually very

uneventful and without redness or pain. The post peel mask ensures there is little skin edema. Head movements and friction clothing can cause more trauma to the neck skin than to the face. A neck peeling is often more uncomfortable for a patient than a face peeling. Patients should be informed that picking at flaking skin, especially on the décolletage, will induce redness that could become pigment issues or scars. Postpeel care is essential to maintain the peel results for the long term. On the day after the first peel, patients should start using the following: • • •

IPLase cream to reduce inflammation and redness. Sun protection of SPF 50+. Daily care cream appropriate for the patient’s condition (see Chapter 3).

Follow-up peeling sessions could be planned for once a year, for example.

21 Stretch marks, scars, and pilar keratosis Anterior chemabrasion GENERAL REMARKS Stretch marks, acne scars, and pilar keratosis are three common problems for which treatment results were disappointing in the past. Doctors frequently had to refuse treatment and admit to being powerless to help patients with these conditions. In cases where the doctor did not refuse treatment, he or she often regretted having used inappropriate techniques and having to deal with the resulting complications. Patients would suffer from their doctor’s refusal to treat them, which meant having to delay indefinitely the blessed day when their problems might improve. They also suffered side effects caused by inappropriate treatments.

ORIGINS OF “ANTERIOR” CHEMABRASION The high level of safety and effectiveness obtained when first using the Easy TCA (ETCA) peel led the author to develop complex but effective application protocols for the treatment of stretch marks and scars. ETCA had proved effective for a range of problems, including acne, pigment problems, and skin aging, both on the face and on other parts of the body. ETCA consists of an acid solution and an active postpeel cream that the doctor applies to the treated area immediately after the acid solution has produced pinpoint or cloudy-white frosting and that is then left to work until the following morning. The ETCA basic protocol provides a peel to the basal layer of the epidermis or the Grenz zone but also can be used up to the papillary dermis, simply by adding more coats, one at a time, to achieve a pink-white frosting. The postpeel cream has to be applied once by the doctor, immediately at the end of the peeling. It is not a neutralizing cream, but an active cream with a high concentration of vitamins C, E, and H; tretinoin precursors; phytic acid; anti-free-radical agents; selenium; methionine; tyrosinase inhibitors; trace elements; fatty acids; and other actives. This cream is used to block unnecessary and self-maintained immediate postpeel inflammatory reactions; to provide a strong stimulus to the dermis, epidermis, and regeneration processes; and to protect against complications. Unlike a conventional trichloroacetic acid (TCA) peel, the postpeel cream is responsible for a large part of the results and the low level of side effects. The cosmetic problems dealt with in this chapter, however, do not respond well to any chemical peels, even when they reach the papillary dermis. In fact, publications about peelings do not cover stretch mark treatments except for recognizing their inefficacy. In an attempt to achieve better results, deeper peel procedures were tried that went as far as the reticular dermis. However, peels are dangerous at this depth; the complications are discussed in Chapter 37. Other authors have suggested a combined technique of a chemical peeling and dermabrasion, but always in the order of a peel followed by dermabrasion. This technique is known

as chemabrasion. For a better understanding and to distinguish between the two techniques, we could use the term posterior chemabrasion for a peel followed by dermabrasion and anterior chemabrasion for the technique described in this chapter— dermabrasion followed by a peel. The treatment the author has developed consists of using sandpaper dermabrasion followed by ETCA acid solution and postpeel mask cream. Applying the postpeel mask cream, after the peeling and under occlusion, deepens the treatment: the longer the occlusion is left, the deeper the treatment will be. Repeating the peels allows the epidermis to renew itself gradually (a chemical resurfacing effect) while “filling” the dermis with fibroblast products, the fibroblasts having been stimulated by the treatment. Internal and gradual retraction reduces the width of the stretch marks (a filling-shrinking effect). The combination of sandpaper abrasion, with or without the application of the acid solution and occlusion of the ETCA postpeel cream,1 allows a range of depths of action.

TREATING STRETCH MARKS Table 21.1 outlines details of the treatments for stretch marks.

Classification of Stretch Marks The Deprez–Adato classification2 is based on the clinical appearance of the stretch marks (Table 21.2). Stretch marks in stages 2B to 4 seem to respond best to this treatment. The best indications are old and deep stretch marks, which respond much better than recent and superficial ones (Figures 21.1 and 21.2).

Equipment Needed for the Abrasive Protocol The sandpaper abrasion kit consists of 10 sheets of single-use sandpaper (3M Wet-or-Dry P220) sterilized3 with gamma rays, and a yellow disinfecting and healing powder: Yellskreen, containing bismuth subgallate (BSG).

Mechanisms of Action of the Technique The mechanisms of action are shown in Table 21.3. Abrasion The entire area—not only the atrophic base of the stretch marks—must be abraded. Other techniques (laser and microdermabrasion) have failed because they tend to stimulate only the atrophic base of the stretch marks, where there are very few keratinocytes capable of proliferating and very few fibroblasts available to fill the dermis. Sandpaper abrasion produces even, physical resurfacing, leveling the skin and stimulating the healthy skin between the stretch marks to regenerate. The inflammatory reaction caused by the treatment stimulates the growth of healthy keratinocytes on the edge of the stretch

Stretch marks, scars, and pilar keratosis: Anterior chemabrasion    153 Table 21.1  Evaluation of Treatment of Stretch Marks Techniques for stretch mark treatment

Efficacy

Remarks

Linear microdermabrasion (corindon crystals)

Low

Linear diamond drill abrasion Linear application of 25% TCA Linear application of 50% TCA Linear application of phenol

Low

Do not apply acids after such microdermabrasion: the acids will penetrate only in the lines of skin abrasion drawn by the method. Dangerous, high risk of scarring Pigment problems

Linear sandpaper dermabrasion Microneedling Microneedling followed by peeling

Low

Full abdomen application of TCA 25% Full area application of TCA 40%

Low

Full abdomen application of phenol light or deep

Low

Full abdomen sandpaper dermabrasion Posterior chemabrasion

Low

Anterior chemabrasion with ETCA

Visible results

Low Low Low

Low Medium

Low

Medium

Pigment problems, risk of scarring Pigment problems, risk of scarring, risk of toxicity Pigment problems

Figure 21.1  Correct indications for anterior chemabrasion and ETCA.

Use a 2.5 mm needle. Use a 2.5 mm needle, ETCA, and postpeel mask. Pigment problems Very high risk of scarring and pigment problems, infection Do not do it; this treatment is dangerous with a very high risk of toxicity. Pigment problems, risk of scarring Pigment problems, risk of scarring Pigment problems, risk of scarring

Table 21.2  Deprez–Adato Classification of Stretch Marks Stage 1

Inflammatory

Stage 2A

Ladder rungs (–)

Stage 2B Stage 3A

Ladder rungs (+)

Stage 3B Stage 4

Nonpalpable depression Palpable depression 4. When Unideep is used on skin phototypes 4–6, the skin requires preparation for 4–6 weeks prior to peeling: Skin Tech Blending Bleaching Cream twice daily, possibly with a 3% hydroquinone cream. There should be classic herpes prevention for patients with a medical history (3 days before and 3 days after peeling). Immediately before Peeling Cleanse the skin with Skin Tech Cleanser, rinse and dry the skin, and then disinfect and degrease it with a 50% alcohol/50% acetone solution. To degrease the skin properly, it must be wiped with acetone several times. Preparing the Applicator Dental Cotton Tube:  The ideal applicator is a cotton dental swab held in a clamp (Figure 23.1); this makes it easier to handle and to apply the right amount of pressure. The cotton swab in the kit is too long and needs to be cut into two equal halves for use as an applicator. Double-Ear Cotton Bud:  Unideep also can be applied using a double cotton bud, as for ETCA or phenol application.

Preparing the Peel Solution Inject into the vial of base solution the entire contents of the Aktivator TCA 50% vial to obtain a concentration of TCA 25% w/w.

Trichloroacetic acid to the papillary dermis: Unideep    199 Table 23.1  Description of Unideep Kit Base solution Trichloroacetic acid Postpeel mask Various

One 4 ml vial of solution containing four alpha hydroxy acids, antioxidants, trace elements, and saponines Aktivator TCA 50%: One 3.2 ml vial containing a 50% w/w TCA solution Two 10 ml tubes of Skin Tech postpeel mask cream designed to control inflammation and pain after the peeling One dosage card for Skin Tech postpeel mask, a small container for mixing the TCA with the base solution, cotton buds, and instructions for use

Control of Burning Sensation Most patients can easily tolerate this treatment without nerve block anesthesia if the peel is done slowly, cosmetic unit by cosmetic unit. More squeamish patients may prefer to have intravenous sedation, along with nerve blocks. Analgesic Medication The patient can take an acetaminophen plus codeine tablet half an hour before going to the doctor. The patient may also benefit from taking a second tablet 1 or 2 hours after the peel, at the peak of the discomfort. Cryoanesthesia Any pain can be eased considerably by simply chilling the skin before the first application and between the different coats. Cold packs (e.g., 3M products: Figure  23.2) or a ventilator can be used for this. If neither is available, a bag of ice or simply contact with a cold surface (e.g., an empty bottle) soon eases the burning sensation. Cold packs can be applied directly on the acid if they have been dried beforehand. Nerve Blocks A local anesthetic (nerve block) may be necessary for sensitive patients. With nerve blocks, peel application is painless and quicker. (See Chapter 33 for details on how to perform nerve blocks.) After nerve blocks have been applied to the area under treatment, the peel solution is applied to the face. It is first

Figure 23.1  Unideep applicator held in a clamp.

Figure 23.2  Cryoanesthesia with 3M’s cold pack.

applied on the forehead and temples, until an even pink-white frosting is obtained; the postpeel mask cream is applied on the area that has just been treated before moving on to the next area. The face is done in three stages: forehead and temples, nose and cheeks, and the chin. The postpeel cream soon stops the burning sensation. Vocal Anesthesia In many cases, vocal anesthesia or medical hypnosis can alleviate the burning sensation of the acid in Unideep. Topical Anesthesia For reasons outlined in Chapter 33, anesthesia with a topical cream should not be used before a peel to the papillary dermis.

Figure 23.3  The face is divided into five zones for application.

200    Textbook of Chemical Peels

Figure 23.6  Epidermal sliding. Figure 23.4  The first coat of Unideep often produces uneven frosting that will even out with the second coat.

Unideep peeling solution is applied to five different areas (Figure 23.3). The physician should complete the application in one area before moving to the next (Figure 23.4).

The Following Layers Several successive layers are necessary to obtain uniform pinkwhite frosting (Figure 23.5). Let each layer dry before applying the next one. Each of the five areas will be treated sequentially; when peeling has finished in one area, apply the Skin Tech postpeel mask and then apply the peeling solution to the next area. No pause is required between two zones.

The First Layer Use the applicator included in the kit, held with tweezers. Soak the applicator in the peeling solution, drain it slightly on the edge of the small container kit, and apply the Unideep peeling solution to the skin using regular circular movements. A peeling depth of 5/7 (papillary dermis) needs a uniform pink frosting.

The Last Layer The last layer is the one after which the clinical “sign” appears that corresponds to the required depth. The “sign” is not a volume (milliliters) or a temporal concept (minutes), but a clinical concept: the appearance of a pink-white uniform frosting, associated with the sign of “sliding” when the skin is pinched (Figure 23.6); it is a sign of peeling to the papillary dermis (deep 5/7). A gray-white

Application

(a)

Figure 23.5  (a, b) Sequenced application.

(b)

Trichloroacetic acid to the papillary dermis: Unideep    201

Day 0: Afternoon and evening Apply postpeel mask

Day 6 Apply vaseline

Days 3 and 6 Check if infection

– 2 Weeks

Day 7–8 Makeup allowed

U 0

Protective Home care 1

2

3

4

5

6

7

Specific Home care

8 to 30

IPLASE (reduces erythema) 3x/d Vit E antioxidant (moisturizing) every time the patient feels the skin tensed Skin Tech Cleanser (Cleanse skin) Blending Bleaching (Pigment control) 2x/d

Melablock HSP, SFP 50+

09 am, 12 pm, 03 pm

After day 30 Smokers, polluted cities: Pigment control: Moisturizing: Dry skin, + 40 years old: Dermal tensor: Dermal filling: Melablock HSP, SFP 30

Nutritive ACE Blending Bleaching Vit E Antioxidant DHEA Phyto Actilift Atrofillin 09 am, 12 pm, 03 pm

if PIH risk, give the patient Blending Bleaching 3 x/day 2 weeks before Unideep.

Figure 23.7  Postpeel care.

frosting signals a reticular dermis (depth 6/7) peeling. This depth is not recommended with Unideep. Skin Tech Postpeel Mask Once the uniform pink frosting has appeared in an area, immediately apply 1 g of the Skin Tech postpeel mask on the treated area before beginning to treat the next area. The postpeel mask stops the pain, redness, swelling, and burning sensation of the skin caused by the peeling, in a few minutes. Postpeel inflammation is quickly controlled and the risk of side effects is limited, but application of the mask does not eliminate the possibility of side effects. After frosting occurs, the solution should not be neutralized. At the end of the peel on the five areas, reapply an additional 2 g of the postpeel mask on the face with a soft massage. At the end of the procedure, half a tube of postpeel cream should have been applied to the face. It should be rubbed in, and the solution and cream left in place to work until the next morning. The next morning, the patient should apply the rest of the postpeel cream to the face, after washing with neutral soap or cleansing lotion.

cream and skin tolerance. If a postpeel temporary intolerance appears, the application of daily care cream should be postponed for a few days.

Postpeel Desquamation Postpeel desquamation can take different forms, depending on the patient’s phototype: the darker the original phototype, the darker the skin will appear after peel. A patient with a clear phototype will exhibit a soft darkening, while a phototype 4 or 5 patient will exhibit dark brown skin during the week after the peel (Figures 23.9, 23.10, and 23.11).

RESULTS See Figures 23.12, 23.13, and 23.14 for examples of results.

POSTPEEL AFTERCARE From the 1st to the 15th day after the peel, the patient should generously apply Skin Tech IPLase Mask cream to the face to reduce erythema (Figures 23.7 and 23.8). The postpeel daily care recommended by the doctor is essential to guarantee results and safety. Special attention should be paid to possible PIH. The patient must apply Blending Bleaching Cream twice a day for a few months. A sunscreen such as Skin Tech Melablock-HSP SPF 30 or 50+ is indicated in all cases, for a minimum period of 3–6 months, depending on patient’s skin type and sun exposure. The doctor should be able to control, predict, and prevent possible complications and treatment. He or she should check the

Figure 23.8  Application of a thick coat of postpeel mask.

202    Textbook of Chemical Peels

(a)

(b)

(c)

Figure 23.9  Postpeel at days 5 (a), 6 (b), and 8 (c) on a clear phototype.

Trichloroacetic acid to the papillary dermis: Unideep    203

(a)

(b)

Figure 23.10  (a) Soft flaking after a peeling depth of 3/7; ETCA basal layer peel (pinpoints of frosting) on phototype FZ 3. (b) Flaking at day 6, after a peeling depth of 5/7, pink-white frosting on phototype FZ 4.

(a)

(b)

Figure 23.11  (a) Flaking at day 6 after a peeling depth of 5/7. (b) Pink-white frosting on phototype FZ 2.

204    Textbook of Chemical Peels

(b)

(a)

Figure 23.12  (a) Natural darkening of freckles 24 hours after the application of Unideep; they will disappear 5–6 days after the peel. (b) Freckles 1 month after a Unideep peel.

(a)

(d)

(b)

(e)

(c)

Figure 23.13  (a–c) Combination of peels: Unideep has been applied to the forehead only, and ETCA has been used to treat the rest of the face that is not as badly damaged by postacne pigmentation. (d, e) Forehead view of a full-face Unideep application.

Trichloroacetic acid to the papillary dermis: Unideep    205

(a)

(b)

Figure 23.14  (a) Before peeling and (b) 60 days after one papillary dermis peel: Skin quality is enhanced, fine lines have disappeared, freckles and lentigines have disappeared, and photoaging generally is solved, but a papillary dermis peel is not indicated for suppressing wrinkles.

PRECAUTIONS AND COMPLICATIONS Potential complications from this type of peel are described in detail in Chapter 37.

General Precautions Unideep is a peel to the papillary dermis; therefore it is essential to follow the indications and method of application. Misuse of Unideep could produce the classic side effects of mediumdepth peels. The patient should be warned not to scratch the skin after the peel. Concentrated TCA should not be applied to the skin without mixing it with the base solution.

Specific Precautions for Dark Phototypes The techniques described are for patients with phototype I–III. To treat patients with a higher phototype (IV–VI), extra

precautions should be taken. The patient should prepare the skin by applying Blending Bleaching Cream twice a day for 2–3 weeks before the peel; use sun protection cream (MelablockHSP 50+); and avoid exposure of the skin to daylight. The peel should be applied carefully, and great care should be taken not to have any excess solution. After the peel, Blending Bleaching Cream should be applied as soon as possible, when flaking has finished, and be continued for 6 weeks after the peel.

Pigmentary Changes Pigmentary changes can be treated with three or four ETCA sessions and Blending Bleaching Cream. Total sun protection is essential.

24 Resorcinol Unna’s paste/Jessner’s solution CHEMISTRY Resorcinol (Figure  24.1), also known as resorcin, meta-dihydroxybenzene, 1,3-dihydroxybenzene, and 1,3-benzenediol, has a molecular weight of 110.11 and a relative density of 1.272. It is slightly more acidic than phenol, with a pKa of 9.15. It is soluble in water, alcohol, ether, and glycerol. It comes in the form of white needle-shaped crystals. Resorcinol crystals oxidize easily and turn pink on contact with light, air, or iron.

PROPERTIES OF RESORCINOL Antiseptic Resorcinol has antiseptic properties similar to those of phenol1 and was used to dress minor wounds before the era of antibiotics. It has antifungal properties and was also applied on chancroids and syphilitic ulcers. Its bactericidal effect is 30% of that of phenol.

Proteolytic and Protein Coagulant Resorcinol is a phenol derivative, and its proteolytic power is about 1/40 of that of phenol. It breaks the weak hydrogen links of keratin and acts as a proteolytic agent, even at concentrations as low as 5%.2 At higher concentrations, it can also precipitate skin proteins and become a protein coagulant.

Antipruritic Resorcinol is used in many antipruritic formulations, especially in chronic kidney dialysis. It is mainly used in paste form, usually called Unna’s paste, or in solution form, as Jessner’s solution or Combes’ solution.

INDICATIONS FOR RESORCINOL • • • • • •

Acne: Acne is a good indication for resorcinol. Folliculitis: Resorcinol is effective in this indication, even on the back. Comedones: Resorcinol eliminates comedones. Scars: Superficial scars can be slightly improved, but deep “ice-pick” scars or extended scars do not respond to this treatment. Photoaging: Solar keratoses, pigmentary lesions, epidermal atrophy, and solar elastosis are indications for resorcinol if their histological origins are not too deep. Dyschromias: Resorcinol has been used with varying success to treat melasma, chloasma, postinflammatory hyperpigmentation (PIH), and postacne pigmentation. It can eliminate some freckles. Resorcinol is contraindicated in patients with phototypes IV–VI because of the risk of pigmentary changes.

Obsolete Indications Manquat’s Elementary Treatise on Therapeutics (1903) describes the heroic experiments of colleagues who tested, on their own

bodies, the effects of resorcinol taken in ever-increasing doses until convulsions ensued (ingestion of 10 g of resorcinol in 15 minutes). The indications officially retained in 1903 were the following: • • • •

Antipyretic: Resorcinol was considered a dangerous and rather ineffective antipyretic. Antiseptic: The antiseptic use of resorcinol was recommended for surgery in place of phenol, as it is less toxic and less caustic. Anesthetic: Resorcinol acts as a mild local anesthetic. Psoriasis and eczema: Unna used it in ointments of 10%– 20% to treat psoriasis, and of 2% to treat pityriasis capitis and seborrheic eczema.

HISTOLOGICAL CHANGES Epidermal After a resorcinol peel, the superficial stratum corneum comes away from the germinative layer in the stratum granulosum.3,4 The basal layer shows increased mitosis and accelerated turnover. The total thickness of the epidermis therefore increases, to the detriment of the stratum corneum, and the skin appears more hydrated.

Dermal The fibroblasts in the papillary dermis are stimulated and proliferate: they synthesize a large quantity of new collagen, which is deposited in bands beneath the epidermis (in the Grenz zone). The intercellular matrix is enriched in glycosaminoglycans. Further down, short-lived but rapid vasodilation occurs, signaling the presence of dermal inflammation. Four months after the peel, the histological changes in the dermis, apart from vasodilation, are still visible. The intercellular space has a higher concentration of glycosaminoglycans, and there are more collagen and elastic fibers in the dermis.

INGREDIENTS OF RESORCINOL PEELS Many classic formulas use resorcinol combined with old-fashioned ingredients that may now sound somewhat strange and mysterious.

Wool Fat (Lanolin) Wool fat is obtained from extracts of soapy water in which sheep’s wool has been washed or is extracted with solvents from grease wool. Lanolin is obtained by purifying the grease (or suint). This emollient is a yellow and viscous substance, consisting of fatty acids and fatty acid esters.

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OH

OH

Figure 24.1  Chemical structure of resorcinol.

Petrolatum (Vaseline) This neutral, semisolid unctuous substance, tasteless and odorless, is derived by distilling or purifying petroleum. Thin layers are transparent. Petrolatum is the official generic name; Vaseline is a (genericized) trademark.

Benzoin Axunge Axunge is a greasy excipient used to reduce erythema. It is, in fact, simply lard (i.e., grease extracted from a pig’s epiploon). Benzoin axunge is prepared by adding 5 g of tincture of benzoin per kilogram of melted axunge and stirring until the mixture has cooled.

Benzoin Benzoin, or gum benzoin, is a resinous secretion obtained from cuts made in the trunk or branches of the Styrax benzoin tree. It contains coniferyl benzoate, benzoic acid, benzyl cinnamate, vanillin (a phenol aldehyde), and a number of triterpenes.5 (See Box 24.1) Benzoin resin is a local irritant. A hundred years ago, it was considered to be an aphrodisiac when ingested. At the beginning of the 20th century, benzoin was primarily administered as an antiseptic in fumigation to treat chronic respiratory diseases: small pieces of it were thrown onto a heated metal plate.6 Tincture of benzoin is obtained from dissolving (1/5) benzoin in alcohol.

Ceyssatite and Zinc Oxide Ceyssatite is a white clay (from Ceyssat in France) whose absorbent properties, similar to those of kaolin, have been widely used in cases of hyperhidrosis and eczema. Ceyssatite and zinc oxide have an exfoliating and desiccant action that is absolutely essential for resorcinol to act evenly.

and sodium oxide. It was first found in China, in Kao-Ling. European kaolin is formed by the decomposition of feldspath in granite rock in Brittany or Limousin. Kaolin has good absorbent properties and is gentle on the skin; it is very well tolerated by patients with very sensitive or reactive skin. It is used for its healing, antiseptic,7 and anti-inflammatory qualities and its excellent coverage in Unna’s paste formula.

Benzoic Acid Benzoic acid is a weak carboxylic acid.8 It is not very soluble in water (3  g/l at 25°C) and has a molecular weight of 122. It comes in the form of a white silky-looking solid and is used as an antiseptic and antifungal agent or as a preservative in some fizzy drinks.

RESORCINOL PASTES Formulations of Different Pastes The formulations for resorcinol paste most often used in the past are shown in Table  24.1. The preparation of this paste involves a great deal of work for the pharmacist, who has to use centrifugation and/or ultrasound. The resorcinol crystals have to be thoroughly ground in a mortar before making up the paste to ensure no big crystals remain in it.9 The resulting mixture will be more homogenous and easier to spread. Unna’s paste does not remain active very long, as it oxidizes rapidly. The doctor should therefore always use a freshly made paste. Another formulation contains resorcinol, olive oil, kaolin, zinc oxide, petrolatum, and wool fat.

Preparing the Peel Preparing the Skin The best results are achieved when the patient’s skin has been prepared for 15 days beforehand; see Chapter 2. If the skin has been prepared with tretinoin or alpha hydroxy acids (AHAs), or if the patient has used products (benzoyl peroxide) or techniques (scrub, or abrasion with a massage glove) that increase the permeability of the stratum corneum, the resorcinol paste should not be left on too long. Allergy Test An allergy test should be done before each resorcinol peel, by applying a small bit of paste on the skin behind the ear for Table 24.1  Formulations of Resorcinol Paste

Kaolin Kaolin is a white clay mostly made up of silicon dioxide, aluminum oxide, iron oxide, titanium dioxide, magnesium oxide,

BOX 24.1  Benzyl and Phenyl • Benzene is a molecule. • Benzyl is a group that has to be attached to something else. It is methyl benzene whose methyl group (CH3–) has lost a (H–) • Phenol is a molecule; the suffix -ol means that it has a (–OH) radical. • Phenyl is a group that has to be attached to something else. It is a benzene minus a (–H) or a phenol without its (–OH) group.

Resorcinol Zinc oxide Ceyssatite Benzoin axunge Benzoic acid Dermagor cold cream a

b

c

50%a,b 40 g 10 g 2 g 28 g

50%c 60 g 15 g 3 g

30%c 30 g 15 g 5 g 50 g

2 g 40 g

Trauchessec JM, Vergereau R. Les Peelings. In: Bartoletti CA, Legrand JJ (Eds.). Manuel Pratique de Médecine Esthétique. 2nd ed. Paris, France: Société Française de Médecine Esthétique, 159–167. Rusciani L, Rossi G, Bono R. Les peelings chimiques. Journal de Médecine Esthétique et de Chirurgie Derma­ tologique. 1993; XIX (78): 78–80. Cohen, L, Préparations Magistrales en Dermatologie. In: Arnette (Ed.). Collection des Manuels Pratiques de Médecine Esthétique. Paris, France: 1989.

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20 minutes. This provides a minipeel to evaluate the risk of allergy. This allergy test should be conducted like a localized peel. The skin must be allowed to dry and flake; the normal action of resorcinol on this thinner and more sensitive skin should not be confused with an allergy. Any hint of an allergic reaction (e.g., swelling, redness, itching, blistering, or weeping skin) should rule out this peel immediately. There is one significant cloud on the horizon: the allergy test itself can make a patient who was not previously allergic to resorcinol allergic. It is therefore not wholly predictive. Clean and Degrease The skin should be disinfected (with alcohol) and degreased (with ether or acetone) before applying the paste. Hydrating the Patient The patient must be well hydrated to facilitate diuresis and elimination of the metabolites of the resorcinol. An intravenous drip of saline solution should be set up, but if this is not possible, the patient should be asked to drink several glasses of water before the resorcinol is applied.

Preparing the Paste Resorcinol paste is compact and difficult to apply. It can be easily softened by putting it in a water bath at 45° for approximately 10 minutes. If that is not possible, small blocks of paste should be applied to the patient’s skin. Heat from the skin will slowly “melt” the paste and make it easier to spread, although the resorcinol may penetrate too deeply where contact time has been longer.

Analgesia and Anesthesia No analgesia or anesthesia is necessary. Resorcinol has a mild local anesthetic effect, and a resorcinol peel is neither painful nor stressful.

Positioning the Patient The patient lies down during the peel and for half an hour afterward.

Applying Resorcinol Paste Application The patient’s eyelids are protected with Vaseline or damp cotton (makeup remover) pads. A thick coat of paste is applied with a tongue depressor—enough to make a mask of even thickness. The paste should not be applied to the eyelids or mucous membranes. The paste has to be applied a little way into the hair, and should just touch the eyebrows. On the jaw area, as with phenol, the paste is applied up to 2 cm below the upper jaw. The paste should be rubbed gently to make it more homogenous. Resorcinol paste is often applied on the décolletage and back. Great care must be taken in these areas, however, as the extent of the surface area treated can induce toxicity. Large surface areas should be treated in several stages, and a rest period between two applications will help the body eliminate the metabolites from the detoxification of this phenol compound. Contact Time for a Facial Peel The contact times discussed below are a rough guide only and should be modified to suit the patient’s skin type, the disorder being treated, the results desired, and so forth.

First Application (First Day)  The contact time is 10–25 minutes. A few minutes after the first application, the patient feels some heat and then a tolerable burning sensation. This sensation starts where the resorcinol has penetrated most rapidly. The cheeks are usually more permeable than the forehead. The areas where the patient first feels burning are the first to be cleaned of the resorcinol paste at the end of the peel. The sensation of acid “burning” can sometimes become intense, and a yellow serous fluid may be seen to weep through the partially lysed epidermis. In this case, the patient should be given an analgesic for the first night: acetaminophen plus codeine. After the first application, the skin becomes red in color, as if sunburned. Second Application (Second Day)  The contact time is 20–30 minutes. The resorcinol is left to work for longer: 10 minutes more than the first session, or even 15 minutes more on areas that did not react as well on the first application, mainly on the forehead. After the second application, the skin becomes brownish, and the patient’s social life is disrupted. Third Application (Third Day)  The contact time is 30–35 minutes. The third application must be conducted with extreme caution. If the “resorcinol membrane” that is forming has modified the permeability of the skin, epidermolysis is present, and the skin has been badly injured, rough handling (or paste that is too compact) could pull away the skin and sharply increase the risk of postpeel complications in the form of erythema and pigmentary changes. After the third application, the resorcinol membrane has formed. It is made up of lysed and dried out corneocytes and keratinocytes, stuck together by any serous fluid seeping through the epidermis. Contact Time for a Body Peel The skin on the body is less permeable than the skin on the face, and the contact times will therefore be longer. On the first day, the contact time should be 30–50 minutes, on the second day 40–60 minutes, and on the third day 50–70 minutes. Again, extreme caution is recommended for peels on nonfacial skin because of its limited capacity to regenerate and because the extent of the area to be treated increases the risk of general toxicity.

End of the Peel At the end of contact time, the paste is removed with a tongue depressor and a dry gauze pad. A small amount of paste can be left on the skin at the end of the peel so that a thin layer of resorcinol remains to give full results. It is not strictly necessary to remove the paste in the same order in which it was applied. The paste can be left to work longer in certain places to increase the strength of the peel locally—for example, on the more resistant skin on the forehead. If the doctor wishes to remove all of the paste, the following solution can be used: • • •

Tincture of benzoin, 50 ml. Tincture of Quillaja,10 50 ml. Rose water, 100 ml.

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IMMEDIATE POSTPEEL CARE The patient remains lying down for approximately half an hour after the peel. The back of the table is raised to move the patient gradually from a lying position to a sitting position, and he or she continues to be hydrated. The patient then goes home, with an analgesic or an anti-inflammatory to deal with any pain or unpleasant burning. 3M cold packs can help ease the sensation of heat. Resorcinol peels owe some of their effectiveness to the presence of siccative agents.11 Any topical hydration of the skin must therefore be strictly avoided until flaking has begun. Actual downtime will start after the second application of the resorcinol paste and will last for 8 days. It is important to warn the patient about the downtime and explain clearly how the face will look during the week it is flaking. The resorcinol membrane flakes starting on the fourth day. The more mobile areas of the face, around the face and eyes, will flake first. The resorcinol membrane slowly cracks, making the skin look around 100 years old. It grips the skin in a straitjacket, sometimes making it difficult for the patient to speak and eat. The patient should anticipate a liquid diet for a few days: yogurt, soup, broth, consommé, purée, and so forth. The patient must not pull off the strips of peeling skin. At the most, the strips can be cut off with scissors, without pulling the skin at all. The skin is pink and sensitive underneath the resorcinol membrane. As soon as flaking starts, the skin needs hydration (vitamin E hydrating and antioxidant cream, or even Vaseline if necessary). Effective sun protection (see Chapters 2 and 3) must be used permanently for 1–3 months. How long sun protection is used depends on the risk of hyperpigmentation (skin phototype IV, sunny climate, working outside, etc.).

Repeating the Peel According to Unna, the resorcinol paste can be applied again as soon as flaking is complete. Physicians are rarely called upon to repeat an application of resorcinol paste nowadays. The results of an Unna’s paste peel remain modest in relation to the complexity of the treatment and the downtime involved, and patients are not prepared to accept these conditions.

JESSNER-TYPE RESORCINOL SOLUTIONS Formulations of Different Solutions Some authors use m/m instead of m/v, which changes the actual concentration of the active ingredients. It is also important to stress the need for the pharmacist to use the crystal form of the lactic acid and not the solution form. Lactic acid comes in liquid form with a concentration of 85%. The pharmacist should use lactic acid crystals and not solution to prepare the Jessner solution. Moreover, different molecules, many of them unknown, are used to denature alcohol, to make it unfit for drinking, and there is a risk of potential chemical interactions with the acids. The alcohol used by the pharmacist must be pure, not denatured. Resorcinol solutions have been used at concentrations of 10%–50% in alcohol or ether to treat keratoses. Resorcinol solutions have the distinct advantage of not having to be neutralized. Eller and Wolf’s Solution (1941)12 • Resorcinol (crystals), 17 g. • Salicylic acid13 (crystals), 8.5 g. • Lactic acid14 (crystals), 8.05 cm3. • Rose oil, 0.05 cm3. • Alcohol 95°, ad 100 ml.

Five to eight coats are applied one after the other with cotton, depending on the depth of peel desired and the skin type. Three coats produce frosting and six coats produce edema. Eller and Wolf recommended constant hydration of the patient before and after treatment. Urkov’s Solution (1946) • Resorcinol, 38 g. • Salicylic acid, 6.6 g. • Lactic acid (solution), 13 cm3. • Alcohol 95°, ad 100 cm3. After leaving the solution to rest for 24 hours and filtering it, UV exposure was what made it effective. Solutions not exposed to UV did not appear to work. The skin was also prepared by UV exposure, and the solution was applied five times, allowing each coat to dry before the next application. Urkov then applied an occlusive mask. This mask allowed the superficial layers to hyperhydrate by blocking transepidermal water loss (TEWL). The hyperhydration dissolved the salicylic acid that would have precipitated on the skin without occlusion and could not have penetrated, as only the acids in solution can readily penetrate the skin barrier. He then applied zinc stearate powder (which is antiseptic and anti-inflammatory). The erythema subsided in 5–6 days and exfoliation was superficial. The solution can be kept in the refrigerator for 10 days. Jessner’s15 Solution or Combes’16 Solution (1950s) • Resorcinol (crystals), 14 g. • Salicylic acid (crystals), 14 g. • Lactic acid (crystals), 14 g. • Ethanol 95° (not denatured), ad 100 ml. Jessner’s solution must be kept in a glass, light-protected, hermetically sealed bottle. It can be kept in the refrigerator for more than 2 years like this. When the solution oxidizes, it turns pink. Contact with the fingernails can turn them orange-yellow.

Other Combinations Resorcinol solutions have been used in combination with glycolic acid, trichloroacetic acid (TCA), and 5-fluorouracil (5-FU). Many modified versions of Jessner’s solution have been presented, containing kojic acid, hydroquinone, and other ingredients. The effectiveness of these resorcinol solutions depends on skin preparation, skin sensitivity and thickness, the type of applicator and the force of application, the number of coats applied, the type of solution used, the quality of the solution’s preparation, and other factors. Moreover, products with a tyrosinase-inhibiting action (kojic acid, hydroquinone, etc.) produce their effect only in the long term. Single application of these products cannot treat melasma in any way. Only repeated applications, allowing the gradual absorption of products that inhibit melanocyte metabolism, can be considered as an effective treatment.

Jessner’s Formula Indications Jessner’s solution provides an exfoliating peel, effective in the treatment of acne and dyschromias of superficial origin. Safety It is a relatively safe peel. Overpeeling is rare with this treatment, but phototypes IV–VI are still contraindicated because

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of the risk of pigmentary changes. Unlike resorcinol paste, Jessner’s solution does not cause dizziness, tinnitus, or faintness. When applying the solution on large surface areas, however, it must be taken into account that the potentially toxic agents that it contains may be absorbed and are likely to be eliminated via the liver and kidneys. According to Rubin, applying Jessner’s solution on the face, neck, and décolletage in a single session remains without danger of salicylism. Salicylism was described, however, again by Rubin, when doing Jessner peels together on the face, neck, arms, and lower limbs.17

•

Jessner’s solution has penetrated more deeply than anticipated. After three coats, the stratum corneum separates from the skin, there is no blistering or epidermal necrosis, and the dermis is not directly affected. Level 3: Applying additional coats deepens the effect of Jessner’s solution. The erythema becomes established and the frosting tends to spread over a wide area, sometimes over the whole of the treated area. Flaking is more pronounced, and the skin is brownish and comes away in long strips. This can last for approximately 10 days. Downtime is common at this depth, even if there is rarely any scabbing.

Standard Application of Jessner’s Solution (Original Formula) Preparing the Skin  Standard skin preparation increases the depth of penetration of Jessner’s solution and improves the results—while increasing the risk of complications. An allergy test is essential, especially because of the resorcinol in the formula.

Postpeel Care The skin still feels tight and dry, but it should not be hydrated. When flaking has finished, the patient can wear makeup and should use effective sun protection. The patient must not help the flaking along at the risk of causing erythema and pigmentary changes.

Cleaning and Degreasing  The skin is cleaned and degreased with alcohol and acetone. Care should be taken not to abrade the skin manually with the gauze pad while degreasing.

Jessner’s as a Preparation for a TCA Peel

Applying the Solution  Applying Jessner’s solution is about as painful as a TCA peel at 15%. It is applied gradually, leaving each coat to dry completely before applying the next coat. The strength of the peel depends on the number of coats applied; it is therefore possible to penetrate the skin gradually. Carelessly applying one coat immediately after the other would take the peel beyond the desired effect and increase the risk of complications. It takes time to do a peel with Jessner’s solution. The depth of action also depends on the force of application: the greater it is, the deeper the acids will penetrate. Patients with thin skin should be treated with lighter hand pressure than patients with thick skin. •

•

Level 1: An even coat is applied to the area to be treated, regardless of the type of applicator (brush, cotton buds, cotton balls, gauze pads, etc.18). It is always advisable to use disposable applicators to avoid any risk of transmitting infection. The first coat usually causes erythema and occasionally some pinpoint frosting. Some “pseudo-frosting” usually can be seen after the ethanol has evaporated: this is caused by the ingredients of the solution, especially the salicylic acid, precipitating on the skin. Unlike genuine frosting, which is protein coagulation, pseudo-frosting can be brushed off easily. The patient should be fanned with a handheld or portable fan to alleviate the “burning” sensation and eliminate any unpleasant fumes. If the application remains at level 1, only a very slight drying of the skin will be observed afterward. Level 2: The skin is left to dry for 4–5 minutes between two successive coats. The second and third coats trigger more pronounced erythema and cloudy white frosting, as well as some pain and discomfort. The discomfort will last for approximately a quarter of an hour. Trauchessec19 applies the solution once a week until results are achieved. The first treatment consists of only one coat, the second of two, and the third of three coats of solution. After level 2, the patient’s skin feels dry and tight. The top layers of the epidermis, dried out by the solution, appear transparent but still stick to the underlying cells. Flaking occurs within 4–5 days. Locally, some areas may turn a brownish color where

Jessner’s solution can be used as a preparation for a deeper peel. Monheit Technique The skin is prepared and cleaned in the usual manner. The Jessner’s solution is applied to level 1: erythema occurs, along with some localized pinpoint frosting at most. Five minutes should be left between each coat. The last coat is left to dry, and then TCA is applied—this will penetrate more quickly and more evenly20 because of the breakdown in the epidermal barrier function. It will also be more painful. This technique could be used on patients with thick and oily skin when better TCA penetration is needed.

Jessner’s as a Preparation for an AHA Peel A Jessner’s peel would improve and even out AHA penetration through the skin. Moy Technique The skin is prepared and cleaned in the usual manner. Jessner’s solution is applied to level 1. The last coat is left to dry for 5 minutes, and then glycolic acid is applied until the erythema spreads. This is followed by neutralization. Because of the erythema already caused by Jessner’s solution, it is difficult to judge the progress of the AHA peel, and it is common for it to penetrate too deeply, causing unexpected frosting. This more delicate technique should only be used for treating patients with very thick and oily skin that can tolerate high concentrations of AHAs being left on the skin for long periods before neutralization.

Jessner’s for the Neck and Décolletage Jessner’s solution is applied in the usual manner, but at a rate of one peel every 2–4 weeks. Under no circumstances should the patient help the skin to flake, which could leave depigmented or hyperpigmented patches.

Jessner’s for Keratoses To treat actinic keratoses with Jessner’s solution, the skin is first degreased carefully with acetone. Jessner’s solution is then applied once a week for approximately 8 weeks. This treatment is not very effective, however, as no more than 15% of the actinic lesions disappear.

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TOXICITY AND SIDE EFFECTS J. Andeer tested the toxicity of resorcinol at the end of the 19th century.6 He consumed gradually increasing doses of resorcinol and made objective and careful notes of the sensations he felt and the symptoms he developed. In this way, he tested a daily intake of 1 g of resorcinol and gradually increased the doses until he was taking 10 g of resorcinol in 15 minutes. This triggered auditory, visual, muscular, and proprioceptive symptoms, then convulsions with breathing difficulties and muscle contractions. He was fortunate enough to be able to report that all these phenomena disappeared after 5 hours of “resorcinol agony.” History does not tell us if he repeated the experiment to evaluate its reproducibility, but we know that other colleagues have tried the same kind of experiment with resorcinol and many other toxic agents as well. Although it belongs to the phenol group of chemicals, resorcinol has very different exfoliating properties and is far less toxic than phenol itself. The routes of metabolic detoxification are mainly via the liver and kidneys. As a precaution, patients with liver or kidney deficiencies should be ruled out for treatment with resorcinol, as should patients with arrhythmia and women who are pregnant or breast-feeding.

Toxicity Resorcinol is toxic by ingestion of an average dose of 6  g. Serious accidents have been described after ingestion of 3.5 g, however.6 It irritates the mucous membranes and the skin, and ingestion can cause methemoglobinemia, cyanosis, convulsions, or even death. Cases of methemoglobinemia have been described after application on leg ulcers but not after a peel on normal skin. The problem raised with the use of Jessner’s solution is more the fear of salicylism than the toxicity of the resorcinol itself. Cases of salicylism have been described after application of Jessner’s solution to the face, chest, arms, and legs.17 The size of the surface area treated, the patient’s body weight, and the patient’s degree of hydration are all key factors. The risk of toxicity increases with the surface area treated. There is a greater risk in patients with low body weight and patients who are not well hydrated.

Secondary Hypothyroidism Thyroid injury after chronic skin application of resorcinol has been reported several times. In 1977, Katin and colleagues21 published a case of hypothyroidism following regular application of a 2% resorcinol cream in a chronic dialysis patient suffering from pruritus. The mechanism of action seems to be as follows: the presence of a hydroxy group in the meta position in the resorcinol would block the metabolism of iodine by inhibiting the peroxidase needed to oxidize iodide into iodine, the only form that can be assimilated by the body.

Allergies Unna’s Paste Allergies to resorcinol have been widely described. It is therefore wise to do a skin sensitivity test behind the patient’s ear 8 days before a resorcinol peel. Any contact with resorcinol can sensitize the patient (or the physician) to it, so the test must be repeated before each peel. The fact that the first peel does not trigger an allergic reaction is no guarantee that the next peel will not trigger one. Allergy to resorcinol is permanent—there is no point trying again.

In the allergy test, a small quantity of Unna’s paste is applied to a patch of skin 2 cm × 2 cm behind the ear and left for 15 minutes. The test is read immediately and then again 48 hours and 5 days later—although Letessier3 recommends just one reading, after 4 days. It is important not to confuse an allergy with the skin’s natural response to the chemical peel applied behind the ear. A highly localized and normal skin reaction to the peel will occur: erythema followed by flaking. The appearance of any blistering or pruritus contraindicates any further contact with resorcinol completely and definitively. If a patient is allergic, Unna’s paste causes reversible facial eczema, with no cosmetic benefit. Jessner’s Solution The allergy rate to resorcinol is less than 0.1%.17

Hyperpigmentation Pigmentation disorders are relatively common after a resorcinol peel. Effective sun protection (see Chapter 3) must be used for 1–3 months after the peel. The people most prone to pigmentary changes are those who had pigmentation problems before the peel, those who take oral contraceptives or are on hormone therapy, and those who have a record of posttraumatic or PIH or have a high density of melanosomes (phototypes IV–VI). Potential problems with pigmentary changes are treated in the usual manner, as described in Chapter 37. Pigmentation problems such as ochronosis after a resorcinol peel, also described in the literature, are more complicated to treat.

Prolonged Erythema A few areas of mild erythema, which changes color with the cold, alcohol, or emotion, can very occasionally last for several weeks. Erythema after a resorcinol peel is usually reversible without treatment but requires preventive treatment against pigmentary changes, especially in high-risk patients (see the preceding paragraph and Chapter 37).

Dizziness and Nausea Dizziness and nausea can occur during or after application of the paste. Some authors attribute these symptoms to peripheral vasodilation and the resulting low blood pressure. This explanation is not satisfactory, however, as facial vasodilation is in no way correlated with low blood pressure. Other facial peels produce at least the same degree of vasodilation without causing low blood pressure or faintness. Furthermore, there would have to be a great deal of peripheral vasodilation to make blood pressure so low that a patient in the lying position can feel it. Blood pressure readings taken after a peel are not low enough to explain this “dizziness.” It appears instead that the dizziness and nausea are symptoms of the beginnings of resorcinol poisoning. Fortunately, the symptoms soon resolve. Because resorcinol is a phenol compound, using Unna’s paste and Jessner’s solution on large areas can theoretically lead to typical phenol complications. Although resorcinol is usually 40 times less toxic than phenol itself, 100 g of Unna’s paste contains 40 g of resorcinol. That is the toxic equivalent of 1 g of phenol. The precautions of slow application (in 1 hour) that are taken with phenol are not observed for resorcinol and, with resorcinol, the area treated is often larger. Resorcinol is a small molecule that, like phenol, is

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easily absorbed by the capillaries. Rapid application of a thick and warm layer of resorcinol can introduce a relatively large quantity of the substance into the bloodstream and trigger the start of neurological toxicity typical of phenol compounds. As a result, the face can be treated in perfect safety, but when large areas are being treated, as is the case with a peel on the back, it is essential that the treatment consist of several separate peels.9 Arouette9 reports an unpublished clinical case of an extensive application of Unna’s paste bringing on coma in a few hours with full recovery.

Secondary Infections A recurrence of herpes lesions should be anticipated, and preventive treatment should be taken if necessary. Scratch lesions22 can trigger impetigo on the face. Scratching is the only explanation for signs of infection after a peel with Unna’s paste or Jessner’s solution.

Scarring As with any superficial peel, under normal conditions the risk of developing scars is very low. Nevertheless, scabs and dry skin should not be pulled off.

Inadequate Results If the results are considered inadequate, the patient might benefit from additional peels. A maintenance resorcinol peel can be done every year, if indicated. According to Unna (quoted by Arouette9), “under some circumstances, it is necessary to do several successive exfoliations that can be performed without interruption.”

NOTES 1. For comparison with phenol, see Chapters 25 and 26. 2. Fintsi Y. Exoderm-lift – liquid formula. 1996. 3. Lettessier S. Chemical Peel with Resorcin. In: Roenigk RK, Roenigk HH (Eds.). Dermatologic Surgery, Principles and Practice. 2nd ed. Oxford, UK: Marcel Dekker, 1999: 1115–19. 4. Collins PS. Chemical Face Peelings. In: Evaluation and Treatment of the Aging Face. Springer, 1995: 34–67. 5. Terpenes are a class of compounds whose chemical structures are based on a number of “isoprene units” derived from the hydrocarbon CH2 = C(CH3)–CH = CH2; they may themselves be hydrocarbons but also may contain alcohol (OH), aldehyde/ ketone (CO), and carboxylic acid (COOH) groups. Monoterpenes are C10 compounds derived from two isoprene units, sesquiterpenes (C15) are derived from three isoprene units, diterpenes (C20) from four, and tritepenes (C30) from six. Terpenes are widespread in plants, where they are largely responsible for the odor, and they are the major constituents of plant-derived “essential oils.” Among the best known terpenes are R-pinene (turpentine), camphor, menthol, and citronellal (all monoterpenes), and farnesol (a

6. 7. 8.

9.

10.

11. 12. 13.

14. 15.

16. 17. 18.

19. 20.

21.

22.

sesquiterpene that is a constituent of the essential oils of many plants). Certain terpenes have important biological roles: vitamin A, for example, is a diterpene, and steroid hormones have a structure related to triterpenes (and are biosynthesized by a similar route). Manquat A. Traité Élementaire de Thérapeutique de Matière Médicale et de Pharmacologie. 5th ed., tome 1. 1903: 240–60. Kaolin (like ceyssatite) has absorbent properties that allow it to trap microorganisms. Note the distinction between benzoic acid (C6H5COOH), in which a carboxylic acid group is attached to the benzene rign, and phenol (C6H5OH), in which the substituent on the benzene ring is a hydroxy group. Arouette J. Dermabrasion, Relèvements, Peelings. In: Blackwell A. (Ed.). Collection des Manuels Pratiques de Médecine Esthétique. 1989, Paris. Quillaja bark is a natural soap containing 9%–10% saponins that is used in phytotherapy for dandruff, athlete’s foot, and irritated or sensitive skins. Used alone, a resorcinol peel at 5% triggers light exfoliation. The real peeling effect starts at 25% and becomes more obvious at 40%. Dr. Eller and his assistant Shirley Wolf described this formula in New York in 1941. Salicylic acid (3%–5%) triggers light exfoliation. A concentration of 15% is needed for a superficial peel. A concentration of 50% (beware of salicylism) produces a dermal peel. Such weak concentrations of lactic acid are ineffective in themselves but may enhance penetration of the other ingredients. Max Jessner qualified as a dermatologist in Germany in 1922. At New York University Hospital in the 1950s, he developed the solution for the treatment of acne that bears his name. Dr. Jessner’s aim was to improve the performance of peels while reducing the risk of side effects, by exploiting the synergy between the different ingredients. Dr. F. C. Combes made wide use of Jessner’s formula in the 1960s and is better known in the United States. Rubin MG. Manual of Chemical Peels, Superficial and Medium Depth. Philadelphia: JB Lippincott, 1995. Frosting is reached more quickly with a brush than with a double cotton bud, unless greater pressure is applied. Brushes should be used once only or disinfected with povidone–iodine. Single-use brushes are preferable: would you like to treat your skin with a brush that has already been used on acres of unknown skin? Trauchessec JM. Teoria y practica de los peelings. Med Estet. 1996; 40: 11–21. This would not be the case with AHAs before a TCA peel (Coleman technique). AHAs do not penetrate evenly and might cause the TCA to penetrate still more unevenly. Katin MJ, Teehan BP, Sigler MH, Schleifer CR, Gilgore GS. Resorcinol induced hypothyroidism in a patient on chronic hemodialysis. Annals of Internal Medicine. 1977; 86(4): 447–9. And overenthusiastic personal hygiene—for example, using a sponge such as a Buf Puf, nonprescribed cosmetic scrubs, a face cloth (which is a breeding ground for microbes), etc.

