You are in: eMedicine Specialties > Dermatology > SURGICAL Chemical PeelsArticle Last Updated: Jan 19, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: Raymond T Kuwahara, MD, Dermatologist, Private Practice Raymond T Kuwahara is a member of the following medical societies: American Academy of Dermatology Coauthor(s): Ron Rasberry, MD, Chief of Dermatology, Veterans Medical Center at Memphis; Associate Professor, Department of Dermatology, University of Tennessee at Memphis Editors: Zoe Diana Draelos, MD, Clinical Associate Professor, Department of Dermatology, Wake Forest University School of Medicine; Primary Investigator, Dermatology Consulting Services; Private Practice; Michael J Wells, MD, Associate Professor, Department of Dermatology, Texas Tech University Health Sciences Center; Christen M Mowad, MD, Assistant Professor, Department of Dermatology, Geisinger Medical Center; Catherine Quirk, MD, Clinical Assistant Professor, Department of Dermatology, Brown University; Dirk M Elston, MD, Director, Department of Dermatology, Geisinger Medical Center Author and Editor Disclosure Synonyms and related keywords: chemoexfoliation, chemo-exfoliation, chemoexfoliants, skin peel, chemical peel, skin resurfacing, exfoliation, cosmetic exfoliation, chemical exfoliation HISTORY OF CHEMOEXFOLIATIONSection 2 of 11
  Since the days of ancient Egypt, people have been using chemoexfoliation methods, also known as chemical peeling, to rejuvenate skin. The original chemoexfoliant was lactic acid, an active ingredient of sour milk that was used topically by the nobles as part of an ancient skin rejuvenation regimen. In the Middle Ages, old wine with tartaric acid as its active ingredient was used for the same purpose. Today, these historical chemoexfoliants are known to contain alpha hydroxy acids, which are the active ingredients responsible for the skin exfoliation. The chemical peel produces a controlled partial thickness injury to the skin. Following the insult to the skin, a wound healing process ensues that can regenerate epidermis from surrounding epithelium and adnexal structures, decrease solar elastosis, and replace and reorient the new dermal connective tissue. The result is an improved clinical appearance of the skin, with fewer rhytides and decreased pigmentary dyschromia. Modern day chemical peeling originally was promoted by dermatologists, such as P.G. Unna, who first described the properties of salicylic acid, resorcinol, phenol, and trichloroacetic acid (TCA). Slowly, the early practitioners of chemical peels began to develop other peeling agents for varying depths of penetration. In the 1960s, Baker and Gordon developed a deep peeling agent, which was able to smooth deeper furrows, especially around the mouth. From the 1980s to the present, an explosion has occurred in the mass of research on this subject, with the elucidation of many different types of peels, each for a specific range of problems. STAGES OF WOUND HEALING AFTER CHEMOEXFOLIATIONSection 3 of 11
Coagulation and inflammation Clotting factors are activated, as are monophages and lymphocytes. Inflammatory mediators are activated, such as C5a, leukotriene B4, and kallikrein. Reepithelialization Preventing scab formation is important for faster and more even healing. Biosynthetic occlusive dressings can be used to hasten the healing process. Granulation tissue Granulation tissue usually appears the second day and consists of fibroblasts, inflammatory cells, fibronectin, glycosaminoglycans, and collagen. Angiogenesis This process begins with endothelial cell migration to the wound site and is essential for wound healing. The erythema following a chemical peel primarily is caused by the new capillary growth in the area. Collagen remodeling Collagen remodeling is the main reason that chemical peels are able to reduce wrinkles. The process of remodeling involves a reorientation of the collagen in a parallel fashion and begins as collagen is formed following the peel. GENERAL PEELING CONCEPTSSection 4 of 11
The process of performing a chemical peelAn evaluation of the patient by the clinician is necessary to determine the appropriate treatment based on the dermal defect. If it is determined that a chemical peel is warranted, the appropriate agent is selected based on the patient's Fitzpatrick skin type and Glogau's photoaging group, as well as other variables that may affect peel penetration. The patient must be educated concerning the chemical peel process and give signed consent if performing a medium or deep peel. The skin should be defatted properly with acetone. Delicate areas that need to be protected should have petroleum jelly applied to the lips, inside the nose, and optionally in the nasolabial fold, medial canthus, and lateral canthus. The correct peeling agent then is applied for the appropriate amount of time. When performing a combination peel, pouring one agent at a time is advisable because of the ease in which the agents may be confused when poured into similar cups. Then, the peeled area should be neutralized, and the patient should be sent home with proper instructions along with advice to call should any