Advances In Chemical Peeling

Advances In Chemical Peeling

Gary D. Monheit, M.D.
Associate Professor
Department of Dermatology
University of Alabama at Birmingham
Birmingham, Alabama

The explosion of interest in chemical peeling by cosmetic surgeons and dermatologists has paralleled the general public interest in youthful appearance, photo aging skin and it's rehabilitation. A number of home treatment programs, cosmetic agents and over the counter chemicals have entered the general market to rejuvenate skin and erase the marks of sun damage and age. Though 90% of these products do little more than abrasive exfoliation and moisturization, the quest for youthful skin continues and the cosmetic surgeon remains at it's forefront.

Concurrent to the public's desire for rehabilitation of aging skin has been a new renaissance in chem-exfoliation. Just fifteen years ago, the name chemical peel was associated only with the deep phenol peel and heavy concentrations of trichloracetic acid. There was little understanding of the injury pattern created and its correlation with skin regrowth, potential side effects and complications. Objective analysis by Gordon-Baker, Litton and Kligman documented the histologic depth and injury pattern of the deep peel.1 With the pioneer work of Drs. Reznick and Ayres, a clinical and scientific background for the use of trichloracetic acid was begun.2 Histologic correlation of peel depth with varying concentrations of phenol and trichloracetic acid performed by Dr. Sam Stegman, serves as the scientific basis for our objective understanding of wounding depth and the efficacy of chemical peeling.3 A classification of peeling agents emphasizes depth penetration as a reflection of activity rather than chemical formulas. Thus, labeling a peel as superficial, medium, and deep depth is more meaningful than the chemical names phenol or trichloracetic acid. A new understanding of peel injury and repair has emerged, along with an appreciation of variations in patient skin type, pigmentation, and degree of photo aging. Utilizing the Fitzpatrick,(Table I) and the Glogau system (Table II) of pigmentation and sun damage, one can individualize the strength of chemical agents to match skin types.4 Wounding depth of each agent has been correlated with histology. Trichloracetic acid light and medium depth peeling has been quantitated with depth of injury, morbidity and degree of results. The risks of deep peeling with greater than 50% trichloracetic acid can be weighed against the patient's need and degree of photo damage.

A new emphasis has been placed on the medium depth peel, the combination peels and repeated lighter peeling regimens. Brody has pioneered the use of 35% trichloracetic acid with carbon dioxide freeze in selective areas.5 The physical and chemical agent used together produces a deeper peel than that found with 35% trichloracetic acid alone. Similarly, a combination of chemical agents, the Jessner - Trichloracetic acid peel has combined wounding agents to create an enhanced level of efficacy.

This brings us to our present usage of peeling agents and the future of chem-exfoliation. The successful usage of the newer agents available depend upon the cosmetic surgeon's full understanding of photoaging skin and skin types. The photo types are taken into careful consideration in the choice of agents used to prepare the skin, to peel the skin, and for skin after care. The cosmetic surgeon can assess the degree of skin damage and choose the appropriate wounding agent to achieve realistic and desirable results for the patient. Mild photoaging damage may respond better to repeated light TCA peels or the alpha-hydroxy acid (AHA) peels. These should be performed in combination with retinoids, abrasives and sunscreen protection. For this type of patient, an ongoing program of daily skin care, multiple peels and protection against further photo aging is the full package necessary for skin rejuvenation. Physicians and patients must understand that repetitive superficial peels do not produce the same effects of deeper chemical peels as promised by many lay concerns.

Patients with moderate photoaging skin will achieve a more desirable result with a combination medium depth peel. The combination includes either the Jessner 35% trichloracetic acid peel or the CO2 freeze - 35% trichloracetic acid peel. Both of these combinations achieve more desirable results than 35% TCA alone. The combination enhances the depth of the peel to a moderate depth chemical peel (i.e. mid dermis).7 It's use for pigmentary dyschromia, fine rhytides, weathering of the skin and sallow texture, gives greater results than 35% trichloracetic acid alone. Other choices would include the use of plain phenol, or one of the new combination peels such as additive trichloracetic acid as per Drs. Fulton or Obagi.

Severely damaged photo aged skin including perioral rhagades, deeper rhytides and textural changes require a deeper peel, and the Gordon-Baker phenol peel is my choice. The depth of this peel though, will produce hypopigmentation and a change in texture of the underlying skin in many patients. This is especially important in Fitzpatrick skin types III-VI, and those patients with sebaceous skin.

The cosmetic surgeon, thus, should be familiar with at least two or three chemical peeling agents so that he can use the appropriate tool for the patient's skin type and degree of photoaging.(Table III) It is impossible to be familiar with all the agents on the market, and I think it is best for the clinician to be proficient in a light, a medium depth and a deep peeling agent. My choices are:

The chemical peel procedure itself is not an all or none phenomena, in that the steps taken in the procedure each add a variability to the depth of the peel. This allows the clinician to modify peel depth in patients, and even in regions of the face or neck. For example, a deeper injury may be necessary in the perioral area to improve skin texture and rhagades, while that may not be necessary on the cheeks and temples. The surgeon can choose a Baker-Gordon peel for the lip and Jessner's TCA 35% for the remainder of the face.

Several stages can be modified to enhance the efficacy of the peel: skin preparation, cleansing and degreasing the skin, application of an adjunct agent and application of active peeling agent.

The Jessner - trichloracetic peel will produce excellent results for moderate photo aged skin. However, deeper rhagades and rhytides in the perioral area, in the periorbital area and glabella, show limited response to this level of chemical peeling. For those patients with moderate photo aging on the cheeks and forehead and more severe aging skin in the periorbital area, a combination chemical peel may be the answer. The author has used the Baker's phenol peel in the periorbital, the perioral and glabellar area while using the Jessner 35% trichloracetic acid peel over the rest of the face. This combination has a distinct advantage in that the clinician has specifically chosen the peel solution to be used for each of these facial areas, and thus will not be over-treating the entire face with a deep chemical peel. He can thus limit the morbidity and complications of the deep chemical peel and simplify the procedure. Because the deep agent is only used on limited portions of the face, the patient would not need IV fluid loading and the necessary monitoring required for a full face phenol peel.10 The medium depth peel used over the rest of the face will blend since deep peels result in hypopigmentation and/or textural changes. The patient will have a softer, more even result when a medium depth peel is on the rest of the face to achieve "blending". Combining individual agents in distinctive areas in our patients provides the surgeon with more precise tools to treat the many faces of aging skin.

This brings us to the horizon of chem exfoliation, and I feel the future will offer us a greater understanding in the nature of photo damage and it's early correction. Programs of skin care will be more common and patients will be treated with ongoing protocols to continuely reverse the factors and environmental wear and tear of aging. These will include repeated peelings, as well as using topical pharmacologic agents, home exfoliants, and sunscreen protection. The physician will remain in the forefront in the field of cosmetic pharmacology and surgery. He must function as a guide to his patients who are barraged daily with promises from proprietary companies, cosmetic counters and salons. He must dispel the promised miracles and discuss the benefits of skin care realistically and objectively. This is an exciting time for the cosmetic surgeon to explore the new tools and techniques of chemical peeling.

Fitzpatrick's Classification of Skin Types

Skin Type Color Reaction to Sun

Table II
Photo Aging Group - Glogau's Classification

TABLE III

Back to Dr. Monheit's Bio