25 Phenol Chemistry, formulations, and adjuvants CHEMISTRY OF PHENOL As a class, phenols are compounds in which a hydroxy group is attached to a benzene ring. The name phenol also is used to refer specifically to the simplest compound in this group, which is also known as hydroxybenzene, benzenol, or carbolic acid (Figure 25.1).1 Phenol has a molecular weight of 94.11, a specific gravity of 1.071, and a boiling point of 182°C. It can react vigorously or even violently with other compounds, including formaldehyde, acetaldehyde, and trifluroacetic acid, as well as aluminum chloride, nitrobenzene, some nitrates and nitrites, and other oxidizing agents. Phenol crystals are white or pink, and melt at 41°C. Most commercial phenol has a purity of 98%, but 100% pure phenol is obtainable.2 Phenol was formerly obtained from coal tar but is now made by hydrolyzing chlorobenzene at 350°C or, more frequently, by air oxidation of cumene3 and treatment of the resulting cumene hydroperoxide to yield phenol and acetone (Figure 25.2). Estimates of the amount of phenol produced worldwide vary, but since 1980 more than 5,000,000 tons have been produced. Phenols may have more than one hydroxy group attached to the same benzene ring—for example, the three isomeric4 dihydroxybenzenes catechol (ortho-dihydroxybenzene or 1,2-benzenediol), resorcinol (meta-dihydroxybenzene or 1,3-benzenediol), and hydroquinone (para-dihydroxybenzene or 1,4-benzenediol); see Figure 25.3. Molecules that have a single benzene ring with one or more hydroxy substituents are known as “simple phenols.” Examples are phenol itself and the three dihydroxybenzenes mentioned in the previous paragraph, as well as the cresols (discussed later). There are also “diphenols” (Figure 25.4) and polyphenols. Polyphenols are complex molecules containing several benzene rings with one or more hydroxy substituents. They are widespread in nature, often lending plants their color. Polyphenols (flavonoids and anthocyanins) constitute an important group of antioxidants used in antiaging medications; flavonoids (Figure 25.5) are a distinctive group of polyphenols with a specific structure, containing two benzene rings, one of which is fused to an oxygen-containing ring.

PHENOL DERIVATIVES Medicine has made wide use of phenols in many indications, as we shall see later in this book. Medical publications on peels abound in terms that are no longer in use and names of outdated molecules, which makes some texts difficult to read. It is therefore worthwhile to briefly review these terms and compounds.

Cresols—Lysol Cresols are simple phenols in which the benzene ring has one methyl and one hydroxy substituent. There are three isomers:

ortho-, meta-, and para-cresol5 (Figure  25.6). Coal tar cresol or cresylol is a mixture of the three isomers and is also called cresylic acid, hydroxytoluene, or methylphenol. Coal tar and cade oil are mixtures of cresol and guaiacol (see later discussion). Lysol is the trade name of a solution of cresols in saponified vegetable oil, developed to counter the difficulties of putting cresol in solution form. It was an alkaline detergent containing 47%–50% crysylol (= cresol = cresylic acid = cresylic phenol) as well as a little guaiacol, xylol, and other ingredients. Chemically, therefore, it was a poorly defined solution that nevertheless had the advantage of providing a clear solution when mixed with distilled water. Crude cresol comes from coal tar and consists of the three isomers: orthocresol 35%–40%, meta-cresol 35%–40%, and para-cresol about 25%. Cresol mixtures are used as preservatives, deodorants, and disinfectants. Ortho-cresol is a solvent and disinfectant. Meta-cresol is mainly used in insecticide chemistry or to produce antioxidants. Para-cresol is mostly used in perfumery. Many foods contain cresols: butter, wine, tomatoes, asparagus, cheeses, bacon, and smoked foods. Cresol is four times as toxic as phenol. Cresol mixtures are irritating to the respiratory tract and the skin. Although only anecdotal information is available on the potentially carcinogenic effects of cresols in humans, the US Environmental Protection Agency has classified these molecules as “possible human carcinogens.” Signs of intoxication include abdominal pain and vomiting. Other symptoms have also been described, such as heart, liver, and kidney problems. Facial paralysis, coma, and death are also possible with higher concentrations, even through simple skin contact.

Guaiacol Guaiacol (Figure  25.7) is also called o-methoxyphenol, 1-hydroxy-2-methoxybenzene, or catechol methyl ether. It is found in Valda lozenges and expectorants, and is also used to make vanillin. It was originally extracted from a tree (Acacia catechu Willd) and then distilled from guaiac resin. Nowadays, pure guaiacol is synthesized from catechol, of which it is the methyl ether. Guaiacol salicylate has analgesic and anti-inflammatory properties. Its analgesic properties are due to the inhibition of cyclooxygenase and prostaglandin synthesis and the release of bradykinin. Guaiacol salicylate is anti-inflammatory as it stabilizes the lysosomal membrane and inhibits the action of the chemical mediators of inflammation.

Halogenated Phenols Halogenated phenols are more powerful disinfectants than simple phenols, as they are more lipophilic. They are also more toxic to the central nervous system. The chlorinated phenols are the most active. Toxicity is specific to each compound.

214    Textbook of Chemical Peels

OH

OH

OH

O

HO

Figure 25.1  Chemical structure of phenol. OH OH CH3 CH

CH3

CH3

Figure 25.5  An example of a polyphenol: the flavonoid catechin.

CH3 OOH

OH (a)

OH CH3

(b)

Figure 25.2  Chemical structure of (a) cumene and (b) cumene hydroperoxide.

CH3

OH

OH

OH

CH3 (c)

(b)

(a) OH

OH

Figure 25.6  Chemical structures of (a) ortho-cresol, (b) metacresol, and (c) para-cresol.

OH

(a)

OH

OH (c)

(b)

OCH3

Figure 25.3  Chemical structures of (a) catechol, (b) resorcinol, and (c) hydroquinone.

Figure 25.7  Chemical structure of guaiacol. OH

OH

O C

O

OH

C

OH

OH

Figure 25.4  An example of a diphenol: 2,3’-dihydroxybiphenyl.

Phenolic Acids Phenol acids are phenols in which there is also a carboxylic acid group attached to the benzene ring. They include salicylic acid (ortho-hydroxybenzoic acid) and para-hydroxybenzoic acid (Figure 25.8). Acetylsalicylic acid (aspirin) and sodium salicylate are derivatives of salicylic acid. Like phenol, they have

(a)

OH (b)

Figure 25.8  Chemical structures of (a) salicylic acid and (b) parahydroxybenzoic acid.

Phenol: Chemistry, formulations, and adjuvants    215

antipyretic and analgesic properties. The methyl, ethyl, and propyl esters of para-hydroxybenzoic acid (parabens) are used as preservatives in pharmaceuticals, cosmetics, and foodstuffs.

OH

Bisphenols Bisphenols (not to be confused with the diphenols), are formed by two phenols linked with a bridge (–CH2–, –O– or –S–) in the ortho position, which makes the product easier to tolerate. Bisphenols are often chlorinated to increase their disinfectant power. Dichlorophene, tetrachlorophene, and hexachlorophene (Figure 25.9) are members of this group of compounds. Septisol is a hexachlorophene soap used widely as a wetting agent in old phenol peel formulations.

Picric Acid Picric acid (Figure 25.10) is 2,4,6-trinitrophenol. It is used in the treatment of burns in a 1% solution because of its stimulating effect on keratogenesis. The dry crystals are extremely sensitive to friction or shock6 and were widely used as an explosive before the discovery of TNT (trinitrotoluene). Picric acid can be synthesized from phenol, benzene, or aspirin. It is soluble in water and alcohol. It turns the skin yellow. Applying swabs with 1.2% picric acid is not irritating to the skin but produces light flaking within 2–4 days. Using picric acid on open wounds and ulcers appears to stimulate epidermal regeneration.

Acetaminophen Acetaminophen (known as paracetamol in the United Kingdom) is N-acetyl-para-aminophenol (Figure  25.11). It has the same detoxification pathways as phenol and also carries the risk of inducing methemoglobinemia. To be on the safe side, it should not be used as an intravenous analgesic during a fullface phenol peel, so as not to saturate the detoxification pathways. Paracetamol is also an intermediate in the pathway for

CI

CI

HO

CI

CI

CI

CH2

OH

CI

Figure 25.9  Chemical structure of hexachlorophene.

OH O2N

NO2

NO2

Figure 25.10  Chemical structure of picric acid.

HN.CO.CH3

Figure 25.11  Chemical structure of paracetamol (acetaminophen).

detoxification of aniline derivatives, before hepatic glucuronide and sulfate conjugation allow them to be eliminated in urine. The aniline derivatives acetanilide and phenacetin were once used as analgesics and antipyretic agents but turned out to be excessively toxic; they were replaced by acetaminophen, which had been shown in 1949 to be their major metabolite.

DIFFERENT FORMULATIONS OF PHENOL PEELS Peels of the Past Reviewing publications on phenol peels reveals many different formulations. The first surgical operation in which phenol was used as a disinfectant took place in March 1865 (Lord Lister, 1827–1912). At the very beginning of the 20th century, Manquat’s treatise on pharmacology7 described in detail the use of phenol as an anesthetic and disinfectant, at concentrations of approximately 5% in aqueous, oil, or alcohol solutions. Preparation involved the use of various ingenious tricks to prevent the solutions from separating into multiple layers and to prevent the formation of isolated caustic droplets. After a relative lull, other formulations started to appear in medical publications. They reflect the constant search for the ideal solution and the increasingly clear understanding of the mechanisms that lie behind the excellent results achieved with today’s phenol peels. From this mass of publications, the author has selected 13 major authors or groups of authors whose formulas will be surveyed in alphabetical order. 1. Ahronson presented a glycerinated phenol formulation: 88% liquid phenol is solubilized in anhydrous glycerol (glycerin) and a few drops of alcohol. This highly concentrated formula, used without occlusion, produces a peel that is not as deep as a peel with Baker–Gordon solution. 2. Ayres achieved a medium-depth peel by combining phenol and trichloroacetic acid (TCA). These two formulas are no longer used today, as there are many other modern peel solutions that provide effective medium-depth peels using other molecules, such as TCA, that are not potentially toxic. 3. Two Baker solutions are described. The first contains liquid phenol USP 5 cm3, distilled water 4 cm3, croton oil 3 drops, and septisol 5 drops. The second contains liquid phenol USP 3  cm3, distilled water 2  cm3, croton oil 3 drops, and septisol 8 drops. The water determines the concentration, which is variable. Baker’s solution has to be stirred constantly, as it is not stable and separates into layers if left to rest. 4. Brown and Kaplan presented a more complex solution of phenol (at varying concentrations between 60% and 95%)

216    Textbook of Chemical Peels Table 25.1  Exoderm Formulas

mixed with saponified cresol in oil at concentrations of up to 10%. The application technique included a patch test behind the ear. This test made it possible to assess the necrotic effect of the solution on the patient. If the necrosis was too severe, the test was repeated with increasing concentrations of oil until the right solution for the patient was found. They recommended applying the solution area by area, leaving 2 hours between applications. The peel took 2 days to complete. 5. Combes, Sperber, and Reisch used an aqueous solution with a high concentration of phenol, combined with citric acid and sodium salicylate. 6. Eller and Wolff, on the other hand, advocated an alcohol solution with a much lower concentration, around 25%, with salicylic acid. This was also applied in several stages (four at the most), with 1 or 2 hours between each application depending on how sensitive the skin was. 7. Grade’s three formulas (aqueous phenol with croton oil), which had widely varying amounts of phenol and water, had to be left to rest for 6 weeks before use. This resting time was needed for “peroxides” to form and buffer the solution. 8. Klein presented a solution that was largely based on Baker’s, but with different concentrations. 9. Karp’s three formulas are well known: the first was almost 80% glycerinated phenol; the second combined phenol with acetic acid, boric acid, salicylic acid and citric acid, but could only be applied locally, as it was too strong. Karp called his third formula “the phoenix”: it was an aqueous solution of glycerinated phenol combined with acetic acid and sodium salicylate. 10. Litton proposed using a detergent other than septisol and recommended using glycerol. He was one of the first to describe an increase in the thickness of the Grenz zone after a phenol peel. 11. Litton’s solution, as well as that of Truppman and Maschek, had the dual advantage over Baker’s of being stable in space and time. These aqueous and glycerinated solutions with concentrations of approximately 50% in phenol contained croton oil. Once prepared, they could be kept for several years when stored away from light and heat sources. Litton’s solution contains more croton oil than that of Truppman and Maschek. 12. Urkov used a simple alcohol solution of phenol and treated deep wrinkles with electrocoagulation after the peel.8 He then applied an occlusive dressing for up to 3 days. His postpeel treatment was based on the “dry technique.” 13. Verner Kellson’s aqueous solution uses two types of phenol: Lysol (an oil solution of cresol) and phenol with various oils, including croton oil. The water has to be distilled, as Lysol forms calcium cresate when mixed with tap water. The solution then becomes opalescent instead of clear.

Formula 1a

Formula 2

Formula 311

Liquid phenol Phenol crystals Distilled water Alcohol Olive oil Sesame oil Glycerol Croton oil Resorcinol

Liquid phenol Phenol crystals Distilled water Alcohol Olive oil Sesame oil Glycerol Croton oil Resorcinol

Liquid phenol Phenol crystals Distilled water Alcohol Olive oil Sesame oil Glycerol Croton oil Resorcinol

Septisol TCA 30%

Septisol Salicylic acid Buffers

Saponins Citric acid Buffers

a

Formulation certificate with bottles of Exoderm.

Peels of Today Exoderm The author’s late friend, Yoram Fintsi, deserves special mention in this book, because he was one of the main catalysts for the current success of phenol peels, thanks to the formula he developed, Exoderm. According to Fintsi, the Exoderm formula was made in 1986 and then refined in 1990. Thereafter, Fintsi in Israel and Benhamou in France improved the formulation. Several formulations were put forward, one after the other, as shown in Table 25.1. The elements in common are listed above the dashed line. The first two formulas used septisol, a disinfectant soap with hexachlorophene, while the third formula— the one used today—simply contains saponins. The first formula contains TCA, the second salicylic acid, and the third citric acid. The last two formulas are buffered to stabilize the pH. Fintsi commented on his own current Exoderm formula in his article “Exoderm, a Novel, Phenol-Based Peeling Method Resulting in Improved Safety.”9 Hetter Formulas In 1996, Hetter put forward a series of formulations based on the principle that by simply changing the concentration of croton oil, the depth of the peel could be varied (Table 25.2). Changing the concentration of croton oil is, indeed, one way of changing the strength of a phenol peel. It is not, however, the only way, and it is perfectly possible to do a phenol peel without croton oil. It is also possible to vary the depth of action of phenol without changing the concentration in croton oil. It is not, of course, a matter of questioning the intense cytotoxic effect of croton oil (see the section on adjuvants later in this chapter), as Hetter10 stresses in 2000. Nor is it a matter of questioning Hetter’s legitimate refutation of the dogmas that claim, on the one hand, that lower concentrations of phenol wound more deeply (a lower concentration of phenol can penetrate

Table 25.2  Hetter Formulas Very light peel

Medium light peel

Medium heavy peel

Heavy peel

4 cm 88% phenol 6 cm3 water 16 drops septisol 1 drop croton oil

4 cm 88% phenol 6 cm3 water 16 drops septisol 1 drop croton oil

4 cm 88% phenol 6 cm3 water 16 drops septisol 2 drops croton oil

4 cm3 88% phenol 6 cm3 water 16 drops septisol 3 drops croton oil Take 3 cm3 of the above mixture and add 2 cm3 88% phenol and 5 cm3 water

3

3

3

Phenol: Chemistry, formulations, and adjuvants    217

more rapidly11 through an epidermis that is made more permeable by protein lysis and can therefore be more toxic) and, on the other hand, that phenol has an “all-or-nothing” action, which is clearly untrue as also said by Dr. Hetter. Attempts are currently being made to market “completely nontoxic” phenol peels. However, the phenol molecule is clearly defined, and so is its toxicity, as we shall see later. A “phenol” peel that is called “nontoxic” cannot, by definition, contain phenol. Lip & Eyelid Formula Lip & Eyelid Formula is a phenol peel that the author first developed to increase dermatological safety and to achieve results without any occlusion on the sensitive skin of the eyelids. The same solution was then applied to the wrinkles around the mouth and then to the whole face, but with 24 hours’ occlusion in these two indications. It is an oil solution of phenol at more than 60%. Four different oils are used in the various stages of the product’s preparation. The aim of the oily formulation is to slow down the penetration of the phenol through the skin and to improve dermal and epidermal maceration. It limits the toxicity of phenol by saturating the biochemical hepatic detoxification pathways more slowly. Split-face treatment comparing Exoderm and Lip & Eyelid Formula showed a higher efficacy of the latter.

STORING PHENOL PEEL SOLUTIONS Pure phenol is resistant to light, but the presence of impurities, even in small traces, turns it red due to oxygen fixation. This coloring does not change the properties of the product. Exoderm solution must be stored away from light12 and humidity, however. It can be stored for 3 years in its original, unopened bottle. The contents of an opened bottle must be used within 1 year. Baker’s solution must be prepared for immediate use, unlike Litton’s solution, which can be kept for 3 years in the refrigerator. Medical publications report using the same solution successfully over many years. Lip & Eyelid Formula also remains stable for at least 3 years if kept in the refrigerator in the original, closed bottle.

ADJUVANTS OF PHENOL PEELS General Remarks Solutions with a high concentration of phenol cause rapid protein coagulation, which translates clinically into immediate frosting of the skin. This opaque coagulation acts as a shield that increases the skin’s impermeability, stops the surface phenol from penetrating, and prevents it from passing rapidly into the reticular dermis. A solution with a concentration higher than 80% therefore produces a more superficial peel than might be logically expected. Solutions with lower concentrations, of 15%–20% for example, are keratolytic and penetrate the skin more easily to a depth where they are picked up by the drainage routes of the skin. The phenol is transferred rapidly for metabolization. A small quantity of free phenol, which can only act on the dermis for a short space of time, does not make for excellent results. If larger quantities of these low concentration solutions are applied to the skin in an attempt to get around this problem, the increased rate of reabsorption of phenol could saturate the detoxification pathways and the risk of intoxication is higher. At both higher and lower concentrations, effectiveness is blocked and adjuvants are needed to make it more effective. Everything that surrounds the phenol molecule, from prepeel treatments to formulation methods, can be considered an

“adjuvant.” Unlike superficial or medium peels, preparing the skin before a phenol peel is not intended to enhance or even out the penetration of the phenol, as it does not need help to penetrate the skin. Tretinoin or fruit acids are not necessary in prepeel preparation, and perfect results are achievable without using them. Small, benign tumors can be treated with electrocoagulation immediately before the peel. Urkov, for his part, treated deep wrinkles with electrocoagulation after applying phenol and before applying the occlusive dressing. The skin must be cleansed and degreased thoroughly to get rid of any epidermal lipids and debris that can interact with or partially inactivate the phenol. Prepeel and postpeel care, which are discussed in detail in Chapters 32 and 35, help to prevent or treat potential complications. Adjuvants can, for example, enhance the spread of the phenol within the epidermis, reduce skin surface tension, enhance liquefaction necrosis of the epidermis, help the phenol reach the dermis (where it causes a severe inflammatory reaction that generates collagen and elastin, and blocks its action in the upper reticular dermis), and slow down and/or reduce the capillary absorption of the phenol (thus allowing time for sulfate and glucuronide conjugation of the toxin before its elimination).

Different Chemical Adjuvants The peel solutions should never be prepared simply by dissolving phenol in one of its potential solvents. Since phenol was introduced into treatment, doctors who use it have tried to: •

•

Moderate (tame) its systemic toxicity. Different substances have been combined with phenol to reduce its adverse effects. It should be noted that the only demonstrated way to avoid cardiac toxicity lies in the application technique for a full-face phenol peel. Improve its effectiveness. Different chemical adjuvants have been combined to modify the action of phenol.

The application technique and prepeel and postpeel care have very important roles. The latest formulations are therefore tamed and adjuvanted. The qualitative formulas of recent products are known, but the percentages and preparation methods are not revealed. Fintsi explained that adjuvanted and tamed phenol peels must be prepared according to a precise method and that he was afraid that if he revealed the exact proportions of the ingredients, doctors would try to make up the formula themselves without keeping to the necessarily strict order of preparation, and that this could lead to disastrous results. Logic must prevail in the attempt to understand how adjuvants work: it should be remembered that phenol has an anesthetizing action on sensitive nerve endings through protein coagulation; this anesthetizing effect develops within 10–15 seconds after application. This means that 15 seconds after application, the phenol is already in the dermis: it is therefore doubtful that combining it with products that penetrate more slowly, such as salicylic acid or citric acid, can improve the already rapid penetration of phenol. On the other hand, there is no doubt that phenol improves the penetration of these adjuvants, if they can survive without reacting chemically with the phenol solution itself. Resorcinol See Chapter 24 for more details. Although resorcinol is known to have allergenic properties, no allergies have been reported

218    Textbook of Chemical Peels

when it has been used in small quantities with phenol. However, the combined use of these two substances in the same peel solution does not appear to have any clinical value, as the phenol will have finished working before the resorcinol has started. Resorcinol cannot therefore modify the effect of phenol. No data are available on the potential clinical effect of resorcinol on skin that has just been coagulated by phenol. Trichloroacetic Acid TCA is an acid whose strength of action is proportional to the concentration used. However, it also depends on numerous other factors that are described in detail in the chapters on TCA. Salicylic Acid Salicylic acid is a keratolytic agent that dissolves the amorphous intercorneocyte matrix and thus diminishes the barrier function of the stratum corneum. It is sometimes combined with phenol but does not improve its action. See also the comments on resorcinol and TCA above. Croton Oil Croton oil is extracted from the seeds of the shrub Croton tiglium, of the family Euphorbiaceae. In the past, these seeds were also called Moluccas seeds, Tilly seeds, or small Indian pine nuts. Rubbing 2–10 drops of pure croton oil or croton oil with olive oil on the skin causes an intense burning sensation within 5 minutes that lasts for several hours and is followed by erythema. Clusters of small blisters then form and turn into pustules that dry, scab, and fall off within a few days without leaving any scars. If, however, the croton is applied too vigorously, keloid scars may result.7 The crotonic acid (Figure 25.12)13 that it contains is an irritant that accelerates epidermal lysis and enhances the cutaneous penetration of the phenol. Some authors maintain that a phenol peel will only produce good results if croton oil is present. The croton oil enhances dermal penetration and epidermal protein coagulation, and thus lower concentrations of phenol can be used. We have seen, however, that many phenol peel formulations do not contain croton oil. The irritant action of croton oil is used to advantage in cancer research to enhance the penetration of carcinogens through the skin barrier. Croton oil is therefore a co-carcinogen. In 1994, Wilmer et al.14 showed that keratinocytes can produce interleukin (IL)-type substances, growth factors, and tumor necrosis factor (TNF). Phenol and croton oil induce keratinocyte production of IL-8 (at noncytotoxic concentrations), TNF-α and also a growth factor. TNF-α is a cytokine synthesized (among others) by the keratinocytes in the stratum spinosum and the stratum granulosum. It stimulates the differentiation of keratinocytes

CH3

H C

H

C

O C OH

Figure 25.12  Chemical structure of crotonic acid.

into corneocytes and thus accelerates the full regeneration of the protective stratum corneum. Amazonian Indians used croton extracts as a vulnerary15 agent. It appears that an alkaloid, taspine, is (partially) responsible for the healing effect on wounds. Its mechanism of action is probably due to the chemotaxy of the fibroblasts being stimulated, which improves the efficiency of the first stages of healing without affecting the following stages.16 At the beginning of the 20th century, the vesicant properties of croton oil were used to good effect on people with edema. Rubbing croton oil on large areas created numerous vesicles, the combined serous fluids from which produced enough liquid to relieve edema in the lower limbs of heart patients. Experiments were conducted involving the ingestion of croton oil: this produced intestinal inflammation with diarrhea and weight loss.17 Croton oil is a powerful toxin that taken orally in small quantities of around 20 drops can cause fatal hemorrhagic gastroenteritis.18 Septisol Septisol is a liquid soap with hexachlorophene, a bisphenol used as a disinfectant. It is also a surfactant. At low concentrations, hexachlorophene uncouples the oxidative phosphorylation of cells and causes morphological changes in membranes.19 It might be keratolytic.20 Intoxication of infants from hexachlorophene preparations (in France, in 1972) resulted in neurological (encephalitis) and cutaneous symptoms. These products have turned out to be dangerous after chronic use if not rinsed off or if applied to damaged skin or to large areas of the body with an occlusive dressing. Saponins Liquid soap helps to reduce surface tension (Box 25.1) and therefore improves the penetration of active agents. It also improves maceration under an occlusive dressing. Anionic and cationic soaps, like alcohol, enhance the action of ­phenol.19 Formulation requirements are strict. If there is too much ­surfactant, the phenol ends up within a micelle and its action is reduced. If there is not enough, the solutions are not stable. Cresol—Lysol In the past, saponified cresol as well as Lysol were used as wetting agents to increase the penetration and therefore the

BOX 25.1  Surface Tension The forces of attraction and repulsion are more or less evenly distributed within a liquid. The surface molecules, however, are unable to balance the lateral intermolecular forces of attraction. The tension on the surface of a liquid acts like an elastic membrane, opposing penetration in the liquid. Agents called surfactants, wetting agents, or detergents reduce this elastic surface tension and enhance penetration in the liquid. Wetting agents also have antiseptic properties. There are two large groups:

1. Cationic surfactants (cetrimide, lauralkonium, etc.): Powerful bactericides and fungicides 2. Anionic surfactants (e.g., sodium lauryl sulfate): Used to sterilize the skin before surgical operations

Phenol: Chemistry, formulations, and adjuvants    219

strength of phenol. See the discussion of cresols earlier in this chapter. Acetic Acid For a description of acetic acid, see the beginning of Chapter 12. Oil Formulations21 versus Aqueous Formulations A cell membrane is a “fluid mosaic” of phospholipids in two layers. The hydrophilic poles face outward, and the hydrophobic poles form the inside of the membrane. The lipid cell surface is strewn with proteins. If we compare a cell membrane to a chocolate cream sandwich cookie, the hydrophilic poles would be the cookies on the outside and the hydrophobic poles would be the chocolate cream in the middle. The surface proteins would be found in the small holes on the surface of the cookies. If we compared a cell membrane to a jam sandwich, the hydrophilic poles would be the slices of bread and the lipophilic, hydrophobic poles would be the jam. The surface proteins would be set in the air bubbles in the bread. At the beginning of the 20th century, the relative impermeability of cell membranes to many water-soluble components had already been attributed to the lipid nature of the membranes. Molecules that are soluble in nonpolar solvents (e.g., olive oil, sesame oil, and ether) enter cells more rapidly than water-soluble molecules with the same molecular weight.22 Fatsoluble molecules “dissolve” in the lipophilic layers and readily penetrate the interior of the cell. The ratio of the solubility of a substance in olive oil in relation to its solubility in water provides the oil/water partition coefficient. Phenol has a good oil/water partition coefficient.19 The ability of a molecule to penetrate the cell membrane is proportional to its partition coefficient. Adding oils to phenol enhances its action in the epidermis and papillary dermis and slows down the penetration of the oil-bound phenol through the skin so that it reaches the deeper dermal layers more slowly. Phenol is also soluble in water and has a low molecular weight (94.11). Very small molecules that are water-soluble and nonpolar pass through cell membranes much more quickly than one might expect given the molecular structure of the actual membrane and the partition coefficient. These small molecules appear simply to pass between two adjacent molecules in the membrane, without really dissolving in the pole taken up by the fatty acid. It is also possible that the proteins set in the membrane are highly permeable to these tiny water-soluble molecules. With increasing molecular weight, membrane permeability decreases and stops molecules with a molecular weight greater than 200 from getting through. Phenol’s low molecular weight and its high partition coefficient would allow it to pass through the membrane rapidly if it were not bound to oily components. Moreover, phenol coagulates membrane proteins. The vascular endothelium has two absorption pathways. There are 4 nm pores that form the intercellular spaces. These pores represent only 0.02% of the capillary surface. Diffusion is the main pathway, and the principles set out above also apply to the capillaries. The antiseptic derivatives of phenol have structural modifications (halogenation and alkylation) that, by increasing their liposolubility, improve their antiseptic action. Brown and Kaplan made use of the “buffering” property of oils in phenol solutions. Their formulation contained up to

95% phenol combined with oils. A patch test behind the ear had to be conducted before the facial peel. If there was skin necrosis, they reduced the strength of the phenol by gradually adding oil in small quantities until the right dose was found for the patient’s skin. To increase the strength of the mixture, on the other hand, soap (saponified cresol) was added or the concentration of phenol was increased. Glycerol Adding glycerin to phenol makes it less irritating. Glycerinated phenol at 10% is no longer an irritant. Buffers Buffers keep the pH of a solution stable. Phenol is more aggressive in an acid environment. The presence of buffers keeps the solution at an appropriate pH. The pH of today’s phenol solutions is usually close to the skin’s physiological pH. Alcohol and Water Alcohol is used at different points during preparation to help products solubilize more efficiently in the aqueous solution. Phenol, for example, is more soluble in alcohol than in water. The purer the phenol crystals, the more soluble they are in water. Alcohol also enhances the action of phenol.21 Water is also used as a solvent for certain products or to modify the concentration of the phenol.

NOTES 1. In this book, phenol is used in this sense; the plural phenols refers to the group of compounds in general. 2. Material Safety Data Sheet. Fisher Scientific, Waltham, MA. 3. Cumene (isopropylbenzene, 2-phenylpropane, cumol), molecular weight 120.2, is a colorless liquid with a strong depressant effect on the central nervous system. 4. Isomeric compounds (isomers) have the same empirical formulas but different chemical structures. 5. Also known as ortho-methylphenol and ortho-hydroxytoluene, etc. 6. This is fortunately not the case with solutions. 7. Manquat A. Traité Élémentaire de Chérapeutique de Matière Médicale et de Pharmacologie. 5th ed. 1903: 240–60. 8. Was this to make up for the inadequate results of this formulation? 9. American Journal of Cosmetic Surgery. 1997; 14: 49–54. 10. Hetter G. An examination of the phenol–croton oil peel: Part III. The plastic surgeon’s role. Plastic and Reconstructive Surgery. 2000; 105: 725–63. 11. Quicker penetration is not synonymous with greater effectiveness. 12. To limit the risks of photochemical reactions. Storing the solution at low temperatures slows down the chemical reactions and is the best way to store any chemical. 13. Crotonic acid is also known as 2-butenoic acid and has a molecular weight of 86.09. 14. Wilmer JL, Burleson FG, Kayama F, Kanno J, Luster MI. Cytokine induction in human epidermal keratinocytes exposed to contact irritants and its relation to chemical-induced inflammation in mouse skin. Journal of Investigative Dermatology. 1994; 102: 915–22. 15. Vulnerary means promoting the healing of wounds. 16. Porras-Reyes BH, Lewis WH, Roman J, Simchouritz L, Mustoe TA. Enhancement of wound healing by the alkaloid taspine defining mechanism of action. Proceedings of the Society for Experimental Biology and Medicine. 1993; 203: 18–25. 17. Pol O, Ferrer I, Puty MM. Diarrhea associated with intestinal inflammation increases the potency of mu and delta opioids

220    Textbook of Chemical Peels and the inhibition of gastrointestinal transit in mice. Journal of Pharmacology and Experimental Therapeutics. 1994; 270: 386–91. 18. Klein DR, Little JH. Laryngeal edema as a consequence of chemical peel. Annual Meeting of the American Society for Esthetic Plastic Surgery, Las Vegas, 1982. 19. Giroud JP, Mathé G, Meyniel G. Pharmacologie Clinique. Expansion Scientific Français, 2003: 1590–91.

20. Ashen S. Unoccluded Baker–Gordon phenol peels—Review and update. Journal of Dermatologic Surgery and Oncology. 1989; 15: 998–1008. 21. See also Chapter 27. 22. Bene RM, Levy MN. Physiology. 3rd ed. Mosby Yearbook, Inc., 1993.

26 Phenol Properties and histology MISCIBILITY WITH WATER

PROTEIN COAGULATION

Phenol is not completely miscible with water; to obtain a homogeneous solution, an excess of water is required.1

Phenol coagulates proteins simply by combining with them, and this produces frosting similar to that occurring when the normally transparent proteins of an egg white become cloudy on cooking, as a result of their three-dimensional structure being modified (Box 26.3). The coagulated proteins and phenol can be separated by the action of alcohol.5 For the phenol and proteins to form a stable bond, the temperature must be raised. When phenol comes into contact with the skin or mucous membranes, it causes immediate proteolysis if the concentrations are high enough, with protein coagulation occurring at higher concentrations.

NEUROLYSIS AND LOCAL ANESTHESIA Phenol has been widely used to treat a large number of disorders, including spasticity and chronic pain, because of its neurolytic and local anesthetic properties (5% solution). Topically applied, phenol has a lasting local anesthetic action that can affect all the layers of the skin and occurs at the same time as frosting (Box 26.1 and Figure 26.1). Phenol has been used as a surface anesthetic to perform small operations. It is neurolytic;2 it coagulates the sensitive nerve endings at the base of the epidermis and in the superficial papillary dermis. During a phenol peel, the first application of acid causes an intense burning pain that can be alleviated by prior or immediate application of something cold. After frosting, the anesthetic effect takes hold and spreads beyond the frosted area by up to a centimeter. During a phenol peel, after an initial period of analgesia, patients complain of renewed pain that they all describe differently, however. The second wave of pain is more likely to come from the rapid onset of inflammatory edema; this distends the tissues and stimulates the deeper nerve endings. This pain wears off during the first night after the procedure, when the edema is at its height and is no longer actively distending the tissues.

CARCINOGENICITY Phenol is not considered to be carcinogenic.3 On the contrary, long-term histological studies show that phenol (even when the formula contains croton oil) has a protective effect against skin cancers (Box 26.2). A logical explanation of this protective effect may lie in the fact that the cells that take the brunt of UV rays are the keratinocytes closest to the stratum corneum, the ones that form, for example, the top of the dermal papillae. On the other hand, the keratinocytes that are in the lower regions of the dermal papillae are protected compared with those higher up: the UV photons have been partially absorbed or diffracted by the epidermal layers above them. In addition, the sebocytes4 or keratinocytes that make up the shaft of the hair are anchored more deeply in the skin, at a depth where the harmful effects of the sun are not as severe. The cells that are most active in skin regeneration after a deep peel are those that are least damaged by the sun’s rays, the cells that have undergone the least UV-induced genetic mutation. After a phenol peel, the skin is much healthier than the skin that the acid coagulated, and statistically will develop fewer cancers. Moreover, phenol may well coagulate and eliminate any intraepidermal cancer in situ.

DISINFECTION Phenol is a powerful disinfectant that is more active in vivo than in vitro, because it coagulates the proteins of living organisms. It is bacteriostatic (at a concentration of 2 g/l) and bactericidal (at a higher concentration of 10 g/l). From 13 g/l (about 1.3%), it is tuberculostatic and fungistatic. It is not considered to be virucidal,6 although one commercial formulation containing 0.13% of glutaraldehyde and sodium phenate has a virucidal activity (according to AFNOR Norm T727). Some more lipophilic phenol derivatives have been declared virucidal against HIV and the hepatitis B virus.1 The fragility of the HIV envelope would explain this action, though the action against the hepatitis B virus is not so clear. Many patients report that labial herpes outbreaks are less frequent or even disappear altogether after a phenol peel (Box 26.4). Phenol is found in bactericidal, tuberculostatic, and fungistatic concentrations in all phenol peel formulas. Even after 24 hours’ contact, no phenol derivative has shown any sporicidal action.

HISTOLOGY OF PHENOL A study8 on guinea pigs showed that the reticular dermis reacts to injury as if it were made up of two distinct layers, whereas histologically there is no evidence that these two layers exist, and the reticular dermis appears to be homogenous. (Figure 26.2 is a schematic illustration of the layers of the skin.) When the uppermost part of the reticular dermis is attacked, it reacts by reorganizing the tissues, while the deeper part forms scars. It must be remembered that the deeper dermis contains fibroblasts that can react phenotypically as “conventional” fibroblasts as well as myofibroblasts. Myofibroblasts are differentiated (in response to cytokines) fibroblasts that can both synthesize a strong collagen bundle and activate a cytoplasmic motor running on actin. This transforms them into “nonmuscular” motor cells that can activate a contractile capacity comparable to that of a smooth muscle cell. The myofibroblasts interact among themselves, as if they were holding hands across their thick and resistant collagen

222    Textbook of Chemical Peels

BOX 26.1  Tip about Pain

BOX 26.2  Tip about Carcinogenicity

Phenol has anesthetic properties that appear together with the frosting, on average 15 seconds after application. Inflammatory pain—a local pulsatile, painful hot sensation— occurs 15–20 minutes later.

Studies show that peelings are not carcinogenic. More recent studies demonstrate that even superficial peelings have a protective anticancer activity.

BOX 26.3  Tip about Phenol Penetration A fast and strong proteinic coagulation, as occurs after application of 80% phenol on the skin, can act as an impermeable shield that prevents further penetration of more acids.

BOX 26.4  Tip about Herpes Labialis Antiherpes prevention is recommended before a phenol peel. Nevertheless, it seems that people with a history of herpes labialis show much less herpes activity after a phenol peel on the lips.

bundles and, after taking each other’s hands, were bending their arms to draw closer to each other and thus contract the skin. Myofibroblasts (Box 26.5) are the skin’s final bulwark, the last defense against physical, chemical, and biological attack. When a peel injures the dermis to a depth where there are fibroblasts capable of turning into myofibroblasts, it means that there are many keratinocytes (that have been destroyed) upon which the body can no longer count to regenerate the skin, and

Figure 26.1  Immediately after application of phenol to the upper lip, the anesthetic effect is enough to be able to pinch the skin and draw blood without any feeling of pain (note the red spots in the photograph, taken during a chemical cheiloplasty).

Stratum corneum disjunctum Stratum corneum compactum Keratinocytes

K

K GZ

GZ

Epidermal basal layer Grenz zone

K

K

GZ

Papillary dermis Reticular dermis Hypodermis

Figure 26.2  Schematic diagram of the layers of the skin adapted to peelings.

GZ

GZ

Phenol: Properties and histology    223

BOX 26.5  Tips about Myofibroblasts Normally, fibroblasts do not exert much tension on the matrix of noninflammatory tissue, but when all the layers of the skin are affected by an injury, local growth factors send fibroblasts to colonize the fibrin plug closing the wound and forming the temporary matrix. The fibroblast invasion and neoangiogenesis form the granulation tissue. The fibroblasts that have invaded the temporary matrix already exert a certain amount of traction on this tissue. The mechanical stress then stimulates the fibroblasts to produce more collagen and to turn themselves into “protomyofibroblasts.” The persistent stress induces the phenotypic transformation of the protomyofibroblasts into differentiated fibroblasts, the myofibroblasts, which secrete actin fibers and increase their contractile force while producing collagen and releasing proteases. Usually, the myofibroblasts disappear via apoptosis (programmed cell death) as soon as the scar is solid, but where stress persists, they do not disappear and gradually form a hypertrophic scar.

that skin regeneration will be slow and therefore dangerous for homeostasis. The activation of the myofibroblast actin-based contractile motor, which alone can draw the edges of the wound together, increases the entire organism’s chances of survival. The deep reticular dermis therefore reacts like an entrenched guard that has nothing to lose and prefers to produce a scar

(a)

rather than undergo extensive necrosis. When a peel injures the reticular dermis, the safety margin is therefore narrower and the risk of scarring is greatly increased. In 1985, Kligman studied and documented the long-term aftereffects of a phenol peel in his remarkable study “Long-Term Histologic Follow-Up of Phenol Face Peels.”9 Fintsi also studied the histological effects of phenol peels. It is still very difficult, however, to tally the clinical results and the histological changes of the different types of peels: the formulations, adjuvants, and concentrations are different, as are the methods of preparation and application of the various active agents used. Each patient has different cell characteristics, in either the quality or the quantity of phospholipids, sterols, and proteins embedded in the cell membranes. Doctors are guided by their own experiences and follow the application protocol they have gradually developed in the course of their practice. This disparity makes it difficult to compare the results of different studies. Some general principles can, however, be drawn: we can consider that all peels produce comparable histological effects. The differences arise from the extent of the inflammation caused and how this inflammation is controlled, as well as the relative depth reached. As far as medium and deep peels are concerned, effectiveness increases when the injury is close to the deep reticular dermis. The risk of retractile scars developing is greatly increased at this depth. There is therefore a fine line between achieving excellent results and the incidence of scarring. At the same peel depth, however, phenol peels produce the most significant changes and the most spectacular results (Figure 26.3).

(b)

Figure 26.3  (a) Full-face phenol peel immediately after 24 hours’ occlusion. The darker patches are the areas that have not undergone liquefaction. This makes no difference to the overall result, as can be seen in (b), which shows the same patient 12 days after the full-face phenol peel with Lip & Eyelid Formula. The skin tone is completely even, even in the nonliquefied areas.

224    Textbook of Chemical Peels Table 26.1  Action of Phenol on Epidermis Superficial epidermal layers

Basal layer

The epidermal layers are dissolved down to the basal layer in 24–36 hours under an occlusive mask. Thereafter, the architecture of the cells returns to normal and the histological coloring evens out. After a peel, the palisade structure of the keratinocytes is more even. Phenol restructures the architecture of the basal layer. It does not completely destroy the melanocytes; they are still found in the basal layer after peeling. In some histological studies, the density of melanocytes is sometimes higher overall. The melanocytes have, however, become incapacitated or partially incapacitated: melanin synthesis is reduced, as is the ability to transmit melanosomes to the neighboring keratinocytes. This histological observation explains any hypopigmentation or depigmentation following a phenol peel. How much the phenol damages the melanocytes largely depends on the formulation of the solution used and the application technique, which explains why total achromia occurs more often with some formulations than others. For example, with Baker’s formula, the risk of developing “porcelain skin” is higher than with Lip & Eyelid Formula. PIH is more frequent than achromia when using today’s phenol formula.

EPIDERMAL CHANGES A phenol peel usually produces complete epidermolysis in keratinocytes and all other living cells in the epidermis. The Langerhans cells, which play an important role in the skin’s immune defenses, are also affected. There is a certain amount of dermolysis accompanying the destruction of the epidermis (Table 26.1).

Table 26.2  Action of Phenol on Dermis Papillary dermis

Mid and deep dermis Deep dermis and hypo­ dermis

The fibroblasts are small and have horizontal dendritic processes; each fibroblast is in contact with several collagen fibers. These observations explain the dense horizontal arrangement of the new collagen in the papillary dermis after a phenol peel. The fibroblasts are larger and are in contact with just one bundle of collagen fibers. The fibroblasts are even larger here (four times bigger than in the papillary dermis), and the dendritic processes are long and form a continuous network. Collagen synthesis by the fibroblasts causes scars to contract. Myofibroblasts (see Box 26.1) are cells produced by fibroblast differentiation. They contain myofilaments that make them look like smooth muscle cells and are involved in the phenomena of scar retraction. Depending on the depth reached by a peel, different types of fibroblasts are stimulated and will react in a specific way because of their different genetic programming. All of these histological changes explain how the skin becomes thicker and the sometimes dramatic face-lift effect of deep peels.

Dermal lymphocyte infiltration associated with photoaging is reduced after a phenol peel. On the other hand, there is significant lymphocyte infiltration in the reticular dermis 2–5 days after a phenol peel. Overall, the wrinkled superficial layers are liquefied and replaced by structurally young and homogenous tissue. The inefficient elastotic dermal layers are renewed and/or pushed

DERMAL CHANGES On contact with the papillary dermis, phenol destroys the entire elastotic layer within it. Thereafter, the architecture of the dermis is spectacularly restored. Immediately underneath the basal membrane, in the Grenz zone, a dense new layer of collagen fibers is formed, arranged parallel to the basal membrane and interspersed with good-quality elastic fibers in an effective network.10 Brown described this histological reaction as early as 1960. The new collagen and elastin that is formed covers the sun-damaged structures that have not been destroyed by the phenol and pushes them deeper down. The fibroblasts are strongly stimulated and secrete all the components of the extracellular matrix: ground substance, collagen, elastin, and so forth.The morphology of the fibroblasts varies widely depending on their location (Table 26.2). The blood vessels that are newly formed after a phenol peel provide an effective and lasting supply of nutrients to the new skin. After a deep peel, the body takes 4–6 weeks11 to regenerate a structurally normal skin. During these 6 weeks, the skin appears very red, as the many newly formed blood vessels are showing through an incomplete, thinned, and pale epidermis. Six weeks is usually the minimum time that erythema lasts after a phenol peel. After this time, inflammation may persist and the skin can still appear red for several more months.

Figure 26.4  The skin of a 78-year-old patient 10 years after a full-face phenol peel and 1 year after a medium-depth TCA maintenance peel.

Phenol: Properties and histology    225

deep down by the synthesis of new fibers. The quality of the new collagen is not quite as good as the collagen that had been present since birth. However, it is produced in sufficient quantities, along with new elastin, to provide better support to the newly rebuilt epidermis.12 The newly formed blood vessels supply the dermis with the nutrients it had slowly been deprived of because of the gradual vascular degeneration caused by photoaging.

LONG-TERM HISTOLOGICAL FOLLOW-UP AFTER A PHENOL PEEL The changes described in this chapter last a long time. In histological sections taken 15 years after a phenol peel (Baker’s formula), the difference between the treated and nontreated skin is incredible, and this explains why, most of the time, only one phenol peel is necessary for long-lasting rejuvenation of the face. Other authors13 have confirmed these histological results after 15–20 years and even talk about permanent results in some patients. In 1985, Kligman10 showed that dermal reconstruction lasts for 20 years at least and that the risk of cancer is reduced. Clinically, the rejuvenated appearance of the skin can be maintained for a great many years (Figure 26.4).

NOTES 1. Dauphin A, Darbord JC. Hygiène Hospitatière Pratique. 2nd ed. 2. It is used in the treatment of pain in certain cancers to achieve neurolysis of the nerve routes responsible for transmitting the sensation of pain.

3. Fisher Scientific. Phenol [Material Safety Data Sheet]. 4. Sebocytes are in fact keratinocytes that have been differentiated phenotypically into cells capable of producing sebum. When under attack, they can quickly dedifferentiate, turn back into keratinocytes, and regenerate the skin. 5. By separating the phenol from the protein that it has coagulated, alcohol can enhance the action of the acid on another protein. 6. Giroud JP, Mathé G, Meyniel G. Pharmacologie Clinique. Expansion Scientifique Français, 2003: 1590–91. 7. Regelson W. DHEA, Melatonin and Hormone Replacement. In: Updates, Anti-aging Medical Therapeutics, Vol 1. Modesto, CA: Health Quest Publishers, 1997: 75–81. 8. Hayes DK, Berkland ME, Stombaugh KI. Viability of skin flaps subjected to simultaneous chemical peel with occlusive taping. Laryngoscope. 1989; 99: 1016–19. 9. Kligman AM, Baker TJ, Gordon HL. Long-term histologic follow-up of phenol face peels. Plastic and Reconstructive Surgery. 1985; 75: 652–9. 10. Petes W. The chemical peel. Annals of Plastic Surgery. 1991; 26: 564–71. 11. Dembinstri M. Exoderm Method, the Non Surgical Face Lifting. In: Proceedings of the 44th Congrezzo Nazionale della Società Italiana di Chirurgia Plastica Ricostructiva ed Estetica. Bologna, Nov. 1995. 12. Asken S. Unoccluded Baker–Gordon phenol peels—Review and update. Journal of Dermatologic Surgery and Oncology. 1989; 15: 998–1008. 13. Matarasso SL. Glogan RG. Chemical face peels. Dermatologic Clinics. 1991; 9: 131–50.