complications arise. Indications for chemical peelIndications include actinic keratoses, actinic rhytides, pigmentary dyschromias, superficial scarring, radiation dermatitis, and acne vulgaris. Upper epidermal defects, such as melasma, can be treated with superficial peels, while deeper defects, such as deep wrinkles, may require a deep peeling agent. Medium-depth (superficial dermis) defects, such as mild dermatoheliosis, require a medium-depth peel. Deep perioral rhytides may require a deep peel, such as the Baker Gordon solution. Relative contraindicationsGlogau photoaging classification In type I, the patient, usually aged in the second or third decade, shows mild, early photoaging that consists of mild pigmentary changes, absence of keratoses, and minimal wrinkles. The patient requires minimal or no makeup. In type II, the patient has "wrinkles in motion" (ie, wrinkles that appear when making facial gestures or other dynamic facial muscle activity). Early-to-moderate photoaging is recognized by early senile lentigines, keratoses that are palpable but not visible, and the emergence of parallel smile lines. The patient's age usually is in the third or fourth decade. Female patients usually wear some foundation. In type III, the patient has "wrinkles at rest." Advanced photoaging is recognized by obvious dyschromia, telangiectasias, visible keratoses, and wrinkles at rest. The patient is usually 50 years or older, and female patients almost always wear heavy foundation. In type IV, the patient has "only wrinkles." Severe photoaging is characterized by yellow-gray coloration of the skin, prior history of skin malignancies, and skin that is thoroughly wrinkled. The patient's age is usually in the sixth or seventh decade. In addition, the patient cannot wear makeup because it "cakes and cracks." The Glogau photoaging classification is a visual grading system used to quantify photodamage. Patients with photoaging type I are not good candidates for deep peeling because the peel may be more damaging than beneficial, while a superficial peel would be more efficacious. Patients with type IV may benefit from deep peeling, while a superficial peel may hardly make a difference on this type of skin. Patients with skin types II and III ordinarily benefit from superficial or medium-depth peels depending on the exact circumstances concerning the patient. Other variables described in this article also should be considered, including the Fitzpatrick skin type, when determining which peeling agent to use. Fitzpatrick skin typing is graded from 1-6, with the first 3 skin types being of white skin and with progressively more active response to tanning. Type 4 is light brown skin, and type 5 is dark brown skin. Type 6 skin never tans and is essentially black skin with an equivalent SPF of 8. Fitzpatrick skin types 5 and 6 are usually not ideal candidates for medium and deep peels. The best candidates are the light skin types 1, 2, and 3, which have less chance for such complications as pigment dyschromia and scarring. Although skin types 5 and 6 are not ideal for peels, they can be peeled using such superficial agents as salicylic acid or glycolic acid. Degree of photoaging damage Patients with severely damaged skin may not be good candidates nor are those at the opposite end of the spectrum with excellent skin. Smoking Patients must understand the necessity for smoking cessation. The dynamic action of puffing can worsen perioral rhytides, and the chemicals in the smoke can cause enzymatic reactions that weaken the skin and cause further wrinkling around the mouth and eyes. Prior cosmetic surgery Waiting several months following surgery that involves the face is recommended. Give the skin time to heal prior to subjecting it to chemoexfoliation. General health With phenol peels, the patient should be in good general health since phenols can cause arrhythmias. Good kidney and liver function are necessary for adequate excretion and detoxification. A screening blood chemistry that includes blood urea nitrogen, creatinine, and liver function is wise. ECG monitoring is necessary during the peeling process. Mental health Patients who are mentally unstable may be overly self-conscious and may not be prepared for their aesthetic appearance immediately following the peel. Medications Oral contraceptive pills can cause melasma, further worsening the skin discoloration that the chemical peel was intended to eradicate. Patients taking blood thinners, such as warfarin, should avoid deep peels because of the possibility of blood oozing from the peel site. Patients taking aspirin usually do not have complications, but, if the medication is not necessary, advising them to stop taking it 1 week prior to a deep peel is advised. Herpes Treating patients who have a history of herpes simplex with acyclovir is prudent. Acyclovir (400 mg) should be started 2 days prior to the peel and continued for 5 days after the peel to reduce the risk of recurrent herpes infection. History of scarring Patients need to be asked if they have a history of hypertrophic scarring. Many people who have hypertrophic scarring can develop keloids. This usually is