Medium Depth Combination Peels
Gary D. Monheit, M.D.
Associate Professor
Department of Dermatology
University of Alabama at Birmingham
Birmingham, Alabama

A classification of peeling agents emphasizes depth of penetration as a reflection of activity rather than chemical formulation. The labeling a peel as superficial, medium or deep depth is more meaningful than using chemicals or brand names.1 A new understanding of peeling injury and repair has emerged along with an appreciation of the variation in patient's skin type, pigmentation and degree of photoaging. Utilizing the Fitzpatrick and Glogau system of pigmentation and sun damage, one can individualize the strength of chemical agents to match the skin types.2,3

Medium depth peeling is thus defined as the use of a chemical agent to wound skin through papillary dermis. It is most useful for the removal of epidermal or superficial lesions and to improve skin texture in moderate photodamaged skin (grade II Glogau photoaging skin). Medium depth peeling agents create changes through necrosis of the epidermis and part or all of the papillary dermis with an inflammatory reaction in the upper reticular dermis. The procedure is performed to remove actinic keratoses, mild photoaging of the skin including rhytides, treat pigmentary dyschromias, and improve depressed scars.4 (Table I)

Medium-depth chemical peeling
Medium-depth chemical peeling is defined as controlled damage from a chemical agent to the epidermis and papillary dermis that can be performed in a single setting. The benchmark for this level peel was 50% trichloroacetic acid. It has traditionally achieved acceptable results in ameliorating fine wrinkles, actinic changes, and pre neoplasia. However, since higher concentration TCA itself is an agent more likely to be fraught with complications, especially scarring, in strengths of 50% or higher, it has fallen out of favor as a single agent chemical peel.5 It is for this reason that the combination products along with a 35% TCA formula have been found equally effective in producing this level of control damage without the risk of side effects. Agents currently used include combination products – Jessner’s solution, 70% glycolic acid, and solid carbon dioxide with 35% trichloroacetic acid.6 (Table II)

Brody first developed the use of solid CO2 applied with acetone to the skin as a freezing technique prior to the application of 35% trichloroacetic acid. The preliminary freezing appears to break the epidermal barrier for a more even and complete penetration of the 35% trichloroacetic acid.

Monheit then demonstrated the use of Jessner’s solution prior to the application of 35% trichloroacetic acid. The Jessner’s solution was found effective in destroying the epidermal barrier by breaking up individual epidermal cells. This also allows a deeper penetration of the 35% TCA and a more even application of the peeling solution.8 Similarly, Coleman has demonstrated the use of 70% glycolic acid prior to the application of 35 % trichloroacetic acid. Its effect has been very similar to that of Jessner’s solution.9

All three combinations have proven to be as effective as the use of 50% trichloroacetic acid with a greater safety margin. The application of acid and resultant frosting is better controlled with the combination products. The “hot spots” that result from higher concentrations of TCA can be controlled, creating an even peel with less incidence of dyschromias and scarring. The combination peel produces an even, uniform peel with much less a risk of complications.10 The Monheit version of the Jessner’s solution – 35% TCA peel is a relatively simple and safe combination. This technique is used for mild-to-moderate photoaging including pigmentary changes, lentigines, epidermal growths, dyschromias, and rhytids. It is a single procedure with a healing time of seven to ten days. It is useful also to remove diffuse actinic keratoses as an alternative to chemical exfoliation with topical 5-fluorouracil chemotherapy. Topical chemotherapy is applied for three weeks creating erythema, scabs and crusts for up to six weeks.11 The combination peel will produce similar therapeutic benefits within ten days of healing. It thus reduces the morbidity significantly and gives the cosmetic benefits of improved photoaging skin.

The procedure is usually performed with mild preoperative sedation and nonsteroidal antiiflammatory agents. The patient is told that the peeling agent will sting and burn temporarily and aspirin is given before the peel and continued through the first twenty-four hours if the patient can tolerate the medication. Its anti-inflammatory effect is especially helpful in reducing swelling and relieving pain. If given before surgery, it may be all the patient requires during the postoperative phase. For full-face peels, though, it is useful to give preoperative sedation (diazepam 5 to 10 mg orally) and mild analgesia, meperidine 25 to 50 mg (Demerol – Winthrop, New York), and hydroxyzine hydrochloride 25 mg intramuscularly (Vistaril – Lorec, New York). The discomfort from this peel is not long lasting, so short acting sedatives and analgesics are all that are necessary.12
Vigorous cleansing and degreasing is necessary for even penetration of the solution. The face is scrubbed gently with Ingasam (Septisol - Vestal Laboratories, St. Louis, Missouri) with four-inch by four-inch gauze pads and water, then rinsed and dried. Next, an acetone preparation is applied to remove residual oils and debris. The skin is essentially debrided of stratum corneum and excessive scale. A thorough degreasing is necessary for an even penetrant peel. The physician should feel the dry, clean skin to check the thoroughness of degreasing. If oil is felt, degreasing should be repeated. A splotchy peel is usually the result of uneven penetration of peel solution due to residual oil or stratum corneum, and a result of inadequate degreasing.