27 Phenol Skin penetration and detoxification SKIN PENETRATION OF CHEMICALS The skin has many different functions: it can be the site of action of a product or the reservoir for a product, it can simply be a transit site, or it can be an impermeable barrier. The skin’s main role is to form a barrier limiting the transfer of molecules in and out. It is especially adapted for this thanks to the multiple external layers of corneocytes. For the stratum corneum to be impermeable to both chemical and physical agents,1 it is essential for it to be intact. It is this layer that forms the main barrier to the penetration of active products through the skin. Corneocytes are made up of α-keratin filaments, buried in an amorphous matrix rich in disulfide bonds. There is a thick protein envelope of involucrin around each corneocyte, and the intercellular spaces are full of extremely hydrophobic lipids. The outer layer of the plasma membrane is hydrophilic. The outer layer of skin can be described as a hydrophilic “brick wall” sealed with hydrophobic “mortar.”2 The whole forms an efficient barrier against both hydrophilic and hydrophobic molecules. This barrier is so efficient that chemicals can penetrate living or dead skin to the same degree, just as there is the same degree of penetration through the whole skin or the stratum corneum alone.2 Consequently, eliminating all or part of the stratum corneum drastically enhances the absorption of physical and chemical agents that could not have penetrated an intact protective stratum corneum. The ability of a product to penetrate the skin also depends on how it interacts with the corneocytes and the intercellular matrix. At the same molecular weight, a proteolytic product will penetrate the skin more readily than a product that is not proteolytic. The more liposoluble a molecule is, the greater its partition between the vehicle and the skin barrier and as a result its ability to penetrate is improved. Another factor to be taken into account is how solvents interact: ethanol diffuses better in the stratum corneum when it is mixed with oil rather than water.2 How well hydrated3 the stratum corneum is also plays an essential role in the skin’s absorption capacity. When the stratum corneum is hydrated, products can be absorbed up to 10 times more efficiently.2 Hydration swells the corneocytes and makes them less dense and less resistant to diffusion. The fact that on facial skin the stratum corneum is not very thick means that molecules are absorbed more quickly. The skin on the face is more permeable than the skin on the limbs and the torso, but less permeable than the skin on the genital organs.

WHAT HAPPENS TO PHENOL AFTER PENETRATION Lymphatic Absorption The lymphatic system, which is highly permeable even to large protein molecules, slowly collects some of the phenol in the

interstitial fluid. The total daily volume carried by the lymphatic system is approximately equal to the volume of blood of the same individual. This absorption route is very slow and therefore negligible from a toxicological point of view (Figure 27.1).

Capillary Absorption Phenol penetrates rapidly through the skin and is immediately absorbed by the dermal blood vessels. The metabolization and/ or excretion sites immediately pick up the phenol that has penetrated into the bloodstream.

Metabolization and Elimination Twenty-five percent of phenol is metabolized into water and carbon dioxide and eliminated directly through the lungs. The remaining 75% is eliminated in free and conjugated form or undergoes oxidation. Phenol is oxidized to hydroquinone in the liver. Still in the liver, it is esterified by the transfer of the sulfuryl group of 3’-phosphoadenosine 5’-phosphosulfuric acid to the hydroxy group of the phenol and produces phenylsulfuric acid: this is sulfate conjugation. Phenol also undergoes glucuronide conjugation through exchanges with glucuronic acid. The conjugated phenol is no longer toxic to the organism, and can be eliminated by the kidneys. Other detoxification enzymes have been identified, such as phenol 2-monooxygenase, phenol O-methyltransferase, and phenol Β-glucosyltransferase.4 Active transport processes excrete organic acids such as glucuronide, and phenol sulfate conjugates in the proximal tubule. All forms of free or detoxified phenol are therefore found in urine.

Hepatic and Renal Integrity Because of the way in which phenol is metabolized, hepatic and renal integrity is a prerequisite for a phenol peel. Applying phenol more quickly than it can be detoxified and eliminated by a deficient liver or kidneys could result in severe intoxication. An interesting study in 1953 by Ruedmann and Deichmann5 concluded that hepatic and renal integrity were absolutely vital when using phenol. They wanted to draw the attention of practitioners to the potential dangers of applying phenol to large surface areas of the body, even though this type of treatment previously had presented only minor drawbacks. A patient did die, however,6 after a phenol solution with a concentration of 2.3%7 was applied under an occlusive dressing8 on one-third of the body surface area and on flesh burnt by kerosene.9 This death led the authors to study the metabolism of phenol by applying 1  g of phenol to 75% of the body surface area in a first group of human “guinea pigs.” Three other groups were given total doses of up to 4  g on the same body surface area (75%). A rest period of 90 minutes was left between successive applications of 1 g.

Phenol: Skin penetration and detoxification    227

Concentration? Adjuvants? Formulation, phenol Sequestered in applicator, etc.

100% phenol Epidermis Dermis

Oily? Dry? Thick? Thin? Prepared? etc. Thick? Hydrated? Rich in proteins? Rich vascularization? Occlusion?

E = quantity of phenol sequestered in the epidermis

100 - E

D = quantity of phenol sequestered in the dermis

100 - (E+D)

Slow lymphatic elimination

L = quantity of phenol eliminated by the lymphatic system

100 - (E+D+L)=T

T = quantity of potentially toxic phenol

Capillary resorption slowed down by oils, edema, etc. About 70–75% (T) Hepatic detoxification

Phenol + 3′-phosphoadenosine 5′-phosphosulfuric acid phenylsulfuric acid (sulfate conjugation) Phenol + glucuronic acid phenyl glucuronide (alucuronide conjugation) Quinone and catechol subsequently undergo renal elimination

About 20–25% (T)

Pulmonary metabolism Elimination of H2O and CO2

Renal elimination of conjugates Active transport of detoxified phenol in the proximal tubule

Elimination of non-conjugated free phenol Diuresis, hydration

Figure 27.1  Metabolization of phenol.

Toxic Phenolemia

Aqueous or Oil Vehicle

Doses of free and conjugated phenol show the following results: the levels of free circulating phenol do not vary much whether 1, 2, 3, or 4 g of phenol is applied on the skin or if a rest period of 90 minutes is left between each gram applied. The peak values in free phenol recorded were approximately 0.60–0.80  mg/100  ml. Benatar10 describes a reassuring 1962 study by Litton in which he recorded the following blood concentrations after applying 3 ml of 50% phenol on the face: after 1 hour, 0.68  mg/100  ml; after 2 hours, 0.19  mg/100  ml; and after 3 hours, 0.10 mg/100 ml. According to the same author, phenol only becomes systemically toxic at a concentration of 23 mg/100 ml, which, for a total blood volume of 4 l, requires a total of 1 g in the blood at any given moment. Detoxification by conjugation is initiated immediately after applying phenol on the skin.

Phenol in aqueous solution is absorbed very differently from phenol in oil solution. Maximum blood levels reached 0.9 mg/100 ml when phenol was applied in an oil solution and 1.1  mg/100  ml in an aqueous solution. In 1950, Deichmann11 published a study on the reabsorption of phenol in an aqueous and an oil vehicle: 71 mg of phenol was absorbed by the skin of a rat in 1 hour’s contact with an aqueous solution of phenol at 4.7%, whereas only 15 mg was absorbed when the same concentration was present in (mineral) oil solution. Phenol penetrates the skin more slowly from an oil solution than from an aqueous solution. In this way, it also becomes less toxic. Applying 4  g of phenol to the skin does not make the blood concentration of the free form or conjugated form of phenol any higher than if 3 g were applied. Deichmann did not offer any explanation of this phenomenon, but the rest period of 90 minutes between

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each 1 g application most probably allowed enough time for the phenol to be detoxified. After 3 g, the phenol levels returned to normal within 48 hours. A little longer was needed to eliminate 4 g. On the third day, the blood levels of phenol reached doses lower than that of any normal individual, that is, around 0.15  mg. No sign of systemic intoxication was detected in the course of this study. It must be noted, however, that control mechanisms were not as sophisticated as they are today and continuous Holter electrocardiogram recording monitors were, for example, not yet available.

EFFECTS OF OCCLUSION In the past, it was thought that applying a dressing was the cause of local necrosis. In fact, the necrosis occurred when very tight, thick dressings soaked in phenol were applied to the wounds. According to studies by Ruedemann and Deichmann,5 applying a dressing (unsoaked) after applying phenol actually reduces the speed with which the phenol is absorbed— although not the total quantity. There are two advantages to a dressing: it allows surface maceration and increases the contact time with the epidermis. In this way, it can improve the cosmetic results. Impermeable occlusion reduces the rate at which phenol is absorbed through the skin and increases the chances of hepatic metabolization, as the organism is not overloaded or saturated by a massive influx of phenol. Peaks of free phenol are lower under occlusion. The literature is unclear on whether occlusion improves the results of phenol. In 1980, McCollough and Hillman12 reported that the results of phenol (Baker’s solution) without occlusion were comparable to those of phenol under occlusion. They went on to say that not using occlusion improves patient comfort and lowers the risk of complications. What is true for Baker’s solution is not necessarily true for other formulas, however. In 1989, Baker published a study showing that occlusion with Vaseline produces the same results as occlusion with impermeable tape. Stegman,13 Alt, and Brody published studies that show that phenol is more active under occlusion. Occlusion can therefore be used to increase the depth of action of a peel when the practitioner wants the penetration to be deeper. This is the case with Lip & Eyelid: occlusion is recommended when treating wrinkles around the lips and chin, but not for the treatment of eyelid wrinkles. Occlusion with Vaseline appears to be as effective as an impermeable occlusive dressing. There is one small practical problem with using Vaseline: heat from the skin makes it more liquid, and as it liquefies it tends to drip onto the eyes and neck, and onto the clothes, hands, and anything else the patient touches. The presence of Vaseline also rules out spot application the day after the peel. The duration of occlusion has also been discussed at great length, with Baker recommending 48 hours’ occlusion. When I use occlusion, I leave it on for 24 hours. I have not noticed any difference with longer occlusion times—which seems logical, as after 24 hours all the phenol applied has had plenty of time to be reabsorbed by the skin; leaving it for more than 24 hours merely increases the risk of secondary infections. The importance of the question of occlusion becomes clear when it is considered that many surgeons take off the occlusion under anesthetic or sedation, which increases the cost and the risk for the patient. On the first day, there are very few nerve endings left that have survived the phenol, and taking off the whole

occlusive mask at once, pulling it downward, is painful only very briefly. Another question is whether the occlusion should be applied immediately after the phenol or not. Phenol is a volatile compound, and applying occlusion immediately after it has been applied will stop it from partially evaporating and will therefore allow for longer maceration of a greater quantity of phenol. The sooner occlusion is applied after phenol, the deeper the effect will be.

URINARY ELIMINATION The by-products of phenol are rapidly eliminated in the urine. After intoxication with phenol, these by-products make the urine a dark color—anything from light olive green to dark brown. The intensity of the color has no direct relation to the severity of intoxication.

SPECIFIC PHENOL SENSITIVITIES Very young children are particularly sensitive to phenol, and incidents of intoxication were recorded at the beginning of the 20th century after simply applying phenol dressings on the intact skin of infants and after ingestion of 0.25 g of phenol.14 In the early 1900s, Nothnagel and Rossbach described alcoholism as a situation that improves resistance to phenol. A logical explanation can be found in the ways in which alcohol and phenol are metabolized. Alcohol is oxidized to acetic acid in the body. Certain conjugation mechanisms bring acetic acid into play through acetylation of the phenol function. The detoxifying conjugation could be between the phenol and the acetic acid. Deichmann studied basal blood phenol levels before and after application of phenol to the skin. Basal blood phenol levels were lower than before treatment, showing that the body adapts to the detoxification process. Wine is known to contain numerous aromatic molecules, including polyphenols. Wine drinkers15 develop a more effective polyphenol detoxification metabolism than nondrinkers, which could explain their relative resistance to intoxication with phenol.

NOTES 1. All peels remove the stratum corneum, at least partially, and make the skin permeable to chemical, physical, and environmental attacks. Total sun block is essential after any kind of peel. 2. Guzzo CA, Lazarus GS, Werth VP. Dermatological Pharmacology. In: Hardman JG, Limbird LE, Molinoff PB, Ruddon RW, Gilman AG, Chren MM, Bickers DR. Goodman & Gilman’s The Pharmacological Basis of Therapeutics. 8th ed. New York: McGrawHill, 2000: 1572–88. 3. Young and well-hydrated skin is more sensitive to a peel than old and sun-damaged skin. 4. Kyoto University Ligand Chemical Database: http://expasy. hcage.ch/cgi-bin/get-enzyme-entry? 2.4.1.35/2.1.25/1.14.13.7. 5. Ruedmann G, Deichmann WR. Blood phenol level after topical application of phenol-containing preparations. JAMA. 1953; 152: 506–9. 6. Deichmann WB. Local and systemic effects following skin contact with phenol: A review of literature. Industrial Hygiene and Toxicology. 1949; 31: 146–54. 7. This proteolytic concentration means the solution penetrates rapidly. 8. Occlusion stops phenol from evaporating and enhances maceration in the flesh exposed by the burns. 9. Loss of skin impermeability means that the solution penetrates rapidly.

Phenol: Skin penetration and detoxification    229 10. Benatar D. Lee peeling au phenol. Journal de Médecine Esthétique et de Chirurgie Dermatologique. 1988; XV(60): 319–23. 11. Deichmann WB, Miller T, Roberts JB. Local and systemic effects following application of dilute solutions of phenol in water and in camphor-liquid petrolatum on the skin of animals. Archives of Industrial Hygiene and Occupational Medicine. 1950; 2: 454–61. 12. McCollough EG, Hillman RA. Chemical face peel [Symposium on the Aging Face]. Otolaryngology Clinics of North America. 1980; 13: 353–65.

13. Stegman SJ. A comparative histologic study of the effects of three peeling agents and dermabrasion on normal and sundamaged skin. Aesthetic Plastic Surgery. 1982; 6: 123–35. 14. Manquet A. Traité Élémentaire de Thérapeutique de Matière Médicale et de Pharmacologie. 5th ed, Vol. 1. 1903: 240–60. 15. It should be noted that when this observation was made in France, at the beginning of the 20th century, the majority of cases of alcoholism were due to wine.

28 Phenol toxicity Causes, prevention, and treatment When phenol is dumped into river water, it is very toxic to aquatic fauna and lethal at a concentration of 1 ppm. The genuine toxicity of phenol and the almost apocalyptic descriptions of its side effects, which can even lead to death by cardiovascular collapse, severely limited its cosmetic use until the second half of the 1990s, especially in Europe. English-language publications state that, even so, a phenol peel is “one of the most frequently used techniques in the treatment of photoaging.”1 As discussed in Chapter 27, phenol is rapidly absorbed by the skin and mucous membranes. It is also rapidly eliminated by the lungs in the form of water and carbon dioxide, and by the kidneys in free form and in sulfate- and glucuronide-conjugated form. Detoxification starts immediately after phenol has been applied.2 Phenol vapor enters the pulmonary circulation very rapidly, and because of this respiratory absorption, doctors who use it (regularly) have to wear a mask. The treatment room must also be properly aired and ventilated to prevent the patient, who is already absorbing phenol through the skin, from absorbing any significant amount through the respiratory route. Keeping the patient well hydrated (with a saline drip) promotes diuresis and therefore renal elimination of free phenol as well as conjugated or oxidized phenol. Some authors recommend intravenous hyperhydration before and during the peel and sometimes forced diuresis with an intravenous injection of furosemide. This hyperhydration is not necessary when phenol is applied carefully.

DATA OBTAINED FROM LABORATORY ANIMALS In rats, the oral LD50 is 530  mg/kg.3 In rabbits, 70% of the phenol applied to the skin is absorbed in 30 minutes and 99% within 24 hours.4 In 1944, Deichmann and Witherup5 published the results of their experiments on the toxicity of phenol in laboratory animals. Their conclusions were as follows: “the rate of absorption of phenol/skin surface unit is not closely dependent on the concentration of the phenol, but is largely dependent on the total surface area of skin exposed to the product.”

MEDICATIONS CONTAINING PHENOL There are many pharmaceutical products widely used in medicine and dentistry that contain phenol, sometimes in fairly high concentrations. Bonain’s local anesthetic mixture, combining menthol, cocaine, and phenol, is well known, and is used, for example, as an intranasal analgesic treatment for certain facial pains. Other products containing phenol include hemorrhoid creams, chilblain solutions, ear drops or wax remover drops, psoriasis treatments, and mouth sprays with phenol in concentrations ranging from 3 mg/ml to 50 mg/g. Applying these products locally introduces only a small quantity of phenol into

the organism at well-spaced intervals, and does not appear to cause intoxication.

Phenol Soap Phenol soap with a concentration of 5 g/100 g introduces a small amount of the active product into the organism with each wash. Even if resorption, and therefore phenol toxicity, depends more on the surface area covered than on the concentration of the product,6 each wash delivers only a small quantity of phenol, which is soon rinsed off.

Gargles Tercinol is a phenol solution with a concentration of 15 g/100 g. It is recommended to dilute a teaspoon of concentrated solution in a glass of water and to gargle three or four times a day. One teaspoon is generally equivalent to 5 ml and therefore contains about 0.75 g of phenol. It is applied to irritated mucous membranes, and a small amount of the product will be swallowed every time it is used unless the user is an expert at gargling. Some 2–3 g could come into contact with the irritated mucous membranes every day. The package notice warns patients of the potential side effects of phenol.

Dental Wick Some dental wicks contain up to 375 mg/g of phenol. They are introduced into the dental cavity being treated and are reapplied every 10 minutes. The explanatory notice simply recommends not touching the mucous membranes. Nevertheless, it is possible for the patient to accidentally ingest a total of 1  g, although the time lapse allows any phenol that might have been ingested to be eliminated without toxicity. The products with the highest concentrations of phenol benefit from its antiseptic and local anesthetic properties.

Mouthwash Argentofenol is a disinfectant mouthwash recommended to be dabbed on the mucous membranes every other day. It contains up to 35% phenol. Phenol is still used in medicine and dentistry, sometimes at high concentrations. Side effects remain rare, as the product is relatively diluted, applied in small quantities or to small surfaces and therefore readily eliminated, even when applied repeatedly during the day. There is plenty of time for the liver to detoxify and the kidneys to eliminate the phenol.

Phenol Peel During a full-face phenol peel, 2.5–5  ml of phenol solution is usually applied on the skin. The conventional formulas (Litton and Baker) use concentrations of around 50%. Applying 3–4  cm3 of solution therefore leaves 1.5–2  g of phenol on the

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skin. It is important to be aware of the fact that the toxicity of phenol solutions appears to be paradoxical, as, up to a certain point, diluted solutions can be more toxic than concentrated ones. Publications report that simple aqueous dilutions of 2 parts phenol to 1 part water (i.e., solutions with a concentration of around 33%7) are usually the most dangerous. Some phenol peel formulations still use this concentration, however, confusing speed of penetration with cosmetic effectiveness.

PARADOXICAL TOXICITY At a concentration higher than 80%, phenol is a keratocoagulant. The first applications of phenol precipitate the skin proteins and thus create a biological barrier that prevents further applications of phenol from penetrating too rapidly. Concentrations lower than 80% are keratolytic,8 as they break the disulfide bonds between the keratin molecules and allow more of the solution to penetrate more rapidly. Reducing the concentration of a phenol solution can therefore make it more dangerous, both locally and systemically. Lowering the concentration of phenol in a peel solution is therefore not enough to make it nontoxic, and quicker penetration should not be confused with improved results. Solutions with lower concentrations penetrate more rapidly through the skin and are more rapidly absorbed: they are therefore more toxic at the same time as being less effective from a cosmetic point of view. The distinction between keratolytic and keratocoagulant must be given careful consideration. It is clinically obvious that solutions that are assumed to be keratolytic cause protein precipitation, or coagulation. Roenigk9 published an interesting article on this subject: in spite of the concentration of approximately 50% (48.5% to be precise), phenol acts as a keratocoagulant in Baker’s solution because of—according to him—the combination with croton oil and septisol. Other protein coagulating peels do not use septisol or croton oil, however. Stone8 performed a histological study of the depth of penetration of various phenol formulas: the Gordon–Baker formula at 48.5% phenol, the Verner–Dickinson formula at 67%, and liquid phenol at 88%. The results, in keeping with the principles set out above, show that Baker’s formula penetrates twice as deeply as Verner’s and four times as deeply as liquid phenol at 88%. Although phenol is absorbed rapidly by skin tissue, only a part of it will gradually reach the innermost regions, as the skin proteins flocculate almost immediately, and this creates a physical catchment area for the phenol as well as a natural dam that prevents it from penetrating the deeper layers too quickly.

LESSONS FROM MEDICAL HISTORY General Remarks The average fatal dose (death within 24 hours) in humans is 8–15  g by ingestion (according to Nothnagel and Rossbach in Manquat10). Individual predisposition largely explains the variations in the toxic dose. In 1903, Manquat10 reported two extreme cases: his colleague, Bouchard, had “by mistake injected” (sic) two patients with enemas containing 48 g of phenol. Their temperatures fell to 35°C, went up to 41.8°C in the evening, returned to normal the next day, and remained stable the following days. There is no information available on the long-term outcome of this accident: chemical intestinal necrosis, fistulization, secondary infection, survival, death, or liver and kidney toxicity? Ingesting just 0.5  g of phenol can lead to symptoms of toxicity, and sometimes an oral dose of 5  g is enough to

cause death. The patient shows signs of corrosive esophagitis and gastritis, then signs of kidney damage, cardiac collapse, breathing difficulties, and a feeling of inebriation followed by coma. Medical history tells us that the “Lister” technique took the life of many patients. Lord Lister, born in England in 1827, was the first surgeon to use phenol to disinfect the air in the operating theater (1867). This technique saved many patients, but others started to die when phenol was first used to disinfect wounds or when catgut was disinfected with phenol oil. Phenol proved toxic when applied directly in too great a quantity to skin that was unprotected by the stratum corneum. Lysol, used as a household disinfectant for toilets and bathrooms, is an oil mixture of cresols and other ill-defined phenols dating from before the First World War. Even if Lysol is less toxic and less irritating than phenol, it was the method of choice for suicide11 and abortion12 at the beginning of the 20th century.

Phenol Administration Routes in the Past Every possible route (apart from perhaps intra-arterial injection) was used to administer phenol: • • • • • • •

Oral or rectal routes (0.5–1  g of phenol in enemas, 6–12 times a day in the case of typhoid fever); the rectal route was preferred. Topical route (diphtheria). Intrapleural injection (3 g). ENT route: gargles or ear drops. Intravenous route (treatment of varicose veins). “Tissue” route (neurolysis, etc.). Inhalations (whooping cough).

Authors at the beginning of the 20th century knew all about the toxic effects of phenol and described the symptoms in detail. It is obvious that the doses used caused frequent and serious accidents. Doctors then became more cautious and used a maximum concentration of 0.5 g of phenol in enemas, to be repeated every 3 hours, so as not to reach a total daily dose of 4 g. Doses of 4–20 g/ day were considered dangerous or lethal. Manquat10 reported: “inside the body, we have nearly always administered phenol in enemas (0.5 to 1 gram of phenol to 200 to 500 grams of vehicle) that have sometimes been repeated every three hours (Desplats). A dose of 4 grams has brought the patient’s temperature down as low as 34° (Van Oye). Caution dictates that we should not go beyond 0.5 g per enema,” and that “We sometimes prescribe a dose of 1 to 4 grams in a potion; patients have difficulty tolerating this preparation.” Desplats recommended the following “lemonade”: • • • •

Phenic acid:  2 to 4 grams Lemon water:  100 grams Simple syrup:  100 to 150 grams Water:  q.s. for one liter

Take 100 grams of this solution every 3 hours. A simple calculation shows that patients at the beginning of the 20th century were supposed to ingest 800 g of this “lemonade”: every 24 hours, that is, 1.6–3.6 g of phenol per day. Toxic accidents, however, were described when a dressing soaked in phenol left some of the product in a cavity that was having difficulty draining, and in the majority of serious cases phenol was injected into perirectal cell tissue.10 Reading these old texts

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provides access to a whole theory of symptoms that today are only seen in cases of industrial poisoning. All this—and even the fact that phenol was considered highly toxic by inhalation—did not stop Bethene and Court13 from suggesting the inhalation of liquid phenol fumes to treat whooping cough in 1954. The plasma concentrations reached were far higher than those described by Litton during full-face peels.

SYMPTOMS OF PHENOL INTOXICATION Gastrointestinal Symptoms Ingesting more than 0.5 g of phenol triggers anorexia, nausea, and belching. Symptoms of gastroenteritis (colic, vomiting, and diarrhea) occur with slightly higher concentrations. Massive ingestion destroys the mucous membranes in the upper digestive tract. It has been reported that gastric problems can occur after applying phenol dressings externally. Experience of conventional14 phenol peels also shows that a small percentage of patients complain of nausea or even vomiting shortly after a deep peel. This nausea and vomiting occur within a few hours after the application of an occlusive mask.15 The cause-and-effect relationship between these symptoms and excessive phenolemia has not been officially established.

Neurological Symptoms Generally, there are no neurological symptoms when doses of less than 1–2 g have been ingested. The neurological symptoms are headaches, tinnitus, hypoacusis, paresthesia, muscular hypotonia, and stupor. If the dose is fatal, the patient falls into a coma after a feeling of inebriation and dies without convulsions. Phenol stimulates the motor neurons of the anterior horn.16

Cardiovascular Symptoms Cardiovascular complications have been known since the 19th century: the pulse was described as becoming irregular and weak, slowing down to become extremely weak or imperceptible. Hemoglobinuria and methemoglobinemia were also described. Details of these complications are considered later in this chapter, as well as techniques for avoiding and treating them.

LESSONS FROM TOXICOLOGY CENTERS In 1993, a retrospective study was conducted over 5 years at the Poison Center Philadelphia.17 It involved 96 cases of poisoning with Creolin, a disinfectant containing 26% phenol. This concentration is known to be potentially toxic, as it enhances penetration through keratolysis. Exposure was oral in 60 cases, dermal in 2 cases, and both oral and dermal in 12 cases. Only 1 case of inhalation was recorded. •

•

•

Oral exposure: Eleven patients (14%) experienced rapid central nervous system (CNS) depression that was rapidly reversible. Fourteen patients experienced vomiting, coughing, and stridor. Dermal exposure: Seven patients (100%) also had respiratory symptoms. On contact with the skin, phenol precipitates keratin and forms a white film, followed by redness and then necrosis. A 5% solution causes a burning sensation and then local anesthesia.18 Antidotes to phenol: Isopropanol (isopropyl alcohol) and polyethylene glycol seem to be the most effective local

•

antidotes, both histologically and because they slow down blood penetration.19 Immediately rinsing the area of skin that has come into contact with the phenol with plenty of water gets rid of some of the toxin and prevents precipitation of some of the epidermal proteins. Mixed exposure (oral plus dermal): Four people experienced vomiting, coughing, and stridor. Skin and mucous membrane burns were recorded in approximately 25% of the poisonings.

It is remarkable that no cardiovascular complications were recorded in this study. Medical publications report that when a person is exposed rapidly to a sufficient quantity of phenol (in general, 3–4 g of phenol applied quickly to the face), abnormal heart rhythms may occur. These abnormalities appear 15–20 minutes after the beginning of the peel and are often rapidly reversible. If any arrhythmia had developed during these cases of poisoning, it would no doubt have occurred rapidly and disappeared again by the time the patient arrived at the hospital. This argues in favor of the autonomous reversibility of arrhythmias with phenol. The authors cautiously conclude: “The absence of serious toxicity and major chemical burns in this series does not eliminate concern with the corrosive and systemic risks of phenol poisoning.” It should also be noted that phenol was widely used for 112  years between 1867 (Lister) and 1979 (in a study by Truppmann and Ellenby20) without any cardiovascular monitoring and with relatively few serious or fatal complications considering that very often it was applied in nonmedical circumstances (by lay peelers). Baker6 himself asserted that in 5000 cases of full-face or partial treatments, he did not note any abnormal heart rhythms—or any systemic toxicity—that could be attributed conclusively to phenol. McCollough and Maloney21 pointed out that in 25 years of using phenol, they came across a certain number of arrhythmias of toxic origin, but that none of these cases needed any specific treatment apart from waiting for the sinus rhythm to return and adding 15 minutes to be on the safe side. Asken22 confided that in 15 years of performing phenol peels using the Baker–Gordon method, he never came across a case of arrhythmia that needed treatment. However, in 1997, the author of this book was faced with a patient who experienced relatively severe arrhythmia when a full-face phenol peel was applied. How this arrhythmia developed is described later in this chapter. The fear of arrhythmic complications is the main brake on the use of phenol peels today. It is therefore worthwhile studying this problem in detail. The conclusions that can be drawn from reading about these complications in medical literature help us understand how to apply phenol with greater safety, though the possibility of arrhythmias occurring cannot be avoided.

CARDIOVASCULAR COMPLICATIONS For more than 50 years, lay peelers used phenol in full-face peels for cosmetic purposes without any medical monitoring. Cases of deaths related to phenol peels date from this era until the 1960s. In 1973, Litton, Fournier, and Capinpin23 published the results of a survey covering cardiovascular complications (Figures 28.1–28.7) during phenol facial peels. In the 493 questionnaires returned by plastic surgeons, only 3 cases of cardiac arrhythmias were reported. It should be noted, however, that

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Figure 28.4  Bigeminy.

Figure 28.5  Trigeminy.

Figure 28.1  Sinus rhythm.

Figure 28.6  Quadrigeminy.

Figure 28.7  Ventricular tachycardia. Figure 28.2  Supraventricular tachycardia.

Ventricular QRS complex

Atrial QRS complex No P wave

T wave

P

Figure 28.3  Premature ventricular contraction.

T

heart monitoring was only (very) rarely used in this era and in this indication. Reading all the works on the cardiac toxicity of phenol clearly shows that arrhythmias (easily triggered by the rapid application of large quantities of phenol) were only rarely diagnosed or published, and the fact that they tend to resolve spontaneously allowed practitioners to sleep peacefully. Truppmann and Ellenby routinely used cardiac monitoring when doing phenol peels and detected many arrhythmias. In 1979, they published the results of a study on 48 patients treated with phenol peels.20 Saponified and nonsaponified Baker or Litton formulas were studied. They report that 23% of patients treated with phenol showed arrhythmia, on average 17.5 minutes after the phenol was first applied. These arrhythmias were often premature ventricular (Figure  28.3) or supraventricular contractions, bigeminy, or supraventricular (Figure  28.2) or ventricular tachycardias (Figure  28.7). Tachycardia, which in extreme cases can sometimes reach 220–230 beats per minute, can turn into ventricular fibrillation and lead to cardiac arrest. These seem to be the first documented reports of cardiac arrhythmias that definitely can be attributed to phenol in humans. The authors also state that when they applied phenol

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slowly, taking more than 1 hour, no incidence of arrhythmia was detected. The types of arrhythmia encountered were the following: • • • • •

Ten patients of the 48 treated with facial peels showed arrhythmia. Four patients showed premature ventricular contraction; aged 30, 36, 59, and 71. Two patients showed bigeminy; aged 24 and 43 (Figure 28.4). Two patients showed paroxysmal tachycardia; aged 55 and 67. Two patients showed ventricular tachycardia; aged 36 and 73.

In response to these studies, Baker27,28 claimed that, in the course of 5000 phenol peels, he never came across a case of arrhythmia. His observation was based on the following evidence: • • • •

To refine their conclusions, the authors studied the potential influence of different parameters: • • • • • •

•

Products used in anesthesia: No correlation could be found. Oxygenation before and during the peel: No correlation could be found. Saponified or nonsaponified formula: No correlation could be found. Preexisting arrhythmia: No correlation could be found (other authors24 have confirmed this lack of correlation). Age of the patient: No correlation could be found. Speed of application: Fifty percent of patients who received a phenol peel in less than 30 minutes developed arrhythmia, with the average time for arrhythmia to occur being approximately 17.5 minutes; no patient developed arrhythmia when the peel was applied over a minimum period of 60 minutes. Surface area treated: No arrhythmia occurred before phenol was applied on at least half of the face.

Lotter in 1980 and Litton in 1981 published the results of two countersurveys. Lotter25 highlighted the fact that only 23% of doctors performing phenol peels use cardiac monitoring to check the progress of the application. Litton recorded in his study26 that after reading Truppmann and Ellenby’s article,20 13% of plastic surgeons who had answered his questionnaire now reported arrhythmias under phenol and that 51% of practitioners now monitored phenol peels with a cardioscope. The question asked of the plastic surgeons was: Have you seen any cardiac complications during a phenol peel? The answers were as follows: Yes: 5% No: 87% Tachycardia: 6% Arrhythmia: 1% Premature ventricular contraction  1% Of the doctors questioned, 51% said they used monitoring, while 42% never used it and 7% only sometimes monitored their patients. The conclusion that can be drawn from these studies is: putting the patient on cardiac monitoring is a legitimate precaution that allows the doctor to act immediately in case of cardiovascular complication. On the other hand, not monitoring the patient does not necessarily make the prognosis for complications any worse, and most of the time they seem to resolve spontaneously.

Complications can take practitioners by surprise during any cosmetic procedure, and facial peels are no exception to this rule. The most common complications involve pigmentation, and through careful patient selection these complications can be avoided. Hypertrophic scars are extremely rare after a chemical peel. Systemic toxicity also is extremely rare.

Nevertheless, Baker recommended that all patients should be monitored during full-face phenol peels, which seems obvious to us nowadays. Baker stated that he only observed “normal” irregularities during his phenol peels and never had a patient die. He considered the cases of premature supraventricular contractions and the two cases of paroxysmal tachycardia reported by Truppmann and Ellenby20 to be epiphenomena, not very serious and fairly frequent during minor procedures, especially if an anesthetic containing adrenaline (epinephrine) is used. The two cases of bigeminy reported by Truppmann and Ellenby did not bother him either, as he often came across bigeminy during routine procedures and drew the logical conclusion that phenol should not automatically be blamed for everything. He was, however, alarmed by the two cases of ventricular tachycardia in the patients who received a “rapid” application of phenol in less than 1 hour, and stressed the importance of taking time over the peel. Baker also recommended taking at least 1 hour to apply any phenol peel. Finally, he concluded that phenol peels produce results that no other surgical technique can rival and that an experienced practitioner, aware of the complications and risks, can, by carefully selecting his patients, apply phenol peels without any fear of dire consequences. In 20 years of using phenol, he did not observe any cardiac complication that could be directly attributed to phenol with certainty.28 Nevertheless, all of these opinions, even when they come from such well-known medical experts, cannot aspire to the status of scientific facts. Gross29 decided to reproduce the study by Truppmann and Ellenby, using the same nonsaponified formula in 100 consecutive peels on the face and neck (up to the clavicles in the anterior region and up to the 7th cervical vertebra in the posterior region). Given the number of arrhythmias that occurred after the 54th patient, the method of application had to be changed. Out of 54 patients, 31 (57%) developed cardiac arrhythmia (supraventricular and/or ventricular). Unfortunately, Gross did not reveal the quantities of phenol used. Logically, it was used in large quantities, because the surface area treated included the face and neck up to the 7th cervical vertebra. Moreover, the premedication contained substances that change the heartbeat, such as beta-blockers. The rest of the patients were therefore treated in two sessions with a 24-hour interval in between: the face was treated in the first session and the neck in the second. In this series, “only” 22% of the patients developed arrhythmia. No correlation was found between the age of the patients, their gender, the preexistence of cardiovascular diseases, and the incidence of arrhythmias. On the other hand, the blood concentrations reached

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in this study seem to be very high, up to 33.29  mg/100  ml. These figures differ enormously from those in Deichmann’s or Litton’s studies (see discussion later in this chapter). We know that the systemic toxicity of phenol can manifest from 23 mg/100 ml.30 The arrhythmias seem to occur in the following order: tachycardia and premature supraventricular contractions that develop into atrial fibrillation (pulsus irregularis perpetuus). Arrhythmias lasts on average 2–19 minutes and are spontaneously reversible, depending on the clearance of the phenol and the gradual lowering of blood concentrations after hepatic detoxification and renal elimination. This study did not show any relation between blood levels and the occurrence or severity of arrhythmias. Each patient appears to have his or her own particular sensitivity to phenol. In conclusion, Gross recommended dividing the face into different sections and leaving a rest period of 20 minutes between each zone (see Chapter 33). Baker’s point of view is fully shared by Cortez,31 who, in a retrospective study of hundreds of phenol peels that he performed between 1983 and 1990, did not observe any cardiac toxicity when the precautions for use were followed. A study by Wexler et al.4 on rabbits found a correlation between the rapid onset of arrhythmia and the speed with which phenol is absorbed through the skin: 70% of phenol is absorbed in 30 minutes in rabbits. Forced diuresis (intravenous furosemide) while the peel is being applied prevents cardiac arrhythmia by increasing renal elimination of free phenol, even before the conjugation and oxidation processes of detoxification could protect the organism. In addition, slow application of the solution in at least 1 hour meant that no arrhythmia was observed, as this leaves enough time for the phenol to be detoxified. A study on humans, limited to 10 patients, was published in 1990.32 Continuous electrocardiogram (ECG) recordings (halters) were taken before, during, and after the peels. Many ectopic beats were recorded, but no direct relation with the application of phenol was established, although one case of arrhythmia was found to be suspicious. Despite a review of the study documents, the author of this book is unable to analyze the different factors that might have influenced this study with any precision. In 1985, Warner and Harper33 published an article reporting a suspect case of multifocal premature ventricular contractions and bigeminy in a child34 weighing 36  kg who received a dose of 2.4 g of 40% phenol in 0.8% of croton oil, hexachlorophene, and water.35 This large quantity36 was applied to 1.9% of the body surface area (we know that the absorption surface is at least as important, if not more, than the total quantity of phenol applied) and under general anesthetic. Arrhythmias from phenol usually occur rapidly, in approximately a quarter of an hour, and in this case they occurred after 55 minutes. Phenolemia was not measured and, according to the authors, there was nothing in the case history that could have attributed the arrhythmia to phenol. The child had already had several phenol peels in the past for dermatological problems and had never experienced any problems, but because of Truppman’s and Ellenby’s descriptions, the authors assumed that phenol was the culprit. Another study37 compared the toxicity of trichloroacetic acid (TCA) and phenol (Baker’s solution); the conclusion was that “it would appear advisable” to set up a cardiac monitor during a full-face peel with Baker’s solution, whereas TCA does not cause any type of arrhythmia.

Previous studies have shown that cardiac monitoring is an essential prerequisite when doing a phenol peel on the face, even if serious arrhythmia can be avoided by applying the product in at least 1 hour. Applying phenol without any cardiac monitoring is not good medical practice, and any subsequent complications could be considered professional malpractice based on negligence. It should be remembered that vagal reactions are not uncommon during any treatment that is stressful for the patient and that they need to be detected in order to be treated correctly.

PREVENTION OF CARDIAC ARRHYTHMIAS By observing the following seven points, the risks of cardiovascular complications can be significantly reduced:4,38 1. 2. 3. 4. 5. 6. 7.

Prepeel checkup: ECG, liver, and kidney (blood analysis). Application over more than 1 hour. Monitoring (ECG and pulse oximetry).39 Good general health. Good patient selection. Good hydration.40 Lidocaine as a preventive.41 This point is highly debatable, because arrhythmia can be avoided simply by taking more than 1 hour to apply the phenol. Simple lidocaine used to do nerve blocks before the phenol peel should be considered a cautious technique.

TREATING ARRHYTHMIA DURING A PEEL There are several articles describing the appropriate treatment for heart arrhythmias occurring in the course of a phenol peel.20,24,26,33

At the First Signs of Arrhythmia If the ECG shows the least sign of arrhythmia—even slight, seemingly insignificant, and supraventricular—the application of phenol should be stopped immediately and the intravenous drip speeded up to hydrate the patient more and force diuresis to eliminate not only the conjugated phenol but also free phenol. Under these conditions, the arrhythmia should show rapid signs of improvement and not get any worse. Fifteen minutes after the last arrhythmia, the phenol can be reapplied again carefully. It is essential for the anesthetist, the doctor doing the peel, and/or an assistant to read the ECG constantly. A certain amount of competence in ECG reading is therefore recommended before doing a full-face phenol peel. There would be no point plugging in an ECG monitor and being unable to detect basic heart rhythm abnormalities. Some authors4 recommend the use of furosemide to increase diuresis, but furosemide can cause abnormal ionic plasma levels, which can in turn cause arrhythmias or make them more likely. Be that as it may, furosemide rapidly increases the elimination of free phenol in urine, even before the processes of hepatic conjugation, which come into play very rapidly, have been able to detoxify it. Experiments undertaken by Wexler et al.4 show the following results in animals. When 2  ml of Baker’s solution is applied quickly on the skin of rabbits weighing 3  kg and sedated with pentobarbital, on a surface area proportionally 5–8 times larger than the human face, numerous heart arrhythmias are observed. It is interesting to note that the doses required to induce arrhythmias in rabbits are high. Forced diuresis with

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furosemide significantly reduces the arrhythmias. By applying the product slowly, arrhythmia is avoided altogether, in spite of the extremely high doses and the extent of the surface area treated.

“Benign” Arrhythmias Simple, isolated supraventricular extrasystoles can occur frequently during any type of procedure, simply because the patient is under stress. The right reaction to these benign arrhythmias is to stop applying the phenol and wait for the sinus rhythm to return “naturally.” These seemingly benign extrasystoles can in fact be a sign of more serious arrhythmias. It is best to be prepared by having all the necessary equipment ready and to keep a close eye on the ECG to pick up any more significant changes in rhythm. It is a bit late at this stage to be wondering whether the lidocaine is at hand or if the battery in the laryngoscope is charged.

More Serious Arrhythmias Bradycardia In the case of bradycardia, intravenous atropine is indicated. In cases of severe phenol poisoning, it has been reported that the pulse rate can at first increase and then drop off. Tachyarrhythmias Arrhythmia can evolve rapidly: within a few seconds, benign supraventricular arrhythmias can turn into other types of rhythm disorders, such as nodal tachycardia, atrial fibrillation, and multiple ventricular extrasystoles, in doublets or triplets. It is important to act quickly, which is easy to do when everything that is needed to deal with these arrhythmias (which fortunately are very rare) is readily available and the patient is on a drip. The patient should be put on oxygen to maintain good blood oxygen levels. Treatment consists of slow intravenous injection of 50 mg of lidocaine without adrenaline (epinephrine). Usually, the arrhythmia rights itself in less than 10–15 minutes. A total maximum dose of 100  mg, in two slow intravenous injections of 50 mg (in 1 minute), provides a strong and rapid antiarrhythmic effect (50 mg of lidocaine may be sufficient to get the patient back into a regular sinus rhythm). If lidocaine does not bring the rhythm back to normal, bretylium tosylate may be indicated42 (if in an area equipped for resuscitation).33 Other antiarrhythmics are now available and can of course be used, depending on the type of arrhythmia and the competence of the doctor injecting them.

Blood Pressure In cases of severe phenol poisoning, blood pressure can rise slightly and then drop significantly afterward.43

Collapse and Cardiac Arrest To the best of the author’s knowledge, collapse, ventricular fibrillation or flutter, torsade de pointes, and other extremely serious arrhythmias have not been described during peels. However, they can occur with severe phenol poisoning, usually caused by accidental intravascular injections of phenol. In Truppmann’s and Ellenby’s study, none of these serious arrhythmias were described, and cardioversion and defibrillation were not necessary if more than 1 hour was taken to perform the peel. If medication proved insufficient and the arrhythmia led to collapse, external heart massage and/or an electric shock of 200 J

would resuscitate the patient. Again, however, there is no risk of this level of arrhythmia when a phenol peel is applied correctly, and as already noted, a full-face phenol peel performed in more than 1 hour does not trigger any arrhythmia. The author of this book has come across only case of arrhythmia.44 It occurred when influenced by a highly respected colleague who claimed that he performed all his full-face peels in 30 minutes, without any ECG monitoring, as he had never had any patients feel unwell. The absence of an ECG obviously meant that he could not pick up on any arrhythmias. His experience could lead to the conclusion that the arrhythmias potentially caused by a full-face phenol peel remain benign and resolve without treatment. However, this conclusion would be hasty and irresponsible. In 1994, Lalanne et al.24 described two cases of cardiac arrest after the injection, in 3 minutes, of 1.4 and 1.8 g of phenol in an aqueous solution with a concentration of 6% (2 × 15 ml). The injections were strictly extravascular but were near the aorta. The injections were made into the semilunar ganglia and were given as painkillers to patients with inoperable pancreatic cancer. These patients were in a poor state of health generally, on numerous drugs, and under general anesthesia.45 There is an accumulation of numerous risk factors here, and the phenol peels were applied under completely different conditions. The complications occurred almost immediately, 2–3 minutes after the injection, and started with a drop in arterial oxygen saturation to 92%. The arrhythmia began with polymorphous ventricular extrasystoles that rapidly turned into ventricular tachycardia, ventricular fibrillation, and cardiac arrest. The treatments described earlier got the patients back to normal rhythms. In 1993, Gaudy et al.46 described the same type of accident, in which 30 ml of 6.6% phenol solution (around 2 g) was injected for palliative splanchnic neurolysis in a patient with cancer of the pancreas. It seems obvious that, in spite of the fact that the injection was extravascular and given by a competent practitioner, there was massive vascular absorption, which can cause accidents that are fortunately reversible after treatment. It is most likely that the injections were made in edematous tissue that had been damaged by surgery beforehand and that this enhanced penetration. When intoxication has been severe and death narrowly avoided, jaundice and oliganuria43 follow—a sign of the hepatic and renal toxicity of phenol. These cases do not fall within the strict framework of a phenol peel performed correctly: hepatic and renal toxicity are complications linked to acute poisoning.

OTHER TYPES OF TOXICITY Toxicity by Inhalation Phenol vapors are heavier than air (vapor density 1.2). The best way to ventilate a room where a phenol peel is being performed is therefore at ground level and not higher up. This is important, as phenol vapors can travel considerable distances at ground level. Care should be taken with electric heaters, as there is a risk of the vapors coming into contact with a source of heat that can start a fire: the mixture of phenol vapors and air has a flashpoint of 79°C (174°F).43 The olfactory sensitivity threshold is 0.047  ppm. Therefore, it is difficult to eliminate phenol vapors from a room; it can take hours. The presence of 250  ppm in inhaled air poses an immediate danger to health and life. Acute poisoning from phenol vapors can produce the same symptoms as

Phenol toxicity: Causes, prevention, and treatment    237

oral poisoning. Chronic exposure47 to phenol vapors produces the following symptoms: vomiting, difficulty swallowing, excessive salivation, diarrhea, anorexia, headaches, dizziness, weakness and myalgia, mental disturbances, dark urine, and sometimes skin eruptions. Postmortem examinations of animals given fatal doses of phenol vapors show the presence of myocardial necrosis and acute pneumonia, as well as vascular, liver, and kidney damage.43

Ophthalmic Toxicity Direct contact with phenol crystals, concentrated solutions, or vapors (45 ppm) causes serious damage to the eyes: hyperalgesic chemical conjunctivitis, severe iritis, and possibly corneal opacification with loss of vision and edema of the eyelids. In some cases of poisoning through direct accidental eyelid contact, the seriousness of the injury to the eyelids has required surgery.48 The results of phenol coming into direct contact with the eye can vary from complete recovery of vision to loss of the eye, depending on the severity of the lesions. Chronic, repeated, or prolonged exposure to phenol vapors can cause conjunctivitis. A gray discoloration of the sclera along with brown patches of pigmentation at the insertion of the rectus muscle tendons of the eye have been described after chronic exposure.43 Any direct contact between phenol and the eyes requires raising the eyelids and rinsing immediately with copious amounts of water or saline solution. The eye should be flushed with saline solution for 30–60 minutes, while waiting for the opinion of an ophthalmologist. Ophthalmic Vaseline or a Vaseline-based antibiotic eye ointment should always be put in the eyes before applying phenol, as Vaseline largely deactivates phenol.

Hepatic and Renal Toxicity Some cases of hepatic and renal toxicity after severe poisoning with phenol derivatives have been reported in the literature, but the author has not been able to find any such record in medical publications dealing with phenol peels.

NOTES 1. Glogau RG, Matarasso SL. Chemical peels: Trichloroacetic acid and phenol. Dermatology Clinics. 1995; 13: 263–76. 2. Ruedemann R, Deichmann WR. Blood phenol level after topical application of phenol-containing preparations. JAMA. 1953; 152: 506–9. 3. Rats seem to be resistant, as this LD50, applied to an average human weight of 65 kg, would give a figure of 34.45 g of phenol. 4. Wexler MR, Halon DA, Teitelbaum A, Tadjer G, Peled IJ. The prevention of cardiac arrhythmias produced in an animal model by the topical application of a phenol preparation in common use for facial peeling. Plastic and Reconstructive Surgery. 1984; 73: 595–8. 5. Deichmann WB, Witherup S. The acute and comparative toxicity of phenol and o-, m-, and p-cresols for experimental animals. Journal of Pharmacology and Experimental Therapeutics. 1944; 80, 233–40. 6. Baker TJ. Chemical Rejuvenation of the Skin. 7. Arouette J. Dermabrasion, Relèvements, Peelings. In: Blackwell A. (Ed.). Collection des Manuels Pratiques de Médecine Esthétique. Paris: Arnette, 1989. 8. Stone PhA. Peelings au phénol Baker–Gordon et modifies. J Med Esth Chir Derm. 1996; XXII(90): 93–7. 9. McCulloch EG, Langsdon PR, Maloney BP. Chemical Peel with Phenol. In: Roenigk RK, Roenigk HH (Eds.). Dermatologic Surgery, Principles and Practice. 2nd ed. Oxford, UK: Marcel Dekker, 1996: 1147–60.