found in patients with Fitzpatrick skin types 5 and 6 but can develop in patients with skin types 1, 2, 3, and 4. Medium and deep peels penetrate into the superficial and deep dermis, which may stimulate keloidal development in patients who are inclined to develop keloids. Weak superficial peels can be considered in skin types 4 and 5 since penetration is only into the epidermis. Patients with a history of scarring are not candidates for major skin resurfacing, such as laser or medium/deep peels. Expectations A discussion between the physician and patient is necessary prior to a chemical peel, especially a deep peel. Examples of before-and-after results should be shown, and the possibility of complications must be explained to the patient. Follicle unit density Previous use of isotretinoin must be noted. Patients should wait until 6 months after the last dose of isotretinoin to reduce the risk of scarring. Patients who have had recent radiation treatment need to have a skin biopsy performed to ascertain the existence of hair follicle units, since these follicle units are where the reepithelialization occurs. FACTORS AFFECTING PEEL DEPTHSection 5 of 11
Patient history History is taken to determine the amount of sun-induced damage, history of hypertrophic scarring or keloid formation, and a general medical history. Items of interest include a history of prior surgeries, dermabrasion, or recent laser therapy. In addition, medicines, such as isotretinoin, need to have been stopped for at least 6 months prior to chemical peeling. Peeling agent concentration Peeling agent concentration can vary, even though the label indicates the same concentration. The different methods used to determine concentration of acid can produce some variation. From strongest to weakest, these methods are dilutions of a saturated solution, weight-to-weight method, weight-to-volume method, and grams of acid crystal mixed to 100 mL of water. Free acid availability The pH of the agent, or free acid available pKa, is another measurement. The pKa of the solution is the pH at which half is in acid form; therefore, a lower pKa means that more free acid is available. Many products advertise the acid percentage; however, pKa is a more accurate determinant of strength. Application of peeling agent The clinician can vary the number of coats depending on the depth of peel desired. The peel frost, or facial whitening indicating depth of epidermal damage, can aid in the determination of this number. Frequency that patient receives a peel Most patients can tolerate a monthly superficial peel, while medium-depth peels can be performed at 6-month intervals if necessary. Method of application The acid should be applied with a brush, cotton, or sponge applicator. The acid should not form pools in the facial folds nor drip from the face. The more acid that the clinician applies, the deeper the peel. Contact time How long the peeling agent is applied also determines the depth of the peel. After the appropriate time has past, neutralization is performed. Some chemical peels, such as salicylic acid and trichloroacetic acid, do not require a neutralization step since the skin neutralizes the acid. Glycolic acid peels must be neutralized. Always wash the patient's face with water following the peel. Density of adnexal structures Recent radiation treatment can affect the density of adnexal structures. The reepithelialization process partially occurs from the adnexal structures; therefore, some clinicians advise that a punch biopsy be performed to verify their existence. Occlusion Products available, such as biosynthetic occlusive dressings, may decrease pain and speed healing. Examples include hydrogel membrane products, such as Vigilon (Hermal Labs, Delmar, NY); polyurethane membranes, such as Meshed Omiderm (Doak Dermatologics, Fairfield, NJ); and silicone membrane Silon II (BomMed Inc, Bethlehem, Pa). Rejuvenation regimen Patients may treat the skin before and after a peel with such agents as tretinoin, hydroquinone, or an alpha hydroxy acid. These may help the skin heal faster and also allow the chemical peel agent to achieve better penetration. Ointments Petroleum jelly and other occlusive ointments may act as an occlusive barrier to a minor degree. Defatting The skin should be cleaned and excess fat removed with such agents as acetone, rubbing alcohol, or Septisol, or a combination of these agents. Three parts alcohol with 1 part acetone works well. A thorough defatting of the skin is necessary for proper penetration of the peeling agent since most agents are not lipid soluble. Application The peeling agent can be applied with 4 X 4 gauze, cotton swabs, or the foam applicator that comes with the peel kit. Popsicle sticks are good applicators for the paste form. Apply the peeling agent in cosmetic units, beginning with the forehead and finishing with the chin. Feather the peeling agent into the hairline and the shadow of the mandible. Reapplication of the peeling agent may be necessary if the frost is uneven or is not white enough. Frost The change in coloration of the skin to a whitish tint is called frost. This represents the end stage of