After thorough cleaning, the Jessner’s solution is applied with either cotton-tip applicators or 2” x 2” gauze. (Table III) The Jessner’s solution is applied evenly with usually one or two coats to achieve a light but even frosting. The frosting achieved with Jessner’s solution is much lighter than that produced by TCA and the patient is usually uncomfortable, feeling only heat. A mild erythema appears with a faint tinge of splotchy frosting over the face. Even strokes are used to apply the solution to the unit area covering the forehead to the cheeks to the nose and chin. The eyelids are treated last creating the same erythema with blotchy frosting. (Fig 1)

The TCA is painted evenly with one to four cotton-tipped applicators that can be applied over different areas with light or heavier doses of the acid. Four cotton-tipped applicators are applied in broad strokes over the forehead and also on the medial cheeks. Two mildly soaked cotton-tipped applicators can be used across the lips and chin, and one damp cotton-tipped applicator on the eyelids. Thus, the dosage of application is technique dependent on the amount used and the number of cotton-tipped applicators applied. The cotton-tipped applicator is useful in quantatiting the amount of peel solution to be applied.

The white frost from the TCA application appears complete on the treated area within 30 seconds to 2 minutes. Even application should eliminate the need to go over areas a second or a third time, but if frosting is incomplete or uneven, the solution should be reapplied. TCA takes longer to frost than Baker’s formula or straight phenol, but a shorter period of time than the superficial peeling agents do. The surgeon should wait at least 3 to 4 minutes after the application of TCA to ensure the frosting has reached its peak. He then can document the completeness of a frosted cosmetic unit and touch up the area as needed. Areas of poor frosting should be retreated carefully with a thin application of TCA. The physician should achieve a level II to level III frosting. Level I frosting is erythema with a stringy or blotchy frosting, seen with light chemical peels. Level II frosting is defined as white-coated frosting with erythema showing through. A level III frosting, which is associated with penetration through the papillary dermis, is a solid white enamel frosting with little or no background of erythema.13 A deeper level III frosting should be restricted only to areas of heavy actinic damage and thicker skin. Most medium-depth chemical peels use a level II frosting and this is especially true over eyelids and areas of sensitive skin. Those areas with a greater tendency to scar formation, such as the zygomatic arch, the bony prominences of the jawline, and chin, should only receive up to a level II frosting. Overcoating trichloroacetic acid will increase its penetration so that a second or third application will drive the acid further into the dermis, creating a deeper peel. One must be careful in overcoating only areas in which the take up was not adequate or the skin is much thicker. (Fig II)

Anatomic areas of the face are peeled sequentially from forehead to temple to cheeks and finally to the lips and eyelids. The white frosting indicates keratocoagulation or protein denaturation of keratin and at that point the reaction is complete. Careful feathering of the solution into the hairline and around the rim of the jaw and brow conceals the line demarcation between peeled and nonpeeled areas. The perioral area has rhytids that require a complete and even application of solution over the lip skin to the vermilion. This is accomplished best with the help of an assistant who stretches and fixates the upper and lower lips which the peel solution is applied.

Certain areas and skin lesions require special attention. Thicker keratoses do not frost evenly and thus do not pick up peel solution. Additional applications rubbed vigorously into the lesion may be needed for peel solution penetration. Wrinkled skin should be stretched to allow an even coating of solution into the folds and troughs. Oral rhytides require peel solution to be applied with the wood portion of a cotton-tipped applicator and extended into the vermilion of the lip. Deeper furrows such as expression lines will not be eradicated by peel solution and thus should be treated like the remaining skin.