10. Manquat A. Traité Élémentaire de Thérapeutique de Matiére Médicale et de Pharmacologie. 5th ed., Vol. 1. 1903: 240–60. 11. After voluntary ingestion of Lysol, death occurs within 3–4 hours; at autopsy, corrosive esophagitis and gastritis were of course noted. 12. Backstreet abortionists readily used irritant solutions, phenol and Lysol solutions among them, as uterine enemas to induce abortions. It is likely that this method was just as dangerous for the mother as for the fetus, because of the rich vascularization of the uterus. Autopsy would show a high concentration of phenol in the right side of the heart, which drains all the veins of the body and therefore the phenol-laden blood. 13. Bethune M, Court D. Vaporizing fluids containing phenols. British Medical Journal. 1954; i: 1494. 14. As opposed to “tamed” formulations. 15. Vomiting can cause reversible petechiae (see Chapter 37). 16. Dauphin A, Darkord JC. Hygiène Hospitalière Pratique. 2nd ed. Association de Pharmacie Hospitalière de l’lle de France. Editions médicales internationales. 17. Spiller HA, Quadrani-Kushner DA, Cleveland P. A five-year evaluation of acute exposure to phenol disinfectant (26%). Journal of Toxicology—Clinical Toxicology. 1993; 31: 307–13. 18. Giroud JP, Mathé G, Meyniel G. Pharmacologie Clinique: Bases de la Théapeutique. 2nd ed. Paris: Expansion Scientific Français, 1978. 19. Hunter DM, Timerdery BL, Leonard RB, McCalmont T, Schwartz E. Effects of isopropyl alcohol, ethanol and polyethylene glycol/ industrial methylated spirits in the treatment of acute phenol burns. Annals of Emergency Medicine. 1992; 21: 1303–7. 20. Truppman E, Ellenby JD. Major electrocardiographic change during chemical face peeling. Plastic and Reconstructive Surgery. 1979; 63: 44–8. 21. McCulloch EG, Langsdon PR, Maloney BP. Chemical Peel with Phenol. In: Roenigk RK, Roenigk HH (Eds.). Dermatologic Surgery, Principles and Practice. 2nd ed. Oxford: Marcel Dekker, 1996: 1147–60. 22. Asken S. Unoccluded Baker–Gordon phenol peels—Review and update. Journal of Dermatologic Surgery and Oncology. 1989; 15: 998–1008. 23. Litton C, Fournier P, Capinpin A. A survey of chemical peeling of the face. Plastic and Reconstructive Surgery. 1973; 51(6): 645–7. 24. Lalanne B, Baubion O, Sezeur A, Tricot C, Gaudy JH. Circulatory arrest after splanchnic neurolysis with phenol in unrespectable cancer of the pancreas. Annals de Chirurgie. 1994; 48(11): 1025–8. 25. Lotter cited in Botta SA, Straith RE, Goodwin HH. Cardiac arrhythmias in phenol face peeling: A suggested protocol for prevention. Aesthetic Plastic Surgery. 1988; 12(2): 115–17. 26. Litton C, Trinidad G. Complications of chemical face peeling as evaluated by a questionnaire. Plastic and Reconstructive Surgery. 1981; 67: 738–43. 27. Discussions following Litton and Trinidad. 28. Baker TJ. The voice of polite dissent. Plastic and Reconstructive Surgery. 1979. 29. Gross BG. Cardiac arrhythmias during phenol face peeling. Plastic and Reconstructive Surgery. 1984; 73: 590–4. 30. Benatar D. Le peeling au phénol. Journal de Médecine Esthétique et de Chirurgie Dermatologique. 1988; XV(60): 319–23. 31. Cortez E. Chemical face peeling. Otolaryngology Clinics of North America. 1990; 23: 947–60. 32. 1990 study. 33. Warner MA, Harper JV. Cardiac dysrhythmias associated with chemical peeling with phenol. Anesthesiology. 1985; 62: 366–7. 34. We have already seen that infants are more sensitive to phenol than adults. 35. This keratolytic concentration makes for rapid penetration, and blood vessel uptake of the phenol is quicker in a formula that does not contain any oils other than croton. 36. More than is usually applied during a facial peel. 37. Stagnone GJ, Orgel MG, Stagnone JJ. Cardiovascular effects of topical TCS 50% and Baker’s phenol solution. Journal of Dermatologic Surgery and Oncology. 1987; 13: 999–1002.

238    Textbook of Chemical Peels 38. Botto SA et al. Cardiac arrhythmias in phenol face peeling: A suggested protocol for prevention. Aesthetic Plastic Surgery. 1988; 12: 115–17. 39. Both are essential, as the onset of arrhythmia is often preceded by a significant drop in oxygen saturation. Besides, arrhythmia cannot be detected by a pulse oximeter. 40. 500 ml of saline solution before the peel to trigger diuresis. 41. The lidocaine used to carry out any facial nerve blocks should be taken into account. 42. Note that 2 ml intravenous vials contain 100 mg. 5 mg/kg should be injected and repeated after 15–30 minutes, 10 mg/kg if necessary. The total maximum dose is 30 mg/kg.

43. Fisher Scientific. Phenol [Material Safety Data Sheet]. 44. This arrhythmia occurred before the research that allowed the author to write this book was undertaken. 45. General anesthesia is not always considered to be an additional risk factor during phenol peels. 46. Gaudy JH, Tricot C, Sezeur A. Troubles du rythme cardiaque graves après phènolisation splanchnique peopèratoire. Canadian Journal of Anesthesia. 1993; 40: 357–9. 47. This has no relation to what a doctor performing phenol peels, even on a regular basis, can inhale. 48. A phenol peel always causes severe edema in the eyelids. Scarring, however, is very rare.

29 Phenol Choice of peel and combination treatments INFLUENCE OF THE PATIENT’S AGE AND GENDER Age

easily use makeup to hide it, but this is difficult for men. Men can, however, wear a tinted sunblock to hide the redness.

A phenol peel is mainly indicated to treat facial skin for severe photoaging. It is the only type of peel that can eliminate deep wrinkles1 and regenerate elasticity and firmness in the treated skin in a single treatment. Phenol peels are therefore usually aimed at people who are (well) past their 40s. There is no real age limit, and phenol has been used on patients of advanced years (Figure  29.1) as well as on other much younger patients. Old age is not in itself a contraindication to phenol, 2 and it is remarkable to note that the skin regenerates perfectly well at any age. The oldest patient that the author has treated was 82 when she had a phenol peel, and she was not the oldest patient to ever receive a phenol peel. Phenol has been used on children to treat specific disorders. Young adults have also been treated with phenol for acne scars or scars of other origins. However, because of its toxicity and the profound changes it makes to the skin, phenol should not be used without a good reason. Phenol should not be used to treat something that alpha hydroxy acids (AHAs) or trichloroacetic acid (TCA) can treat just as well. The strength of a peel should always be adapted to the problem being treated: there is no point in applying a peel that is too superficial or too deep.

Shaving The question of shaving often comes up, and it is true that stubble can pose a technical problem for a patient who wants to shave at all costs. This is a minor concern, however, as the patient has to wait for only 10 days after a phenol peel before shaving. On the 11th day, the doctor might allow the patient to shave carefully, after evaluating the condition of the patient’s skin. Wearing a beard can even be an advantage and make the demarcation line less visible (Figure 29.5).

Gender Thickness of the Skin A man’s skin is often more resistant, thicker, and oilier (Figure 29.2) than a woman’s skin. Sagging skin is more common than photoaging in men, and men are often better candidates for a face-lift than a peel. It is the type of skin more than the gender that determines the results of a phenol peel. If aging has resulted in a thick skin sagging, without dyschromia (see also Figure 29.7), and if the folds are more pronounced than the wrinkles and fine lines, a peel is not at all indicated either in a man or a woman, as, even if phenol produces a “three-dimensional face-lift” effect, the extent of the retraction is no substitute for surgery (Figures 29.2 and 29.3). When aging has resulted in sun-damaged thinning skin with wrinkles and age spots, a peel is an excellent indication and produces surprising results, in both men and women (Figure 29.4). Men with light skin phototypes and thin and sundamaged skin respond very well to phenol. The gender-based distinction is purely statistical: in general, women can be said to respond better to phenol than men, but this does not rule out men for this treatment. The only problem that proves awkward after treating a man’s skin is postpeel erythema (Figure  29.5). Women can

Makeup Patients regularly ask about wearing makeup after a phenol peel. Patients who usually wear foundation can go back to using it when the skin has finished flaking, around the 8th day and with the doctor’s permission. The first time makeup is used signals the long-awaited return to a normal social life. Some patients do not usually wear makeup, and it is important to tell them that it will probably be essential for them to wear foundation after the peel to hide the erythema, which can last up to several months. The reddest areas should be covered with a green (to counteract the redness) makeup stick before foundation is applied. If the patient refuses to use makeup, she should be advised to use a tinted sunblock, and this should be discussed with her before the peel.

INFLUENCE OF THE PATIENT’S PHOTOTYPE Although phenol has been used successfully on patients with a “Mediterranean” skin type or on Asian patients with a fair skin, it is nevertheless aimed at patients with a light skin phototype. Patients with Fitzpatrick skin type I—III are excellent candidates. Patients with Fitzpatrick skin type IV and patients with severely sun-damaged skin will have to accept the possibility of a visible demarcation line3 on the neck. This demarcation line (Figure  29.6) can be made less obvious both by a good peeling technique and by combination with other peels on the neck.4 Darker skin types are not such a good indication, because of the change in skin tone after the peel. Most patients with a lot of wrinkles, however, prefer to exchange their wrinkles for a difference in skin color that can easily be disguised with makeup. Skin phototype is even more important when using phenol locally; a local5 phenol peel can only be applied on light skin phototypes that will not show any significant and visible difference in color on the eyelids and around the mouth. The same applies to patients with a lot of freckles, keratoses, or lentigines,

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(a)

(b)

Figure 29.1  An 82-year-old patient (a) before and (b) after a full-face phenol peel.

Figure 29.2  A patient 8 years after a full-face phenol peel: the quality of the skin has remained much improved, but the wrinkles and sagging did not really benefit from the peel. A face-lift would be indicated for this patient.

Figure 29.3  Two years after a full-face phenol peel on a patient with thick and oily skin, the quality of the skin has improved but the folds and sagging remain unchanged. A face-lift would have been a better indication for this patient.

Phenol: Choice of peel and combination treatments    241

(a)

(b)

Figure 29.4  (a) Photoaging before a phenol peel. (b) Three weeks after Lip & Eyelid Formula (full-face phenol peel).

Figure 29.5  A patient 15 days after a full-face peel: wearing a beard can limit the effect of the demarcation line caused by the erythema.

Figure 29.6  Ten days after a Lip & Eyelid peel around the mouth on a tanned patient: the phenol has taken away the tan. Easy TCA (four sessions) or Unideep (one session) will even out the skin tone.

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or freckles.6 The two peels should be done in the same session: the phenol first, followed immediately by Unideep on the rest of the face, around the area treated with phenol.

PHENOL PEEL VERSUS OTHER MEDICAL OR SURGICAL TECHNIQUES Peel versus Face-Lift

Figure 29.7 The sagging—more pronounced than the photoaging—contraindicates a phenol peel, which would have no effect on this patient.

which only disappear from the areas treated with phenol but remain in the surrounding areas. The difference in skin quality is also very visible. These patients should only be treated with a full-face peel. It is nevertheless possible for these patients to have a local phenol peel combined with a full peel to the papillary dermis. Combining Lip & Eyelid Formula with Unideep provides a phenol peel and a peel to even out skin with lentigines, keratoses,

(a)

There is not much point in considering this question, as a full-face peel is no substitute for a full face-lift, and vice versa (Figures 29.7 and 29.8). The indications are different; peels and face-lifts complement rather than compete with each other.7 When the damage is localized, the doctor alone can advise his or her patient on which treatment or combination of techniques to use. A face-lift cannot treat wrinkles on the upper lip, but laser treatment, dermabrasion, or Lip & Eyelid Formula can get rid of them. These treatments should be performed on the same day as the surgical face-lift while the patient is still under anesthetic. Wrinkles around the lips sometimes benefit from a combination of dermabrasion and phenol: Lip & Eyelid Formula is locally applied on the day of the face-lift and left under occlusion for 24 hours; the following day, the surgeon evaluates the results of the peel on the upper lip; if some wrinkles still persist, they can be touched up with the peel solution.8 It is also possible, on the first day, to perform dermabrasion9 after a focal application of phenol on the lip. If surgical blepharoplasty is not combined with a facelift, Lip & Eyelid Formula can be applied on the eyelids at the same time as the face-lift. The patient in Figure 29.9 is a typical case where the facial photoaging10 would benefit far more from a full-face phenol peel than from a neck- and face-lift. Nevertheless, phenol, with difficulty, tightens and rejuvenates the neck, which will only benefit from surgery followed by a peel to the papillary dermis or several peels to the Grenz zone (with Easy TCA) to improve the quality and the color of the skin after the surgical face-lift.

(b)

Figure 29.8  Excellent three-dimensional tightening effect from a phenol peel: (a) before treatment and (b) 3 months after.

Phenol: Choice of peel and combination treatments    243

(a)

(b)

Figure 29.9  (a) Photoaging, thin skin, and slight sagging: a good indication for a full-face phenol peel. Aging of the neck: a neck- and face-lift is indicated before the phenol peel. (b) Results of a full-face phenol peel (Lip & Eyelid), 14 days after the peel. There is spectacular improvement in the skin. Oddly enough, some of the lentigines have been replaced by telangiectasias. They must be treated quickly, to avoid extravasation of iron pigments and potential multiple localized tattoo marks.

When the wrinkles are on the eyelids and around the mouth, the problem is therefore easily solved. In the case of sagging and wrinkled skin, it is clear that the best results can be achieved with a combination of treatments that should be conducted at different times (see discussion later in this chapter). The large majority of patients are in this situation, and the degree of facial ptosis will be the deciding factor in whether to suggest a face-lift or a phenol peel. A face-lift gives better results for facial ptosis (Figure  29.10); a peel gives better results for wrinkles and dyschromias. A surgical face-lift can only tighten damaged skin that will not have enough elasticity to remain tight definitively.

Phenol Peel Combined with a Surgical Face-Lift We have seen that there is no problem with performing a localized phenol peel at the same time as a surgical face-lift if the two treatments are aimed at different areas. When both treatments are indicated for the whole face,11 the face-lift should be done first, followed by a rest period of around 6 months before the deep peel (Figure 29.11). The peel will have the additional advantage of softening the scars from the face-lift while restructuring the histology of the epidermis and the dermis and removing the marks and fine lines that did not respond to the face-lift. With a phenol peel, a demarcation line is left under the jaw12 that is partially hidden by shadow. A face-lift after a phenol peel could raise this demarcation line to the cheeks: any face-lift should therefore be done before a phenol peel. More

importantly still, using a phenol peel (or even a deep TCA peel13) at the same time of operation on an area that has just been treated with a surgical lift can potentially cause extensive facial necrosis. The general principle is not to undermine the skin’s inner vitality with surgery at the same time as injuring the outer layers of the skin with a peel. In other words: a facelift should not be done on the same day as a full-face deep phenol peel. A study14 from 1989 looked at the viability of dorsal skin flaps (on guinea pigs) subjected in vivo to transposition and suture immediately followed by a single application of phenol (Baker’s solution) and 24-hour occlusive tape dressing. Thirtysix skin flaps were raised and sutured back into place, and only 18 were treated with phenol. Analysis of the results clearly shows that combining a surgical lift and phenol at the same time of operation is not a wise choice, as the average necrosed surface area without phenol was 3.1 cm2, compared with 6.3 cm2 for the peeled flaps. Another study15 on animals came to the conclusion that raising a skin flap causes changes in the tissue of the reticular dermis and the underlying tissue, which makes it more sensitive to any subsequent injury. The risk of compromising the viability of a raised skin flap is therefore too high to opt for a simultaneous face-lift and deep peel. On the eyelids, however, the fat hernia around the orbit was removed through the transconjunctival approach and combined—in expert hand—successfully and safely with a local phenol peel.16 McCollough and Maloney17 combined surgical blepharoplasty with a phenol peel, but left the skin to rest for 3 months before doing the eyelid peel.

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Figure 29.12  Aptos thread.

Phenol Peel and Aptos Threads A new technique involves inserting barbed or spiral threads under the skin to tighten sagging tissue (Figures 29.12 and 29.13). These are known as Aptos threads or Russian threads, as in their current form they were designed by Dr. M. Sulamanidze from Moscow.18 The Aptos threads are inserted deeper than the phenol penetrates. There is therefore no risk of interaction between the phenol and the thread that would, in any case, resist it chemically. However, this technique poses three problems: Figure 29.10  This is the same patient as in Figure 29.8. Two years after full-face Exoderm, the improvement on the cheeks is still well maintained. However, sagging has partially recurred, the results on the upper lip are inadequate, and the color of the skin is slightly uneven. The patient, who enjoys boating in sunny climates, has not avoided the sun as recommended. Treatment will consist of a spot application of Lip & Eyelid Formula on the upper lip (using an occlusive technique), combined with one Easy TCA peel per week for 4 weeks to even out the skin tone. Daily care comprises Blending Bleaching Cream and Melablock-HSP ® 50+. HSP (heatshock proteins) sunblock is sunblock containing stimulants that produce proteins that protect against heat damage.

(a)

1. 2.

3.

The entry points of the threads must not come into contact with the phenol, as there is a risk that the inflammation will push them out. The inflammation caused by the phenol peel affects all the layers of the skin. This reaction, combined with the inflammation caused by the thread itself, could make the tissue in which the threads have to anchor themselves more fragile and cause them to rapidly unhook. Phenol is, of course, a disinfectant, but a phenol peel coagulates all of the skin’s immune structures, and the skin becomes very prone to infection. The risk of secondary infection from the thread is increased.

(b)

Figure 29.11  (a) A patient after surgical face-lift. (b) The same patient: phenol peel (Lip & Eyelid) after a face-lift.

Phenol: Choice of peel and combination treatments    245

(a)

(b)

Figure 29.13  (a) Aptos springs. (b) Springs.

is more comfortable for the patient with phenol than with laser. Histologically, the depth of action of phenol is deeper than that of the laser and reaches the reticular dermis. The authors concluded that both ablative laser and phenol peels remain useful clinical tools. The records show that the battle has been won by phenol because of the high number and the severity of complications caused by CO2 lasers. Fintsi also presented a split-face study, applying phenol (Exoderm—Fintsi’s formula, congress presentation, Stiges, Spain) on one half of the face. One of his colleagues, a laser specialist, applied a CO2 laser to the other half of the face. The results were clinically obvious, and it was clear that they were better on the half of the face treated with phenol—so much so that the patient asked for another phenol treatment to even out the two sides. We could perhaps conclude, however, that the CO2 laser might be a better indication for patients with very thick and oily skin, especially on the chin and nose.

EASY PHEN LIGHT It is therefore preferable not to insert Aptos threads at the same time as performing a phenol peel. Moreover, phenol partially tightens the skin, and it may well be more worthwhile to use Aptos threads as a second line of treatment, when the phenol has taken full effect, after at least three months. The presence of threads inserted in the skin several months previously is not a contraindication for a phenol peel, and it is possible to decide on the opposite course of action if the doctor thinks this is a better option for the patient: Aptos threads can be inserted first and a phenol peel can be done afterward.

Phenol Peel versus Carbon Dioxide Laser Resurfacing Several studies have been conducted comparing the results of a full-face phenol peel and resurfacing with a carbon dioxide (CO2) laser, sometimes known as a carbon dioxide laser peel. A study by Langsdon, Milburn, and Yarber19 looked at four female volunteers with sun-damaged facial skin and wrinkles. A phenol peel was applied to the left half of the face and a Sharplan Silktouch Flashscanner CO2 laser was used to treat the right half. The clinical results were similar in both cases, although the laser appears to give better results in areas where the skin is very thick (e.g., the chin). The laser, however, causes more hypopigmentation and complications, and the postpeel period

New peeling technologies have allowed the development of a variety of phenol peels. Easy TCA Pain Control, a lighter peel that contains a small amount of phenol, is a patented formula that deepens the effect of the Easy TCA classic peel while controlling the pain of TCA application. Another phenol formula, Easy Phen Light, is a hybrid peel that contains TCA and phenol (30%). Easy Phen Light is a deep peel that acts at the level of the deep papillary dermis, or superficial reticulary dermis. The depth reached by Easy Phen Light is considered “the interface between the papillary and reticulary dermis.” The results of this peel are usually deeper than those of a papillary dermis TCA peel (e.g., Unideep) and usually more superficial than a deep phenol peel (e.g., Lip & Eyelid Formula). The results of the Easy Phen Light peel vary depending on the quantity of peeling solution allowed to interact with the skin. The best results are obtained by application of the full 3 ml of the peeling solution to the face. Easy Phen Light presents some advantages over Lip & Eyelid Formula (Table 29.1). Deep phenol peels (e.g., Lip & Eyelid Formula) are compared to light phenol peels (e.g., Easy Phen Light) in Table 29.2. Postpeel recommendations for patients are listed in Table  29.3, while general care is shown in Figure  29.14. Figure  29.15 illustrates the clinical case of a patient who presented with photoaging. She had yellowish skin, with many lentigines and one large keratosis on the forehead.

Table 29.1  Comparison of Easy Phen Light and Lip & Eyelid Formula

Type of procedure Pain during application

Pain after application Quality of result

Lip & Eyelid Formula

Easy Phen Light

Ideally should be applied in a surgical setting, respecting every security rule. Can be done without anesthesia when applied as a local peeling (chemical blepharoplasty or cheiloplasty) but needs nerve blocks and neuroleptanalgesia when applied as a full-face procedure. Inflammatory pulsating burning sensation up to 4 a.m. the next day. Pain stops but usually resumes, for several hours only, during the third night. This is the deepest possible peeling: depth 7/7. Best quality results of a photoaging treatment.

Can be done as an office procedure, if every security rule is respected. Is less painful than Lip & Eyelid: many patients describe the pain of Easy Phen Light as more tolerable than the pain induced by Easy TCA. Not painful after peel. Better results than papillary dermis TCA peel (depth 5/7). Results are of a lower quality than with a deep phenol peel (depth 7/7).

246    Textbook of Chemical Peels Table 29.2  Comparison of Deep and Light Phenol Peels Deep phenol peel Full face Peel type Indication

Combination treatment Suitable phototypes Ideal patient Main contraindications

Presentation Quantity needed Peeling depth Prepeel conditioning Pain level during peel Pain after peel Anaesthesia Application duration End point Occlusion Postpeel care if not occluded Remove occlusion Control day 3 Control day 6 Usual downtime Postpeel erythema Desquamation Sun protection How to apply (video) Postpeel care Result

Light phenol peel Local

Full face

Local

Deep phenol: Lip & Eyelid Formula Light phenol: Easy Phen Light Lentigine Important photoaging Eyelids and/or lip-chin Definitive photo aging Not for deep wrinkles Fine wrinkles (not deep Large lentigine Deep wrinkles wrinkles) Pretragal or subglabella Deep rejuvenation Rejuvenation folds “Botulinic toxin” suitable 3 to 8 days before peel I–IV 45–85 years old: deep photo aging, deep wrinkles, little 35–65 years old: deep photo aging, superficial sagging wrinkles, little sagging Active infections, florid herpes, insulin-dependent diabetes, collagen diseases, immunity problems, Ehler Danlos, pregnancy, breast-feeding, cancers, hepatic or renal or respiratory or cardiac insufficiency, recent wounds or scars, hypertrophic scars, history of local radiotherapy, keloids, recent tretinoin use (less than 6 months), use of IMAO, other logical medical contraindications (children, risk of dyschromy, etc.) 3 ml 3 ml 0.15 to 0.40 ml 3 ml 0.15 to 0.40 ml Deep reticular dermis Limit papillary-reticular dermis Blending Bleaching Cream and sun protection 3 weeks before peel in case of hyperpigmentation risk (depends on the patient) Strong (due to large surface) Light, 12 seconds Very light to none +/– hot and pulsatile (inflammatory) up to 3 a.m. the Not painful next day (acetaminophin can be taken) None None or nerve blocks Oral antalgic Nerve blocks + (sensitive patient) (sensitive patient) neuroleptanalgesy None Nerve blocks + oral antalgic Mandatory + 1 hour — + 45 min — Split application Split application Deep gray-white frosting + edema (proteocoagulation) Light gray-white frosting; edema is more important (proteolysis) Occlusion 24 h Occlusion 24 h except eyelids No occlusion No occlusion Occlusion 24 h Specific postpeel mask + Specific postpeel mask + Specific postpeel mask + Yellskreen powder Yellskreen powder Yellskreen powder Day 1, apply Yellskreen Day 1, apply Yellskreen — — Apply Vaseline on the edges of treated areas, to make patient comfortable Apply Vaseline at day 6, on the whole treated area, to unstick dead skin 7–8 days 6 days Depends on how many points 3 weeks to 3 months (shorter if IPLase cream [Skin Tech] Virtually no erythema (if there is: IPLase cream [Skin used) Tech]) Very strong, 1 week Thinner skin layer, 1 week Melablock-HSP, SPF 50: 3 months Melablock-HSP, SPF 30: 1 month Divide the the face into several areas* IPLase to treat rednesses and inflammation, sun protection* Amazing rejuvenation, treats deep wrinkles, Very good rejuvenation, does not treat deep wrinkles tridimensional face-lifting

* See details at www.skintech.info.professionals. Table 29.3  Patient Self-Care General Day 0–1 Day 3 Day 6 Day 7 Days 8–15 After Day 15

Sun protection

Do not scratch; do not moisten, remove, Contact doctor with any questions or doubts. or peel away the yellow powder. At home, apply Yellskreen powder if the Take a painkiller tablet if necessary (afternoon and/or before sleep). treated area becomes wet. See the doctor; he or she will apply Vaseline on the edges of the treated area. See the doctor; he or she will apply Vaseline on the entire treated area to help remove Yellskreen. Makeup is allowed. Protective home care 1 . Cleanse the skin using Skin Tech Cleanser only. 2. Apply IPLase mask 3 times/day; it helps to reduce redness. Specific home care 1 . Cleanse the skin using Skin Tech Cleanser only. 2. Refill dermis: Apply Atrofillin cream or use antioxidants and moisturizer: Nutritive ACE lipoic complex cream. 3. Pigment control: Apply Blending Bleaching Cream morning and evening. Days 15–90: Be careful with sun exposure and use Melablock-HSP, SPF 30 Days 1–15: Avoid any sun exposure and (9 a.m., 12 p.m., 3 p.m.) use Melablock-HSP, SPF 50+ (9 a.m., 12 p.m., 3 p.m.)

Phenol: Choice of peel and combination treatments    247

if PIH risk, give the patient Blending Bleaching 3 x/day 2 weeks before treatment Day 0 Apply: Easy Phen Light, postpeel mask and Yellskreen

– 2 Weeks

Day 3 Check if infection Vaseline on the edges

EPL Day 0

Day 6 Check if infection Vaseline everywhere

3 1

2

Day 7–8 Makeup allowed

Protective Home care

6 4

5

EPL = Easy Phen Light YELLSKREEN: Protective yellow powder INFECTION* : appears as red points around Yellskreen

7

Specific Home care

8 to 15

After day 15 – During 3 months

Skin Tech Cleanser (Cleanse skin) DO NOT PULL AWAY YELLSKREEN Skin is regenerating under the scab Vaseline unsticks Yellskreen

IPLASE (reduces erythema) 3x/d Nutritive Vit ACE lipoic complex Evening Melablock HSP 50

09 am–12 pm, 03 pm

Melablock HSP, SFP 25

09 am–12 pm, 03 pm

BLENDING BLEACHING (Pigment control) 2x/d

EPL

4 to 6 weeks

EPL

Figure 29.14  Postpeel general care.

(a)

(b)

(c)

(d)

Figure 29.15  (a) Before treatment. (b) Topical application of Easy Phen Light, up to gray frosting + 24 hours’ occlusion. (c) On day 5 Vaseline dissolves the bismuth subgallate powder. (d) Final result.

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(a)

(b)

(c)

(d)

Figure 29.16  (a) The cosmetic disadvantages to the use of bismuth subgallate last for a week. (b) The use of bismuth subgallate in another patient. (c) A patient who has opted not to use bismuth subgallate still faces cosmetic disadvantages for a week, in addition to the risk of infection. (d) Another patient who has opted not to use bismuth subgallate.

Figure  29.16 illustrates the options with or without the use of bismuth subgallate. With its use (Figure 29.16a and b), a patient may be unhappy about his or her skin color for a week, but without bismuth subgallate (Figure  29.16c and d), the patient is not only unhappy about the skin appearance for one week, but also is afraid to look at the skin and more at risk for infection. Therefore, the use of bismuth subgallate is recommended.

NOTES 1. The nasolabial folds respond to phenol only if they are light and the skin is thin. 2. The contraindications are described in Chapter 31. 3. For photos, see Chapter 37. 4. TCA, for example: one session of Unideep (a peel to the papillary dermis) or four sessions of Easy TCA (less aggressive). These peels should be combined with a depigmenting cream such as Blending Bleaching Cream.

Phenol: Choice of peel and combination treatments    249 5. Chemical eyelid or lip surgery (see Chapter 36). 6. These disappear after Unideep, a TCA peel to the papillary dermis. 7. Stuzin JM, Baker TJ, Gordon HL. Treatment of photoaging. Clinics in Plastic Surgery. 1993; 20: 9–25. 8. When wrinkles persist, the doctor might also decide on a second period of occlusion. 9. Using sandpaper or a diamond fraise. Microdermabrasion is not recommended here. 10. Atrophic, sallow skin, numerous lentigines and benign tumors, solar/senile keratoses, Hutchinson’s freckle, wrinkles and fine lines, and wrinkles around the mouth and eyes. 11. For example, when the patient presents with severe photoaging and sagging skin at the same time. 12. For photos, see Chapter 37. 13. This refers to a TCA peel to the reticular dermis. A TCA peel to the papillary dermis (e.g., Unideep) is, on the contrary, applied immediately after a surgical lift. 14. Hayes DK, Stambaugh KI. Viability of skin flaps subjected to simultaneous chemical peel with occlusive taping. Laryngoscope. 1989; 99: 1016–19.

15. Hayes DK, Berkland ME, Stambaugh KI. Dermal healing after local skin flaps and chemical peels. Archives of Otolaryngology— Head and Neck Surgery. 1990; 116: 794–7. 16. McKinney P, Zukowski ML, Mossie R. The fourth option: A novel approach to low lip blepharoplasty. Aesthetic Plastic Surgery. 1991; 15: 293–6. 17. McCulloch EG, Langsdon PR, Maloney BP. Chemical Peel with Phenol. In: Roenigk RK, Roenigk HH (Eds.). Dermatologic Surgery, Principles and Practice. 2nd ed. Oxford: Marcel Dekker, 1996: 1147–60. 18. Some attempts at copies can be found on the market. Some of these copies are extremely crude, others tend to break easily, and others are too thick and can be felt through the skin. 19. Langsdon PR, Milburn M, Yarber R. Comparison of the laser and phenol chemical peels produce similar results in facial skin resurfacing. Archives of Otolaryngology—Head and Neck Surgery. 2000; 126: 1195–9.

30 Phenol Indications A phenol peel is the deepest type of peel, the one that gives the most dramatic results but that is also the most dangerous. Its indications are precise and limited to cases that cannot be treated by other peels. If an alpha-hydroxy acid (AHA) or trichloroacetic acid (TCA) peel can solve a skin problem, it will be chosen over a phenol peel without hesitation. The main indication for a phenol peel is severe photoaging.

TREATING WRINKLES: PHENOL PLUS BOTULINUM TOXIN Fine lines, wrinkles, furrows, and folds do not respond to phenol in the same way. Wrinkles and fine lines caused by sun damage are far more responsive to phenol (Figure  30.1) than expression lines or, above all, skin folds due to excess skin.

Deep Wrinkles These can respond very well to a phenol peel (Figure  30.2). Deep cheek wrinkles (Figure 30.3) caused purely by sun damage are one of the best indications for a phenol peel. Expression wrinkles are also an excellent indication, on condition that movement is blocked by botulinum toxin approximately 8 days before the peel. Without this highly effective synergetic combination, kinetic wrinkles will disappear during the first few weeks after the phenol peel but will come back afterward, much to the annoyance of patients.1 “Compression” wrinkles that form during sleep are particularly problematic and difficult to eliminate: they come from an excess of skin combined with loss of elasticity, and form during the night as a result of continuous pressure from the head on the pillow that “chisels” the skin. Filling techniques can be tried but can be disappointing in this indication in the long term. The only real solution is to change unconscious sleeping habits, which is almost impossible. Special pillows have been designed specifically to combat this problem.

Folds and Furrows These usually result from excessive skin laxity. Deep folds and furrows are not a good indication for phenol. They result from intrinsic aging and can sometimes be filled before a phenol peel. There is no need for a long interval between filling and peeling; the two treatments can even be done at the same time if the filler is resorbable.2 Furrows and folds can be filled immediately before the phenol peel. It is easy to understand how the severity of the inflammatory reaction after the phenol peel does not help the implant in the long term, but the clinical results of this combination speak in its favor. Folds and furrows can also be filled after a phenol peel, after the inflammatory erythema has subsided. An injection given too soon after the peel, during the erythematous phase, can easily cause bruising.

Expression Lines Expression lines on the forehead and between the eyebrows and crow’s feet have a natural tendency to recur partially and rapidly, even after a phenol peel. A botulinum toxin injection before the peel prevents expression lines from imprinting themselves on the skin as it renews itself, and this combination is very satisfactory, improving results significantly. The botulinum toxin should be injected 1 week before the peel so that new collagen can be synthesized on an immobile dermis. The injection can also be given 8 days after the phenol peel, if not done beforehand. Injecting botulinum toxin during the postpeel period of erythema and edema increases the risk of the toxin moving as well as the risk of temporary cosmetic complications caused by the toxin. The duration of the toxin’s effect does not seem to change much, however.

Wrinkles around the Mouth and Eyes The chemical blepharoplasty and/or cheiloplasty (labioplasty) technique is described in detail in Chapter 36. Wrinkles on the lower eyelids, drooping upper eyelids, and loss of elasticity are excellent indications for a local application of phenol (Figures 30.4 and 30.5). Wrinkles around the upper and lower lips respond very well to a local application of Lip & Eyelid Formula (Figure 30.6).

Radial Wrinkles on the Upper Eyelids “Radial” wrinkles on the outer canthus of the upper eyelid respond well to localized treatment with phenol using the occlusive technique (Figure 30.7).

Other Wrinkles Other wrinkles, such as cheek wrinkles or forehead wrinkles, are excellent indications for a full-face phenol peel but are usually not treated locally, as not only are the results less obvious than after a full-face peel but also the difference between the treated area and the surrounding skin can be too obvious. This type of local treatment is reserved for very particular cases, when there is no risk of tone and structure differences between the locally treated area and the surrounding skin.

LAXITY AND SKIN ELASTOSIS Thin, elastotic, and distended skin is ideal for a phenol peel (Figure 30.8). Results are better than with a surgical face-lift. On the other hand, a phenol peel, even under the best conditions, cannot completely lift jowls. Although phenol is indicated in many cases of facial sagging, large amounts of excess skin still have to be resected surgically. Surgery does not, however, change the texture of the skin, and applying a phenol peel after surgery rejuvenates skin texture, removing all

Phenol: Indications    251

(a)

(b)

Figure 30.1  Full-face phenol (Lip & Eyelid Formula): (a) before and (b) 30 days after the peel. The combination of botulinum toxin and phenol work together on the forehead, crow’s feet, frown lines, and sometimes wrinkles on the upper lip.

the wrinkles and marks that surgery has no effect on. When the skin is thin, a full-face phenol peel can often produce sufficient retraction to make a surgical face-lift unnecessary. The same applies for upper blepharochalasis: a surgical blepharoplasty is still the best choice in this indication, but excellent results can be achieved with a single application of Lip & Eyelid Formula, and drooping skin can be retracted satisfactorily, as described in Chapter 36. Oddly enough, eyelid retraction is automatically restricted to “normal” tension, and the author has never had any cases of ectropion, entropion, or lagophthalmia.

DYSCHROMIAS We have seen that phenol has a marked effect on dyschromias, and it incapacitates melanocytes, even if it does not destroy them histologically (Figure 30.9). Even if many melanocytes are still physically present in the basal layer, 3 they can no longer produce melanin (partially or completely).

Melasma and Postinflammatory Hyperpigmentation Phenol is a good indication for all types of hyperpigmented lesions: lentigines, pigmented keratoses, chloasma, melasma, freckles, and postinflammatory hyperpigmentation (PIH).4 However, phenol is not the first choice of treatment, as other, less aggressive, peels will do most of the time. Hyperpigmentation problems have to be treated differently depending on how deep they are: epidermal hyperpigmentation can be treated with a more superficial peel than dermal hyperpigmentation, which will only respond to a deeper peel. Phenol may be indicated to treat severe and resistant melasma definitively. Some patches

may recur after a period of lightening. Patients must be warned of this possibility. The problem can largely be avoided by recommending that the patient uses Blending Bleaching Cream5 for several months after the phenol peel. Asken6 has drawn attention to the fact that the distribution of melanosomes is particularly uneven in melasma; a phenol peel may accentuate this uneven pigmentation even more.

Wood’s Lamp It is useful to evaluate the depth of pigmentation: a Wood’s lamp can be used to do this, as shown in Figure 30.10. The worse the pigmentation appears when exposed to the Wood’s light (i.e., the more patchy the skin appears), the more superficial the melanin is and the treatment will soon take effect. Superficial pigmentation does not need to be treated with phenol and can be treated effectively with less aggressive peels.

Asian Skin Light Asian skin is not a contraindication to phenol. Between 1986 and 1992, phenol was applied to 710 light-complexioned Asian patients and proved to be highly effective and very safe to use.7

Freckles Histologically, freckles are characterized by a normal number of melanocytes in the basal layer. The melanocytes are, however, larger and more “dendritic,” and give up their melanosomes more readily to the keratinocytes. Freckles disappear completely and definitively with phenol. A TCA peel to the papillary dermis8 will also get rid of freckles. A local phenol peel is contraindicated on light skin phototypes—which in principle

252    Textbook of Chemical Peels

(a)

(b)

(c)

Figure 30.2  (a) Before full-face phenol. (b) Fifteen days after full-face phenol (Exoderm). Kinetic wrinkles are starting to come back. (c) Thirty days after full-face phenol: the phenol has solved all the skin problems apart from the expression lines, which have come back.

are a good indication for phenol—with freckles, as they will disappear where the phenol has been applied and will persist in the surrounding areas. A combination of local Lip & Eyelid and Unideep (TCA to the papillary dermis) is suitable to avoid this freckle demarcation line.

Lentigo Maligna Lentigo maligna9 is a flat, multicolored, pigmented lesion with an irregular shape that may be precancerous. It has a slow radial growth phase, and its diameter can vary from a few millimeters

to several centimeters. It is usually found on the face, temples, or cheekbones, in patients more than 50 years old. The average age of onset is 65, and the incidence increases with age. Lentigo maligna is formed by melanocyte proliferation that is purely intraepidermal. Histologically, there is an increase in the number of atypical melanocytes in the basal layer of the epidermis. Some of the melanocytes may have multiple nuclei. These atypical melanocytes are found at a distance from the clinical border of the lesion. The epidermis is atrophic and the dermis elastotic. This lesion is, in fact, associated with chronic sun

Phenol: Indications    253

(a)

(b)

Figure 30.3  (a) Sun-damaged cheek skin. (b) Complete restructuring, 30 days after a full-face phenol peel (Lip & Eyelid Formula).

(a)

(b)

Figure 30.4  Rejuvenation of the eyes: (a) before; (b) 30 days after a full-face phenol peel (Lip & Eyelid Formula).

(a)

Figure 30.5  Chemical blepharoplasty (Lip & Eyelid): (a) before; (b) after.

(b)

254    Textbook of Chemical Peels

(a)

(b)

(c)

 

Figure 30.6  Long-term removal of wrinkles around the lips after a phenol peel: (a) before; (b) after 1 year; (c) after 3 years. The contour of the lips has been plumped with an injection of a slow resorbable filler, 1 year after the phenol peel.

(a)

(b)

 

Figure 30.7  (a) Occlusion of localized phenol to treat the radial wrinkles of the outer canthus of the upper eyelids in a 75-year-old Caucasian patient. This treatment should be combined with a botulinum toxin injection (8 days before the peel) and a TCA peel to the papillary dermis (Unideep) in the same session to even out the skin tone of the rest of the face. (b) Three weeks after this combination of treatments, the radial wrinkles have disappeared. There is no visible demarcation line.

exposure over many years, mainly in patients with a light skin phototype. Adnexal spread is not uncommon, and numerous melanophages are found in the dermis. This lesion can, however, degenerate into a superficial melanoma, whose prognosis is good, as, more often than not, it does not produce metastases. When lentigo maligna is diagnosed at the age of 45, the statistical risk of it developing into melanoma is 47% over the lifetime of the patient. When it is diagnosed at the age of 67, the risk of it turning into a malignant melanoma is 22%. In both cases, the 5-year survival rate is 90%. That is why dermatological monitoring and sun protection are usually all that are recommended. If the lesion is extensive, surgical excision and a skin graft are sometimes necessary. The excision must be wide and the excision margin at least 1 cm beyond the clinical border of the lesion. The cure rate is then 91% with a 9% recurrence rate in

4 months. Mohs microsurgery is also widely used. Many other treatments have been studied. Cryotherapy should theoretically produce good results because melanocytes are particularly sensitive to cold, but this treatment has a 50% recurrence rate. 5-Fluorouracil (5-FU), used alone, gives poor results. With carbon dioxide and argon lasers, radiotherapy, and electronbeam therapy, there have been many recurrences. Curettage, dermabrasion, and electrodessication have produced few positive results and a high rate of recurrence. Topical hydroquinone and tretinoin have no effect on the lesion. It is not the author’s intention to suggest that a phenol peel is the ideal treatment for lentigo maligna, but only to say that, unlike the majority of other treatments suggested, the author has never seen a recurrence of flat lentigo maligna after a phenol peel, be it full-face or local (Figure 30.11).

Phenol: Indications    255

(a)

(b)

Figure 30.8  (a, b) Pronounced photoaging, combined with slight sagging, is an excellent indication for a full-face phenol peel.

(a)

(b)

Figure 30.9  Before (a) and after (b) a full-face phenol peel (Lip & Eyelid Formula): a combination of yellow skin, wrinkles, fine lines, and lentigines in a patient who smokes. Thirty days after the peel the erythema is normal. The patient is not wearing any makeup. Botulinum toxin was injected 8 days before the peel (forehead, frown lines, and crow’s feet).

256    Textbook of Chemical Peels

(b)

(a)

 

Figure 30.10  (a) Wood’s lamp. (b) Patient with melasma seen under this light.

(a)

(b)

Figure 30.11  Lentigo maligna combined with severe photoaging: (a) before and (b) after a full-face phenol peel.

KERATOSES

Seborrheic Keratoses

Extensive multiple keratoses (solar or senile) on the entire face should be treated with a full-face peel, whereas isolated keratoses can be treated by other methods (see Chapter 22). According to McCollough and Maloney,10 laser treatment has no advantage over chemical treatment. Vergereau, for his part, published a study confirming the advantage of applying Only Touch TCA over laser, dry ice, or coagulation. Several forms of keratoses can coexist.

Seborrheic keratoses (Figure  30.12) are very common and are found on areas of skin that have been exposed to the sun as well as unexposed areas. The lesions are always benign but can sometimes be difficult to distinguish from malign melanomas. Beyond a certain thickness, the keratotic layer makes them unresponsive to peels, even to phenol. They can be treated by shave excision with a snare and radiofrequency (Ellman unit) immediately before applying the phenol. When treating

Phenol: Indications    257

coagulation along with the superficial layers of the skin. Deeper telangiectasias can become even more deeply embedded in the dermis as the new layer of dermal collagen and elastin form. Therefore, a phenol peel usually brings about an improvement in the appearance of telangiectasias. However, in some cases, the extent of postpeel neovascularization can make them worse or cause new vasodilations to appear. “Raised” telangiectasias may become more visible in patients with thin and transparent skin. Facial telangiectasias can be electrocoagulated immediately before the phenol is applied, while the patient is under nerve-block anesthesia for the peel. An Ellman radiofrequency unit is completely satisfactory in this indication.

XANTHELASMA Figure 30.12  Seborrheic keratosis.

seborrheic keratoses by shave excision without combining it with phenol, a TCA peel to the basal layer or to the papillary dermis can be applied to even out the structure of the skin once it has completely healed.

Actinic Keratoses Actinic (or solar) keratoses11 form mainly on areas of skin that have been exposed to the sun: the face, the pinna of the ear, and the hands, for example. They are tumors that are often precancerous: 10%–20% (25% according to some authors) develop into skin cancer, often of the spinocellular carcinoma variety. Many patients with actinic keratoses or even subclinical epithelioma in situ could benefit from a phenol peel on the face,12 possibly preceded by curettage of the largest lesions. Patients who have been treated with 5-FU are often reluctant to put up with the necrotic appearance of their skin after each treatment. A phenol peel eliminates the actinic keratoses while making the skin look younger overall. Many authors describe very long-term results, if the patient is prepared to change his or her attitude to sun exposure after the peel and, as well as avoiding the sun, is prepared to use SPF 50+ sunblock every day thereafter. In case of recurrence, inadequate results, or the appearance of new lesions, the patient can be treated again 4–6 weeks after the first peel. Patients treated with phenol are at far less risk of developing cancer later.4

Xanthelasmas are permanent and often symmetrical yellowish plaques that appear on the inner canthus of the eyes (Figure 30.13). All four eyelids can be affected by this non-premalignant dermatitis. They can be soft or hard. In 50% of cases, they are associated with hyperlipidemia. Women are affected twice as often as men. Xanthelasmas are formed by a buildup of xanthoma cells: macrophages swollen with free or esterified cholesterol and mainly located in the superficial layers of the reticular dermis. Phenol can therefore reach them (Figure 30.14). Other treatment options include surgical excision, carbon dioxide laser, argon laser, electrocoagulation, and cryotherapy. Dichloroacetic acid has also been used in this indication, dissolving the xanthelasma and healing with minimal scarring.

ACNE AND ACNE SCARS Active acne is not an indication for phenol because of the risk of secondary infection, among other things, and because there are other less aggressive and highly effective treatments (Box 30.1).14 Acne scars15 that are deep, adherent, crater-like, sometimes atrophic, sometimes hypertrophic, and keloid16 are a complex problem, and it is clear that no easy treatment exists to date that can claim to eliminate them completely and definitively. Applying a phenol solution will of course bring about a

SUPERFICIAL CANCERS Phenol necroses the epidermis and part of the dermis and eliminates intraepidermal skin cancers in situ. Carcinomas form from cells in the epidermis. To the author’s knowledge, no scientific article has reported skin cancers being caused by the application of peeling agents. If the literature is to be believed, a phenol peel treatment has the added advantage of lowering the frequency of other precancerous lesions forming and probably other cancers in situ in sun-damaged skin. From a toxicological point of view, topically applied phenol13 is not recognized as a carcinogenic or teratogenic agent. It is still necessary, however, to make a definite diagnosis before applying chemical agents to suspect pigmented lesions.

SUPERFICIAL TELANGIECTASIAS A phenol peel is not used to treat telangiectasias, even though the more superficial ones usually disappear through protein

Figure 30.13  Xanthelasma. (Courtesy of Dr. Munelly, UK.)

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(a)

(b)

(c)

Figure 30.14  (a) Eyelid xanthelasma before a local phenol peel. (b) Five days after the peel: normal erythema. (c) Nine days after the peel, the xanthelasma has gone.

cosmetic improvement, but may well be disappointing to both doctor and patient in some severe cases. The patient in Figure  30.15 is an interesting case from many points of view. A phenol solution (Exoderm) was applied correctly and deeply enough to treat the many acne scars (Figure 30.16). An occlusive dressing was then applied for 24 hours. On examining the skin at the end of occlusion, the scars had improved only very slightly, and an extra coat of phenol was applied to the cheeks after 24 hours, without occlusion this time. On examination after seven days, the results appeared inadequate (Figure  30.15) and another spot application was made without much success. When discussing treatment possibilities for acne scars with a would-be patient, the doctor should be extremely cautious. Skin that is very scarred can, however, be completely renewed, evened out, and smoothed using a combination of

BOX 30.1  Acne Scars Alternative Treatment Acne scars are treated with a very high success rate by using the anterior chemoabrasive technique described in Chapter 21, in association with an Easy TCA peel. • Superficial and medium-depth acne scars receive a single anterior chemoabrasion. • Deep acne scars might need a double anterior chemoabrasion.

treatments such as subcision,17 dermal filling,18 dermabrasion, punch excision, punch elevation, possibly micro skin grafts, or even injections of cultured stem cells or fibroblasts (Isolagen).

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(a)

(b)

Figure 30.15  Acne scars treated with a full-face phenol peel (Exoderm). On the 8th day, there is a distinct improvement in the structure of the skin: wrinkles have disappeared, along with small active acne lesions. However, the improvement in the acne scars remains limited.

(a)

(b)

Figure 30.16  (a) The application of phenol on this patient produced normal skin frosting but did not reach the deeper acne scars, which are still the same color. (b) An extra coat of phenol causes “buff-colored” patches to appear—a sign that the product has reached the maximum depth of penetration.

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Treating severe acne scars therefore requires specific technical “preparation” before applying phenol to allow complete and definitive renewal of the architecture of the skin, as well as to even out the tone of skin that has been damaged by the acne itself and by the treatments given before the phenol peel. It is therefore imperative to cure the acne before treating the consequences and not to forget that taking isotretinoin (Roaccutane) in the year before or after a phenol peel poses a major risk of atypical scarring, often on the cheeks. Results are excellent, however, on more superficial scars: permanent removal of scars, tightening effect on the skin, and overall normalization of skin tone. Some authors19 prefer to treat acne scars with dermabrasion, on condition that the hand guiding the wheel is expert enough to be able to control the depth of skin abrasion precisely and to vary the depth depending on the area and the size of the scars being treated. Dermabrasion may be prescribed as monotherapy or in combination with other techniques (Figure 30.17). The results of microdermabrasion as monotherapy for treating severe acne scars are disappointing.