the chemical peel and shows that keratin agglutination has occurred. Depending on the agent used, the white tint may vary from a brighter white in a superficial peel to a grayish white in a deep peel. Neutralization Neutralization of the chemical peeling agent is an important step once the clinician has achieved the proper depth of the peel, which is determined either by the frost or how much time has elapsed. Neutralization can be achieved by cold water or wet, cool towels applied to the face following the frost. This soothes the sharp tingling discomfort caused by the peeling agent. Other neutralizing agents that can be used include bicarbonate spray or soapless cleanser. Peels for which this neutralization step is less important include salicylic acid, Jessner's, and phenol. INSTRUCTION AND CONSENTSection 6 of 11
Following the peel, it is important that the patient follow instructions given by the physician to prevent complications. If possible, the patient should stay out of the sun; when unavoidable, the patient should apply a strong sunscreen and wear a hat. An ointment, such as petroleum jelly or bacitracin, should be applied to the involved skin. The patient should be made aware that the skin will exfoliate and may look cosmetically unattractive for a period of time depending on the depth of the peel. For superficial peels, a follow-up appointment can be scheduled at the time of the next peel. For deeper peels, patients should be seen 2-3 times the week following the peel to provide for early intervention if problems develop. The patient should be instructed to remain vigilant for signs of infection. If the patient has a history of cold sores, treating the patient with acyclovir (400 mg PO bid) or an equivalent drug is advisable, beginning 2 days prior to the peel and continuing for 7 days after the peel. CHEMICAL PEELING AGENTSSection 7 of 11
Superficial peeling agents TCA (10-35%) has been used for many years and is safe to use at lower concentrations. At higher concentrations, such as 50% and above, TCA has a tendency to scar and is less manageable than other agents used for superficial peels. TCA is found in several proprietary peels at varying concentrations, and some kits have instructions and buffering agents so the peel can be diluted as deemed necessary. Jessner's peel is a combination of salicylic acid 14%, lactic acid 14%, and resorcinol 14% in alcohol. This agent is easy to use, with no timing necessary. Apply the agent, wait for a light frost, and then neutralize with water. Salicylic acid has been used for several decades and is found in medications, such as Whitfield's ointment at 4% and Trans-Ver-Sal at 17% concentrations. Adverse effects, usually only found with high-dose oral ingestion, include headache, nausea, and ringing of the ears, each of which may be resolved with a few glasses of water and rest. These have never been reported with a peel procedure. Salicylic acid is lipid soluble; therefore, it is a good peeling agent for comedonal acne. The salicylic acid is able to penetrate the comedones better than other acids. The anti-inflammatory and anesthetic effects of the salicylate result in a decrease in the amount of erythema and discomfort that generally is associated with chemical peels. The most common concentration used today is 20-30% and can be purchased in easy-to-use kits. Carbon dioxide uses a solid block of carbon dioxide ice dipped in an acetone-alcohol mixture and then applied to the skin for 5-15 seconds, depending upon the desired depth. Carbon dioxide is easier to use, and the depth of the peel can be controlled more easily than with liquid nitrogen; Carbon dioxide is at -78°C, while liquid nitrogen is at -196°C. Alpha hydroxy acid peels include lactic acid, glycolic acid, tartaric acid, and malic acid that are synthesized chemically for use in peels. Various concentrations can be purchased, with 10-70% concentration used for facial peels, most commonly 50% or 70%. Medium-depth peels Three combination peels currently being used are carbon dioxide and TCA 35%, Jessner's and TCA 35%, and glycolic and TCA 35%. These peels are as effective as the other medium-depth peels with less chance of scarring and pigment dyschromia. An endless number of combinations are possible, more than can be covered in this overview. TCA 50% is seldom used because of a higher risk of scarring and the availability of the combination peels. Full strength phenol (88%) is a very caustic agent that causes immediate keratin agglutination, preventing further penetration of the agent deeper into the dermis. Again, the increased risk of scarring and pigment dyschromia makes this agent less attractive to the practitioner. If diluted and mixed with other complementary chemicals, this agent can be used effectively as a deep peeling agent. Pyruvic acid rarely is used today because of its fast action that causes difficulty in controlling the depth of this peeling agent. A product currently is being developed that uses ethyl pyruvate and has a higher pH and greater buffering ability than other related products. Deep peels Baker Gordon peel produces the most dramatic results and is the most