OTHER SCARS Atrophic Scars Resulting from a Face-Lift A surgical face-lift always leaves scars. If there are no serious complications, these scars are not really visible and patients do not complain. Secondary infections are not common, but they are not rare either, and in some patients the skin surrounding the scar behind the ear becomes necrotic. The scar shown in Figure 30.18 is the result of a secondary infection after a surgical face-lift. Note the central atrophy and

(a)

depigmentation surrounded by a hyperpigmented ring. There is a telangiectasia in the middle of the scar. The patient wanted to have a phenol peel but was refused because of the risk of the facelift scar not healing properly. The telangiectasia can be treated separately, however, and the peripheral PIH, which shows up the central atrophic hypopigmentation, could be treated with a more superficial peel (Easy TCA) combined with a topical depigmenting treatment (Blending Bleaching Cream). The visual impact of the scar would be reduced if the skin tone were evened out. Normal face-lift scars are not usually too unsightly, but some patients want a treatment to soften them or eliminate them. A full-face phenol peel is the best option (Figure 30.19), but a local application of phenol precisely on the scar is also a possibility, in combination with another more superficial peel (to the papillary dermis, the Grenz zone, or the basal layer). Standard scars from an upper blepharoplasty do not seem to respond as well to a phenol peel. Scars on the body are not an indication for phenol.

Traumatic Scars These can be treated with localized application of phenol and a series of Easy TCA peels (Figure 30.20).

Dermabrasion Scars These too can be treated with a local phenol peel combined with Easy TCA (Figure 30.21).

NEVUS Another less well-known indication for a phenol peel is the treatment of generalized verrucous epidermal nevi, a disorder

(b)

Figure 30.17  (a, b) A patient treated with an Exoderm peel (full-face phenol occlusive peel), followed by mechanical dermabrasion (postchemabrasion). (Courtesy of Dr. Y. Fintsi.)

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that can be associated with a certain number of bone, ophthalmic, or neurological malformations. Treatment consists of shave excision of the lesions followed by an application of phenol to the hyperpigmented areas of the face.20 Giant hairy nevi have been treated with phenol: 40% solution, combined with croton oil (0.8%) and hexachlorophene soap. It should be remembered that some nevi fade after a phenol peel and that others, after a period of fading, become hyperpigmented.

OTHER INDICATIONS Dilated Pores Dilated pores are not the best indication for phenol, and the abrasive technique21 combined with Easy TCA seems more effective.

Neurolysis and Chemical Sympathectomies Phenol is sometimes used in paraaortic injections in the semilunar ganglions to achieve neurolysis as an analgesic technique in cases of inoperable cancers (30 ml of a 6% phenol solution can be injected in this indication) (see also Chapter 28). There are descriptions in the literature of the use of phenol in chemical sympathectomies in the treatment of palmar hyperhidrosis, Raynaud’s syndrome, and obliterative arteriopathy.

Urinary Incontinence Figure 30.18  Atrophic scar after a face-lift, resulting from a local secondary infection.

(a)

Phenol has been used in injections beneath the bladder trigone in the treatment of urinary incontinence due to spina bifida (30  ml of 6% phenol). Aqueous solutions of phenol have been injected as a sclerosant in cases of hydrocele.22

(b)

Figure 30.19  (a) A face-lift scar that is not too unsightly. However, the skin tension lines converging on the scar emphasize it. (b) Thirty days after a full-face phenol peel (Lip & Eyelid Formula), without any makeup; the tension lines have gone and the face-lift scar is less visible.

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(a)

(b)

(c)

(d)

Figure 30.20  (a, b) Post-traumatic scar and PIH, 6 years after a road accident. (c) Local application of phenol to the scar. Frosting occurs immediately. An impermeable occlusion will be applied for 24 hours and followed in the standard manner with an application of bismuth subgallate powder. The patient will also have four sessions of Easy TCA peels, at a rate of one peel per week, to produce cloudy white frosting on the hyperpigmentation. Daily depigmenting care is Blending Bleaching Cream. (d) Results after the third Easy TCA peel and one application of localized phenol to the scar between the eyebrows. The edges of the scar are less marked, the base of the scar appears less atrophic, and the skin tone has evened out.

(a)

(b)

Figure 30.21  (a, b) A scar resulting from lip dermabrasion: the upper left half of the lip is still wrinkled because the mechanical dermabrasion was too superficial, whereas the upper right half of the lip is scarred as a result of the dermabrasion being too deep. The patient is seen in an attempt to correct this unsightly scar and a local phenol peel is suggested. Lip & Eyelid solution will be used locally and combined with four Easy TCA peels to even out the results.

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(c)

(d)

Figure 30.21 (Continued)  (c) Frosting on the upper lip after application of Lip & Eyelid solution. The scar reacts with frosting of a different color where the tissue is most fibrous. (d) Three weeks after treatment, the wrinkles on the upper left half of the lip have disappeared. The scar on the upper right half of the lip has softened and evened out, and the color is similar to that of the surrounding skin.

Spasticity and Chemical Neuroablation Publications indicate 5% phenol injections to treat spasticity in pediatrics. The use of chemical neuroablative techniques dropped off rapidly with the arrival of more specific treatments. Injecting neurolytic solutions (e.g., phenol 23 or alcohol solutions) causes nonspecific damage to all the structures that come into contact with these products, namely both motor nerves and sensory nerves, muscles, aponeuroses, and subcutaneous tissue. The effects of chemical neurolysis last several months, and subsequent injections often do not produce the same results. It is now acknowledged that the risk of complications linked with these injections is too high, considering that there are other techniques that are less dangerous, more specific, and more effective. Injecting phenol for the purpose of chemical neurolysis is now only indicated for patients suffering from pain that is unresponsive to any other treatment and whose life expectancy is not longer than 3 months. Recently, there have been reports of phenol being used to produce chemical neurolysis and a “botulinum toxin-like” effect.

Hemorrhoids Martindale reports the use of injections of an oil solution of phenol as a sclerosant for hemorrhoids. The phenol is injected into the tissue surrounding the internal hemorrhoids as a hardening agent and painkiller. 23

Various Phenol has been injected into the soft tissue of the lower back to relieve chronic pain. Phenol ablation is sometimes preferred to surgery to treat ingrown toenails or onychogryphosis.

NOTES 1. See the section on inadequate results in Chapter 37. 2. It is possible, for example, to inject hyaluronic acid immediately before the phenol peel. 3. Given that the exact role of melanocytes is not yet completely understood—although we know that it is not just restricted to

4. 5. 6.

7.

8. 9.

10.

11. 12. 13. 14.

15. 16. 17. 18. 19. 20.

21. 22. 23.

the production of melanin—it is interesting to note that they are still where they should be: in the basal layer of the epidermis. Cortez E. Chemical face peeling. Otolaryngology Clinics of North America. 1990; 23: 947–50. Blending Bleaching Cream should be applied twice a day from the 10th day after Lip & Eyelid, if the skin is ready. Asken S. Unoccluded Baker–Gordon phenol peels—Review and update. Journal of Dermatologic Surgery and Oncology. 1989; 15: 998–1008. Wang Li, Zhao QM, Zhang CU, et al. Clinical observation of face peeling for ephelides and phenol excretion in wine [in Chinese]. Journal of Clinical and Experimental Medicine. 1992; 8: 179–81, 247. Unideep is therefore a good treatment for freckles. Lentigo maligna is also known as Dubreuilh’s melanosis and Hutchinson’s freckle. Different authors consider it either as a malignant melanoma in situ or as a premalignant melanocytic dysplasia. McCulloch EG, Langsdon PR, Maloney BP. Chemical Peel with Phenol. In: Roenigk RK, Roenigk HH (Eds.). Dermatologic Surgery, Principles and Practice. 2nd ed. Oxford: Marcel Dekker, 1996: 1147–60. See also treatment with localized TCA (Only Touch), described in Chapter 22. Usually, phenol peels are not recommended for nonfacial skin. The same applies to AHAs and TCA. Active comedonal, microcystic, papular, or papulopustular acne are good indications for Easy TCA or Easy Phytic. Many dermatological treatments are equally effective. See also Chapter 21. They often result from pustular or nodulocystic acne or acne conglobata. With a Nokor needle or Sulamanidze’s wire scalpel. Ideally combined with subcision. Farrior RT. Dermabrasion in facial surgery. Laryngoscope. 1985; 95: 534–45. Basex J, el-Sayd F, Sans B, et al. Share excision and phenol peeling of generalized verrucous epidermal nevus. Dermatologic Surgery. 1995; 21: 719–22. “Pre-chemabrasion”; see Chapter 21. Martindale W, Reynolds JEF. The Extra Pharmacopoeia. 30th ed. King of Prussia, PA: Rittenhouse Book Distributors, 1993. “Phenolization”: 5%–7% phenol in aqueous solution.

31 Phenol Contraindications, precautions, and safety CONTRAINDICATIONS AND PRECAUTIONS Insulin-Dependent Diabetes Insulin-dependent diabetes is an absolute contraindication to a phenol peel. Diabetes significantly increases the risk of secondary infection; the vascular and/or immune disorders associated with this illness mean that complications are more of a probability than a possibility. Stabilized, non-insulin-dependent type 2 diabetes is not an absolute contraindication to a phenol peel. The doctor must take particular care with these patients to avoid secondary infections.

Florid Herpes Active herpes is an absolute contraindication to a phenol peel. A history of herpes is not a contraindication to phenol, but requires treatment to prevent herpes recurring. For more details, see Chapters 32 and 37.

Other Obvious, Absolute Contraindications Who would dream of doing a phenol peel on a woman who is pregnant or breast-feeding? Or on a patient with an obvious malign lesion? Or a patient recovering from a serious illness? A patient with immunodeficiency?1 On a patient with Ehlers–Danlos syndrome?2 On one with scleroderma or collagen disease? The doctor must use his or her professional skill and experience to rule out any patient who poses an increased risk.

Local Anesthesia with Adrenaline (Epinephrine) Adrenaline (epinephrine) is a cardiac irritant that increases the risk of arrhythmias. For more details, see Chapter 37.

Preexisting Heart Condition A phenol peel should not be performed after myocardial infarction or cardiac decompensation. Unstable angina also rules out a phenol peel, as the stress associated with a peel could trigger an angina attack. No clear link has ever been established between a personal medical history of a heart condition, if currently stabilized, and the incidence of cardiovascular complications during a phenol peel. Apart from arrhythmias, to the best of the author’s knowledge, there is no mention in the literature of any serious heart problems occurring as a complication of a phenol peel.3 Of course, we cannot know for certain that such complications are always reported in scientific journals, even though any serious complications following cosmetic interventions always make headline news in the popular press and on TV. As far as the author knows, however, recently there have been no serious health problems resulting from a phenol peel.

Preexisting Kidney or Liver Disease Liver or kidney deficiency increases the risk of toxicity, as the normal detoxification and elimination processes will not be functioning properly (see Chapter 28).

Patient History Recent Postoperative Wounds As discussed in Chapter 30, a phenol peel can improve the appearance of stabilized surgical scars on the face. Phenol should not be used to treat recent postoperative wounds that have not yet stabilized, however, as there is a significant risk of necrosis. History of Local Radiotherapy In addition to all the structural changes that can follow exposure to ionizing radiation, there is a possibility that the pilosebaceous units might atrophy. This would delay epidermal regeneration and promote the formation of nasty scars. History of Keloid Formation It is better to select a peel whose depth of action does not go beyond the papillary dermis. Use of Isotretinoin Recent use of oral isotretinoin is an absolute contraindication to phenol. For more information, see the section on scarring in Chapter 37. Use of MAO Inhibitors Monoamine oxidase (MAO) inhibitors are contraindications to the use of the majority of analgesics and psychotropic drugs required for patient comfort. This would make a phenol peel almost unbearable for a patient on MAO inhibitors, who is, by definition, psychologically unstable. Refusal or Inability to Wear Makeup Patients who absolutely refuse to wear makeup during the postpeel period are not the best candidates for a phenol peel, as the erythema and potential dyschromias, even if temporary, are best covered up with makeup. Patients at Risk of Dyschromia Patients with dark skin should be warned about the demarcation line between the treated and untreated areas, both with a full-face peel and a localized phenol peel. Patients on estrogen–progesterone hormone-replacement therapy (HRT) need close monitoring for pigmentary changes. McCollough and Maloney4 ask their patients to try to stop HRT or the contraceptive pill for at least the first 6 months after a

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peel. If they cannot stop HRT during this time, they are warned of the risk of pigmentary changes. Patients who work outside most of the time should also be warned of the high risk of hyperpigmentation and of the absolute necessity not only to wear an effective sunblock, but also to change their general attitude to the sun.

Patients with Mental or Behavioral Risks The patient has to understand the peel procedure and the limits of a deep peel. He or she must agree to comply with the strict rules of the procedure before, during, and after the peel. Any cosmetic procedure in which the patient is required to take an active part, and especially a deep peel, is strictly contraindicated for patients who do not have a minimum level of intelligence. The patient has to be capable of understanding and accepting the necessity to wear sunblock and makeup after the peel and be aware of the time needed for the skin to regenerate completely. Squeamish patients will overwhelm the doctor with complaints, worries, questions, and reproaches. It is better to test a patient’s mental and physical resistance by first suggesting a painless peel without complications and then progressing to a medium-depth peel before considering a phenol peel. Individual tolerance can be tested in this way, and the patients themselves gradually learn what a peel is and what it can do for them. Patients should be shown a series of photographs that illustrate what the face looks like day by day during the first week after a peel. Ideally, the patient’s immediate family should also see these photographs. Without this precaution, paranoid patients, friends, and family may not believe it when the doctor tells them that everything is proceeding as normal.

Isolated Patients Being alone is not in itself a contraindication to a phenol peel. The dramatic results of a peel could in fact bring separated couples back together,5 but a few rules are necessary for the patient’s safety. Current phenol formulas allow patients to remain on their feet: the patient can go home almost immediately after a phenol peel. However, phenol peels cause significant edema that can sometimes make it difficult for patients to open their eyes. It is therefore out of the question for a patient who lives alone to go home after the peel. The patient needs help performing daily activities during the first 3 days after the peel. Clinics with hospital beds can keep patients on-site during the first few days or even the first week after a peel.

Neck Peel A phenol peel is better intended for facial skin, and there are other treatments for the rest of the body.6 Specific Precautions If a phenol peel on the neck proves necessary, the following precautions must be taken:

•

Skin Regeneration After an intraepidermal peel, to the basal layer or the Grenz zone, the skin regenerates from leftover islets of keratinocytes. In the case of a deep peel, the skin regenerates from its appendages.7 The face has more pilosebaceous units than the neck, and facial skin regenerates more quickly, with less risk of scarring. Solution to the Problem of Neck Peels The answer is to do a peel to the papillary dermis on the neck and décolletage. This peel can be performed at the same time as the phenol face peel or in the weeks following the face peel.

Sun Exposure Complete sun avoidance and effective sun protection is a must for 2 or even 3 months (see Chapters 2 and 3). Postinflammatory hyperpigmentation (PIH) is not at all uncommon, even after a phenol peel. After the immediate postpeel period, which requires close and almost daily monitoring, it is advisable to see patients again after 15 days, 30 days, and 2 months and to warn them of the need to treat any early signs of hyperpigmentation immediately. It should be noted that PIH frequently resolves itself without treatment after a phenol peel.

Cost One of the drawbacks of a deep peel is the high cost, which means that this technique is not within everyone’s reach. The results that can be achieved offer excellent value for the money, however, and no patient who has benefited from this treatment has ever complained about the cost.

Disorders that May be Aggravated Telangiectasias, seborrheic dermatitis, eczema, acne rosacea, lupus, and other autoimmune disorders are among the forms of dermatitis that may be aggravated by a phenol peel.

SAFETY FACTORS Patient Selection Choosing the right patient is a key safety factor. The few, but strict, indications and contraindications should be taken into account, as well as the results of the essential preliminary clinical checkups.

Local and Systemic Safety The following is a summary of some of the safety rules: •

• • • •

No impermeable dressing should be applied: no occlusion. The solution should be applied sparingly on the skin of the neck. Any movement or friction likely to cause scarring should be avoided after the peel. The phenol must not be allowed to macerate in the folds of the neck. This maceration is equivalent to occlusion.

After treating the face, the solution should be applied extremely slowly on the neck or, preferably, should be postponed until the following day so as not to overload the body’s metabolization and elimination pathways. It is especially important in this case to avoid the toxic complications associated with phenol being applied too rapidly on too large an area.

• •

The product should only be applied to the face. There is a large number of pilosebaceous units in the face that help the epidermis regenerate properly. It is better not to treat the neck with phenol, both for local, dermatological reasons and so as not to increase the absorption area. Using the right formulation and the proper application technique ensures perfect results every time. A “Number 1”

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• • • • • • •

•

• • •

•

phenol formula should not be applied using the application procedure for a “Number 2” formula. In some cases, this precaution is not essential, but in others it is. All contact between phenol and the eyes should be avoided. No phenol should be applied in cases of liver or kidney deficiencies or serious heart disease. Phenol is contraindicated for patients with Ehlers–Danlos syndrome, collagen disease, insulin-dependent diabetes, and active infections (acne, herpes, etc.). Phenol should be applied extremely carefully and in accordance with all the safety rules (equipment, skill). Doctors should inform their professional insurers that they perform this type of peel. The toxicity of phenol is paradoxical, and low-concentration solutions are potentially more toxic than high-concentration solutions. A phenol solution should contain oil to slow down absorption and allow enough time for the liver to detoxify it and the kidney to eliminate it. The solution must be stable, tamed, and adjuvanted. As well as improving the cosmetic results, using occlusion also slows down the absorption rate of phenol and reduces its toxicity. Occlusive masks must be applied carefully to prevent air bubbles or pools of phenol from forming. The doctor must be aware of all the potential complications, watch out for any signs, and be ready to treat them should they occur. Phenol should be applied slowly, in a minimum of 1 hour, on healthy patients with normal liver and kidney function who can be expected to achieve good cosmetic results. The patient should be hydrated, ventilated, and monitored (pulse oximeter and electrocardiogram). A venous drip should be set up beforehand, and if necessary glucose serum can be administered to avoid hypoglycemia. The risks of general anesthesia and products that could irritate the myocardium can be avoided by using local nerve blocks or deep sedation.

PHENOL-RELATED SPECIFIC PROBLEMS Complete Contraindications Contraindications include insulin-dependent diabetes; active herpes; liver, respiratory, cardiac, or kidney insufficiency; active infections; anemia; and logical contraindications such as pregnancy, young age, cardiac problems, cancers, collagen diseases, immune diseases, and so forth. The practitioner is fully responsible for the selection of his or her patient and must be fully informed about any potential contraindication described in the medical literature. A non-limitative list of risks of complications is presented in the next section. Phenol peelings are not usually used for treating skin other than that of the face. Patients with active acne, skin types greater than IV, nasolabial folds or marionette lines, or flaccid necks are not appropriate indications. Phenol peelings can be applied only on a surface equal or less than 4% of the body surface (the face, for example). Phenol is absorbed rapidly by the skin and mucous membranes. It is also eliminated immediately by the lungs and kidneys (in free form, as sulphate or glucuronide conjugates). Detoxification begins immediately in the liver, after application. A perfect aeration and ventilation of the treatment room will prevent respiratory absorption by a patient already under

transcutaneous absorption. Phenol vapors enter the pulmonary circulation very quickly, and it is recommended that the doctor applying the phenol wear a mask to avoid breathing them in. Keeping the patient well hydrated (with a bag of saline solution IV) promotes diuresis and renal elimination of free, conjugated, and oxidized phenol. Some writers recommend intravenous hyperhydration before and during the peeling, and sometimes forced diuresis with an intravenous injection of furosemide. Hyperhydration is not necessary when phenol is applied carefully—that is, in more than an hour, allowing the detoxification mechanisms time to do their job. Phenol toxicity problems, in particular cardiac arrhythmia, are mainly associated with full-face techniques, when application has been too fast and overpassed the detoxification potential of the patient. It is the doctor’s responsibility to accept or refuse to treat a patient, based on a clinical examination and the results of additional tests requested. The doctor must use his or her professional skills and experience to rule out any patient at increased risk.

Risks of Complications Arrhythmia Respect for the 8 points listed below can help to reduce the risks of cardiovascular arrhythmia during a full-face peel or if the doctor has any doubts. 1. Prepeel clinical examination and assessment: electrocardiogram (ECG), blood analysis, liver-kidney function. 2. Slow application, for more than an hour, and a respect the application protocol. 3. Full monitoring (cardioscope, pulse oximeter, tensiometer). 4. Patient in good general health: no infections, no anemia, good respiratory health; obtaining a cardiological/pneumological opinion, if necessary. 5. Good selection of patients (note contraindications). 6. Good hydration, intravenous saline solution. 7. All required resuscitation equipment (verified and in good working order) available, including a defibrilator, to deal with any potential issues.

Insulin-Dependent Diabetes Insulin-dependent diabetes is an absolute contraindication for a phenol peel because of the risk of infection and of vascular and/or immunity problems associated with this illness. Diabetes mellitus type 2, controlled without insulin, is not an absolute contraindication for a phenol peeling. Additional attention must be paid to patients who are non-insulin-dependent diabetics to avoid secondary infections.

Active Herpes Active herpes is an absolute contraindication for a phenol peeling. Any history of herpes requires prevention: on average 3 days before and 4 days after the peeling.

Other Obvious Absolute Contraindications • • • • • •

Pregnancy or breastfeeding. Obvious malignant lesion. Recovering from a grave illness. Recovering from cardiovascular disease or anemia. Depressed immune system. Ehlers-Danlos syndrome.

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• • •

Scleroderma, connective tissue disease, wound healing disorders, and any dermatological condition that might interact with the phenol treatment. Liver, kidney, or respiratory dysfunction; increases the risk of toxicity, as detoxification and elimination are not in proper functioning order. Surgical intervention in the same area: a face-lift contraindicates the application of a full-face phenol peel, though not on the area around the mouth or eyes (unless there has been some surgical intervention in that area).

Local Anesthesia with Epinephrine Epinephrine is a potential heart irritant that increases the risk of arrhythmia. Preexisting Heart Disease The existence of angina pectoris is an exclusion factor. The existence of a heart condition in the patient’s personal history that has been fully stabilized has not been linked with any certainty to the occurrence of cardiovascular complications during phenol peelings. However, in this case it is preferable to avoid peeling. Recent Surgical Wounds The peel can improve the appearance of facial surgical scars that have stabilized. However, recent surgical wounds that have not stabilized should not be treated with phenol due to the major risk of necrosis. History of Local Radiotherapy In addition to all the structural changes that can follow the skin’s exposure to ionizing radiation, the possible atrophy of the sebaceous glands would delay regeneration of the epidermis from these glands and encourage the development of unsightly scars. History of Keloids For these patients, it is preferable to choose a peel that does not go beyond the papillary dermis in depth. Use of Retinoids The recent use of retinoids is an absolute contraindication for phenol. It is recommended to leave a period of at least 6 months between the last use of retinoids (or similar medication) and undergoing a phenol peel. Use of Monoamine Oxidase Inhibitors MAO inhibitors contraindicate the use of the majority of analgesics and psychoactive drugs necessary for the comfort of the patient. It is practically impossible for a patient on MAO inhibitors, who is by definition psychologically unstable, to bear a phenol peeling. Patient Who Cannot or Will Not Wear Makeup Patients who refuse to use any kind of makeup during the postpeel period are not the best candidates for a phenol peel. Without makeup, any persistent erythema would be very noticeable. Patients with Risk of Dyschromia Patients with dark skin (types IV–VI), or patients with lighter skin types who have visible photoaging should be warned that there will be a demarcation line between the treated and untreated areas, and that this happens with a full-face peel as well as a localized phenol peel.

Patients on estrogen or progesterone hormone replacement therapy (HRT) should be monitored closely for pigment changes. It is sometimes recommended that patients stop (HRT) or the contraceptive pill for at least the first 6 months after a peel. Patients who work mostly outdoors should also be warned of the high risk of hyperpigmentation and the absolute necessity not only to wear an effective sunscreen, but also to modify their general “daylight” behavior. Patients with Mental or Behavioral Disorders The patient must be able to understand the process and limitations of a deep peel. He or she must agree to comply with strict rules before, during, and after the peel. Any cosmetic procedure that requires intervention on the part of the patient, and particularly a deep peel, is strictly contraindicated for patients lacking minimum intelligence. The patient must be able to understand and accept the need to wear sunblock and makeup after the peel and be aware of the time needed for the skin to recover completely. Overly sensitive patients are likely to bombard the doctor with complaints, worries, questions, and recriminations. It is preferable to assess the patient’s mental and physical tolerance and propose a less painful peel that does not entail complications before moving on to a deeper peel. Personal tolerance levels can thus be tested, and patients gradually become aware of what a peel involves and what it can do. The patient should be shown a series of photographs illustrating the appearance of the face day by day during the first week following a peel. Ideally, these photos should also be shown to the patient’s immediate family or friends. Without this precaution, paranoid patients or family or friends might not believe the doctor’s assurances that it is all part of the normal process. Isolated Patients Being alone is not in itself a contraindication for a phenol peeling, but patient safety requires a few rules. Today’s phenol peelings are formulated to allow outpatient treatment: the patient can go home soon after the phenol peeling. However, a phenol peeling triggers significant swelling that can sometimes make it difficult for patients to open their eyes during the first night or the day after the peeling. It is therefore out of the question to allow a patient living alone to go home after the peeling. The patient has to be helped in all aspects of daily life for the first three days after the peeling. Clinics with hospital beds can also keep patients on-site for the first few days. Neck Peeling Ideally, a deep phenol peeling (Lip & Eyelid Formula) is intended for facial skin only, and the rest of the body should be treated with other peels. Easy Phen Light or Easy TCA Pain Control can be applied to the neck down to the 7th cervical and collarbone, but not at the same time as the treatment of facial skin, because the surface of absorption would be too large and increase the risk of toxicity. If a phenol peel is considered necessary on the neck, the following points should be observed: • •

The peel on the neck should be performed the day after the facial peel. Do not apply any waterproof or occlusive bandage on the neck.

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• • •

The solution should be applied sparingly to the skin of the neck. Motion and friction after the peel should be avoided, as there is a risk of scarring. Avoid maceration of phenol in the folds of the neck. Such maceration is equivalent to an occlusive bandage.

Skin Regeneration Regeneration comes from the pilo-sebaceous units in the case of a deep peel. The face is more richly endowed with pilosebaceous units than the neck, and regeneration on the face is quicker and carries a lower risk of scarring than a peel performed on nonfacial skin. Sun Exposure Exposure to the sun should be avoided completely, and an effective sunblock (Melablock-HSP 50+ or 30) used for 6 months following the peel. PIH is not uncommon, even after a phenol peel. After the immediate postpeeling period, which requires close and almost daily monitoring, it is advisable to see patients again after 15 days, 30 days, and 2 months, and to warn them of the need to treat the beginning of hyperpigmentation immediately. Conditions That Can Be Aggravated Some skin disorders that can be made worse by a phenol peel are telangiectasias, seborrhoeic dermatitis, eczema, acne rosacea, lupus, and other (auto-)immune diseases. They are contraindicated for a phenol peel. Choice of Patient Choosing the right patient is one of the main rules of safety and involves taking account of the indications, contraindications, and results from a number of essential preliminary clinical tests. A phenol peel should not be applied if there is any doubt or if the hoped-for result is impossible to achieve. Local and Systemic Safety The following list summarizes some of the safety rules to observe when applying a phenol peel. 1. The product should be applied only to the face, where the numerous sebaceous glands allow the epidermis to regenerate better. 2. It is preferable not to treat the neck with phenol for local dermatological reasons and so as not to increase the area of absorption. It is important to determine the lower limit of the treatment on the face. Do not go beyond the area of shadow under the jawbone. 3. The right choice of formula and complying with the technical details of its application can give fully reproducible results. The doctor must not apply a peeling with formula “Number 1” using the application protocol for formula “Number 2.” In some cases, this precaution is not essential, but in others it is. 4. Any risk of contact of the acids, especially phenol, with the eyes should be avoided; in case of contact, flush with saline and consult a specialist.

5. Do not use phenol on patients with liver, lung, or kidney dysfunction; cardiovascular disease; or blood disorder. 6. Do not use phenol on patients suffering from EhlersDanlos syndrome, connective tissue disorder, insulindependent diabetes, or active skin disorders (acne, herpes, lupus, etc.). 7. Great care should be taken, and all the safety rules (regarding equipment and skills) should be observed. 8. Doctors should notify their professional insurers that they perform this type of peeling. 9. The toxicity of phenol is paradoxical: less concentrated solutions have the potential to be more toxic than solutions of a higher concentration, depending on the speed of application and the surface area treated. 10. The phenol solution must be stable. Unstable solution should be discarded. 11. In addition to improving the cosmetic result, applying an occlusive bandage slows down absorption of phenol and can reduce toxicity. The masks must be properly fitted to prevent air from getting trapped, folds from forming, or phenol from pooling. 12. The doctor must be aware of all potential complications, monitor for them, be able to treat them, and have the necessary equipment to deal with them. 13. Phenol should be applied slowly, in at least 1 hour, on patients in good health, with normal liver and kidney function, and who can be expected to have a good esthetic result. 14. Hydrate, ventilate, and monitor (pulse oximeter, car dioscope, tensiometer) the patient. An intravenous drip should be set up beforehand and, if necessary, a glucose solution can be administered to avoid hypoglycemia. 15. A local lidocaine nerve block and/or deep sedation avoid the risks associated with general anesthesia or products that might irritate the myocardium. 16. Do not leave the vial of phenol with the top off: if the vial is open, the solution will evaporate, changing the concentration of the active product with potentially serious consequences. Never handle the bottle of phenol near the patient’s eyes, and generally avoid projection of phenol on the patient or the caregiver.

NOTES 1. Because of the risk of secondary infection, patients with immunodeficiency (e.g., HIV) should be ruled out from a full-face phenol peel, as should patients with hypogammaglobulinemia. 2. See the section on scarring in Chapter 37. 3. Fiatsi Y. Exoderm, a novel, phenol based peeling method resulting in improved safety. American Journal of Cosmetic Surgery. 1997; 14: 49–54. 4. McCulloch EG, Langsdon PR, Maloney BP. Chemical Peel with  Phenol. In: Roenigk RK, Roenigk HH (Eds.). Dermatologic Surgery, Principles and Practice. 2nd ed. Oxford: Dekker, 1996: 1147–60. 5. Doctors should not suggest a peel as the answer to a patient’s personal problems. A peel repairs the skin, not the soul. 6. Vigneron JL. Les peelings en dehors du visage. Journal de Médecine Esthétique et de Chirurgie Dermatologique. 1993; XX(75): 53–6. 7. Rusciani L, Rossi G, Bono R. Les peelings cliniques. Journal de Médecine Esthétique et de Chirurgie Dermatologique. 1993; XIX(78): 75–80.

32 Phenol Prepeel preparation The preparation procedure for a local phenol peel has some aspects in common with those for a full-face phenol peel; however, a local application of phenol is far easier.

EIGHT DAYS BEFORE THE PEEL Photographs Before any treatment, top-quality photographs (TIFF format) should be taken of the patient’s face, profile, and three-quarter profile (Figure 32.1), with and without flash. A flash changes the appearance and color of the skin: dyschromias are less apparent and reliefs are flattened. Pigmentation and relief are more clearly visible on photos taken without flash, especially in natural, low-angled light (Figure 32.2). Any preexisting abnormalities will be recorded to avoid any potential medical and legal problems later. In this way, a “round eye” appearance after surgery, lagophthalmia, or ectropion should be photographed and noted in the file. Nevi and other lesions should be photographed in particular. The whole peel procedure could also be filmed. The patient, preferably accompanied by a member of his or her family, will have seen sequenced photos showing the after-effects of a phenol peel, day by day.

Preparing the Skin Many phenol peel techniques require skin preparation before the peel to ensure that penetration is even and to reduce complications (see Chapter 2). No specific preparation is necessary before Lip & Eyelid Formula.

Botulinum Toxin Botulinum toxin should be injected 1 week before the peel into the patient’s forehead or glabellar wrinkles, crow’s feet, lip wrinkles, or radial wrinkles around the outer canthus of the upper eyelid. Blocking the muscles allows the skin to regenerate more evenly. The results will be of better quality and longer lasting. This is also the ideal moment to shave off any benign skin tumors, remove small sebaceous cysts, and fill any deep furrows.

Medication The patient should be given a prescription for: •

•

A strong analgesic to be taken before the peel to test for tolerance. Acetaminophen plus codeine is usually strong enough and well tolerated. (Beware of patients on monoamine oxidase [MAO] inhibitors: they are contraindicated in combination with many other drugs, including some analgesics or sedatives that have to be used for the patient’s comfort during and after the peel.) A benzodiazepine (e.g., 2 mg lorazepam).

• • • • • •

Aciclovir (or, better, valaciclovir) if the patient has a history of herpes. Sterile white Vaseline for postpeel care. An antipruritic (e.g., promethazine). Domperidone to settle the stomach in case of postpeel nausea. Makeup that matches the patient’s skin color: Couv-rance or Covermark are both well tolerated by patients starting on the 8th day after the procedure. Single-dose carmellose sodium eye drops to be used freely after the phenol peel to alleviate any eye irritation, which is common during the hours following a full-face phenol peel.

Legal Documents The patient should be given the following documents to read and sign: informed consent (Box  32.1), authorization to take and use photographs (Box 32.2), and a general questionnaire on health and coagulation (Box 32.3).

Clinical Examination The patient should be given a full clinical examination and be questioned carefully; the results should be recorded in the patient’s file. The patient should be given a cardiovascular examination before the peel if there is any doubt as to his or her cardiovascular health, or merely as a precaution; the doctor then should obtain the opinion of a specialist to confirm that there is no cardiovascular contraindication to the peel. The patient should be asked to have a biological examination. The results must be checked before the start of the peel. It is essential to check the patient’s blood count1 and liver and kidney function, to make sure there is no bacterial or viral infection, diabetes, or immunodeficiency.

THE NIGHT BEFORE AND MORNING OF THE PEEL The evening before the peel, patients should take lorazepam if they are worried about not getting to sleep. Patients who are very nervous or anxious can take another lorazepam tablet on the morning of the peel, together with 10–20  mg of domperidone.

ONE HOUR BEFORE THE PEEL The patient should arrive at the clinic half an hour to an hour before the peel and should not have eaten for more than 4 hours. •

If the peel is to be done without deep sedation, the patient should immediately be given premedication, as per the doctor’s usual practice: for example, one sublingual tablet of Temesta 2.5  mg (lorazepam) if the patient has not taken any that morning and 15 drops of tilidine (a major

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(a)

(b)

(d)

(c)

(e)

Figure 32.1  (a) Right profile. (b) Three-quarters right. (c) Full face. (d) Three-quarters left. (e) Left profile.

(a)

(b)

Figure 32.2  The same patient during the same consultation (a) without flash and (b) with flash; relief and lip wrinkles are flattened by the effect of the flash. The nasolabial folds, on the other hand, are more clearly visible with flash.

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BOX 32.1  Example of an Informed Consent Form Place and date Mrs./Mr. ––––––––––––––––––––––––– Address: –––––––––––––––––––––––– Date of birth: ––––––––––––––––––––– Tel: ––––––––––––––––––––––––––––– Authorizes Dr. –––––––––––––––––––– to perform on my person/on ––––––––––––––– for whom I am legally responsible. A CHEMICAL PEEL OF THE TYPE ––––––––––––––––––––––––– I declare that I have been properly informed of the details of this treatment, of the composition of the solution that will be applied on my skin, of its immediate effects, of the process of skin recovery, of the postpeel care after treatment, and of the precautions to be taken during the months following the peel. I have also been informed that, because of the variability of individual reactions, it is not possible to be given a precise date when normal activities may be resumed. I have also been informed of the usual risks of local anesthesia, sedation, and the treatment itself, and I accept them. The doctor has informed me of alternative methods of treatment to the above-mentioned chemical peel, and I choose this latter course of treatment with full knowledge of the facts. Should any unforeseen situation or complication arise that requires medical intervention not described in the explanations given beforehand, I authorize the medical team to make any decision that they deem necessary or useful. I have been fully informed of the fact that the doctor cannot guarantee perfect results after the first application, and accept the possibility of having a touch-up. I acknowledge that I have been given valid answers to all my questions, either in the written documentation that I have received written in language I can understand and that I have read carefully, or orally by the doctor during consultations prior to treatment. Date and signature preceded in handwriting by the words “read and approved.” Originally drawn up by the Sociedad Española de Medicina y Cirugía Estética, Barcelona, SEMCC.

BOX 32.2  Example of a Photographic Consent Form Place and date Mrs./Mr. ––––––––––––––––––––––––– Address: ––––––––––––––––––––––––– Date of birth: ––––––––––––––––––––– Tel: ––––––––––––––––––––––––– I authorize Dr. –––––––––––––––––––– to use the photographs taken before and after treatment in: Medical science congresses or conferences Scientific articles or papers to be published in medical reviews Media publications I do not authorize the use of photographs I have checked the points I agree to and deleted the point or points that I do not agree to. This document comes in two copies: one for the patient and one for the doctor. Signature, preceded in handwriting by the words “read and approved.”

•

analgesic) or any other strong analgesic the doctor usually prescribes. It is best to use an analgesic that the patient can tolerate easily. If the peel is to be performed under deep sedation or neuroleptanalgesia, the anesthetist should deal with premedication.

ADVANTAGES OF BENZODIAZEPINE Using benzodiazepine as premedication is very worthwhile. There are four obvious advantages: 1. Anxiety and fear of pain increase the perception of pain. Benzodiazepines play an auxiliary role as an analgesic. 2. Benzodiazepines cause a certain amount of amnesia. More than 2.5 mg of sublingual lorazepam can produce partial

amnesia that lasts for more than 10 hours. Midazolam produces short-term but deep amnesia that makes the patient forget any pain he or she may have felt in the course of the treatment. 3. Benzodiazepines are neurostabilizers that can counteract the initial toxic neurological effects of local anesthetics or phenol. 4. A long-acting benzodiazepine greatly improves patient comfort. It makes the patient feel drowsy, which reduces facial movements and therefore helps keep the postpeel occlusive mask in place. Also, when a patient has taken 2.5 mg of sublingual lorazepam as premedication, he or she will feel much less pain immediately after the peel. A calm patient is a patient who does not complain, does not fidget, does not speak, does not smoke, and does not scratch.

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BOX 32.3  Example of a General Questionnaire and Coagulation Questionnaire Are you taking medication that contains aspirin or an anti-inflammatory? Yes/No Are you currently taking medication to thin the blood? Yes/No Do your gums bleed when you brush your teeth? Yes/No Have you ever had any problems with bleeding: During dental treatment? Yes/No During child birth? Yes/No During surgery? Yes/No Have you ever had blood in your stools? Yes/No Do you bruise easily? Yes/No Do you feel that you bleed a long time when you cut yourself? Yes/No Are your periods abnormally heavy? Yes/No Do you have any other problems with bleeding? Yes/No Do any members of your family have problems with bleeding? Yes/No Are you on any medication at present? Yes/No If yes, which? (give details below) –––––––––––––––––––––––––––––––––––––––––––––––

Figure 32.3  Four different types of occlusive dressing that can be used for occlusive phenol.

Have you ever been treated for heart trouble? Yes/No Do you get palpitations? Yes/No Have you ever had any treatment for the lungs? Yes/No Do you have asthma? Yes/No Have you ever had phlebitis? Yes/No Have you ever had a pulmonary embolism? Yes/No Have you ever had an operation? Yes/No For what? (give details below) ––––––––––––––––––––––––––––––––––––––––––––––– Have you ever had a local anesthetic? Yes/No If you did not tolerate it, what happened? (give details below): ––––––––––––––––––––––––––––––––––––––––––––––– Are you allergic? Yes/No To what? –––––––––––––––––––––––––––––––––––––––––––––––

PREPARING THE OCCLUSIVE MASK Sleek, Micropore, Blenderm, or Leukoflex The occlusive mask applied at the end of the peel will consist of either a single or a double layer, depending on what type of dressing is used. Sleek and Leukoflex2 can be used in a single layer. Leukoflex has an advantage over other brands in being transparent. Micropore can be applied in two layers, or a layer of Blenderm can be applied on top of the first layer of Micropore (Figure 32.3). Whichever dressing is used, the tape should be precut into 3–5 cm strips (Figure 32.4) and placed within easy reach, ready for the occlusive mask (Figure 32.5) to be applied at the end of the peel.

Figure 32.4  The most common technique involves the use of occlusion for 24 hours. An assistant prepares the strips of occlusive tape, cutting them to the right size (about 3–5 cm long) so that the occlusive mask can be applied immediately after the peel.

SETTLING THE PATIENT The patient is placed in a comfortable position to be maintained for over an hour without moving,3 covered in a warm electric blanket or a metallic survival blanket.

Protecting the Eyes A small quantity of sterile ophthalmic Vaseline should be put in the conjunctival cul-de-sacs. The Vaseline deactivates

Figure 32.5  After cutting, the pieces of occlusive dressings are installed on a sterile base, easy to take.

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the phenol and protects the eyes from accidental contact. Terramycin ointment or ophthalmic gentamicin can be used instead of ophthalmic Vaseline. A syringe of physiological saline (200 cm3 at least) should be prepared, to be kept at hand to rinse out the eyes immediately in case of contact with phenol (which is highly unlikely if the peel is applied correctly).

Ventilation Keeping the treatment room properly aired and ventilated4 and fanning the patient’s face help make the patient more comfortable when the doctor goes through the essential phase of carefully cleansing the skin with acetone and alcohol before the peel (Figure 32.6). It is most unpleasant for a patient to have to inhale the fumes when these products are being wiped on the lips, cheeks, and chin. Good ventilation prevents sweating, especially in hot climates: sweat overhydrates the superficial layers of the epidermis, which can lower the concentration of the active products locally and increase skin permeability. Ventilation also creates drafts that will stop the phenol vapors from stagnating in the immediate vicinity of the patient and doctor.

INTRAVENOUS DRIP AND MONITORING Diuresis Osmotic balance across the plasma membrane is regulated by the concentration of proteins (albumin more than globulins). Relative dehydration would increase plasma oncotic pressure and capillary absorption of water and water-soluble molecules. Phenol is soluble in water, and its absorption rate could be accelerated by the slightest dehydration. Intravenous access should always be set up to help diuresis by infusing 1 liter of physiological saline or glucose solution throughout the procedure and for 1 hour afterward. Proper diuresis is usually considered to be an effective way of reducing the toxic effects of phenol by helping renal elimination.

Cardiorespiratory Monitoring Every patient must be properly monitored with pulse oximetry and electrocardiography (ECG). Even if the peel is done by the book and even when the simplest and least aggressive techniques are used, stress can cause vagal reactions, low blood pressure, and tachycardia. Pulse oximeter monitoring can pick up on any drop in oxygen saturation that could accentuate myocardial irritability and cause arrhythmias.

Figure 32.6  Ventilation during a local application of phenol (chemical cheiloplasty; see Chapter 36).

Without monitoring, a simple vagal reaction can go undetected, and if it is not treated correctly, the patient can pass out or even stop breathing. The pulse oximeter is not very effective at detecting arrhythmias; continuous ECG monitoring is essential, even though some authors5 recommend simply checking the heartbeat and vital signs when more than half the face is treated with a phenol peel. This vague recommendation could be taken as encouraging an amateurish approach, while close and continuous monitoring is essential as a simple precaution. Other authors,6 on the other hand, recommend monitoring the patient up to 4 hours after a phenol peel, which seems excessive given the results of toxicological studies showing how quickly phenol is metabolized and detoxified. The blood levels of phenol recorded by Deichmann and Litton during a full-face phenol peel show a rapid drop in plasma values 2 hours after the beginning of the application. The blood level of phenol always remains below toxicity thresholds when phenol is applied slowly. It is therefore not unreasonable to stop monitoring the patient shortly after the occlusive mask has been applied. By then, approximately 2 hours after the beginning of the application, the liver is detoxifying the phenol effectively, the kidneys are eliminating it, and plasma levels are already going down.

Corticosteroids, Atropine, and Antibiotics Some authors recommend injecting 125  mg of solumedrol intravenously before starting a phenol peel: injecting a steroid is said to reduce postpeel edema and to prevent some of the complications described earlier. However, the author has not noticed any advantage from this injection. The aftereffects of the peel are similar with or without corticosteroids. However, it is worth considering an intravenous injection of prednisolone for patients who smoke and do not have any history of gastric ulcers. Smokers have an increased risk of laryngeal edema immediately after a full-face phenol peel. Atropine should not be injected automatically before a full-face phenol peel. It should be at hand, however, to treat any incidence of bradycardia. As a precaution, it has been recommended to inject a broad-spectrum antibiotic before a phenol peel, although this is not essential for the correct peel procedure.

CLEANSING, DEGREASING, AND DISINFECTING Once the patient is settled in comfortably in the dorsal decubitus position and put on a monitor and drip, the doctor can start cleansing the skin either before or after the anesthetist has started injecting the sedatives. The skin is cleansed and disinfected with a mixture of chlorhexidine,7 water, and alcohol in equal parts (5  cm3 of each). It is then rinsed and dried thoroughly. The whole area is carefully degreased with a swab lightly soaked in acetone (or ether) until all traces of oil or skin debris are gone. The skin must be degreased very carefully, applying medium pressure8 and paying special attention to the base of wrinkles and acne scars. The patient should be properly ventilated (with an electric or handheld fan) to avoid inhaling the acetone and alcohol vapors. It takes approximately 10 minutes to cleanse the skin thoroughly. Applying medium pressure helps extract and eliminate some of the residual sebum from the sebaceous glands, but should not take off the stratum corneum: the doctor must be careful not to abrade the skin with the swab before a phenol peel. Acetone has various functions: it degreases, cleans, and helps the phenol penetrate; it also

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breaks down the barrier function of the epidermis.9 This preliminary phase of careful cleansing, disinfecting, and degreasing is essential to get perfect results. Phenol does not penetrate as evenly and as well through skin that has not been properly cleansed.

ASEPSIS It is easier and more precise to hold the phenol-soaked cottontipped applicator with a bare, ungloved hand. It is therefore imperative for the doctor to disinfect his or her hands surgically to avoid infecting the patient’s skin. The assistant who cuts the occlusive dressings and helps the doctor put them in place should also disinfect his or her hands in the same way, for the same reasons. There are two reasons a mask should be worn: first to avoid contaminating the patient’s skin with respiratory bacteria, responsible for many of the cases of secondary infection described, and second to protect the doctor from partially inhaling the phenol vapors. Standing above the phenol vapors for over an hour, the doctor inhales a fair amount of this volatile chemical, which can have unpleasant side effects such as dysgeusia or nausea.

Any person with any kind of infection should be kept away from the treatment room: it is out of the question for a doctor to perform a phenol peel when suffering from a sore throat, tracheitis, impetigo, or a fungal infection on the hands.

NOTES 1. To screen for anemia, an obvious contraindication for a full-face phenol peel. 2. Leukoflex is included in the Lip & Eyelid Formula kit. 3. Particular care must be taken with patients who suffer from lumbago, as they sometimes find it difficult to remain in a dorsal supine position on a hard surface for a prolonged period of time. 4. By mechanical ventilation with an electric fan, air conditioning, fanning by hand, and so forth. 5. Benatar D. Le peeling au phénol. Journal de Médecine Esthétique et de Chirurgie Dermatologique. 1988; XV(60): 319–23. 6. Konior RJ, Kerth JD. Selected approaches to the aging face. Otolaryngology Clinics of North America. 1990; 23: 1083–95. 7. If there is no chlorhexidine, simple disinfection with 70% alcohol is sufficient. 8. The pressure should be equivalent to scratching. 9. Simply applying acetone increases DNA synthesis as well as synthesis of skin lipids.

33 Full-face phenol Nerve block anesthesia and/or sedation PROPERTIES OF COLD Cold has interesting anesthetic properties1 that develop when the surface of the skin reaches 5°C. The temperature of the dermis and hypodermis is then 15°C. Even if the skin can withstand this temperature for a long time without any obvious damage, in practice it is unthinkable to use cryoanesthesia alone for a full-face phenol peel. Limited areas can, however, be cooled before applying the acids2 to make the application more bearable, when no other anesthetic is being used. To do this, the practitioner can use 3M cold packs (Figure  33.1) or surgical gloves filled with an aqueous solution mixed with antifreeze (75% water and 25% antifreeze). The skin must not be frozen, of course. Some doctors use a facial anesthetic technique that consists in injecting Klein solution3 cooled to just a few degrees Celsius under the skin of the face. This painful technique does not produce sufficient surface anesthesia, and changes all the parameters of how the phenol penetrates through the skin. The skin itself, as opposed to the subcutaneous tissue, is only partially anesthetized by this type of injection, and the peel is still very painful. It is also impossible to inject this solution in the lips, nose, eyelids, and so forth. Doctors who use lasers are familiar with the Dermacool device: it generates cooled air that can be directed locally using a handpiece. This cooling device is sometimes used for local applications of phenol.

ANESTHETIC PROPERTIES OF PHENOL Phenol was used widely in the First World War as an antiseptic and a local anesthetic in surgery. Depending on the concentration and the different adjuvants used, phenol can induce coagulation or lysis of the membrane and interstitial proteins, which clinically manifests as the whitening of the skin that occurs when phenol is applied. An application of phenol immediately triggers intense pain followed by local anesthesia that takes effect within about 15 seconds, as the skin whitens. The pain caused by an application of phenol is therefore very brief. The local anesthetic effect lasts for 20–30 minutes, shortly after which the processes of dermal inflammation intensify and trigger a painful, pulsing heat that, depending on the patient’s own perception, is relatively intense. This pain gradually subsides over the following few hours and goes completely once edema sets in and the inflammation has stabilized, usually the morning after the peel. Phenol can therefore be applied on very small surface areas without any anesthetic: it is enough to tell patients that they will feel an intense burning for 15 seconds, immediately after the phenol has been applied on the skin. The patient should be given painkiller tablets to alleviate the postpeel pain, which can last until the following morning. The eyelids and upper lip can be treated with Lip & Eyelid Formula, without any analgesic other than an acetaminophen plus codeine tablet to be taken 1 hour before treatment. Patients

should also be given a clear description of the pain they will feel. By the time they have counted to 15, the pain will have gone.

TYPE OF ANESTHESIA FOR A FULL-FACE PEEL Unlike a local application of phenol, a full-face phenol peel cannot be done without anesthetic.4 There are several different possibilities.

General Anesthesia According to the medical literature, general anesthesia (GA) should not be considered as an additional cardiovascular risk factor during a phenol peel. However, there are other effective techniques that are less complex and also less dangerous.5 Furthermore, pain is at its height in the hours following treatment—a long time after the GA has worn off. GA is a needless source of stress. GA does not make the patient more comfortable or any safer. On the contrary, it adds the inherit risks of GA to those of the phenol peel. GA is not the ideal choice for a full-face phenol peel. It is never indicated for a local phenol peel.

Facial Nerve Blocks Facial nerve blocks (FNBs) are quick and easy to administer, are not painful, and cause few complications in the hands of an experienced doctor. A drop of 2% lidocaine can be injected very superficially with a fine-gauge (32G) needle in precisely the same place that the nerve itself is injected with a 25-gauge needle. It is not possible to see the backflow of blood before injection with a 32G needle.

Allergy to Local Anesthetics Allergies to local anesthetics (LAs) are rare, and the term allergy is often used to describe numerous problems that are more likely an overdose or a vagal reaction. Publications report that the frequency of allergic reactions to LAs is no more than 1% of all the side effects encountered.6 Lidocaine is an amide local anesthetic that does not cause many allergies. Procaine, on the other hand, is an ester-type local anesthetic: when it is injected into the organism, it is transformed into N,N-diethylaminoethanol and para-amino-benzoic acid (PABA) when the ester link that binds these two components of procaine is broken. PABA is a well-known allergen. Methyl para-hydroxybenzoate, whose structure is similar to that of PABA, is also called PAB or methylparaben. It is a preservative that binds, like a hapten, to the immunoglobulin E (IgE) on the surface of mast cells and basophils and may be the cause of the few cases of anaphylactic shock that have been described. Other patients may be allergic to metabisulfite conservative, found in preparations containing adrenaline (epinephrine).

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Figure 33.1  3M cold pack. This photo shows the forehead being cooled prior to a trichloroacetic acid peel to the papillary dermis (Unideep).

Toxicity of Local Anesthetics When nerve fibers depolarize, the sensation of pain is carried from the periphery to the brain. LAs are molecules that stabilize the membranes of excitable cells that are susceptible to depolarization. Their general toxicity is directly linked to this property. In cases of overdose, excessive cell membrane stabilization in the central nervous system (CNS) and the cardiovascular system produces severe side effects. Different factors influence the risk of intoxication with LAs. For example, capillary absorption is more rapid in the face than on the body. The large number of facial blood vessels is one factor that speeds up absorption. Other factors that can cause intoxication include lack of adrenaline, low body weight (600 mg of prilocaine, or four 5 g tubes) should therefore not be applied prior to phenol. Eye contact with EMLA must be avoided, as it causes intense and painful irritation. Using EMLA on the eyelids significantly increases the risk of eye contact. The vehicle for EMLA contains carbomer 934, which only gels in an alkaline environment. The alkalinity of the mixture also contraindicates its use on the eyelid skin. The pH of EMLA cream is 9.4 (the excipient contains sodium hydroxide). Phenol is more active in an acid environment. Impregnating the skin, for 1 hour, with a mixture at pH 9.4 will change the physiological balance of the skin, its acidity, its permeability, and the activity of phenol.

•

A few (unsuccessful) attempts to use EMLA as a topical anesthetic before a trichloroacetic acid (TCA) peel have been published, but the authors reported that they were not impressed by the results.

Therefore, EMLA should not be used as an anesthetic before a phenol peel.

The Best Choice of LA for FNB: Lidocaine without Adrenaline (Epinephrine) Lidocaine without adrenaline is therefore the best choice of LA for FNB before a full-face phenol peel. Lidocaine stabilizes the heartbeat, so accidental intravascular injection of small quantities would not be dangerous during a phenol peel. Its short duration of action is the only drawback, but we have seen above that acetaminophen plus codeine and cold packs are enough to alleviate the postpeel pain in the hours following a phenol peel.

Sedation Plus FNB with Lidocaine without Adrenaline (Epinephrine) This is the best technique for doing a full-face phenol peel. The patient and the doctor are at ease, under the benevolent protection of the anesthetist. Applying phenol to the whole face is completely painless, and the patient does not experience or remember any stress or pain. Sedation and intravenous analgesia make up for the speed of sensory recovery after FNB with lidocaine without adrenaline.

HOW TO APPLY FACIAL NERVE BLOCKS Before a full-face phenol peel, the patient is always put on a drip, electrocardiographic monitoring, pulse oximeter, and blood pressure monitor. The doctor has everything he needs at his disposal in case of any allergic, vagal, or other reactions. Although bupivacaine, ropivacaine, or mepivacaine can be employed for FNB, these products should not be used for the reasons outlined earlier, and anesthesia should consist of FNB with lidocaine without adrenaline and with deep sedation. It takes approximately 15 minutes to do all the nerve blocks needed to anesthetize the whole face. If the skin has not been cleaned and degreased before the FNB, the phenol will not be applied until about half an hour after the beginning of the first nerve block on skin that is already recovering sensation. The FNB should therefore be done after the skin has been cleaned and degreased. The FNB should be done in a clockwise (or anticlockwise) sequence, where the phenol needs to be applied. This has the added advantage of diluting the doses of lidocaine in time and leaving a rest period between each zone. The hepatocytes, which initiate phenol detoxification by glucuronide and sulfate conjugation as soon as it is applied to the skin, benefit from these pauses between the different blocks. Administering the nerve blocks sequentially also helps reduce the risks of systemic phenol toxicity.

Frontal and Upper Eyelid Block A frontal FNB anesthetizes the supraorbital nerve, the supratrochlear nerve, and the external nasal nerve (Figures 33.2 and 33.3). The quantities required to anesthetize the whole of the frontal region are two times 1.5  cm3 of 2% lidocaine without adrenaline. The phenol can be applied to this area soon after the anesthetic has been injected (with onset in around 1 minute).

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(b)

(a)

(c)

Figure 33.2  (a–c) Frontal and upper eyelid block.

(a)

Figure 33.3  (a, b) Frontal and upper eyelid block.

(b)

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(a)

(b)

Figure 33.4  (a, b) External route for blocking the infraorbitary nerve.

Midface and Outer Eyelid Block The midface block anesthetizes the lower eyelid, part of the cheek, part of the nose, and the upper lip. This second phase is done after the phenol has been applied to the frontal area. The infraorbital nerve can be reached from the outside (Figure 33.4) or from inside the mouth. The internal route is preferable, as it is easier to anesthetize the upper lip, the nostrils, and the tip of the nose (Figure 33.5). It is best to anesthetize the upper eyelid from the outside, however. The small, outer eyelid nerve block (0.5 cm3 of lidocaine without adrenaline) anesthetizes the zygomatic and lachrymal branches of the facial nerve (Figures 33.6 and 33.7). Approaching the infraorbital nerve internally allows the injection to “fan out” toward the tip of the nose. This technique provides perfect anesthesia of the upper half-lip, the nostril, and half of the tip of the nose on the same side: 1–1.5 cm3 of 2% lidocaine without adrenaline is injected in each side.

Lateral Regions The temporal region can be anesthetized by blocking the auriculotemporal nerve (Figure 33.8). After raising a skin wheal with a 32G needle just in front of the opening of the ear, a 25-gauge is introduced perpendicularly, immediately in front of the tragus

Figure 33.5  Internal route for blocking the infraorbitary nerve.

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(a)

(b)

Figure 33.6  (a, b) The small, outer eyelid nerve block (0.5 cm3 of lidocaine without adrenaline) anesthetizes the zygomatic and lachrymal branches of the facial nerve.

and behind the mandibular condyle (Figure 33.8). It is essential to do an aspiration test because of the proximity of the superficial temporal vessels. The injection should be done slowly and should not meet with any resistance. Resistance would signal that the injection had gone into the intracapsular joint or

the posterior meniscus of the temporomandibular joint. If the ­peeling is performed under deep sedation, this area is usually not blocked. The lower cheek region now needs to be anesthetized (Figure  33.9). This area is not sensitized by the trigeminal nerve but by the ascending branches of the superficial cervical plexus. Sensitivity in the lower cheek can easily be blocked by injecting a “line” of lidocaine under the skin along the lower jaw (Figure 33.9). The pulse of the facial artery should be palpated over the jaw before injecting the lidocaine. The lidocaine should be injected in a line parallel to the lower jaw, on both sides of the pulse, over a few centimeters. The anesthetist should inject a small dose of analgesic before phenol is applied on this area, which is less sensitive and not protected by a nerve block.

Mental Block

Figure 33.7  The small, outer eyelid nerve block (0.5 cm3 of lidocaine without adrenaline) anesthetizes the zygomatic and lachrymal branches of the facial nerve.

A drop of lidocaine is deposited in the gingival crevice so that the injection will be painless. Bilateral injection of 0.5–1  cm3 of 2% lidocaine without adrenaline (canine teeth or premolar–canine junction) anesthetizes the whole of the chin region (Figures 33.10 and 33.11). The lidocaine should be injected in a line and slightly fanned. The older the patient, the further back the injection has to be, as the mental nerve foramen recedes as the bones age. The nerve block anesthetic is applied gradually to the whole face: the forehead and the right midface region followed by the right lateral region. The chin is then blocked and treated before blocking the left midface region and finally the left lateral region. The lateral regions are often treated without nerve blocks; they are more complex and patients can easily tolerate an application of phenol to the sides of the face thanks to analgesics, sedation, or the anesthetizing effect of the phenol itself.

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(a)

(b)

Figure 33.8  (a, b) Block of the auriculotemporal nerve.

(a)

(b)

Figure 33.9  (a, b) Palpate the pulse of the facial artery over the jaw before injecting the lidocaine. The lidocaine should be injected in a line parallel to the lower jaw, on both sides of the pulse, over a few centimeters.

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This would also increase the risk of toxic peaks of lidocaine in the blood.

EVOLUTION OF PAIN IN THE COURSE OF THE PEEL

Figure 33.10  Mental block: external route.

The quantities of lidocaine injected are thus diluted in time, and peak levels of lidocaine are not reached under these conditions. The phenol must be applied in over 1 hour to the whole face: there is no justification for blocking all the sensory nerves in the face at the same time before starting to apply the phenol.

In the course of a phenol peel performed under FNB with lidocaine without adrenaline and with no analgesic sedation, the patient gradually feels a painful, but bearable, sensation of heat develop in the treated areas. The patient will complain of this unpleasant sensation on the forehead as treatment of the midface region is ending. While the second midface region is being treated, the patient feels this heat in the first midface region. The burning sensation on the forehead is subsiding at this stage of the treatment, and so on and so forth. At the end of the peel, the effect of the FNB has worn off, and if the patient has not been given an analgesic before or during the peel, he or she will usually feel a painful burning sensation over the whole face. This can soon be alleviated with a strong analgesic administered by mouth. It is important to check beforehand that the patient can tolerate the analgesic. At the end of the peel, the barrier function of the epidermis is completely incapacitated, and it is possible to achieve rapid and effective analgesia by applying a few grams (at most) of EMLA on the areas where the burning sensation is most painful and where treatment has finished. EMLA should be used only rarely in this indication. This recommendation does not conflict with the previous recommendations, as the speed with which analgesia is produced in this way means that only very small quantities of EMLA need to be applied to the face after a deep peel—far from toxic plasma levels. Also at this point in the procedure, the interactions between the small quantities of EMLA applied and the quantity of active residual free phenol left on the surface of the skin will be insignificant. The burning sensation on the skin is much improved by applying a cooling mask (Figure 33.12) in the hours or days following the peel.

SEDATION Premedication Thirty to 60 minutes before the peel, a 100 mg tablet of hydroxyzine or intramuscular promethazine is usually sufficient. The patient can also benefit from the rapid sedative properties of sublingual lorazepam, as discussed earlier in this chapter. Atropine should not be injected automatically but should be available in case of bradycardia. Analgesic sedation consists of minimal doses of midazolam or intravenous fentanyl, with blood pressure, cardiac, and pulse oximeter monitoring.

Fentanyl This is a strong, short-acting analgesic. The anesthetist “titrates” the analgesic slowly with repeated intravenous injections of 25 µg when the patient complains about the pain. A total dose of 100 µg can be given safely. Some authors administer 50 µg at a time to reach a maximum dose of 250 µg in 1.5 hours.15

Midazolam Figure 33.11  Mental block: internal route (better).

This is a strong sedative with a short onset of action that can be administered intravenously, rectally, intramuscularly, or sublingually. Midazolam can be used as premedication: 4 or 5 drops are given sublingually as soon as the patient arrives at the clinic.

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(b)

(a)

Figure 33.12  A cooling mask (a) can be put in a freezer and placed on the face as soon as the peel is over (b).

It has a short half-life. The anesthetist injects a dose of 1  mg intravenously under pulse oximeter monitoring, even if the risk of respiratory depression is very rare with a 5 mg dose. In case of overdose, flumazenil (Anexate, which comes in 1 mg/10 ml vials) takes less than 1 minute to compete with the central receptors occupied by the midazolam: 0.2 ml is injected intravenously (15 seconds). Additional doses of 1  ml can be reinjected every minute until the patient regains consciousness. Flumazenil has very low toxicity, and doses of up to 100 mg have been injected intravenously without any signs of overdose. Fintsi16 recommended simple intravenous sedation without FNB: he used promethazine and morphine sulfate (5–15 mg) and titrated the doses until the burning sensation subsided. According to him, nerve block anesthesia is not essential with this procedure, but without the FNB, the patient is in pain during the peel and this makes it uncomfortable for both the patient and the doctor. The patient only has a vague memory of the pain. Asken15 reported on a study by Litton showing an accelerated heartbeat slowing down when deep sedation is combined with nerve block anesthesia.

5. 6.

7. 8. 9.

10. 11. 12. 13.

NOTES 1. Cold temperatures slow nerve conduction. Furthermore, the vasoconstriction caused by cold temperatures slows down the rate at which local anesthetics are absorbed, and their effect is prolonged. 2. This is applicable to all types of peels. 3. Klein solution: a mixture of saline solution, lidocaine, adrenaline (epinephrine), and sodium bicarbonate normally used as a local anesthetic in liposuction procedures. 4. Various phenol peel formulas can be found on the market that boast of the possibilities of doing a full-face peel “without

14.

15.

16.

anesthetic.” In some cases, this means “without general anesthetic” and in others the patient is put on strong analgesics, sedation, and premedication. Some low-dose phenol peels (around 30%) are no more painful than a trichloroacetic acid to the papillary dermis, but they are not much more effective either. There is no such thing as a “small” general anesthetic. Which in no way means that 1% of patients are allergic. In an almost 30-year medical career, the author has never come across a patient who is allergic to lidocaine. Correct treatment consists in filling the blood vessels, raising the legs, and putting the patient on oxygen. It must be remembered that the large number of facial blood vessels speeds up the absorption of LAs. Lalanne B, Baubion O, Sezeur A, Tricot C, Gaudy JH. Circulatory arrest after splanchnic neurolysis with phenol in unrespectable corner of the pancreas. Annales de Chirurgie. 1994; 48(11): 1025–8. Which explains why the effect is not prolonged even when the injected dose is increased. The toxicity of prilocaine is 40% of that of lidocaine. Dose-related action. High doses are toxic. Toxic convulsions occur when blood levels of lidocaine reach 10–22 mg/ml. Juhlin L, Hagglund G, Evers H. Absorption of lidocaine and prilocaine after application of a eutectic mixture of local anesthetic (EMLA) on normal and diseased skin. Acta Dermato Venerologica (Stock). 1989; 69: 18–22. Ferrari FP, Rosario Filho NA, Schmidt AV. Allergy skin testing after topical anesthesia [in Portuguese]. Jornal de Pediatria. 1996; 72(4); 215–20. Asken S. Unoccluded Baker–Gordon phenol peels—Review and update. Journal of Dermatologic Surgery and Oncology. 1989; 15: 998–1008. Fintsi Y. Exoderm, a novel, phenol based peeling method resulting in improved safety. American Journal of Cosmetic Surgery. 1997; 14: 49–54.

34 Full-face phenol Application PREPARING THE SOLUTION Lip & Eyelid Formula

APPLYING THE PEEL SOLUTION Preparing the Applicator

Lip & Eyelid Formula is an oily solution of phenol, often called phenol oil. The solution is ready for use, and no preparation is involved. The flask contains 3 ml of solution, which is the quantity usually needed to treat the whole face or perform approximately 15 eyelid treatments.1 It is easy to plunge the applicator straight into the container and to squeeze it out correctly on the neck of the flask. Lip & Eyelid Formula remains stable for many years.

The applicator should not be too thick, so as not to retain too much of the product and to reduce the risk of drips. The doctor usually prepares it “by hand” before starting application and after disinfecting his or her hands. Ideally, the applicators should be prepared beforehand and left in sterile covers. The simplest and most efficient applicator consists of a wooden skewer approximately 15  cm long with cotton wound uniformly around one end to form a cylinder of even diameter (Figure 34.1). Other types of applicators can be used, depending on the doctor’s experience. Some authors suggest applying phenol with a brush to get a more superficial phenol peel.4 The bristles of the brush must be tested for resistance to phenol. Synthetic brushes can react chemically with the phenol. This reaction denatures them and can change the composition of the phenol solution. A gauze pad should not be used to apply a phenol peel, as the rough texture of this applicator could allow the phenol to penetrate too rapidly; besides, the large quantities of solution that gauze can absorb may cause drips and runs or deposit uneven quantities of the product on the skin too quickly; the most serious complications can only be avoided by slow and even application. The use of cotton balls is not advised, as they are not easy to handle in “delicate” areas such as the eyelids and also because of the risk of runs. Cotton buds are not suitable for large surface areas, as they do not allow even application. In a very localized phenol peel (i.e., eyelids or upper lip), however, phenol is applied with a single cotton bud, as it is more precise and uses up less of the product. The applicator should only be used once. A simpler and more recent application mode for full-face phenol uses a double cotton bud, the same as for Easy TCA application. Cotton buds are soaked in the solution, spun dry on the neck of the peeling solution container, and the solution is applied progressively, using circular movements. Circular movements allow a totally uniform application and reduce irregularities in results. Cotton buds can be changed during the peeling if they are damaged.

Baker–Gordon Solution The four ingredients must be mixed immediately before the peel: Liquid phenol (88%), 3 ml Croton oil, 3 drops Septisol, 8 drops Distilled water, 2 ml Other formulas also have to be prepared immediately before the peel; for more information, see Chapter 25. Mixing the four ingredients of Baker’s solution produces an unstable emulsion rather than a truly stable solution. It is recommended to keep strictly to the formula, as any attempt at customizing it can lead to unexpected results and relatively serious complications. Because the emulsion (soap + oil + phenol + water) is unstable, the solution has to be freshly prepared. It must be shaken continuously throughout the peel to keep the emulsion as homogenous as possible. This essential task should be given to an assistant who will be responsible for holding the container throughout the peel. If the Baker– Gordon solution is left unattended, without being shaken, it separates into different phases. Each of these phases has a specific concentration of phenol and produces different peel depths. If the solution is not shaken continuously, each phase could be applied in turn to the patient’s skin and the results would be uneven: inadequate in some places and too deep in others. This could cause scarring, hypopigmentation, or hyperpigmentation. Not shaking the solution could certainly cause certain postpeel complications.

Litton’s Solution If stored in the right conditions, away from sources of air, light and heat,2 Litton’s solution remains stable for several years. After shaking the flask,3 the quantity required for the peel is drawn out (usually 3–5 ml, depending on how thick the applicator is and how much of the product it retains).

Reminders about Skin Preparation No skin preparation is necessary during the weeks preceding the use of Lip & Eyelid Formula. For other formulas, refer to the recommendations that come with the product. Muscle mobility will have been blocked by an injection of botulinum toxin 8 days before the peel. Small benign tumors, in low numbers, can be treated by shave excision immediately before the peel and will therefore benefit from the local anesthesia induced by the nerve blocks. If there are a large number of tumors, they

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(b)

(c)

Figure 34.1  (a–c) Wooden skewer, approximately 15 cm long, with cotton wound uniformly around one end to form a cylinder of even diameter.

can be excised after frosting is obtained to avoid creating too many rapid transcutaneous penetration routes in the treated areas. Telangiectasias can also be electrocoagulated immediately before the phenol is applied. Urkov applied phenol and cauterized deep wrinkles at the end of the peel, before putting on an occlusive mask.

the jaw, and lifts the skin upward. A surgical skin marker is then used to draw the line marking the lower limits of the peel on the stretched skin: the line should start at the angle of the jaw and go toward the chin. The lower demarcation line will be hidden in the shadow of the jaw (Figure 34.2). If the demarcation line is drawn when the patient is lying down, the peel will

Precautionary Details The flask of peel solution is put on a table, within reach of the doctor, and the top should be easy to take off and replace. Replacing the top on the bottle after each use (the assistant’s responsibility) helps reduce the amount of phenol in the air and prevents accidental spills. For all peels, the doctor should avoid holding any vessel containing a chemical peel solution in his hand for a long time and should not hold the product in front of his face. The air space above the face should not be violated. On the same table, a 20 ml syringe of sterile physiological saline and a row of makeup remover pads (preferably sterile) are placed at hand. The doctor will use some of the pads to spread the phenol evenly on the patient’s skin, and the assistant will use the rest to immediately sponge away any tears, often a unilateral reflex reaction. The patient should be on a drip and monitors; the eyes are protected with ophthalmic Vaseline.

Setting the Lower Limits of the Peel Before treatment, the lower limits of the peel must be established with the patient in a sitting position. The practitioner, with hand outstretched, places four fingers on the edge of the patient’s lower jaw, halfway between the chin and the angle of

Figure 34.2  End of the third phase of treatment, up to the lower demarcation line. The phenol has gradually penetrated through the keratosis that was still visible at the end of the second phase of treatment.

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not go far enough under the jaw, and the line between treated and untreated skin may be more visible.

Application Technique The applicator is soaked in Lip & Eyelid solution and carefully squeezed out on the inside of the neck of the bottle to get rid of any excess and avoid drips. The solution must be applied slowly and conscientiously to each square millimeter of the facial skin. Long Applicator The right hand5 holds the handle of the applicator (see Figure 34.1) between the thumb, index finger, and middle finger. By moving the thumb smoothly over the other two fingers,6 the applicator can be rolled over the skin: it is not a rubbing movement but a rolling one. The applicator is pressed on the skin with the same amount of pressure that would be used for scratching. The solution is applied uniformly and the pressure is firm and even. Double Cotton Buds Two cotton buds can be used as an applicator. Open the vial of Lip & Eyelid Formula solution, soak the double cotton buds in the solution, and spin them dry on the neck of the vial. Lip & Eyelid Formula is applied using small circular motions with a double cotton bud, until uniform gray frosting gradually begins to appear. The pressure on the cotton buds is the same as when scratching the skin. The phenol is applied first in the base of the wrinkles. The doctor’s gloved left hand holds the patient’s skin taut to make it easier to apply the phenol and to help it penetrate. Care should be taken to avoid maceration in the bottom of skin folds. A first layer of phenol is gradually applied to the whole region that has been anesthetized. To even out penetration of the phenol that has just been applied, the area should be immediately gone over again with a makeup remover pad, moved perpendicular to the direction of application. The same cotton pad can be used throughout the peel, as it does not come into contact with the eyes. If the phenol is applied horizontally, the pad should be applied vertically and vice versa. Approximately 3 ml of solution is applied on the skin in successive coats to complete a full-face peel in over an hour. The endpoint is the appearance of an even gray-white frosting (see discussion of frosting later in this chapter). An assistant constantly sponges away any small reflex tears with a cotton ball or makeup remover pad, which is thrown away after each use to make sure that the next time the eyes are wiped, no phenol is carried into them with the tears that have just been sponged away. Any touch-ups can be done the next day on the same patient with the solution left in the bottle. Even though a phenol solution is antiseptic, it is out of the question to use this remaining solution on any other patient. Practitioners often ask how many coats should be applied to the skin. Phenol has reached its peak effect when a gray-white frosting appears. Some patches of buff yellow may also appear when the maximum depth has been reached (Figure  34.5). Pink-white or pure white frosting occurs when the phenol has penetrated the papillary dermis (Figure  34.3), and the results would be comparable to those of a trichloroacetic acid (TCA) peel, which is not as good as can usually be achieved with phenol. Some phenol peel formulas need several coats of solution to achieve this type of frosting. Lip & Eyelid Formula is usually

Figure 34.3  Pure white frosting after an application of Lip & Eyelid Formula to the right midface region. The frosting on the forehead has already faded during the rest period.

applied in a single coat, and only a little patience is required for the pure white frosting to turn gray-white.

Clinical Signs of the Phenol Application Frosting Applying Lip & Eyelid Formula to the skin triggers frosting8 (Figures 34.4–34.6) that is more or less intense and occurs more or less rapidly depending on the skin type. Thinner skin frosts more quickly than thick and oily skin (Figure 34.4). The rapidity of the onset of frosting is not always related to the depth of the phenol peel. As soon as the skin comes into contact with an aqueous9 solution of highly concentrated phenol, protein coagulation is abrupt (pure white frosting) but relatively superficial, and this stops the rest of the phenol applied on the skin from penetrating deeply. With an oily solution, on the other hand, frosting occurs more slowly and the color is less intense, which is a sign of deeper penetration. Rapid frosting is often pure white in color, whereas slower frosting gradually turns into a gray-white color that indicates deeper penetration of the phenol into the skin. The appearance of buff yellow patches signals even deeper penetration (Figure  34.5). It is therefore relatively easy to judge the depth of action of phenol: frosting that remains pure white shows that penetration is not as deep as with frosting that turns gray-white. The appearance of buff yellow patches shows that maximum penetration has been reached. Any additional application of phenol would be associated with a major risk of local complications.

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Figure 34.6  All the colors associated with a phenol peel can be seen here. The chin has pure white frosting just after the phenol has been applied. The cheeks have gray-white frosting after the same amount of phenol as applied on the chin has penetrated more deeply. The forehead is a pink color, where the frosting is fading, with patches of buff yellow. Figure 34.4  Phenol penetrates more slowly on keratoses. A little patience is required.

Edema Severe edema (Figure  34.7) occurs quickly after phenol has been applied. The skin soon feels like cardboard because of the speed and extent of the edema that sets in and stretches it.

Gradual Application Nerve block anesthesia is performed sequentially (anesthetize one nerve trunk and apply phenol on the anesthetized area;

Figure 34.5  When Lip & Eyelid is being applied, a pure frosting appears temporarily. It is soon replaced by gray-white frosting that turns a buff yellow color in places, as can be seen here. The appearance of buff yellow patches is a sign that the phenol has reached maximum penetration.

Figure 34.7  Edema is clearly visible on the left side of the face, which was treated before the right side. The arch of the left eyebrow is more prominent than the right. The left side of the nose is swollen, as well as the upper left half lip. The edema line is very visible on the neck. Edema usually occurs at the same time as the frosting fades. The erythema goes beyond the limits of the edema, which in turn goes beyond the limits of the phenol application.

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anesthetize the next trunk and apply phenol on the corresponding area, etc.). This means dividing the face into as many areas as there are nerve trunks to block. The full-face phenol peel is thus done gradually, area by area. Particular care must be taken not to leave thin strips of skin untreated on the borders between the different areas: this would make the face appear “striped,” as the strip of untreated or undertreated skin would show up clearly between the areas regenerated by the phenol. It is easy to be misled by the erythema and edema that develop approximately 10 minutes after frosting and that extend beyond the area that has been in physical contact with the phenol. When treating the next area, the applicator should be taken slightly into the area of erythema and edema. The different cosmetic units are treated in turn, after each corresponding nerve block. First Phase The first phase covers the forehead, the upper eyelids and a temporal “extension zone” on the right-hand side (Figure 34.8). A frontal block and an outer eyelid block (see Chapter 33) are done on each side of the face. The phenol is applied vigorously in the base of each forehead wrinkle before treating the whole of the forehead. There are three borders to this first phase: the anterior hairline, the eyebrows and upper eyelids, and the temporal region.

Upper Eyelids  After the eyebrows, the doctor treats the upper eyelids (Figure 34.9). Any excess of phenol is avoided by using an applicator that has already been used to treat an adjacent area and that has not just been soaked in phenol. The upper eyelid tarsus does not have to be treated; this would cause severe palpebral edema. When the eyelids are being treated, the assistant should be ready to rinse out the eyes with a syringe of sterile physiological saline (prepared before the peel) and sponge away any reflex tears. Temporal “Extension Zone”  At the border between the frontal and temporal zones, it is worth making the most of the anesthesia that the phenol has induced and that extends about 1 cm beyond the frosting (Figure 34.10). The skin of the forehead is thoroughly anesthetized by the nerve blocks, and the phenol application should extend slightly into the temporal zone. Patients should be warned that they will feel a burning sensation on the temples for 15–20 seconds as the phenol is applied to this unanesthetized

Anterior Hairline  Phenol is not toxic to the pilosebaceous units. To avoid creating a visible demarcation line between the skin of the forehead and the hair, the applicator is taken 1 cm into the anterior hairline. Eyebrows  The phenol is applied to the eyebrows against the lie of the hairs to ensure proper contact with the skin. Its action is not deep enough to remove any permanent makeup.10

Figure 34.9  Day 1 after a localized Lip & Eyelid peel of the four eyelids. The upper eyelid tarsus was not treated with phenol: it does not show any skin change, just edema and severe erythema.

Figure 34.8  A single coat of Lip & Eyelid has just been applied to the first zone. The frosting will turn gray-white without another application.

Figure 34.10  End of first phase of treatment. The white line is the virtual borderline passing through the pupils. The area marked out by the colored line is the temporal “extension zone.”

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area. The temporal regions are treated gradually up to a virtual horizontal line that goes through the center of the pupils. The extension zone includes part of the wrinkles of the crow’s feet. The phenol is first applied at the base of these wrinkles; the left hand stretches the skin to make it easier to reach the base of the wrinkles with the applicator. The peel solution is then applied to the rest of the area. Rest Period The phenol is applied slowly and carefully. A rest period of 10–15 minutes is obligatory after the end of the first phase of treatment. It takes approximately 15 minutes to treat the frontal region, the upper eyelids, and the temporal “extension zone.” Twenty-five minutes after the beginning of the treatment, the second phase can be started. Well-equipped clinics can make the most of the obligatory rest period to treat two patients at the same time, in two different rooms. Second Phase The second phase covers the central right-hand side: lower eyelid, midface region, half of the nasal pyramid, upper half lip, periauricular “extension zone,” earlobe, and tragus (Figure 34.11). Lower Right Eyelid  Phenol is applied up to 1–2  mm from the eyelashes. Nerve blocks do not always succeed in fully or properly anesthetizing the eyelid skin. If intravenous sedation is not being used, patients should be warned that they might feel an intense but brief burning sensation. If the peel is done step by step, very slowly, the anesthesia caused by the phenol itself, together with reduced sensitivity caused by the analgesics, are sufficient to apply phenol on the eyelids without causing much pain. “Vocal” anesthesia is essential in this area, and I usually use the following “trick” for the eyelids: the area is supposedly anesthetized by the nerve blocks; I tell the patient that I

Figure 34.11  The second zone being treated with Lip & Eyelid Formula.

am going to test the depth of the anesthesia and that if it is not deep enough, it can be improved. Inadequate anesthesia is signaled by a burning-type pain that lasts around 15 seconds. The phenol is applied to the eyelid as if it were properly anesthetized. The patient interprets any pain as a simple test and finds it bearable, whereas in fact the phenol has been applied. The phenol itself produces sufficient anesthesia for treatment to continue without pain. As soon as the eyelid frosts, application can be completed painlessly. The practitioner and assistant should watch out for any reflex tears while the eyelids are being treated. Nose and Right Midface Region  The right side of the nasal pyramid is treated, as well as the skin just on the edge of the right nostril. As the face ages, the subcutaneous fat in the nose atrophies, and this, together with degeneration of the ligaments or connecting fibers, leads to loss of tip support. The ­resulting nasal tip ptosis contributes to the classic impression of increased nose size with aging. There are surgical nose lift  techniques as well as a filling technique11 that raises the tip of the nose. A phenol peel is a valuable alternative: the tightened dermis often gives the tip of the nose a clinically visible lift. Upper Right Half Lip  The upper lip requires careful treatment: several coats of Lip & Eyelid should be applied. Before treating the whole lip, the solution is applied vigorously in the base of each wrinkle, the skin of the lips is stretched between two fingers of the gloved left hand to open the wrinkles and make the atrophic base accessible (see Figure 34.12). Dermabrasion can be performed after the phenol has been applied,12 when frosting is still apparent, if the doctor considers that phenol alone is inadequate. The term chemabrasion can be reserved for this technique.13 After 24 hours of occlusion, if some lip wrinkles still persist, either the base of the wrinkles can be treated again with phenol or the whole lip can be treated with chemabrasion. To avoid creating a demarcation line on the vermilion portion of the lip, the phenol must go 1–2  mm into the red lip. If the phenol does not penetrate the red lip, not only will there be a demarcation line, but fine lines will also persist and lipstick can bleed into the white lip area. Aging of the lips, combined with fat and jawbone atrophy, often starts with upper-lip ptosis that hides the teeth. In young subjects (under 30 years old), 1–2  mm of the upper teeth can often be seen

Figure 34.12  As for the upper lip, the base of the wrinkles on the chin should be treated first before applying the phenol to the whole chin area.

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when the face is at rest and the mouth slightly open. Surgical techniques that reduce the height of the upper lip have been described, such as “moustache plastic surgery”:14 a simple technique performed under local anesthetic that requires special care in the suturing to do a perfect edge-to-edge repair of the epidermis. After a phenol peel, the upper white lip retracts slightly, and this is often enough to make the whole area look younger and the upper lip appear plumper without resorting to filling techniques. Pretragal “Extension Zone,” Earlobe, Right Tragus  A pretragal nerve block can be done to anesthetize this area, although it can easily be treated without a nerve block, gradually, up to the virtual line between the corner of the mouth and the earlobe. Lip & Eyelid can be applied more vigorously in the pretragal folds, using the left hand to stretch the skin and expose the base of the wrinkles to the phenol. The earlobe and the tragus must be treated so that the results are even over the whole area (Figure 34.13). If the earlobe and tragus are not treated, an area of sun-damaged skin would be clearly visible on either side of the rejuvenated face. Rest Period After these areas have been treated, the 10- to 15-minute rest period between the two phases can be used to apply the occlusive dressing to the first zone that was treated.15 The third phase starts approximately 50 minutes after the start of the treatment. Third Phase This essential phase of the peel covers the rest of the right-hand side: half chin and lower lip, and the right jaw “extension zone” to the neck (Figure 34.14). Lower Half Lip and Right Half Chin  The corner of the mouth requires careful treatment, as the wrinkles here are deep and

Figure 34.14  End of the third phase of treatment. The occlusive dressing has been placed on the frontal region during the second rest period; the second zone will be covered with an occlusive dressing during the third rest period. The color of the frosting will gradually turn gray-white without any additional application of phenol.

atrophic. The fingers of the left hand stretch the skin to expose the atrophic base of the wrinkles to the phenol. The lower lip is treated in the same way as the upper lip (see earlier discussion). The skin on the chin is often resistant to treatment, and several coats may be required. Acne scars and deep wrinkles are particularly resistant in this area, and sometimes require chemabrasion during the peel itself or after 24 hours of occlusion. Right Jaw “Extension Zone”  There is one small lateral region that has not been treated. This region can be anesthetized with a lateral nerve block (see Chapter 33) or can be treated slowly and gradually. This latter option is always chosen when the full-face peel is performed under deep sedation.

Figure 34.13  End of second phase of treatment. The white line shows the virtual line from the corner of the mouth to the earlobe. The colored line shows the pretragal and cheek “extension zone.” The lower part of the extension zone shows a darker patch of skin that comes from the slow penetration of the phenol through keratoses.

Lower Limits of the Peel and the Neck  Phenol is applied up to the lower limits set before the start of the peel; this forms the demarcation line (Figure 34.15). The skin on the neck is structurally different to that on the face: it has fewer appendages and pilosebaceous units. After a deep peel, the skin regenerates from these appendages. A phenol peel on the neck carries an increased risk of scarring. In addition, the usual postpeel facial edema tends to extend downward to the neck, and if the neck is

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Figure 34.15  End of the third phase of treatment, up to the lower demarcation line. The phenol has gradually penetrated through the keratosis that was still visible at the end of the second phase of treatment.

treated at the same time, then the edema that builds up in this area can make patients feel as if they are suffocating—a very unpleasant sensation. Therefore, the neck could—possibly16— be treated at a different time than the face. The best treatment for a sagging neck is still a surgical lift of the lower half of the face, and a “medium-depth” peel can improve the photoaging: a phenol peel on the neck can be avoided in the majority of cases. Nevertheless, some authors (including Baker) treat the neck at the same time as the face: they apply the product up to the clavicles on the anterior neck and up to the 7th cervical vertebra on the posterior neck. Other authors suggest treating the face on the first day and the neck the day after to reduce the risks of toxicity associated with applying greater quantities of phenol to a larger surface area.

Figure 34.16  Application of Lip & Eyelid: fourth phase.

Rest Period After these areas have been treated, the 10- to 15-minute rest period can be used to apply the occlusive dressing to the second zone that was treated. Fourth Phase This phase of the peel covers the left-hand side: lower eyelid, midface region, half of the nasal pyramid, upper half lip, periauricular extension zone, earlobe, and tragus (Figure 34.16). See the details of application in the second phase. Rest Period After these areas have been treated, the 10- to 15-minute rest period can be used to apply the occlusive dressing to the third zone that was treated. Fifth Phase This phase marks the end of the peel, with an application of phenol to the left-hand side, to half of the chin and the upper half lip, and to the jaw “extension zone” to the neck (Figure 34.17). Finishing the Occlusive Mask The occlusive mask is applied to the rest of the treated areas (for details, see Chapter 35).

Figure 34.17  End of application of the phenol peel. Occlusion dressing is nearly complete.

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general instructions for peels and recommendations of medical literature. Position the patient in accordance with the conventionally accepted rules for phenol peels. Prepare the patient and any equipment that might be necessary to deal with any incidents or complications. Among other things, a source of oxygen, an intravenous infusion, a cardioscope, and oximetry monitoring should be available. A defibrillator and standard resuscitation equipment should be installed before performing potentially arrhythmic peeling, such as phenol peelings. Postpeeling monitoring is also very important, and the doctor should make the necessary arrangements for regular follow-ups with the patient and be available at any time for him or her. A phenol peel is a deep peeling technique with which the doctor must be fully acquainted; the doctor must know how to treat any complications that may arise. Any peel containing phenol should be applied with professionalism and patience. The peel solution should be applied slowly and evenly, using a double cotton bud applicator (ear bud). It is extremely important to wipe the patient’s tears with a new cotton pad each time during a phenol peel. Discard each cotton pad after use. After the treatment, the patient will not be allowed to sleep with the treated skin pressing against any surface (i.e., a pillow), as the treated area might stick to the surface, resulting in infection, scarring, prolonged erythema, and other complications. Figure 34.18  Appearance of the face at the end of the peel (Lip & Eyelid). The mask (here Leukoflex) is complete. The appearance of ptosis of the right eyelid comes from the edema that started earlier in this area as a result of the “phased” application of the peel solution.

At the end of the peel, the edema on the face will not be even, as it will have developed phase by phase (Figure 34.18). The patient may complain of a pulsing heat, which can soon be alleviated by applying a cold pack. New, long-acting analgesics can be used to reduce the pain.

FULL-FACE DEEP PEEL USING LIP & EYELID FORMULA Prepeel Care • • • • •

The patient should apply Skin Tech Blending Bleaching Cream twice a day for 2–3 weeks before the peel. Herpes prevention is necessary if the patient has a history (valacyclovir twice a day, 4 days before up to 4 days after the peel). Give the patient an analgesic (acetaminophen and codeine) 30 minutes before the peel. The patient’s skin should always be disinfected and degreased before application (with a mixture of 50% alcohol and acetone). Place one drop of Vaseline-based ophthalmic ointment in the patient’s eyes (i.e., Terracortril ophtalmicum) before starting the procedure and at its end, to avoid postpeel ocular irritation.

Application Toxicity avoidance should be the major concern when applying a deep phenol peel. The physician must strictly follow the

Lip & Eyelid Formula: Full-Face Application Divide the face into five areas to be treated in succession (Figure 34.19). The end point of the peel is gray frosting, eventually associated with yellowish areas showing the maximum possible depth of any peel. The doctor should use two cotton buds as an applicator. Open the vial of Lip & Eyelid solution, soak the double cotton bud in it, and then spin the buds dry on the neck of the vial. Typically, application on one area lasts 5 minutes, and the rest time before application on the next area is 15 minutes. Therefore, each area will take 20 minutes and the full-face peel will be completed in 100 minutes, avoiding cardiac toxicity problems that have been reported in the literature. No toxicity has been reported after a phenol peel since this recommendation has been used.

2

1

3

5

4

Figure 34.19  Zones of the face for application.

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Lip & Eyelid Formula is applied using small circular motions until uniform gray frosting gradually begins to appear. The pressure on the cotton buds is the same as when scratching the skin. 1. Slowly apply the solution on area 1. Allow time for the frosting to appear, and do not apply too much solution. Wait at least 15 minutes before moving to the next area. 2. Apply the solution in the same way on area 2. Wait at least 15 minutes before moving on to the next area. 3. Apply the solution on area 3. Wait at least 15 minutes before moving to the next area. 4. Apply the solution on area 4. Wait at least 15 minutes before moving on to the next area. 5. Apply the solution on area 5. The peeling is done when the 3 ml of the peeling solution have been applied on the face. Keep any solution that remains for a touch-up on day 1. Apply an occlusive dressing, using the transparent tape from the kit. Ensure that there are no bubbles under the dressing. The occlusive dressing may be applied progressively during the waiting time between areas. For example, the dressing can be applied to area 1 after the application of the solution on area 3. The dressing can be applied to area 2 after the application of the solution on area 2, and so on. Day 1 The occlusive dressing should stay in place for 24 hours. After 24 hours, remove the occlusive dressing and apply one thick coat of Skin Tech postpeel mask and then apply a uniform layer of Yellskreen directly on the postpeel mask cream and leave it to dry. Follow-Up See the patient on the 3rd and 6th days following the peel to monitor progress and ensure that there is no infection. In case of infection, the patient should be given antibiotics (usually orally). On the 3rd day, apply sterile white Vaseline around the edge of the treated areas. On the 6th day, apply sterile white Vaseline on the entire treated area. Vaseline will unstick the Yellskreen powder. The patient usually is allowed to wear makeup on the 8th day if the skin is in acceptable condition. Also see Box 34.1.

BOX 34.1  Bad Practice A few doctors have been known to talk (sometimes proudly) of conduct that has more to do with greed than good medical practice: They try to economize on the volume of peel solution by whatever means they can. Technically, it is of course possible to use less solution for a full-face peel, but this kind of misplaced economy is not recommended. The efficacy of a phenol peel is also dependent on the total quantity of phenol that is applied to the skin and that reaches the dermis.7 If too little phenol is applied, the results will be inadequate, and in the long run it will cost the doctor more to do touchups than to apply the right amount of good-quality solution in the first place. As in many other areas, false economies are not worthwhile.

NOTES 1. With one flask, it is possible to treat the upper or lower eyelids of 15 different patients, as approximately only 0.2 ml is needed to do a peel on two eyelids. 2. The refrigerator is an ideal place to keep peel solutions. 3. For phenol as well as other peel solutions: even if a solution is said to be stable, there is no harm in shaking the bottle to avoid all risk. 4. Though using phenol to do a superficial peel means both patient and doctor taking a pointless risk where less toxic agents are available (TCA, AHA, salicylic acid, etc.). 5. Left-handers will understand that they must reverse the hands used. 6. Making the gesture that universally means “to pay.” 7. Cortez E. Chemical face peeling. Otolaryngology Clinics of North America. 1990; 23: 947–60. 8. As with TCA, the frosting is caused by protein coagulation: the three-dimensional structure of the proteins is changed and they become opaque. The same phenomenon is responsible for egg whites becoming opaque when cooked. 9. This is not the case with Lip & Eyelid Formula, which is, on the contrary, a very oily solution. 10. However, the eyebrows may become a little lighter. 11. Developed by Dr. Sammy Passy, Brazil. 12. It is preferable to apply the phenol before dermabrasion, as the dermabrasion might cause the phenol to penetrate too quickly and too deeply through skin whose permeability has been significantly altered by the abrasion. Also, the diffuse bleeding that accompanies the abrasion would partially neutralize the phenol. 13. Asken S. Unoccluded Baker–Gordon phenol peels—Review and update. Journal of Dermatologic Surgery and Oncology. 1989; 15: 998–1008. 14. Regis-Milano G. La plastie en moustache. XIX° réunion du GRCD, Paris, Janvier 1996: 17–18. 15. Information on the choice and preparation of the occlusive postpeel mask can be found in Chapter 35. 16. See Chapter 31 for more information on the risks of treating the neck with phenol. The increased absorption area also carries an additional and unnecessary risk of toxicity for the patient.

35 Full-face phenol Postpeel care IMMEDIATE POSTPEEL CARE

Occlusive or Open Technique?

The care required for the skin and patient after an application of phenol largely depends on the formulation and the doctor’s experience.

Publications on peels mention different possibilities, and once again it is the formula used that determines the application procedure and the need for an occlusive or open technique. Both techniques have been described as giving excellent results. The following discussion weighs the pros and cons of occlusion.

Hospitalization or Ambulatory Peel? The first question to ask is whether or not the patient should be hospitalized. Some hospitals or cosmetic clinics like to combine a phenol peel with other treatments: surgical or medical, nutritional or cosmetic. In these cases, patients remain in the hospital, clinic, or spa for 8–15 days. Some peels require complex and repeated sessions of postpeel care that can only be given if the patient is hospitalized for 8–10 days. It is clear that hospitalization can contribute to patients’ well-being, making life easier and helping them avoid any contact with the public, friends, or relatives during the first week of—unsightly—skin regeneration. Some practitioners, for fear of the potential toxicity of phenol and the possibility of heart rhythm disorders, prefer to hospitalize patients the first night after the peel until the occlusive mask has been removed 24 hours later. This brief period of hospitalization can also be beneficial to the patient, who can be given a titrated intravenous analgesia until the morning after the peel. Some more recent techniques provide a phenol peel of the same quality and are completely ambulatory. Patients are taken home by a friend or relative. They can leave the clinic a few hours after the end of the phenol application,1 on condition that someone stays with them around the clock for the first 72 hours and that the patient can get to the doctor’s office quickly,2 whenever advised or necessary. The severity of the edema on the first day means that the patient is completely dependent on others, and it is important that any localized treatment can be given rapidly. Cardiac toxicity has been discussed in Chapter 28: in summary, when the peel is performed slowly, in over 1 hour, there is no cardiac toxicity. If phenol is applied too quickly on too large an absorption area, arrhythmias develop rapidly; this occurs while the phenol is being applied. Detoxification starts immediately. A few hours after the peel, the risk of phenolinduced arrhythmia is practically nonexistent, if the liver has been able to detoxify the phenol and the kidneys eliminate it normally (see Chapter 28). Peels of the Baker–Gordon or Litton type are often performed with hospitalization. Exoderm or full-face Lip & Eyelid peels are usually ambulatory procedures. With the exception of some techniques, hospitalization, even if brief, no longer seems to be a necessity but is more of a comfort factor for both patient and doctor. Patients are often happy to be able to go home and be in familiar surroundings.