effective peeling agent currently used. The phenol produces a new zone of collagen that is thicker than that produced by laser. This solution is very effective in smoothing wrinkles related to aging and sun damage. This advantage is countered by several disadvantages. The agent may produce premature ventricular contractions or more serious arrhythmia. A long healing time is required, with erythema occasionally lasting as long as 6 months. In addition, the potential for pigmentary changes, scarring, and infection are high with this peel. Despite the problems that may be encountered, a properly administered phenol peel is unmatched by the other peeling agents, and, for perioral wrinkles, the phenol peel even surpasses laser resurfacing. Although dramatic results can be achieved with the phenol peel, the risks and benefits should be weighed carefully before proceeding. Only experienced clinicians should attempt a phenol agent–based peel. The Baker Gordon solution is made of phenol 88%, 2 mL distilled water, 8 drops Septisol, and 3 drops croton oil. This formula penetrates into the middle reticular dermis and requires special monitoring devices, such as an ECG monitor and pulse oximeter, because of the potential of the phenol to cause arrhythmias. The Baker Gordon formula is not often used today because of resurfacing laser technology; however, a deep peel works well on deep perioral rhytides. Deep peels can be occluded or nonoccluded. Occluded method uses zinc oxide tape or other artificial barrier product to prevent evaporation of the phenol from the skin, thus enabling the solution to penetrate deeper. Two variants of the Baker Gordon peel are Litton's formula, which replaces Septisol with glycerin, and the Beeson McCollough formula, which uses aggressive defatting and heavier application of Baker Gordon solution. COMPLICATIONSSection 8 of 11
Pigmentary change Pigmentary change is not an uncommon complication, especially with the deeper peeling agents. In some cases, the peeled area remains stark white. Taking proper precautions (as described earlier) can prevent undesirable pigmentary changes. Scarring By matching the patient and peeling agent properly, the risk of scarring can be decreased. In addition, to further decrease the risk of scarring, the patient should be advised to refrain from picking at the healing skin. Patients with a history of keloids should not undertake medium or deep peels because of the risk of scarring. Medium and deep peels penetrate to the superficial and reticular dermis and, thus, may stimulate keloids. Weaker superficial peels that only exfoliate the stratum corneum or superficial epidermis can be used. Infection By using bacitracin for the medium and deep peels and cleaning the face with a povidone wash, the risk of infection is decreased. Cold sores can be prevented with acyclovir (400 mg PO bid), beginning 2 days prior to the peel and continuing 7 days after the peel. Candidiasis infection also can develop, for which a short course of fluconazole can be used. Cultures need to be taken, and appropriate antibiotics should be administered. Prolonged erythema Patients usually do not complain of erythema because it generally subsides in 30-90 days, but sometimes erythema continues. Prolonged erythema is usually not permanent, and topical hydrocortisone can be used to speed the healing process. Acne Some patients develop acne after a chemical peel. This usually occurs between days 3-9. Cultures should be taken, and an antibiotic that covers gram-positive bacteria should be prescribed. If it is a true acne occurrence, then the appropriate topical treatment also should be started. If severe enough, isotretinoin may be initiated. Milia Small inclusion cysts, sometimes called milia, can appear in the healing process after a chemical peel. These usually appear about 2-3 weeks after reepithelialization and may be aggravated by ointments due to occlusion of the sebaceous glands. SUMMARYSection 9 of 11
Novices at chemical peeling should educate themselves through dermatology conferences, journals, and, possibly, a preceptorship with a local dermatologist. After sufficient knowledge is obtained, starting with superficial problems, like acne, general skin rejuvenation, or melasma, using a superficial peel such as 20% salicylic acid, is recommended. Chemical peels are not a cure-all, and patient expectations should be realistic. Dynamic wrinkles caused by muscle action or sagging due to old age usually requires an alternative treatment, such as facelift, botulinum toxin (BOTOX®), or collagen injections. The clinician should assess each patient, explain the alternatives, and then decide on a course of action. The correct peeling agent needs to be chosen if chemoexfoliation is decided. Proper defatting of the skin is critical for an even peel. Application of the peeling agents needs to be performed correctly. Postpeel instructions need to be explained carefully. If performed correctly, the chemical peel can give excellent results with many satisfied patients. MULTIMEDIASection 10 of 11
REFERENCESSection 11 of 11
Article Last Updated: Jan 19, 2007 | |||||||||||||||||||||||||||||||