Ease and Speed The doctor may find it easier and quicker not to apply an occlusive mask, but this is a hasty conclusion: applying an occlusive mask is a simple procedure and can be done in the obligatory rest periods between each treatment area. No time is wasted. Comfort The occlusive mask improves patient comfort: the skin liquefies beneath the mask, and the liquefied integuments do not drip on the skin. The occlusive mask prevents the skin from sticking to clothes or pillows. When an occlusive mask is put in place, the patient can apply a cooling cold pack to alleviate the painful burning sensation, whereas with the open technique, direct contact with the skin is not possible. Safety With an occlusive mask, patients do not have to treat themselves or be treated by anyone else; nothing has to be applied to the skin, which reduces the risk of involuntary errors, allergies, or secondary infections. The mask prevents patients from touching their skin and importing bacteria from their fingers. The mask prevents contact between the skin and any insects or pets carrying infectious agents, which may be dangerous to skin deprived of its immune defenses. With transparent occlusion (Leukoflex), it is possible to evaluate how the treated skin is developing through the mask. When phenol is applied to healthy skin,3 occlusion slows down the absorption rate but does not alter the total quantity absorbed.4 The liver therefore has more time to detoxify the phenol and the kidneys have more time to eliminate it. This increases the peel’s safety margin. Effectiveness Unlike trichloroacetic acid (TCA), whose effect is restricted by occlusion,5 the effectiveness of phenol is improved by maceration. Stegman proved that applying an occlusive mask allows the phenol to penetrate more deeply and improves the cosmetic results.6

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Asken1 reported that it is possible to increase the penetration and effectiveness of phenol with occlusion, but that the same results can be achieved by vigorously cleansing and degreasing before the peel or by repeatedly applying hydrating and covering agents (Vaseline- or silicone-based products) after a phenol peel.7 This principle is applied in certain phenol peel protocols that vaunt the merits of replacing 24-hour postpeel occlusion with continual application of hydrating products. Using cream- or Vaseline-based occlusion rules out any possibility of a touch-up after 24 hours and deprives the doctor of a valuable weapon in his treatment arsenal. Cortez,6 Beeson et al.,8 and McCullough and Maloney9 have achieved excellent results without occlusive masks, although Cortez applies a hydrating cream such as Eucerin that patients must continue applying themselves throughout the first night and up to 5 days after the peel. The face is washed with a showerhead with warm water every 4–5 hours, before each coat of cream is applied. On the 5th day, the Eucerin is replaced with white Vaseline until the 10th day. This procedure, more complicated for the patient, often results in bacterial infections, which is why other authors9,10 have replaced the hydrating cream with an antibiotic cream such as bacitracin. Fungal resistance or secondary infections are not uncommon, however, and there have been reports of allergic reactions to antibiotic creams applied on skin that is completely permeable. McCullough and Maloney9 recommend the following method. During the first day and night, swabs of cold physiological saline are applied. Thereafter, patients rinse their face under the shower four times a day and apply a bacitracin-type antibiotic cream up until at least the 8th day. Healing takes 10–14 days.11 Any scabs are rinsed under the shower and softened by the water, then coated in bacitracin. Another occlusive technique consists in applying sterile white Vaseline after the phenol: the Vaseline provides perfect occlusion but can sometimes be unpleasant, as heat from the skin liquefies it, making it to drip and shifting bits of skin debris. The patient is then led to wiping the skin frequently and the risk of secondary infection is increased. Prolonged use of Vaseline after a peel is known to cause acneiform or milia lesions to appear. Whichever technique is used instead of the occlusive mask, there is an increased risk of infection, injury, allergies, or errors, and a transparent occlusive mask is recommended during the first 24 hours to improve the peel’s effectiveness, reduce the need for patient participation in postpeel care, and lower the risk of secondary infection.

Occlusive Mask Coming Unstuck:  The occlusive mask sometimes comes unstuck around the edges of the mouth, and lip wrinkles are among the most difficult to treat. Lack of maceration where the mask has come unstuck can lead to inadequate results (Figure 35.1). The mask comes unstuck all the more easily if the patient talks, laughs, eats, chews, or smokes. The patient should therefore be kept in complete isolation for the first 24 hours, without social contact, except for close friends or relatives, who should be encouraged to help the patient avoid facial expressions and communicate without talking. Smoking is strictly contraindicated on the first day because of the lip movements required for puffing on a cigarette and inhaling the smoke. These movements soon make the mask come unstuck around the mouth. However, it is preferable to have a patient smoke calmly and cautiously rather than getting irritable and pulling off the mask too soon in his or her haste for a cigarette or frantically and carelessly inhaling smoke in secret. Vigorous chewing motions also make the mask come unstuck. The patient should therefore be put on a carbohydrate and protein liquid diet so as to avoid chewing movements. A feeding cup should be used instead of a straw to avoid sucking movements. If the mask comes unstuck before the end of 24 hours, the patient should substitute the Leukoflex occlusion with Vaseline.

Making the Occlusive Mask The occlusive mask can be put on the lower part of the face with the patient in a half-sitting position at the end of the peel to make it hold better.

How to Use the Occlusive Mask Pitfalls to Avoid The occlusive mask must be perfectly even. The main pitfalls to avoid are as follows. Air Bubbles, Pockets of Maceration, Tension Lines  The presence of air bubbles reduces local maceration and therefore effectiveness. Pockets of maceration increase local penetration of phenol (risk of dyschromia and scarring). Any tension lines in the mask are transferred onto the skin; they can cause unnecessary pressure and may generate areas of necrosis. Some protocols, however, take advantage of the benefits of intentional, well-thought-out, and controlled tension on the skin while it is regenerating: for example, the Molding Mask (Dr. Roige, Spain). Postpeel care in this case includes the precise positioning of support strips.

Figure 35.1  An occlusive mask that has come mostly unstuck after 24 hours; the results of this peel will be inadequate.

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Precut Epstein Mask Epstein recorded the facial measurements of 24 patients; from there, he determined the average size and designed an adhesive mask that he considers ideal and that includes 10 pieces of precut, standard-sized Steridrape.12 This first occlusive layer is covered with a second layer of adhesive tape. The Steridrape is thin, very adhesive, and completely impermeable, and is perfectly suited to the skin. It is quick to put on, as it only consists of 10 pieces and is easy to adapt to faces that are especially wide or narrow. Classic Mask: Waterproof Tape Choice and preparation of these tapes are discussed in Chapter 32. At the end of the peel, the doctor has several rows of precut strips that can be picked up with the fingertips. They are placed gradually on the skin, with several millimeters of overlap between them, as on a tiled roof. Only one layer of Sleek is necessary. Garcia (Spain) has suggested replacing Sleek with a first layer of Micropore, over which a second layer of Blenderm is applied. Santos (Brazil) uses a double layer of Micropore. The author of this book recommends using Leukoflex, an impermeable and transparent dressing, which is applied in a single layer and through which the skin can be seen on the first day. Specific Areas The anterior hairline is a special area. A first strip of Leukoflex is placed directly on the patient’s skin, at the edge of the hairline. Any hair sticking out over this edge should be cut off so that it does not get pulled out when the mask is removed 24 hours later. A hairnet is placed on the patient’s hair. An impermeable or plastic shower cap should not be used, as it holds the sweat on the scalp and makes the occlusion very uncomfortable for the patient. The (loose) elastic edge of the hairnet is positioned on the first strip of Leukoflex. A second layer of Leukoflex holds the elastic of the hairnet in place; the net thus forms an integral part of the occlusive mask and can be used to pull off the whole dressing smoothly and painlessly when the time comes to remove the mask. A simple gauze pad can be used instead of a hairnet (Figure  35.2). The gauze should be cut close enough to the dressing for the patient to be able to brush or comb the hair, and at the same time there must be enough gauze to hold onto to remove the occlusive mask later. Around the eyes, the occlusion should completely cover the eyebrows but leave enough room for the eyes to open normally (Figure 35.3). The eyelids, where occlusive dressing is not used, should be coated

Figure 35.2  Close-up of the top of the occlusive mask, near the anterior hairline. The sterile gauze included in the mask serves as a “handle” for removing the occlusion after 24 hours.

Figure 35.3  Close view of the occlusive mask in the eye area. Eyebrows are covered but eyelids are not.

in ophthalmic antibiotic ointment or sterile Vaseline. The nose must be properly covered—several thin strips of occlusive dressing are needed to do this. The area underneath the jaw, treated up to the preset limits, should only be partially occluded. Partial occlusion of the area under the jaw serves to create an area of feathering that ends on the demarcation line on the neck. The earlobes should not be occluded.

Medical Postpeel Treatment A drop of artificial tears should be placed in the patient’s eyes at the end of the peel and several times a day over the following few days to reduce eye irritation, common after a phenol peel. An ophthalmic antibiotic cream should be applied to the eyelids. The patient must eat and drink as soon as possible after the peel to enhance elimination of the phenol. A sedative is recommended to reduce anxiety, which can amplify the feeling of pain: lorazepam (2.5 mg) is highly indicated and well tolerated by patients. Medication to regulate gastric emptying (domperidone) can be administered intramuscularly or orally before the patient leaves to prevent any nausea in the first few hours after the peel. In patients with a history of herpes labialis, antiviral prevention should be continued. Patients should be given a telephone number or other means of communication so that they can contact the doctor at any given moment. They should also have a strong analgesic at hand: acetaminophen plus codeine is an effective option and alleviates the pain during the first few days.13 Applying cold packs can also alleviate the sensation of heat after the peel.

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Figure 35.4  The same patient as in Figure 35.3: appearance of the face after 24 hours of occlusion (Lip & Eyelid Formula).

POSTPEEL CARE AFTER 24 HOURS After 24 hours, the occlusion has reached its full effect (Figure 35.4). Maceration is finished and the superficial layers of the skin have been liquefied. It is not necessary for the occlusion to be kept on any longer, as after 24 hours the skin has absorbed all the phenol and the risk of infection increases proportionally with the duration of the occlusion.

Removing the Occlusive Mask A phenol peel causes a liquid to form that unsticks and gradually lifts the occlusive mask during the first 24 hours, which means that it is often easy and relatively painless to remove, though this is not always the case. Removing the occlusive mask can certainly be painful (though only briefly) if the mask is “pulled off” rather than pulled down. When the mask is made correctly, the first few centimeters are left loose on the anterior hairline. It is easy to take hold of the mask here and to pull it down hard, removing it in one swift movement. The patient might cry out at this point, but it is more from surprise than from pain. The patients who find the first 24 hours the most painful are also the ones who find it more difficult to bear the occlusive mask being pulled off: they have a lower pain threshold and can be given a strong analgesic or sublingual midazolam 30 minutes before the mask is removed. Some practitioners suggest (needlessly, in the author’s opinion) removing the mask under anesthetic or sedation, which increases the overall risks and the cost for the patient.

Figure 35.5  Appearance of the face after the occlusion has been removed after 24 hours (Lip & Eyelid Formula).

Appearance of the Face Underneath the mask, the skin is coated in a thick liquid14 with a distinctive smell; this liquid results from the liquefied epidermal layers mixed with inflammatory lymph (Figure 35.5). Good epidermal liquefaction seems to make for a good prognosis, although the final results will not necessarily be proportional to the amount of liquid found beneath the occlusion. After removing the mask, the face is very swollen and looks severely burnt, but the patient does not feel much pain.15 The skin appears crumpled in places, as the edema develops ­rapidly beneath the rigid mask and the skin cannot stretch. This c­ rumpled appearance soon disappears. The residual liquid is wiped from the rest of the face with a sterile cotton pad.

Touch-Ups When the mask is removed, wrinkles and marks should have disappeared completely. Any persistent marks or wrinkles can be touched up immediately after the mask has been removed (Figure  35.6) by applying more Lip & Eyelid solution in the

Figure 35.6  Immediate touch-up of the upper lip and chin after the occlusive mask has been removed after 24 hours.

Full-face phenol: Postpeel care    299

base of the wrinkles or on any resistant marks. Wrinkles on the upper lips are usually the most resistant. Small touch-ups do not require anesthesia: the pain does not last long, as the phenol has produced neurolysis of the sensory nerves. Patients should just be warned that they might feel a brief burning sensation, and the undertreated areas should be treated again slowly. More extensive touch-ups (e.g., the whole midface region) might require short-term nerve block anesthesia in sensitive areas. After 24 hours of occlusion, persistent wrinkles on the upper lip can be treated with chemabrasion: Lip & Eyelid solution is again applied to the whole of the lip, with special emphasis on the base of the wrinkles. Frosting occurs relatively quickly. When the frosting has stabilized, the skin can be abraded with a diamond fraise or sandpaper on the frosting itself. The doctor then decides whether to reapply the occlusive dressing; the duration of occlusion depends on the results achieved with the chemabrasion: if the results are still no better than after the first treatment, the “secondary” occlusion should be left on longer. The skin now needs to be protected and regeneration encouraged.

Bismuth Subgallate Mask or Antibiotic Cream? The advantages of moist or closed occlusive dressings have been extolled since ancient times. Ayurvedic doctors, the Egyptians, the Chinese, and the Greeks all maintained that a closed dressing, often coated in honey, enhanced wound healing. At the beginning of the 20th century, doctors who treated burns with gauze pads soaked in picric acid knew and made the most of the virtues of healing “under a scab.” Thomas Bayton (1797) was the first to rediscover the benefits of occlusion in treating venous ulcers after centuries of medical obscurantism. The latest studies confirm that exposing a wound to the air slows down healing and that occlusion accelerates healing and reduces the risk of infection and pain. The term moist technique could lead to some confusion. A moist technique does not involve applying dressings soaked in physiological saline, for example. The presence of textile

(a)

or skin debris can actually cause infection and delay wound healing. Nor does a moist technique involve using antibiotic creams. What is referred to as a moist technique is actually any procedure that allows the skin to regenerate in conditions that are close to the skin’s physiologically moist environment. Postpeel regeneration is radically different from the regeneration that follows mechanical abrasion or ablative laser treatment. Unlike ablative laser treatment or dermabrasion, a peel does not physically remove the skin, even though it devitalizes it completely. The skin can be considered as the base of a “moist” dressing, even though using powder makes it appear rather dry (Figure  35.7). Sprinkling powder on skin that has been devitalized by phenol but that still serves as a protective layer creates the ideal conditions for rapid skin regeneration without infection.16 The type of powder that can be used is discussed later in this chapter. One of the advantages of using a powder mask is that the patient does not have to treat the skin at all. This reduces the risk of secondary infection, errors, or allergies, and also means that the new epidermis, which is in the horizontal growth phase, will not be pulled away by the constant cleansing of the skin that goes hand in hand with the use of antibiotic creams. As the skin begins to regenerate, the keratinocytes are not yet anchored by desmosomes and the dermal papillae have not yet formed. This new, growing epidermis is an important source of cells with a great potential for regeneration and should not be removed by untimely cleansing. Sprinkling ­bismuth subgallate on what remains of the skin after removing the 24-hour occlusive mask anchors the dead cells in a sort of membrane and actually forms a kind of natural dressing that is dry on the outside but physiologically moist on the inside. There is often discussion about the best postpeel care (Figure 35.8). Occlusive dressings often have been disparaged for fear of secondary infection that could delay healing. A phenol peel has one big advantage over laser or abrasion in that phenol is a powerful disinfectant in vivo even more than in vitro. Infections are less common with phenol than with TCA, for example. Sprinkling on an antiseptic is preferable to applying an antibiotic cream. Indeed, antiseptics discourage the growth

(b)

Figure 35.7  (a) On the 7th day after a Lip & Eyelid peel, the film formed by the necrosed skin, the bismuth subgallate, or Vaseline does not stick to the skin. (b) It comes off in one piece like an occlusive dressing under which the skin receives moisture.

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(a)

(b)

Figure 35.8  (a) A patient wearing bismuth subgallate powder after an Easy Phen Light peeling (Skin Tech): she is not happy to have to live with this yellowish face color during 8 days. (b) A patient wearing no bismuth subgallate powder, after an Easy Phen Light peeling. She is not happy to see her face and she is afraid to see her skin. Moreover, the risk of infection is much higher in her case. Ultimately, it is better to have a patient simply unhappy than a patient unhappy, afraid, and at risk.

of any microorganisms in the wound, whereas antibiotics only work against certain strains of bacteria. Bacterial resistance to antiseptics is much lower than it is to antibiotics. There have been no reports of cross-resistance to different antiseptics, whereas this phenomenon has been widely reported with antibiotics. Allergies are far more common with antibiotics than with antiseptics. The presence of a large amount of exudate can, on the other hand, render many antiseptics ineffective, but a phenol peel does not generate much liquid, and any excess inflammatory liquid is soaked up when the skin is powdered. It is therefore far more advantageous to use a powder mask than antibiotic creams. When this author has used antibiotic creams on patients, secondary infections have been very common, while this has rarely been the case with a mask of bismuth subgallate powder. Several different powders for peels are described in the literature. Thymol Thymol (thymic acid) is extracted from essence of thyme. It is 4 times more bactericidal than phenol and 10 times less toxic. Thymol iodide is used on burns in the same way as iodoform but has the advantage of not being absorbed and not having any odor. It is less irritating on wounds and mucous membranes than dithymol diiodide or aristol. Thymol iodide powder, an

antiseptic that is used often after a phenol peel, physically alters the selective permeability of plasma membranes. It is nevertheless a protoplasmic poison that denatures enzyme proteins and is also an allergen. Bismuth Subnitrate Bismuth subnitrate is an inert powder that has healing and absorbent properties. It sticks well to the skin. It is not very toxic by the systemic route, but can be more so by the local route as a result of combining with proteins. Gallic Acid–Iodoform Gallic acid was used in the past to treat wounds, as was iodoform. Iodoform was discovered in 1822 and used by Hebra for its local anesthetic action—in the form of an iodoform gauze— on burns. Bismuth Gallate Bismuth gallate (formerly known as Dermatol) is antiseptic, astringent, and siccative. Gallium nitrate reduces metalloproteinase activity in wounds and promotes the migratory phenotype of keratinocytes that can move more easily over the temporary protein matrix and close the wound more quickly. It reduces keratinocyte ability to synthesize the d ­ esmosomes that anchor the cell locally and limit its movements.

Full-face phenol: Postpeel care    301

Bismuth Subgallate Bismuth subgallate is also known as bismuth 3,4,5-trihydroxybenzoate dihydroxide, basic bismuth gallate, and gallic acid bismuth basic salt. Its molecular weight is 394.09. It has low toxicity; not much bismuth is absorbed. If bismuth subgallate comes into contact with the eyes, eye drops should be used. Zinc Stearate Urkov used zinc stearate as a healing powder for 5 days after removing the occlusive mask.

Making the Bismuth Subgallate Mask Before sprinkling the powder on the face, a drop of artificial tears should be put in both of the patient’s eyes and protective cotton pads placed on the eyes (Figures 35.9–35.11). The patient is placed in the dorsal decubitus position with eyes closed. A thick coat of postpeel mask is applied on the skin and the Yellskreen (Bismuth subgallate) is sprinkled on the postpeel mask, on which it will stick. This makes an anti-­ inflammatory, anti-erythema, anti-infectious mask that speeds up skin healing. The mask must not be too rigid, however.17 Bismuth subgallate comes in two formats: the Lip & Eyelid kit contains 12 separate sachets for deep localized peels (Figure  35.12a). A large bottle is also available (Figure  35.12b) that allows for easy application by sprinkling the powder directly on the skin. An assistant should gently compact the powder with sterile gauze. Too much powder makes the mask rigid, which is unpleasant for the patient and is sometimes difficult to remove later. A mask that is too thick may also crack after the third day and form jointed plates that can leave visible lines imprinted

Figure 35.10  Bismuth subgallate powder mask: end of making the mask. Note that the peri-ophthalmic area is covered with petrolatum jelly.

Figure 35.11  Eye protection before sprinkling the bismuth subgallate powder on the skin.

Figure 35.9  The eyes are protected before powdering with bismuth subgallate.

on the skin and sometimes even wrinkles that were not there before the peel. The mask should be monitored closely starting on the 3rd day. As can be seen in Figure 35.13, a powder mask that is too dry should be treated locally with an application of sterile white Vaseline.

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FOLLOWING DAYS Days 1–6

(a)

(b)

Figure 35.12  (a) The Lip & Eyelid kit contains 12 sachets of bismuth subgallate. (b) A sprinkler is also available. This makes it easier to apply the powder.

(a)

During the first two days, the patient puts artificial tears in both eyes. For 48 hours, it is the patient who puts the subgallate powder on the areas that need it, that is, where the powder appears moist. Where the powder has not stuck, because of a lack of skin liquefaction, a little Terramycin ointment or sterile white Vaseline should be applied. The patient and doctor should be in contact—even if only by telephone—every day, as the appearance of the face is very worrying for both the patient and friends and relatives (Figure 35.14). The person in contact with the patient must be able to answer any questions, allay any fears, and possibly examine the patient. It is essential that the patient is regularly reassured by the doctor that things are proceeding as normal (Figure 35.15). The pain usually intensifies suddenly on the 3rd and 4th days: patients generally consider the night of the 3rd day to be the most “unpleasant” of the whole week. Strong analgesics might be necessary. Acetaminophen plus codeine, which the patient should have on hand, is sufficient to ease the pain in most cases. Cold packs—chilled but not frozen—can help alleviate the sensation of burning or pulsing heat. Many patients complain of severe itching that can be relieved with a sedative antihistamine such as promethazine. In some cases, the ­antihistamine can be combined with lorazepam. A patient who is asleep on promethazine and lorazepam does not scratch.

(b)

Figure 35.13  (a) A bismuth subgallate mask that is too dry. (b) Application of sterile white Vaseline around the eyes and mouth.

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(b)

(a)

(c)

Figure 35.14  (a) Bismuth subgallate mask on day 1. (b) Day 3: The edema is going down quickly. (c) Day 3: Close-up of the mask on the eyelids. The upper eyelids are coated in an antibiotic ointment instead of the powder.

(a)

(b)

Figure 35.15  The lower demarcation line on the neck should be given special attention and should be coated with Vaseline in case movement is awkward (patient on the 3rd day). (b) The same patient after repeated applications of Vaseline on the 4th and 7th days. The edema that could be seen in (a) has gone.

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Figure 35.16  An infection may occur in the form of a papular reaction on the neck. Oral antibiotics are essential in this case.

No other specific treatment should be applied on the face during the first week. The patient should be seen again on the 4th or 6th day, and the doctor should carefully check for any secondary infections (Figure 35.16). The doctor should apply a thick coat of sterile white Vaseline to the patient’s skin and gently rub it in when he or she sees the patient on the 6th day (Figure  35.17). The doctor

(a)

can also help flaking along but must take care not to damage the skin. Anything that is not stuck to the regenerating skin can be removed. Once the patient is back home, he or she continues to apply a thick coat of sterile white Vaseline to the face and gently rubs it in after carefully washing the hands with antiseptic soap. A thick coat of Vaseline creates an impermeable dressing that prevents transepidermal water loss (TEWL). The water accumulates between the Vaseline and the skin—that is, in the bismuth subgallate powder. It hyperhydrates the powder mask, helping it come away without the patient having to do anything other than pick up the strips (skin plus powder) that fall off by themselves. Throughout the first  week, the patient should be told quite firmly to sleep on his or her back instead of on the side, so that the skin on the face does not stick to the pillow (see Chapter 37).

Day 7 The doctor can use forceps to remove any small bits of the mask that are still on the face. On some patients, the powder mask has not come off by the 7th day, and the doctor should then remove it, taking care not to damage the skin. The skin sometimes appears a bit crumpled under the mask, but the crumpling, caused by the pressure of the mask, disappears within moments (Figure 35.18). If the skin is in good enough condition, camouflage makeup (Avène® or Covermark®) can be applied immediately after sun protection. Sun avoidance and the use of a total

(b)

Figure 35.17  (a) Day 6 after Lip & Eyelid Formula: appearance of the patient on arrival at the medical center. The doctor should apply the first coat of Vaseline and can help flaking along, taking care not to damage the skin. (b) Immediately after an application of Vaseline and doctor-assisted flaking.

Full-face phenol: Postpeel care    305

few weeks but gradually fades within 4–8 weeks. Patients with dark skin or who live in sunny climates should apply Blending Bleaching Cream once or twice a day to reduce the incidence of pigmentary changes.

SUN AVOIDANCE Sun avoidance should be aggressive and permanent during the first 3 months after the peel. Patients who work outdoors are most likely to suffer from uneven skin color or post-inflammatory hyperpigmentation. Permanent sun protection does not mean that patients should stay out of the sun for the rest of their lives, but that they should actively protect their “new” and more sensitive skin. Patients have a natural tendency to avoid sun exposure for some time after a peel. After strict sun avoidance for up to 2–3 months, outdoor activities can be resumed with total sunblock, although sunbathing is forbidden during the first year after a peel. During the first few months, wearing sunglasses (that do not press too hard on the temples or the nasal pyramid) prevents reflex squinting against excess light. It is possible, like Cortez,6 to recommend using a cream with 0.05–0.1% tretinoin for 3 months after the peel, although this is not recommended for use before then, as recent studies show that although retinoids improve postpeel skin regeneration when used before the peel, it seems that they can delay regeneration when they are applied too quickly after a peel or d ­ ermabrasion. The patient should be seen again during the 3rd week to make sure there are no pigmentary changes or other ­complications and to be treated if necessary. It is sometimes necessary to use a depigmenting cream during the first 6 weeks, especially for patients who live in very sunny climates. Figure 35.18  The usual appearance of the skin, 7 days after a phenol peel. The skin is thin, sensitive, and red. The demarcation line is particularly visible between the face and the neck. A TCA peel (Easy TCA) was applied to the neck and décolletage on the 3rd day after the peel, and these areas are now flaking (see also Figure 30.8).

sunblock must be kept up for 3–6 months. Patients who are averse to the idea of having to put any product whatsoever on the skin should be ruled out from a phenol peel. Flaking does not stop on the 7th day, and it is common to see it last several weeks. Applying hydrating cream (Vit E Antioxidant or Nutritive ACE Lipoic Complex) helps to reduce any itching caused by the persistent flaking.

FOLLOWING WEEKS The patient applies a hydrating cream with vitamin E (see Chapters 2 and 3) four or five times a day to prevent the skin from drying out and becoming itchy and to prevent scratching and/or complications. The patient can continue to apply a thin layer of Vaseline as long as it is needed to improve dryness or itching. On the 10th day, the patient can usually return to normal activities, making sure that the skin is protected with an effective sunscreen and wearing makeup to hide the very pink color of the skin. A colorless sunscreen can be mixed with the patient’s usual foundation as well as a colored sunscreen (Metablock-HSP 50 color). Erythema remains severe for the first

TOUCH-UPS Phenol peels do not always produce the results hoped for, but fortunately it is rare that the results are so inadequate as to require extensive touch-ups or a complete re-peel. An extensive touch-up can be done 6 weeks after the peel. Fintsi18 reported an incidence of 30% of local touch-ups after Exoderm. In his study, 21 cases out of 558 had to be given more extensive touch-ups: 20 times for acne and once for a hyperpigmentation problem.

POSTPEEL CARE Care surrounding the peel is divided into four phases: 1.

Prepeel a. Three weeks before, application of Blending Bleaching Cream 2 times/day. b. Herpes prevention 4 days before and 4 days after peel (valacyclovir 500, 2/day). c. Botulinic toxin injection 1 to 8 days before peel. 2. Days 1–8 postpeel: see Figure  35.19. At day 1, remove occlusion, apply postpeel mask and Yellskreen. Important: Yellskreen has to stay in place for 6 days. 3. Days 8–15 postpeel: see Figure 35.19. IPLase allows a strong reduction of postpeel redness. 4. Days 16–90 postpeel: see Figure 35.19. Sun protection is mandatory until the total end of erythema plus 4 weeks.

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Full-face deep phenol peeling (Lip & Eyelid Formula) LE = Apply Lip & Eyelid on lips YELLSKREEN: Protective yellow powder INFECTION* : appears as red poinds around Yellskreen

if PIH risk, give the patient Blending Bleaching 3 x/day 2 weeks before treatment

Day 0 Lip & Eyelid Occlusion 24 h

Day 3 Infection*? Vaseline/edges

Day 6 Check if infection Vaseline full area

Day 1 Occlusion OUT Postpeel mask Yellskreen

– 2 Weeks

LE

1

Day 0

1

LE

4 to 6 weeks

LE

Day 7–8 Makeup allowed

3 2

Protective Home care

6 4

5

7

Days 8 to 15

Specific Home care Days 16 up to 90

Skin Tech Cleanser (Cleanse skin) DO NOT PULL AWAY YELLSKREEN Skin is regenerating under the scab Vaseline unsticks Yellskreen

IPLASE (reduces erythema) 3x/d Melablock HSP 50+ 09 am–12 pm, 03 pm

Melablock HSP 30

09 am–12 pm, 03 pm

Blending Bleaching Cream (Pigment control) and/or Atrofillin (2x/day)

Figure 35.19  Protocol for care post-full-face deep phenol peeling.

NOTES 1. According to Asken, the patient can go home 6 hours after the peel (Asken S. Unoccluded Baker–Gordon phenol peels—Review and update. Journal of Dermatologic Surgery and Oncology. 1989; 15: 998–1008). 2. The patient should be able to get to the doctor within 1–2 hours at the most. 3. As opposed to the use of phenol in the past as a disinfectant for wounds, when occlusion does not slow down the rate of penetration of phenol. 4. Ruedemann R, Deichmann WR. Blood phenol level after topical application of phenol-containing preparations. JAMA. 1953; 152: 506–9. 5. Occlusion dilutes the TCA and reduces its effectiveness. 6. Cortez E. Chemical face peeling. Otolaryngology Clinics of North America. 1990; 23: 947–60. 7. Applying Vaseline or silicone after the peel acts as occlusion. It is in fact cosmetic occlusion rather than physical occlusion. 8. Beeson WH, McCollough EG. Chemical face peeling without taping. Journal of Dermatologic Surgery and Oncology. 11: 985–90. 9. McCulloch EG, Langsdon PR, Maloney BP. Chemical peel with phenol. In: Roenigk RK, Roenigk HH (Eds.). Dermatologic

10. 11. 12. 13.

14.

15. 16. 17.

18.

Surgery, Principles and Practice. 2nd ed. Oxford: Dekker, 1996: 1147–60. Konior RT, Kerth JD. Selected approaches to the aging face. Otolaryngology Clinics of North America. 1990; 23: 1083–95. With Lip & Eyelid Formula (for a full face), healing takes 7–8 days. This is a sterile adhesive plastic used in surgery to cover a field of operation and through which the surgeon can make incisions. Acetaminophen must not be injected intravenously during the peel, however, to avoid any competition among the enzymes responsible for liver detoxification. Patients often complain that some liquid has leaked out from the bottom of the occlusive mask and that they have had to cover their necks. Recall that phenol is a neurolytic agent. It is recommended not to remove the skin on top of a blister for the same reasons. A mask that is too thick or rigid is extremely unpleasant for the patient and could make the skin unusually tight and promote infections. If the mask is too thick or rigid, it must be covered immediately in sterile white Vaseline to soften it. Fintsi Y. Exoderm-lift—liquid formula. 1996.

36 Phenol Chemical blepharoplasty and cheiloplasty CHEMICAL BLEPHAROPLASTY Introduction Surgical blepharoplasty is a technique that has become progressively easier as it has been removed from the strict framework of surgery requiring hospitalization. Once performed readily under general anesthesia, it soon was performed under local anesthesia combined with neuroleptanalgesia, then deep sedation, and is now often done under simple local anesthesia with lidocaine. Lip & Eyelid Formula allows treatment without any kind of anesthesia. Surgical blepharoplasty, when performed by a skilled surgeon, should give excellent results that last several years, after which patients go back to the doctor as they are no longer happy with the results. A second blepharoplasty is then performed, and the results are no different from the previous results. It is common to come across patients who have “benefited” from three successive surgical blepharoplasties over 15 years. The cosmetic results of multiple surgical blepharoplasties are not always of good quality, and patients who have been operated on too often are as easy to spot as patients with rotation-flap hair transplants or large cylindrical punch grafts. Surgical blepharoplasty can change the look of the palpebral aperture, especially when patients want their eyes to look more “cat-like.” A second blepharoplasty can make the tarsal region of the upper lid slightly darker. A third blepharoplasty can be disastrous: the palpebral aperture loses its elasticity and narrows, the eye becomes smaller and less mobile, the skin above the tarsus of the upper eyelid takes on a very dark color that stops abruptly on the scar because of the altered distribution of dilated vertical blood vessels (Figure  36.1). Lagophthalmia entropion or ectropion can develop. The author performed his first chemical blepharoplasty with localized phenol in the 1990s to treat blepharochalasis that had developed just a few years after a surgical blepharoplasty of the four eyelids. The blepharoplasty had been done correctly, well before the patient had reached 40, and 4 years later there was once again a significant excess of skin on the upper eyelid that made the patient’s eyes look heavy and sad. The patient preferred to have nonsurgical treatment. Clinically, it was reasonable to investigate the problem with her. Apart from surgery, what treatment options were there to lift the “curtain” of the upper eyelids? After a quick consideration, a peel seemed to be the only option. Alpha hydroxy acids (AHAs) were ruled out immediately because of the risks involved and the fact that they are ineffective on the eyelids. Trichloroacetic acid (TCA) was ruled out, as the high concentrations needed to get the skin to retract would be dangerous and in any event ineffective. There was therefore only one option left: phenol. The author has not encountered many problems with regular use of full-face phenol peels and, on the contrary, has found them to be very successful. The results achieved locally on the eyelids have often been remarkable (Figure 36.2).

Phenol therefore seemed to be an excellent option for treating drooping eyelids. In fact, the general toxicity of phenol is nonexistent when treating limited areas, and a local anesthetic is all that is needed given the anesthetic properties of the phenol itself.

Anesthesia Chapter 33 is devoted to the details of anesthesia for a phenol peel. Lip & Eyelid Formula can be applied without any anesthetic on small areas, however. Patients feel an intense burning sensation a few seconds after application. They will have been told that the burning sensation lasts only for 15 seconds and that they can have a nerve block if they want. Vocal anesthesia plays an important part, and the patient can take an acetaminophen plus codeine tablet 1 hour before the treatment. Nerve blocks are often used to increase patient comfort: 2% lidocaine without adrenaline (epinephrine) is used, and its duration of action is sufficient. The patient should be given acetaminophen plus codeine tablets for the postpeel pain, which is inevitable during the first 24 hours because of the severity and rapidity of inflammation caused by the peel.

Protecting the Eyes A small quantity of ophthalmic Vaseline is put in the conjunctival cul-de-sacs to protect the cornea, before the bottle of phenol has even been opened. The Vaseline actually deactivates the phenol. The patient has eye drops (artificial tears) to put in the conjunctivae as soon as the phenol has been applied and several times a day over the following days.

Phenol Solution There are many different phenol formulations, and different combinations have been tested with varying results. The Baker–Gordon or Litton formulas potentially pose an increased risk because of their depth of penetration in the thin eyelid skin. After using several different formulas, the author gradually came to develop a phenol oil that meets his high standards of safety and effectiveness. Adapted for the treatment of the eyelids and lips, this solution is called Lip & Eyelid Formula. The eyelids and the lips do not, of course, have the same thickness, resistance, permeability, or reactivity; they are very different, and this is why the application protocol is also different in each case.

Application to the Eyelids (Figures 36.3–36.5) The choice of applicator is important: the large cotton buds normally used in a full-face phenol are not precise enough and absorb too much of the product. Cotton wool or gauze soaked in solution is not suitable because of the risk of drips on the neck or, even worse, in the eyes (remember that phenol is a

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Figure 36.2  Full-face Lip & Eyelid peel: Close-up of the eyelids 30 days after treatment; note the significant retraction of the eyelid.

Figure 36.1  Typical abnormalities of the upper eyelid after several surgical blepharoplasties.

protein coagulant, and any contact with the cornea could damage it irreversibly). A double cotton bud would not be precise enough either. The ideal applicator is a single cotton bud: it is light, precise, and simple—all of which are good qualities when it comes to using phenol. Using a 1 cm3 syringe, 0.2 cm3 is drawn up from the 3 cm3 bottle of Lip & Eyelid, and the cotton bud is soaked by “injecting” 0.10–0.14 cm3 of the peel solution directly onto it. After disinfecting the area with alcohol and carefully degreasing

(a)

with acetone, Lip & Eyelid is applied carefully on the lower lids with the cotton bud. Distinct frosting occurs rapidly and marks the end of the phenol application. The tarsus of the upper eyelid is not usually treated. Applying Lip & Eyelid on the eyelid tarsus induces severe edema that is very uncomfortable for the patient and does not significantly improve results. To treat the second eyelid, the remaining 0.06 cm3 should be “injected” onto the end of the same cotton bud. A bottle of Lip & Eyelid Formula provides enough solution to treat two eyelids on 15 patients. The same quantity of solution is needed to treat the upper eyelids. An assistant should be present whose sole duty is to mop up any tears as soon as they appear to prevent any diluted phenol from dripping onto the face or going up into the conjunctivae by capillarity. A fresh cotton pad should be used for each tear. An evening-out peel is necessary to prevent demarcation lines. It should be applied on the rest of the face when the Lip & Eyelid application has finished and before any occlusion is applied. Patients with a light skin type could be given four

(b)

Figure 36.3  (a) Lip & Eyelid to the lower eyelids and an application of Only Touch (lentigo to the forehead and right cheek) plus Easy TCA as an evening-out peel. (b) Lip & Eyelid on all upper and lower eyelids. The tarsus of the lower lid is not treated.

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Figure 36.4  Lip & Eyelid to the upper eyelids.

Figure 36.6  Occlusion can be applied if necessary, although this is rarely the case. Here, occlusion has been applied using Sleek (see Chapter 32).

essentially extratarsal (Figure  36.6). In the large majority of cases, a chemical blepharoplasty is done without occlusion. After applying the phenol, the doctor applies an eveningout peel, either Easy TCA or Unideep, to the rest of the face. Both of these peels consist of an acid solution and a postpeel cream that stimulates healing, is antioxidant, and is tyrosinaseinhibiting. This special postpeel cream should be applied once only by the doctor at the end of the facial peel. When the phenol is used without occlusion and without impermeable dressing, the Easy TCA or Unideep postpeel cream is applied on the area treated with Lip & Eyelid at the same time as it is applied to the rest of the face.

Immediate Postpeel Care

Occlusion versus Open Technique

With Occlusion Any occlusion is removed after 24 hours, and the dermis is usually laid bare (Figure 36.7) and needs protecting. Applying bismuth subgallate, although highly effective at wound healing in general and in phenol peels in particular, has always caused minor problems for the author on the mobile region of the patient’s upper eyelid. The powder easily falls into the eyes (Figures 36.8 and 36.9). When the powder, which has first been soaked with the products of epidermal liquefaction, dries on the skin, it can form crusted plates that hinge on the skin and that (in the author’s experience) have occasionally created wrinkles that did not exist before the peel. I therefore do not put any powder on the mobile part of the upper eyelid and rather use a “moist” technique—an antibiotic ointment (e.g., ophthalmic Terramycin during the first week after the peel) or just Vaseline. Applying this type of ointment is, in any event, equivalent to occlusion.1

Occlusion causes the phenol to macerate, which is often unnecessary on the eyelids. The lower eyelid can be covered with impermeable tape (there is a roll of tape in the peel kit) if a greater depth of action is required (Figure 36.6), if the wrinkles are deep, or if there is xanthelasma, for example. No occlusion is applied otherwise. Occlusion of the upper eyelid, which is only indicated to increase the depth of action of the peel, will always be

Without Occlusion The patient’s skin, dried out by the phenol, provides an ideal physiological dressing. The doctor can, however, apply a thick coat of anti-inflammatory, antioxidant, anti-erythema postpeel mask (included in the kit) immediately before applying Yellskreen powder (bismuth subgallate), The powder will perfectly stick on the postpeel mask and form a good protective

Figure 36.5  The upper and lower eyelids have been treated with Lip & Eyelid, and the frosting has already faded. The rest of the face has been treated with Unideep as an evening-out peel: Note the even pink-white frosting from the Unideep and the postpeel Unideep cream on the forehead.

weekly sessions of Easy TCA (to the Grenz zone) or a single session of Unideep (to the papillary dermis).

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(a)

(b)

Figure 36.7  (a) After 24 hours of occlusion, the dermis has been destroyed. Note the significant amount of skin liquefaction. (b) Destruction of the dermis after 24 hours of occlusion.

Figure 36.8  Bismuth subgallate powder on lower eyelid.

barrier, allowing wet skin regeneration under the powder, which is not water soluble. After day 6, the patient should apply Vaseline (ophthalmic if possible) several times a day so that the bismuth subgallate powder comes away from the skin by itself, without any outside help.

Subsequent Postpeel Care Patients should be given a small sachet of bismuth subgallate (there are some small sachets in the Lip & Eyelid kit), which they should apply with a cotton bud to any area that appears moist. The patient should be seen as often as necessary, usually on the 1st, 3rd, 6th, and 10th days. The treated area is usually dry within 48 hours, at the most. If additional bismuth subgallate powder will not stick to the skin, it is not necessary (Figure  36.10). Patients should not touch their skin with their bare hands to avoid any risk of infection. In cases where the doctor has opted for a “moist” postpeel technique and has applied an antibiotic ointment or Vaseline, the patient should wash the area with thermal water spray or with a showerhead before each application of cream. The different layers of antibiotic ointment or Vaseline should not be allowed to accumulate without washing in between.

Figure 36.9  Application of bismuth to all four eyelids: chemical blepharoplasty and evening-out peel (Unideep). The Unideep postpeel cream is applied to the face immediately after the peel, on the evening of the peel, and on the following morning. This photograph was taken on day 1.

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Figure 36.10  Day 3: The bismuth subgallate is dry.

Patients sometimes feel some considerable discomfort that they describe as a pulling sensation, a tightening of the skin, caused by the powder mask. This sensation is usually localized around the edge of the mask, where it meets the skin that has not been treated with phenol. Applying Vaseline with a cotton bud to the edge of the treated area can help alleviate this feeling of tightness (see the yellow dots in Figure 36.10: on day 5, the subgallate is dry). From the 5th day onward (or the 4th day if need be), and as long or as often as necessary, sterile white Vaseline or ophthalmic Vaseline should be applied on the bismuth subgallate so that it comes off without any outside help (Figure  36.11). The borderline between the area treated with Lip & Eyelid and the area treated with the more superficial peel may feel painful or just uncomfortable. The doctor should apply a little Vaseline on this area to soften it, even if only a few days have passed since the peel was applied.

Postpeel Developments

Figure 36.11  From the 5th day, Vaseline should be applied on the bismuth subgallate so that it comes off without any outside help.

(Figure 36.13) and fades, more or less slowly depending on the patient, in 3 weeks to 3 months. The erythema takes longer to fade on lighter, more transparent skin. It always resolves, however, and is easily covered up with makeup. (A green ­ makeup stick should be applied first, followed by camouflage makeup, e.g., Couvrance by Avène.) The bismuth subgallate powder comes away from the skin automatically (Figure 36.14) with the Vaseline that prevents transepidermal water loss (TEWL) evaporation. The downtime is 8–10 days maximum.

Effectiveness and Indications The results of a chemical blepharoplasty may be inadequate if there is a large amount of excess skin or for lower eyelid fat pads. In these cases, surgical blepharoplasty is indicated. Applying Lip & Eyelid to the eyelids treats wrinkles and fine lines, dyschromia, keratoses, and sagging eyelids (Figure  36.15) but improves eye bags only when they are caused by sagging skin rather than the presence of subcutaneous fat. Surgery is indicated in this case.

Eyelid Edema Severe eyelid edema, which resolves quickly and lasts 7 days at the most, appears immediately after the solution has been applied (Figure 36.12). It peaks on the morning of the 1st and 2nd days. The edema goes down during the day when the patient is no longer lying down. It spreads to the upper cheek on the 2nd day, the lower cheek on the 3rd day, the lower jaw on the 4th day, and on the 5th day is barely noticeable. It is not uncommon for the patient to be unable to open his or her eyelids on the morning of the 1st day. If the edema lasts longer than 10 days, it is not normal.

Complications

Erythema Erythema develops equally rapidly, a few minutes after Lip & Eyelid has been applied. It peaks during the first few weeks

Risk of Pigmentation Disorders and Prepeel Preparation Even if it is generally accepted that phenol has more of a depigmenting than a hyperpigmenting effect, the doctor must be

Lip & Eyelid is one of the safest phenol peels on the market, but incorrect application can lead to the usual local side effects of chemical peels. Pain Taking a painkiller tablet half an hour before treatment alleviates the pain resulting from the inflammatory edema. A ­second tablet, taken before going to bed, ensures the patient gets a good night’s sleep. The following morning, the pain will have almost completely gone. It is common for some pain to recur on the third day.

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(a)

Figure 36.13  Normal erythema on the 13th day.

(b)

Figure 36.14  Vaseline has been applied the night before, on the 5th day, to remove the subgallate powder.

(c)

Figure 36.12  Normal edema over the first 2 days that has spread to the cheek area. (a) Chemical blepharoplasty of the four eyelids. (b) Chemical blepharoplasty of the upper eyelid only. (c) Chemical blepharoplasty of the lower eyelids only.

prepared for any reactional hyperpigmentation. If the skin being treated is a very “melanin-reactive” phototype or might have a severe inflammatory reaction, the melanocytes should be “sedated” with tyrosinase inhibitors and antioxidants (Blending Bleaching Cream) before and after Lip & Eyelid, both on the areas to be treated and on the surrounding areas. The

cream should be applied twice a day for 2 weeks before the peel and as soon after the peel as possible. The skin can usually tolerate Blending Bleaching Cream from the 10th day after the peel. Melanocyte “sedation” should be continued for a minimum of 6 weeks. If the peel is being performed on a skin phototype I–III and if the patient follows advice to keep out of the sun and use sun protection, there should be no post-inflammatory hyperpigmentation, but there is an increased risk of prolonged erythema on lighter skin types. The sun should be avoided completely, and effective sun protection (Melablock-HSP SPF 50+) should be used for up to 3–6 months. Exposure to UV light should be gradual thereafter. Even when the peel is applied correctly, there is still a risk of pigmentary changes, which are always reversible with Blending Bleaching Cream. Avoiding pigmentary changes is mainly a matter of pre- and postpeel care. Local depigmentation, which can only be treated with a

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(a)

(b)

Eyelid will look rejuvenated and stand out clearly from the surrounding damaged skin. In these cases, it is especially important to combine the peel with Easy TCA or Unideep to minimize the demarcation line if the skin phototype has been properly selected (see earlier discussion). Healthy skin without dyschromia, of phototype I–III, IV at the most, does not pose the risk of a marked demarcation line. The demarcation line can be seen most clearly on the edges of the occlusion. When using the occlusive ­technique, it is best not to cover the whole treated area but to leave an area unoccluded to create a graduated area of ­penetration. If results prove inadequate, they can be touched up or avoided altogether through proper patient selection. Delayed Healing When a chemical blepharoplasty is performed without occlusion, the increased depth of action of the phenol sometimes translates into a persistent moist scab in the inside corner of the upper eyelid (Figure  36.16), where the phenol has macerated more intensely. Applying an antibiotic cream or ointment remedies the problem, and it should resolve before the 15th day. There are no sequelae from this slow healing. If the scab persists for more than 2 weeks, the doctor should remain alert and monitor the patient more closely.

(c)

Other Complications Poor application technique can lead to inadequate results. The technique should be corrected and Lip & Eyelid should be reapplied after 6 weeks. The second peel will heal more quickly than the first. The author has never experienced scarring, entropion, or ectropion with this treatment, but in theory they are possible. Prolonged erythema of several months can be treated, if it bothers the patient, with alternating applications every 2 weeks of corticosteroids (hydrocortisone) and antioxidant creams (Renutriv ACE Lipoic Complex). Bacterial infections should not occur if the technique is correct and postpeel care is conscientious. Herpes prevention is essential in patients with a history of herpes. Postpeel anxiety is common, and the extent of anxiety depends on the patient’s state of mind before the peel. Patients should be able to contact the doctor whenever they feel the need.

(d)

Figure 36.15  Examples of the results of chemical blepharoplasty. (a, b) Chemical blepharoplasty of the upper eyelids and Easy TCA as an evening-out peel. (c, d) Chemical blepharoplasty of the lower lids and Easy TCA as an evening-out peel.

full-face application of Lip & Eyelid, can be avoided by careful patient selection. Demarcation Line There is clearly a risk of a demarcation line on skin with severe dyschromia or sun damage, a lot of wrinkles, freckles, keratoses, or lentigines, as the skin treated with Lip &

Figure 36.16 Benign blepharoplasty.

delayed

healing

after

chemical

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Results

that does not cause bleeding and is very quick (a few minutes). It does not change the appearance of the eyes but, on the contrary, restores their original qualities. It is easy to perform without local anesthetic or with nerve blocks of lidocaine without adrenaline. Results are inadequate for treating fat pads but are excellent, if not perfect, in all resurfacing indications. The low rate of local complications and the lack of general

A photographic record of results is shown in Figures  36.17 and 36.18.

Summary Chemical blepharoplasty of the upper and/or lower eyelids with Lip & Eyelid Formula is a relatively simple technique

(a)

(b)

(c)

(d)

(e)

Figure 36.17  Developments and results: (a) before; (b) +24 hours; (c) +3 weeks; (d) +6 weeks; (e) +14 months.

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(a)

(b)

Figure 36.18  Long-lasting results: (a) before treatment; (b) 1 year after a localized peel with Lip & Eyelid on the lower lid; Unideep was employed as an evening-out peel.

complications make it an ideal technique to rejuvenate the eyes when the patient does not want laser treatment or surgery, and the doctor is experienced in performing peels in general and in using phenol in particular. It is obvious that a chemical blepharoplasty should not be the first peel performed by a doctor who is inexperienced in this branch of medicine or cosmetic dermatology.

HOW TO DO A CHEMICAL BLEPHAROPLASTY USING LIP & EYELID FORMULA Figure  36.19 illustrates the process for a chemical blepharoplasty using Lip & Eyelid Formula.

Prepeel Care • • •

•

•

The patient should apply Skin Tech Blending Bleaching Cream twice a day for 2–3 weeks before peel. Give the patient an analgesic (acetaminophen plus codeine) 30 minutes before the peel. The skin should always be degreased with acetone, disinfected with alcohol, and degreased/disinfected with a mixture of 50% alcohol and 50% acetone before application. Place one drop of Vaseline-based ophthalmic ointment in the eyes (i.e., Terracortril ophtalmicum) before starting the procedure and at its end, to prevent postpeel ocular irritation. Herpes prevention is necessary if the patient has a history (valacyclovir 500 twice a day for 4 days before up to 4 days after the peel).

General Application Position the patient in accordance with the conventionally accepted rules for phenol peels. Prepare the patient and any equipment that might be necessary to deal with any incidents or complications. Among other things, a source of oxygen, an intravenous infusion, a cardioscope, and oximetry monitoring should be available. A defibrillator and standard resuscitation equipment should be installed before performing potentially arrhythmic peels, such as phenol peels.

Postpeel monitoring is also very important, and the ­ octor should make the necessary arrangements for regular d follow-ups with the patient to check the progress of the peel and be available at any time for him or her. A phenol peel is a deep peel technique with which the doctor must be fully acquainted to avoid the complications ­specific to these peels; the doctor must know how to treat any complications that may arise. Any peel solution containing phenol should be applied with professionalism and patience. Phenol peels should be applied slowly and evenly, using a double-type applicator cotton swab (ear bud). It is extremely important to check for tears during a phenol peel and swipe each with a new cotton pad. Discard every cotton pad after use. After the treatment, the patient should not be allowed to sleep with the treated skin pressing against any surface (i.e., a pillow) as the treated area might stick to the surface and result in infection, scarring, prolonged erythema, or other complications.

Local Application Carefully read the directions included in the Lip & Eyelid kit for warnings about side effects and contraindications. Any ­contact between phenol and the eyes can cause partial or total loss of vision. When treating sensitive patients, the doctor should perform nerve blocks. Thirty minutes before the peel, the patient should be given an acetaminophen and codeine tablet. Herpes prevention is necessary for patients with a history of herpes. About Pain In the absence of nerve blocks, applying Lip & Eyelid triggers a strong burning sensation for approximately 15 seconds, after which the skin is numb for about 15 minutes. After 15 minutes, the patient will experience a gradual, unpleasant, warm pulsatile inflammatory sensation that generally lasts until the middle of the first night. Uniformity of Results A local application of phenol should be always performed in combination with a peel of the full area around the

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Eyelids Deep Peeling (Lip & Eyelid Formula) if PIH risk, give the patient Blending Bleaching 3 x/day 2 weeks before treatment Day 0 Apply: Lip & Eyelid Postpeel mask Yellskreen

Day 6 Check if infection Vaseline everywhere

Days 3 Infection* Vaseline on the edges

– 2 Weeks

LE Day 0

3 1

2

LP = Lip & Eyelid on eyelids YELLSKREEN: Protective yellow powder INFECTION* : appears as red poinds around Yellskreen

5

4 to 6 weeks

LE

Day 7–8 Makeup allowed

6

Specific Home care

Protective Home care

6 4

LE

7

Days 8 to 15

Days 16 up to 90

Skin Tech Cleanser (Cleanse skin) DO NOT PULL AWAY YELLSKREEN Skin is regenerating under the scab Vaseline unsticks Yellskreen

IPLASE (reduces erythema) 3x/d Melablock HSP 50+ 09 am–12 pm, 03 pm

Melablock HSP 30

09 am–12 pm, 03 pm

Blending Bleaching Cream (pigment control) or Atrofillin (2x/day)

NON OCCLUSION NO YELLSKREEN on sup. eyelid tarsus

Figure 36.19  Protocol for eyelid deep peeling

phenol-treated one. In the case of chemical blepharoplasty, another peel (i.e., Easy TCA Pain Control, Unideep, Easy Phen Light) should be performed to prevent color or texture differences between the treated area and the rest of the face. Application Protocol Using a 1 ml syringe, draw out 0.3 ml of the Lip & Eyelid solution and drop 0.15 ml directly on a cotton bud; the cotton bud should be moist and shiny but not drip. Then carefully apply the first layer of solution on the upper and/or lower eyelid. Stop the application at 1 mm from the eyelashes of the lower eyelid and before the tarsus of the upper eyelid. The tarsus of the upper eyelid should not receive an application of the peel solution. Uniform frosting appears rapidly, causing a burning pain for 15 seconds followed by local numbness. When the cotton bud appears to be dry, add another 3 drops of the Lip & Eyelid solution to it. A second layer of solution is then applied after obtaining the anesthetic effect of phenol. Allow time for the frosting to appear; do not apply too much solution. At the end of the application, apply the postpeel mask over the entire treated area. Then apply a uniform layer of Yellskreen on the treated eyelids. Do not apply Yellskreen on the tarsus of the upper eyelid. The procedure is now complete.

Follow-Up See the patient on the 1st, 3rd, and 6th days following the peel to monitor progress and ensure that there is no infection. In case of infection, give the patient antibiotics (usually orally). On the 3rd day, apply sterile white Vaseline on the edge of the treated areas. On the 6th day, apply sterile white Vaseline on the entire treated area. Vaseline will help unstick the Yellskreen powder. The patient can wear makeup beginning on the 8th day, if the skin is in the right condition.

Home Care Home care for the peel is divided into four phases (see Figure 36.19). 1.

Prepeel: a. Three weeks before, ask the patient to apply Blending Bleaching Cream two times per day. b. Patients with a history of herpes should perform herpes prevention (valacyclovir 500, two times per day) 4 days before and 4 days after the peel. c. Botulinic toxin injection previous to application of the peeling solution keeps the muscles paralyzed during the skin regeneration phase and allows a better and longer lasting result. Injection of botulinic toxin should take place 1 to 8 days before the peel.

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2. Days 1–8 postpeel: See Figure 36.19. Yellskreen must stay in place for 6 days. 3. Days 8–15: See Figure  36.19. IPLase greatly reduces postpeel redness. 4. Days 16–90: See Figure 36.19. Sun protection is m ­ andatory until the total end of erythema plus another 4 weeks.

Repeating the Peel If needed, the full procedure could be repeated after 4–6 weeks of skin regeneration, if the condition of the skin allows it.

CHEMICAL CHEILOPLASTY A chemical cheiloplasty or labioplasty treats wrinkles around the lips. The principle of the treatment is identical to that of a chemical blepharoplasty, but it is easier to treat wrinkles on the upper lip than on the eyelids. It is also less stressful for an inexperienced doctor. The skin on the lips is more resistant than the skin on the eyelids. It has more appendages and is more apt to heal well.

Chemical Resurfacing of the Upper Lip in Combination with Easy TCA Lip & Eyelid Formula can be applied to the upper lip without nerve block anesthesia. A first quick coat of peel solution induces local anesthesia within 15 seconds. Subsequent applications of phenol will therefore be painless. Easy TCA is applied without anesthetic, and Lip & Eyelid and Easy TCA can be combined when the wrinkles are mainly located around the lips and the skin on the rest of the face does not require a peel to the papillary dermis, which is often the case. The procedure is then very quick. Figure 36.20 shows an example of this approach. When there is more extensive sun damage, it is preferable to combine Lip & Eyelid with Unideep. Figure 36.20 shows an example of a case of upper lip wrinkles in a patient who does not require a peel to the papillary dermis on the rest of the face. Upper lip wrinkles are more common in smokers and in patients whose mouths are very mobile and who use the orbicular muscle of the mouth too often or too vigorously: an injection of botulinum toxin reduces upper lip mobility and produces better results in combination with a deep peel. Because of the severe inflammation resulting from a deep peel, the toxin is injected before the peel (at least 24 hours before). Fifteen units of Dysport or 4 units of Botox are usually enough, injected at four different points on the upper lip (Figure 36.20).

Chemical Resurfacing of the Upper Lip in Combination with a Peel to the Papillary Dermis When sun damage is more severe or if the patient has asked for an evening-out peel at the same time to minimize sometimes long treatments, Lip & Eyelid can be combined with Unideep (Figure 36.21). Although both peels can be done without nerve blocks, patients often appreciate them as they make the procedure more comfortable, especially when TCA is being applied. Patients who are very squeamish may benefit from sedation.

Results Results, as we have seen elsewhere in this chapter and this book, can sometimes be perfect. In other cases they are not perfect but still appreciated by the patient. Results can last for 3–10

years. More superficial peels should be done on a yearly basis to maintain the results.

How to Do a Chemical Cheiloplasty with Lip & Eyelid Formula Prepeel Care • The patient should apply Skin Tech Blending Bleaching Cream twice a day for 2–3 weeks before peel. • Give the patient an analgesic (acetaminophen plus codeine) 30 minutes before the peel. • The skin should always be disinfected and degreased before application (with a mixture of 50% alcohol and 50% acetone). • Place one drop of Vaseline-based ophthalmic ointment in the eyes (i.e., Terracortril ophtalmicum) before starting the procedure and at its end, to prevent postpeel ocular irritation. • Herpes prevention is necessary if the patient has a history (valacyclovir 500 twice a day for 4 days before up to 4 days after the peel). General Application Although phenol toxicity has never been described after a local treatment, the same security procedure as for a full-face peeling is recommended. Position the patient in accordance with the conventionally accepted rules for phenol peels. Prepare the patient and any equipment that might be necessary to deal with any incidents or complications. Among other things, a source of oxygen, an intravenous infusion, a cardioscope, and oximetry monitoring should be available. A defibrillator and standard resuscitation equipment should be installed before performing potentially arrhythmic peels, such as phenol peels. Postpeel monitoring is also very important, and the doctor should make the necessary arrangements for regular follow-ups with the patient to check the progress of the peel and be available at any time for him or her. A phenol peel is a deep peel technique with which the doctor must be fully acquainted to avoid the complications specific to these peels; the doctor must know how to treat any complications that may arise. Any peel solution containing phenol should be applied with professionalism and patience. Phenol peels should be applied slowly and evenly, using a double-type applicator cotton swab (ear bud). It is extremely important to check for tears during a phenol peel and swipe each with a new cotton pad. Discard every cotton pad after use. After the treatment, the patient should not be allowed to sleep with the treated skin pressing against any surface (i.e., a pillow) as the treated area might stick to the surface and result in infection, scarring, prolonged erythema, or other complications. Local Application Any contact of phenol with the eyes can cause partial or total loss of vision. One drop of ophthalmic Vaseline is placed in the eyes before starting the procedure and at the end of the latter, in order to avoid eye irritation post-peeling. Eventually, perform nerve blocks. Eventually give the patient one acetaminophen and codeine tablet 30 minutes before peeling. Herpes prevention is necessary.

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(a)

(b)

(c)

(d)

(e)

(f)

Figure 36.20  Chemical cheiloplasty of the upper lip in combination with Easy TCA as an evening-out peel. (a, b) Before treatment. (c) Application at the base of the wrinkles. (d) Fading frosting. (e) Even application to the whole treatment area: appearance of gray-white frosting (Easy TCA is applied after the lip has frosted and before occlusion). (f) Occlusion, beginning of occlusion. (Continued)

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(g)

(h)

(i)

(j)

(k)

(l)

Figure 36.20 (Continued)  Chemical cheiloplasty of the upper lip in combination with Easy TCA as an evening-out peel. (g) Occlusion +24 hours. (h) Skin liquefaction after 24 hours, when the occlusion has been removed; note the edema on the upper lip. (i) Bismuth subgallate. (j) Results after 30 days (flash photography, with the patient wearing makeup). (k) Results after 60 days (photograph without flash, with patient not wearing makeup). (l) Result of a chemical cheiloplasty. The yellow dots show where the botulinum toxin was injected 8 days before the phenol peel.

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(a)

(c)

(b)

(d)

Figure 36.21  (a) Appearance of the patient’s upper lip before the peel. The rest of the skin is quite badly sun damaged and requires an application of Unideep, a TCA peel to the papillary dermis, if not a full-face phenol peel. (b) After disinfecting and degreasing the whole face, Unideep is applied gradually in sequence. (Unideep is applied in sequence, like phenol, but without the rest periods: see Chapters 23 and 34.) (c) Lip & Eyelid is applied to the right half of the upper lip. (d) Immediately after Unideep has been applied, the patient feels a slight burning sensation that can be alleviated with a cold pack placed directly on the acid before it has dried. The cold pack must be completely dry so that it does not dilute the peel solution.

Pain  In the absence of nerve blocks, applying Lip & Eyelid triggers a strong burning sensation for approximately 15 seconds, after which the skin is insensible for about 15 minutes. After 15 minutes, the patient will experience a gradual, warm pulsatile inflammatory unpleasant sensation that lasts until the middle of the first night.

Uniformity of Result  A local application of phenol should be always associated with a peeling of the full area around the phenol treated one: in the case of chemical blepharoplasty, another peeling should uniformize the result on the entire face for avoiding color or ­texture differences (i.e., Easy TCA PC, Unideep, Easy Phen Light).

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(g)

(e)

(f)

(h)

Figure 36.21 (Continued)  (e) The forehead was treated first and the frosting has faded. Some pinpoint frosting (gray-white) remains in places where the peel has penetrated more deeply (there is a chance of infection or scratching, etc., later on). The pinpoint frosting is similar to that produced by One Touch peel. The midface and cheek region have been treated as described earlier. Unideep is applied to the chin at the same time as the jaw area, where the patient also benefited from a cold pack. The Unideep postpeel cream has been applied to the whole treated area, apart from the lips, which are to be occluded. (f) The base of the lip wrinkles is treated (Lip & Eyelid). (g) This is followed by an application of Lip & Eyelid to the whole of the left half of the upper lip. (h) Unideep is applied to the left midface region and the cheek. The postpeel cream is applied. The chin region and the jaw area are treated with Unideep. (Continued)

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(i)

(j)

(k)

Figure 36.21 (Continued)  This photograph shows an impermeable keratosis that will be treated with a single application of Only Touch (i, j). (k) Shows occlusion of the upper lip after Lip & Eyelid application.

Application of Peeling  Syringe out 0.3 ml of the Lip & Eyelid solution and drop 0.15 ml directly on a cotton bud. Carefully apply Lip & Eyelid solution directly on the bottom of deep wrinkles (a white frosting should appear) before applying the peeling solution on the entire upper lip, until an even gray frosting quickly appears. When the cotton bud appears as dry, drop again 3 drops of the Lip & Eyelid solution on it. A second or third layer could be applied if necessary, after obtaining the anaesthetic effect of phenol, in order to reach the proper frosting: a gray white frosting. At the end of the procedure, apply an occlusive dressing (dressing included in the kit) and then uniformize the results by applying a less deep peeling (e.g., Easy TCA PC, Unideep, or Easy Phen Light) on the rest of the face.

Day 1 The occlusive dressing should stay in place during 24 hours. After 24 hours, remove the occlusive dressing and apply one coat of “Skin Tech® Post Peel Mask,” then apply on it,  a  ­uniform layer of Yellskreen and leave to dry and form a crust. Follow-Up See the patient on the 3rd and 6th day following the peeling to monitor progress and ensure that there is no infection. In case of infection or any other problem, the patient should be given antibiotics (usually orally). On the 3rd day, apply sterile white vaseline exactly on and only on the edge of the treated areas.

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At the 6th day apply sterile white vaseline on the whole area. Vaseline will unstick the Yellskreen powder. Makeup is allowed on the 8th day, if the skin is in a condition to receive it.

Complications See Chapter 37.

Home Care The care to be given round the peel is divided into four phases

SUMMARY OF THE CHEMICAL RESURFACING TECHNIQUE Prepeel

1.

Prepeel: a. 3 weeks before, ask the patient to apply Blending Bleaching Cream 2 times/day b. Herpes prevention 4 days before and 4 days after peel (valacyclovir 500, 2/day) c. Botulinic toxin injection 1 to 8 days before peel 2. Postpeel (see Figure 36.22): a. Days 1–8: At day 1, remove occlusion, apply postpeel mask and Yellskreen. Important: Yellskreen must stay in place for 6 days. b. Days 8–15: IPLase allows a strong reduction of postpeel redness. c. Days 16–90: Sun protection is mandatory until the total end of erythema + 4 weeks.

•

Repeating the Peel If needed, the full procedure can be repeated after 4-6 weeks regeneration if the status of the skin allows it.

• • •

• • •

•

If risk of pigmentary changes: • Skin phototype I–III: Blending Bleaching Cream twice a day for 2–3 weeks before the peel. • Skin phototype IV: Blending Bleaching Cream and 4% hydroquinone 3–4 weeks before the peel. If risk of herpes: valaciclovir or aciclovir. Do not treat very squeamish or low-IQ patients. Tell the patient how the skin will look during the first week: • Crust of yellow powder. • Swollen face. • Social life impossible. Give the patient a painkiller tablet 30 minutes before the peel.

Preparation and Application of the Peel Degrease the skin with acetone (ventilation). Disinfect with alcohol (ventilation). Protect the eyes with sterile ophthalmic Vaseline.

LIPS Deep Peeling (Lip & Eyelid Formula) if PIH risk, give the patient Blending Bleaching 3 x/day 2 weeks before treatment

Day 0 Lip & Eyelid Occlusion 24 h

Day 3 Infection*? Vaseline/edges

LE

Day 1 Occlusion OUT Postpeel mask Yellskreen

– 2 Weeks

LE

1

Day 0

1

LE = Apply Lip & Eyelid on lips YELLSKREEN: Protective yellow powder INFECTION* : appears as red poinds around Yellskreen

Day 6 Check if infection Vaseline full area

4 to 6 weeks

Day 7–8 Makeup allowed

3 2

6 4

5

7

Protective Home care

Specific Home care

Days 8 to 15

Days 16 up to 90

Skin Tech Cleanser (Cleanse skin) DO NOT PULL AWAY YELLSKREEN Skin is regenerating under the scab Vaseline unsticks Yellskreen

IPLASE (reduces erythema) 3x/d Melablock HSP 50+ 09 am–12 pm, 03 pm

Melablock HSP 30

Blending Bleaching Cream (pigment control) or Atrofillin (2x/day)

Day 1: after 24 hours occlusion

Figure 36.22  Postpeel care for the lips (deep peel).

Day 3: vaseline on edges

09 am–12 pm, 03 pm

LE

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• •

• •

If the evening-out peel is Easy TCA: Start with phenol and apply Easy TCA after the phenol. If the evening-out peel is Unideep: • Start with Unideep (see the details of application earlier in this chapter). • Inject ±0.14 cm3 of Lip & Eyelid solution directly onto a cotton bud. • Apply Lip & Eyelid Formula to the whole treatment area. With nerve block anesthesia: Start at the base of the wrinkles and then apply to the whole area. Without nerve block anesthesia: • Apply a quick coat of Lip & Eyelid to the whole area; warn the patient how long the burning will last (15 seconds). • Apply the solution in the base of the wrinkles and to the whole area.

Eyelids Immediately After the Peel • • • •

(In general) no occlusion; only Unideep or Easy TCA® postpeel cream is applied to the eyelids. Eyedrops (artificial tears) several times a day. A painkiller tablet for the evening or night (more if painful). Lorazepam 2 mg to be taken before going to bed.

• •

The 3rd Day •

• • •

Twenty-four hours of occlusion: The transparent occlusive dressing can be found in the Lip & Eyelid kit. If the occlusive dressing comes off accidentally before 24 hours, apply Vaseline as emergency occlusion. A painkiller tablet for the evening or night (more if painful). Lorazepam 2 mg to be taken before going to bed.

The Evening of the Peel • • •

The treated area must not be washed. If the evening-out peel was Unideep: Apply the rest of the tube of postpeel cream. If the evening-out peel was Easy TCA: No particular treatment.

The Following Morning • • • •

The face can be washed with water, but the area treated with Lip & Eyelid should not be washed. If the evening-out peel was Unideep: Apply the rest of the tube of postpeel cream. If the evening-out peel was Easy TCA: No particular treatment. In all cases: Start sun protection (Melablock-HSP) 50+.

Normal recurrence of pain for several hours: Acetamino­ phen plus codeine tablet.

See the Patient Again on the 4th Day • • •

Check that there is no bacterial, viral, or fungal infection. If infection: Treat by mouth, not topically. Apply sterile white Vaseline to any cracks (very locally).

After the 6th Day •

Upper Lip and Chin Immediately After the Peel •

If the subgallate does not stick: Spray with thermal water (such as Vichy water) to enable the powder to stick. • If it still does not stick: Antibiotic cream or sterile Vaseline to be applied four times a day; rinse the skin under the showerhead before applying another layer of cream. Patients should wash their hands thoroughly before touching their skin. If there is an unpleasant sensation of tightness in the area treated with phenol: Apply neutral sterile Vaseline to the edges of this area. •

The patient applies white Vaseline several times a day to help the powder come away.

See the Patient Again on the 7th Day •

Help remove the bismuth membrane.

After the 8th Day • • • • •

The patient can wear makeup or carefully shave. Sun avoidance and protection: SPF 50+ UVA–UVB (Melablock-HSP) for 3–6 months. Blending Bleaching Cream (as soon as the skin can tolerate it) twice a day. Tyrosinase inhibitors, antioxidants, and vitamins to block excess melanin synthesis. Renutriv ACE Lipoic Complex (antioxidant) 2–3 times a day.

See the Patient Again After 15 Days and 1 Month •

If there are pigmentary changes (after approximately 1 month): • Do a few sessions of Easy TCA (pinpoint or cloudy white frosting). • May be combined with a corticosteroid such as clobetasol.

See the patient again after 3 months for the end of treatment.

See the Patient Again After 24 Hours • • •

If occlusion: Remove occlusion. If no occlusion: No treatment (maybe remove Vaseline). Occlusion or not: Powder with bismuth subgallate.

NOTE 1. See Chapter 32 for more information on the use of Vaseline immediately after a peel.

37 Complications of chemical peels GENERAL REMARKS We must humbly accept the fact that there is no magic formula that even the most experienced practitioner could use on all skin types without taking precautions and without risk and whose results would be both spectacular and permanent. Some formulations are of course simpler and less dangerous to use than others, but there is no guarantee of automatic success and complete safety. The practitioner must follow the rules of application for each peel; be aware of its limitations, risks, and indications; and know how to avoid and treat any complications. “Artistic” improvisation usually leads to disastrous results. It is vital to read the instructions for use for each peel before applying it. A thorough knowledge of the symptomatology and physical and chemical mechanisms of peels is essential for the practitioner to be able to work confidently, safely, and efficiently. It is child’s play for any competent doctor to apply liquid to a patient’s skin, but the true skill lies in anticipating the complications, being able to prevent them, and, if prevention fails, being able to treat them. Patients deserve to be treated conscientiously, with respect and optimum safety, by true professionals. Any peel, even a superficial one that is neutralized quickly and even in the most experienced hands, can lead to complications that are not necessarily serious or permanent, but that are more than what a particular patient is prepared to put up with. The deeper a peel penetrates, the sooner it is effective and the greater the risk of serious and permanent complications. This chapter will look at each complication in detail, how to prevent it, and how to treat it. Systemic complications,1 exclusive to phenol peels, are dealt with in Chapter 28. The magnitude of the risk depends on the following factors: • • • • • • •

The type of peeling agent used, its concentration, how it is applied, and the depth it reaches. The doctor’s (lack of) experience, the monitoring and treatment equipment used. Skin preparation (when necessary) and postpeel care recommended by the doctor. The patient’s own sensitivity and compliance with the preand postpeel treatment. The patient’s medical and treatment history. The area to be treated (e.g., the neck poses a greater risk than the forehead). Countless individual and impromptu factors.

It is therefore essential to be knowledgeable, consider, weigh, compare, photograph, note, record, film, explain, palpate, measure, monitor, diagnose, check, and so forth.

GENERAL SAFETY FACTORS If there were a secret to safety, it would lie in a thorough knowledge and understanding of this type of treatment. For doctors

to give patients a wide range of choices, they must know how to use at least the three main types of conventional peels correctly: alpha hydroxy acids (AHAs), trichloroacetic acid (TCA), and phenol (for phenol, the doctor should at least know how to apply it locally). For each type of peel, the doctor must be perfectly acquainted with its indications, results, limitations, and complications to be able to choose the right product for a given patient and to be able to apply it correctly. The patient should be informed of alternative techniques, their possibilities, contraindications, side effects, and cost. The application technique must be flawless and in keeping with the particular procedure for each peel, appropriate to the patient’s skin type and the results expected. The doctor must be aware of and acquainted with the risks of complications and the means to prevent and treat them. It is better to avoid complications through prevention rather than treat them. Each patient is different, and each peel must be suited to each patient, which in no way means trying dangerous experiments with different formulas on a case-by-case basis. On the contrary, it is a matter of choosing among tried and tested treatments the one that is most suitable for the patient’s skin structure and that will give the best results with a minimum of inconvenience. For example, the practitioner should be able to decide whether it is preferable to perform several more superficial treatments or, on the contrary, to do a single phenol peel. If the latter option is chosen, which formula should be used: Baker–Gordon, Grade’s or Litton’s, Verner, Hetter, molding mask, Cora Valenti, Exoderm, or Lip & Eyelid? Should an occlusive mask be applied? Should the peel be neutralized? Should occlusion be left on for 24, 36, or 48 hours? Is postpeel care necessary? If so, what? If TCA is the treatment selected, should it be medium or deep, or is it better to do several sessions with Easy TCA or Unideep? If an AHA peel seems the best choice, should it be glycolic acid, mandelic acid, or ­lactic acid? Or Easy Phytic peel? Should the peels be combined with other treatments, such as botulinum toxin, dermabrasion, filling, surgery, coagulation of telangiectasias, shave excision, mesotherapy, and so forth? In which order should the combined treatments be performed? Peel before toxin or vice versa? Peel before a face-lift or vice versa? Peel before m ­ esotherapy or vice versa? Most peels carry a risk of one of the complications dealt with in this chapter. The likelihood of these complications occurring largely depends on the type of peel and the patient. Classifying peels as very superficial, superficial, medium, or deep is purely theoretical and should not make the doctor any less vigilant. A low-concentration TCA or a simple glycolic acid peel can penetrate deep into the dermis if the peel is applied repeatedly and vigorously, or, as far as glycolic acid is concerned, if the peel is not neutralized in time. Depending on the agent and technique used, complications can be systemic or local, permanent or temporary, serious or not.

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INADEQUATE RESULTS Inadequate results are an acceptable complication when the patient has been forewarned and the practitioner is prepared to compensate and do a proper touch-up. It is unacceptable when the patient has not been warned of this possibility and the doctor does not provide the care the patient deserves.

Reasons for Inadequate Results Wrong Indication If the doctor’s aim is to improve the texture of the skin, treat hyperpigmentation, and even-out the complexion, a single peel to the papillary dermis or four Easy TCA peels to the basal layer Grenz zone are good indications. On the other hand, it would be dreaming to expect to eliminate surgical or acne scars or the wrinkles on the cheek of the patient in Figure 37.1 with glycolic acid or even TCA. Scars are treated with deep peels, often in combination with other treatments (punch elevation, dermabrasion, subcision, laser, filling, etc.). Wrinkles are treated with phenol. Poor Product Knowledge Attempting to use glycolic acid or TCA to achieve a visible lifting effect on “shar-pei skin” is inviting disappointment; only cosmetic and plastic surgery can achieve a lifting effect. It is better to warn patients of the possibility of inadequate results with any peel, even a deep one, if their skin is very thick, oily, and sagging. It is likely that a deep peel would have to be repeated (locally or completely) to achieve the desired results.

Figure 37.1  Wrinkles on the cheeks that will not respond or respond poorly to superficial or medium peels.

In these cases, it is worth considering a combination of a surgical face-lift and a peel. Sagging, thick skin is not a good indication for peels in general (Figure  37.2). Peels can eliminate fine lines, hyperpigmentation, and keratoses and improve the quality of sun-damaged skin. Lack of Prepeel Preparation, Proper Cleansing, and/or Degreasing the Skin The presence of a lipid film on the skin partially deactivates many peels and limits their penetration. An unprepared stratum corneum may be too thick—too impermeable—in places. This relative local impermeability means that the acids do not penetrate evenly and the results will also be uneven. Prepeel preparation is essential for certain peels2 but unnecessary, or even dangerous, for others.3 It is essential to follow the recommendations for each peel solution to the letter. Facial Expressions After a deep peel, facial expressions imprint lines in the newly regenerating dermis and epidermis (Figure 37.3). Injecting botulinum toxin (before or after a peel) prevents dynamic wrinkles from reappearing after a peel. Smoking should be forbidden after a deep peel to prevent the rapid reappearance of “accordion folds” around the mouth. As well as requiring sucking movements,, smoking reduces the oxygen supply to the newly regenerating skin while dramatically increasing the number of free radicals. Smoking accelerates skin aging and slows down healing.

Figure 37.2  Sagging skin that does not respond well to peels.

Complications of chemical peels    327

combining epidermal resurfacing with strong and deep dermal stimulation.

Prevention of Inadequate Results Prevention of inadequate results requires the following: • • • •

Figure 37.3  Reappearance of dynamic wrinkles 10 days after a full-face phenol peel.

Combined Techniques Nonsurgical facial rejuvenation often requires a combination of different techniques, such as (micro)dermabrasion, filling treatments, shave excision, prior surgical removal of small benign tumors, punch elevation of scars, stimulating facial mesotherapy, peels of different depths, and so forth. The doctor can only learn by experience what results to expect, which techniques should be combined, and how best to use the chosen peel on a particular patient. Therein lies the art of peeling. Histology of Lesions Undergoing Treatment Lentigines, for example, result from a problem in the basal layer of the epidermis. Remember, however, that the epidermis extends to varying depths into the dermis to form the dermal papillae. If a lentigo originates in a relatively superficial papilla, a peel to the Grenz zone will solve the problem,4 but if the lentigo originates in a deep papilla, it would take a very deep peel to dislodge it. Histologically, lentigines often have a deep “golf club” structure that makes them difficult to reach. In this way, some problems that are histologically epidermal can only be treated by deep peels. In the diagram in Figure 37.4, a peel to the Grenz zone can resolve problem A, whereas problem B will only respond to a peel to the reticular dermis. This reticular peel can be localized (e.g., with Only Touch) or full-face (phenol peel). Repeated intraepidermal peels, no matter how often they were performed, would do nothing to solve the problem. Stretch marks, to give another example, are characterized by epidermal and dermal atrophy. They can be improved only by

Grenz zone

A

B

Figure 37.4  Lentigines at different depths.

Reticular dermis

Proper targeting of patients. Following the indications and application method of the chosen peel. Thorough knowledge of the products used. Possible combination with other treatments.

In all cases, caution dictates that the patient should be promised less dramatic results than might be hoped for. In this way, in the best-case scenario, the patient will get a nice surprise and be happy with the better-than-expected results. In the worst-case scenario, the doctor will not have made promises he cannot keep. Patients should be made fully aware of the limitations of their treatment. They should be shown photographs—and not necessarily the ones showing the best results. It is always essential to talk with patients before treatment to find out what they want and make sure they get the results they are looking for. It would be pointless to suggest a series of superficial peels to patients who want to eliminate crow’s feet, when a botulinum toxin injection would provide them with the quick results they want. False hopes always create problems for the doctor that raised them. Some patients’ disappointment can turn into a nightmare for the doctor.

Treatment Touch-Up or Different Technique If the selected peel turns out not to be strong enough, a different peel should be used or it should be combined with other treatments. Local or general touch-ups can be done as soon as the condition of the skin permits, that is, when the skin has completely regenerated and when all erythema and flaking has finished. The “rest” time between two peels is usually between 4 and 6 weeks.5 Many peels produce results only after fairly frequent repetition. Repeating Peels • Very superficial (stratum corneum) and superficial (intraepidermal: Easy Phytic) peels have to be repeated to produce visible results. Results usually show only after a certain number of sessions, as they are stimulating rather than destructive. • Peels to the basal layer (Easy TCA) can be repeated four or five times on an average of one session a week. The doctor should always wait for the skin to recover before re-peeling. Skin that is actively flaking should not have another peel applied to it. Some patients need a fifth peel (patients with oily skin or resistant hyperchromia, squeamish patients who do not allow the doctor to apply the solution properly, etc.). • TCA peels to the papillary dermis (Unideep) should not be repeated until at least 1 month later and on condition that the skin has completely recovered from the previous session. • Localized TCA to the reticular dermis (Only Touch): In some cases, lentigines or keratoses do not disappear after the first session of Only Touch. The application protocol for Only Touch provides for a second application where necessary.

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•

The Only Touch peel should be combined with Easy TCA to avoid pigmentary changes and can be applied before the first and the fourth Easy TCA peels. If some lesions resist or recur, a complete cycle of Only Touch plus Easy TCA can be started again after a 6-week rest period. Resistant lesions on the face can be treated locally with a spot application of Lip & Eyelid. However, applying very localized phenol often produces long-lasting (3–6 months or more), localized erythema. This erythema tends to resolve naturally but should be accompanied with protective measures against postinflammatory hyperpigmentation (PIH). Phenol (Lip & Eyelid Formula): If a full-face phenol peel does not produce adequate results, a second peel can be applied to the areas that did not respond to the first peel. The touch-up can be localized or full-face, if the condition of the skin permits and if there has been a long rest period. Skin regeneration after the second peel is much quicker, there is less edema, and postpeel erythema is of a much shorter duration (2 weeks at the most). If a third phenol peel were indicated (in extremely rare cases of very thick skin, patients who smoke, or rapid resumption of facial expressions), it would most often be localized. The author has only once had to do a third phenol peel on the lip and cheek area after inadequate results on skin that was extremely oily and thick. Recovery was even faster after a third application of phenol, and there was hardly any erythema. It should be noted that if a second phenol peel can boost inadequate results, a third phenol peel only brings a very slight improvement over the second.

MELANOCYTE TOXICITY Melanocytes are located in the basal layer of the epidermis and form part of the dermoepidermal interface. Skin color depends—among other things—on the melanocytes’ capacity to give up their melanosomes to neighboring keratinocytes and thus provide a homogenous photoprotective layer of pigments on the surface of the epidermis. It has been shown6 that melanocytes have three different ways of transporting melanin to keratinocytes: • • •

Melanocyte phagocytosis: Transfer of melanin plus cytoplasm plus melanocyte dendrites to the keratinocyte. Membrane fusion between melanocytes and keratinocytes, leading to direct exchanges between melanocytes and keratinocytes. Exocytosis of melanosomes by melanocytes to the extracellular environment, where they are picked up again by keratinocyte endocytosis.

Each melanocyte communicates with 35–40 keratinocytes through its dendrites and forms one “melanization unit.” If the melanocyte transmits eumelanosomes, the keratinocytes receive effective sun protection. On the other hand, if pheomelanosomes are transmitted to the keratinocytes, they will not be properly protected against UV rays. Keratinocytes can synthesize active substances that alter the proliferation, differentiation, and certain biological functions of melanocytes.6 An agent’s melanocyte toxicity is an advantage when treating melanin hyperpigmentation. On the other hand, it is an adverse effect when melanocyte toxicity results in partial, complete, localized, or generalized depigmentation. Complete, generalized, and permanent depigmentation results in “porcelain”

skin and, according to Litton,7 occurs in 3% of phenol peels with his formula. This complication has not been described to date with the Lip & Eyelid Formula.

Melanocyte Toxicity of Different Types of Peels AHAs AHAs are not considered toxic to melanocytes. Therefore, there is little fear of depigmentation when these peels are applied according to the rulebook. When these peels are neutralized, their effect stops, and AHAs cannot therefore do any irreversible damage to melanocytes. If they are not neutralized soon enough, they can, however, cause melanocytic lesions and areas of depigmentation as a result. Uneven penetration of AHAs can damage melanocytes locally. Uneven penetration can occur when: • • • •

There is no skin preparation (except for Easy Phytic peel8). The doctor does not apply the peel evenly. The patient has applied products locally that reduce the thickness of the stratum corneum (tretinoin, glycolic acid, benzoyl peroxide, etc.).9 The patient has used abrasive or hair-removing techniques that alter the relative impermeability of the skin before the peel.

In general, the appearance of frosting during an AHA peel is a sign of overpeeling, and pigmentation problems may well occur. An AHA peel should always be neutralized after erythema and before frosting. TCA TCA is not considered toxic to melanocytes. High concentrations of TCA can, however, coagulate melanocytes and destroy them. Areas of depigmentation can therefore appear if TCA has been too aggressive locally. Aqueous solutions of TCA in particular can penetrate more deeply than they should, as they are neither homogeneous nor stable. An even, intraepidermal TCA peel to the basal layer or Grenz zone does not cause depigmentation. Easy TCA, in the basic protocol, does not produce depigmentation. A TCA peel to the papillary dermis, if applied evenly, does not usually cause permanent, pathological depigmentation. If the TCA penetrates too deeply into the dermis, depigmentation is sometimes accompanied by scarring. Three different degrees of TCA penetration cause three different complications: scarring results from the deepest penetration; depigmentation without scarring results when the TCA penetrates too deeply (but not deep enough to cause scarring) and is ­melanolytic; and a hyperpigmented halo results from an untreated, peripheral inflammatory reaction. Phenol Phenol is considered toxic to melanocytes, although pigmentary changes can sometimes occur after a phenol peel (see later in this chapter). Phenol is by far the most effective agent when it comes to treating many facial hyperpigmentations. In ­general, a slight loss of pigment should be considered as normal after a phenol peel, and not as a complication. For a given concentration, depigmentation is proportional to the total quantity of phenol applied to the skin. That means that several coats of the same product will cause depigmentation more often than a smaller number of coats. The presence of adjuvants can also be

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a risk factor for depigmentation: croton oil is a common adjuvant in phenol formulas and enhances penetration of the phenol. If there is too much croton oil, the phenol can penetrate more deeply and cause depigmentation. The use of thymol iodide as a postpeel mask is another risk factor, as thymol is a phenol derivative that can have a toxic effect on melanocytes in the period immediately following the phenol peel. This risk can be avoided by using bismuth subgallate as a postpeel mask. Phenol is not melanolytic, however: it does not physically destroy melanocytes. Melanocytes are not simply melanin-­ producing organelles but play an active part in many of the biological processes in the skin: • • • •

Cytokine production. Inflammation mediator. Enzyme production. Synthesis of molecules in the extracellular matrix.

Histological sections taken after phenol peels show that melanocytes are still present, though many of them are inactive. Clinically, fewer melanocytes are rendered inactive with the latest formulas (e.g., Lip & Eyelid). This means that longterm prognosis for sun exposure can be better with these peels than with older phenol formulations and that a few months or even a year after the peel, it is often difficult to see a demarcation line.10 The melanocyte toxicity of phenol means the practitioner must choose the product most suited to the patient’s complexion. When persistent (absolute or relative) depigmentation is likely after a phenol peel, it is essential to warn patients that the texture of their skin will be rejuvenated but that in all likelihood they will have to wear foundation on a permanent basis to hide the difference in color between the treated and untreated skin. The risk of depigmentation can pose a problem with badly sun-damaged skin, but, at the same time, this is one of the best indications for phenol. The extraordinary results achieved on photoaged skin are often accompanied by a more visible demarcation line between the areas of healthy, treated skin and the old, untreated skin. Combined use of phenol on the face and Easy TCA or Unideep on the neck help attenuate this demarcation line (see Figure 30.1). The melanocyte toxicity of phenol poses different problems depending on whether the treatment has been applied to the whole face or just locally (e.g., the upper lip). Depigmentation of the whole face is easier to hide with makeup than localized depigmentation, and this should be discussed with the patient. Usually, older patients whose upper lip is very damaged will accept this local depigmentation, easily disguised with camouflage makeup, whereas younger patients find it more difficult to accept being condemned to wearing makeup every day, and often prefer other treatment options.

“base” color, and the area treated with phenol may well return to this original color.

Melanocyte Toxicity Depending on Skin Phototype Black Patients Black patients can be treated with correctly neutralized g ­ lycolic acid or with Easy Phytic Solution. Easy TCA can also be used (pinpoint or cloudy-white frosting); TCA should never be allowed to penetrate the reticulary dermis (see Chapter 16). Phenol should not be applied on patients with a skin phototype above IV. Asian Patients Asian patients might pose a problem of residual depigmentation with deep peels. Patients with dark Asian skin are treated like those with black skin. Lighter Asian skins can be treated with deeper peels. Fintsi69 and Professor Damiano Kim (Korea) applied phenol successfully to patients with light Asian skin. AHAs, Easy Phytic, and Easy TCA can be used in all cases. TCA in simple aqueous solution (TCA–SAS) often triggers PIH on Asian skin. Unideep should be used with caution on Asian skin phototypes. Dark-Skinned Patients Mediterranean or Latin American skin types can be treated with AHAs, superficial TCA, or Easy TCA. A TCA peel to the papillary dermis can be used with caution, avoiding overpeeling and postpeel inflammatory reactions. Patients with skin phototype IV can be treated with phenol if the patient is warned of the possibility of depigmentation in the treated skin. Results can be very satisfactory, as the difference in color between the treated and untreated areas may not be too marked. Red-Haired Patients Red-haired patients, whose skin is often covered in freckles, do not pose any problems with AHA peels or Easy TCA. A TCA peel to the papillary dermis eliminates most of the freckles, and Easy TCA in the basic protocol lightens them. In principle, the texture of their skin makes them good candidates for phenol, as they get wrinkles sooner than darker skin phototypes and do not often suffer from PIH after a medium or deep peel. All the freckles will disappear, however, leaving the skin depigmented and a demarcation line on the neck. Red-haired patients are the ones most at risk of complete depigmentation after phenol: porcelain skin that often will take on the color of areas that have never been exposed to the sun.

Treating Melanocyte Toxicity As yet there is no easy and effective treatment to return color to a skin that has lost it. No doubt in the future melanocyte grafts will be a possibility. For now, makeup is the only solution.

Prevention

ERYTHEMA

The selected peel must be applied in strict accordance with the instructions for use. The practitioner should always bear in mind that the deeper the peel, the more effective it is, but also the more dangerous it is and that phenotype does not always correspond to genotype: an individual who appears to have a light complexion may react dermatologically like a much darker phenotype. With this in mind, family anamnesis might well prove worthwhile. Examining the areas of the body that have never been tanned can provide a clue to the patient’s

Postpeel erythema can be perfectly normal (Figure  37.5) or a warning sign of a more serious complication. Erythema can occur as a reaction even after simply cleansing thin and sensitive skin before a peel. If an erythema develops after the skin has been cleansed gently and without acid products, it may be concluded that it is hypersensitive and should be treated with caution. Chronologically, the skin’s first response to an application of acid is usually erythema. This erythema is caused by the

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•

the peel has been applied. After the acid has been properly neutralized, the erythema should be transient and last one hour at the most. If the practitioner ignores the erythema and does not neutralize, the AHA peel can cause localized pinpoint frosting that will gradually converge and become relatively u ­ niform. An AHA peel that is not neutralized causes scabbing and, in the most serious cases, dyschromia and scarring. Patients often give up on the treatment if the peel is not properly neutralized. Erythema from overpeeling can last for several weeks or months and leave areas of skin that are “smoother” than the surrounding skin.

Easy Phytic Solution This peel deserves special attention because of the fact that it does not need neutralizing (see Chapter 11). It triggers light and uniform erythema that lasts for a few hours at the most. Neutralizing this peel would reduce its effectiveness and negate any benefit. If any abnormal frosting occurs, the peel should be neutralized immediately.

TCA and Erythema

Figure 37.5  Normal erythema after a full-face phenol peel.

inflammatory vasodilation of the blood vessels in the dermis in response to chemical injury. The vasodilation triggers transient dermal edema. This edema is largely responsible for the rapid disappearance of fine lines after superficial peels. The dermis fills with extravasated fluids as a result of vasodilation, and this stretches the epidermis. The fine lines disappear temporarily. Erythema may therefore be the only clinical sign of a superficial peel. The deeper the peel, the more erythema is replaced by frosting due to protein coagulation. The speed with which erythema is replaced by frosting largely depends on the strength of the acid used. Some very strong acids trigger frosting even before erythema becomes apparent.

AHAs and Erythema AHAs in Aqueous Solution Essentially, AHAs trigger erythema—a sign that the peel should be neutralized. Erythema appears more quickly when the skin has been prepared (certain products increase the permeability of the stratum corneum) during the weeks before the peel. •

•

Very localized, isolated erythema signals an area where the AHAs have penetrated rapidly. The doctor should keep a close eye on this area and neutralize it with sodium bicarbonate or another alkaline solution, while leaving the peel to work a little longer on the rest of the treated area that has not yet reached the stage of erythema. Great care should be taken not to let the acid penetrate too deeply locally and trigger frosting, which can lead to complications. After neutralizing, it can help to apply a little cortisone cream on an area of erythema. Even and light erythema is a clear sign that it is time to neutralize the peel with an alkaline solution prepared before

TCA in Simple Aqueous Solution (TCA–SAS) The appearance of light, uniform, and widespread erythema after a TCA–SAS peel does not usually lead to any problems and has a natural tendency to resolve gradually without treatment. The appearance of localized erythema, especially on the cheekbones, should alert the doctor, as it can be a sign of local overpeeling or one or more of the following: • • • • • • •

Too high a concentration of TCA. An inhomogeneous TCA solution. Too many coats of acid applied locally. Too aggressive or uneven prepeel preparation. Scratch lesions becoming infected. The start of a viral infection. An incorrect application technique.

Applying TCA to the skin produces, in sequence, the following clinical signs: erythema, pinpoint frosting, cloudy-white frosting, converging cloudy frosting, even pink-white frosting, pure white frosting, and finally gray-white frosting. The speed with which one sign replaces another is dose-dependent. These signs should appear in sequence when a low-­ concentration TCA peel is applied in successive coats. A more concentrated TCA peel will trigger converging clouds of frosting at the same time as erythema around the frosting (Figure  37.6). Higher concentrations trigger pink frosting instead of ­erythema, and erythema only appears only as the frosting fades in the treated areas. Highly concentrated TCA triggers immediate “pure white” frosting without any hint of pink or gray, which signals coagulation of the skin proteins and the walls of the dermal blood vessels. Although the erythema from TCA is often less severe than that from phenol, it can be vivid and last 15 days to several months. TCA–SAS peels sometimes produce prolonged and spectacular erythema, as can be seen in Figure  37.7. These simple aqueous solutions do not penetrate evenly, and uneven pathological erythema often results. Erythema after a peel to the ­papillary dermis with TCA in simple aqueous solution is usually

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expected to last 1–2 months. A peel to the top of the reticular dermis can last 1–3 months. Persistent erythema is often followed by inflammatory hyperpigmentation that is aggravated by sun exposure. Effective sun protection (see Chapter 3) is therefore essential as long as the erythema persists. Indurated erythema might lead to scarring, and preventive treatment should be started (see the section on scarring later in this chapter). When intraepidermal TCA peels or TCA peels to the basal layer are repeated too often,11 erythema can last even longer. Using tretinoin during the weeks before or after a TCA peel is also likely to trigger or exacerbate erythema.

Figure 37.6  Normal erythema around an area of frosting during a TCA peel to the papillary dermis (Unideep) on the décolletage.

Easy TCA Basic Protocol (Pinpoint or Cloudy-White Frosting)  Light erythema develops immediately after the peel and disappears in around 30 minutes (Figure  37.8). The skin may appear “sunburned,” and this can last up to a maximum of 48 hours in patients with thin and sensitive skin. Because of the action of the postpeel cream, there is often no observable erythema during the days following this peel if it has not gone beyond pinpoint or cloudy-white frosting. The postpeel mask scavenges free radicals and breaks the vicious inflammatory cycle that sets in after any peel. Scratch lesions can, as with TCA–SAS solution, cause localized erythema resulting from local infection (Figure 37.9), which should be treated. Treating Stretch Marks  This more aggressive protocol involves sandpaper abrasion prior to the application of Easy TCA solution and 12–24 hours’ occlusion of the postpeel mask cream. It causes severe erythema within the first few hours of occlusion. After the occlusion has been removed, the skin looks swollen and red (Figure  37.10). During the first week, overall developments are comparable to those of a phenol peel. The erythema can last for several weeks, and the next peel can only be performed after the erythema has completely resolved. As with TCA–SAS, persistent localized erythema is a sign of local complications and should be monitored, while uniform erythema has a natural tendency to resolve gradually without treatment (Figure 37.11).

Figure 37.7 Uneven, pathological erythema after TCA in aqueous solution—a peel to the papillary dermis. (Courtesy of Dr. A. Carvajal, Colombia.)

Figure 37.8  Normal and transient erythema 30 minutes after Easy TCA.

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Figure 37.11  Erythema totally disappeared 5 weeks after Lip & Eyelid Formula of upper eyelid and Unideep (TCA peel to papillary dermis) in the rest of the face. Figure 37.9  Localized erythema around scratch lesions after an Easy TCA peel to the papillary dermis.

Figure 37.10  Erythema 24 hours after treatment of stretch marks: abrasion-occlusion protocol.

Unideep Unideep is a TCA peel to the papillary dermis. Adapted from Easy TCA technology, it consists of a peel solution and a postpeel mask. Thanks to the postpeel mask, the erythema following the peel does not last as long as the erythema after a peel with TCA–SAS to the same depth. The erythema following Unideep lasts approximately 5–8 days (Figure  37.12), and the only treatment that it requires is an application of antioxidant cream (e.g., Renutriv ACE Lipoic Complex) and Vaseline

Figure 37.12  Erythema 5 days after Unideep on the face, apart from the area around the mouth, which was treated with occlusive Lip & Eyelid.

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(a)

(b)

Figure 37.13  Normal erythema after Only Touch and Easy TCA for lentigines: (a) before; (b) 2 weeks after treatment.

(see Chapter 23). If there is persistent localized erythema, there might be a local complication, and treatment is necessary. Effective sun protection must be used. Only Touch Only Touch is an adjuvanted, stabilized, and concentrated TCA peel, used to reach the reticular dermis locally. It should be applied in strict accordance with the recommendations for use (see Chapter 22). The erythema that always follows an application of Only Touch usually lasts 2–3 weeks and gradually resolves without treatment (Figure  37.13). Only Touch should be applied carefully, avoiding any excess product and limiting contact time between the applicator and the skin: the skin should just be touched lightly, with the same pressure as for pushing the buttons on a telephone to dial a number. If contact time is any longer, the acid solution will penetrate too deeply. Too much solution