Eyelid skin must be treated delicately and carefully. A semidry applicator should be used to carry the solution within 2 to 3 mm of the lid margin. The patient should be positioned with the head elevated at 30 degrees and the eyelids closed. Excess peel solution on the cotton tip should be drained gently on the bottom before application. The applicator is then rolled gently on the lids and periorbital skin. Never leave excess peel solution on the lids because the solution can roll into the eyes. Dry the tears with a cotton-tipped applicator during peeling because they may pull peel solution to the puncta and eye by capillary attraction. (Fig III) The solution should be diluted immediately with cool saline compresses at the conclusion of the peel. The Jessner’s-TCA peel procedure is as follows:
1. The skin should be cleaned thoroughly with Septisol to remove oils.
2. Acetone or acetone alcohol is used to further debride oil and scale from the surface of the skin.
3. Jessner’s solution is applied.
4. Thirty-five percent TCA is applied until a light frost appears.
5. Cool saline compresses are applied to dilute the solution.
6. The peel will heal with 0.25% acetic acid soaks and a mild emollient cream.
There is an immediate burning sensation as the peel solution is applied, but this subsides as frosting is completed. Cool saline compresses offer symptomatic relief for a peeled area as the solution is applied to other areas. The peel reaction is not neutralized by saline solution as the reaction is completed when frosting occurs.16 The compresses are placed over the face for 5 to 6 minutes after the peel until the patient is comfortable. The burning subsides fully by the time the patient is ready to be discharged. At that time, most of the frosting has faded and a brawny desquamation is beginning.

Postoperatively, edema, erythema, and desquamation are expected. With periorbital peels and even forehead peels, eyelid edema can occur and may be enough to close the lids. For the first 24 hours, the patient is instructed to soak four times a day with a 0.25% acetic acid compress made of 1 tablespoon white vinegar in 1 pint of warm water. A bland emollient is applied to the desquamating areas after soaks. After 24 hours, the patient can shower and clean gently with a mild nondetergent cleanser. The erythema intensifies as desquamation becomes complete within 4 to 5 days. Thus, healing is completed within 1 week to 10 days. At the end of 1 week, the bright red color has faded to pink and has the appearance of a sunburn. This can be covered by cosmetics and will fade fully within 2 to 3 weeks.

The combination medium-depth peel is dependent on three components for therapeutic effect: (1) degreasing, (2) Jessner’s solution, and (3) 35% TCA. The amount of each agent applied creates the intensity and thus the effectiveness of this peel. The variables can be adjusted according to the patient’s skin type and the areas of the face being treated. It is thus the workhorse of peeling and resurfacing in my practice as it can be individuated for most patients we see.

The medium-depth chemical peel thus has five major indications: (1) destruction of epidermal lesions – actinic keratoses, (2) resurfacing the level II or III moderate photoaging skin, (3) pigmentary dyschromias, (4) mild acne scars, (5) blending photoaging skin with laser resurfacing and deep chemical peeling.

1. Actinic keratoses – This procedure is well suited for the patient with epidermal lesions such as actinic keratoses which has required repeated removal with either cryosurgery or chemoexfoliation (5-fluoruracil). The entire face can be treated as a unit or subfacial cosmetic unit such as forehead, temples, and cheeks, and can be treated independently. Active lesions can be removed, as well as incipient growths as yet undetected, will be removed as the epidermis is sloughed. Advantages for the patient with photodamaged skin include a limited recovery period – 7 to 10 days, with little post operative erythema after healing. There is little risk of pigmentary changes either hypopigmentation or hyperpigmentation, thus, the patient can return to work after the skin has healed.(Fig IV)
2. Moderate photoaging skin – Glogau level II or III damage responds well to this peeling combination with removal of the epidermal lesions and dermal changes that will freshen photoaging characterized as sallow, atrophic skin with fine rhytides. This peel is favored over deeper resurfacing procedures such as laser and deep peel in that it will heal in ten days with minimal risk of textural or color complications. It, though, is only designed for medium-depth damage. (Fig V)
3. Pigmentary dyschromias - Though color change can be treated with repetitive chemical peeling, the medium-depth peel will be a single treatment preceded and followed by the use of bleaching agents and retinoic acid.17 In most cases, the pigmentary problems are resolved with this single peel as an adjunct to the skin care program. (Fig VI)
4. Blending other resurfacing procedures – In a patient in which there is advanced photoaging changes such as crow’s feet and rhytides in the periorbital and/or perioral area with medium-depth changes on the remaining face, a medium-depth peel can be used to integrate these procedures together. That is, laser resurfacing or deep chemical peeling can be performed over the periorbital and perioral areas that has more advanced photoaging changes, while the medium-depth chemical peel is used for the rest of the face. This will blend the facial skin as a unit so that the therapeutic textural and color changes will not be restricted to one area. The patients requiring laser resurfacing in a localized cosmetic unit will have the remaining areas of their face blended with this medium-depth chemical peel. Patients having laser resurfacing or deep peeling to the perioral or periorbital areas alone develop a pseudo hypopigmentation that is a noticeable deformity. The patient requiring laser resurfacing at a localized cosmetic unit will have the remaining areas of their face blended with this medium-depth peel. The alternative – a full-face deep peel or laser resurfacing has an increased morbidity, longer healing and risk of scarring over areas such as the lateral jaw line, malar eminences, and forehead. If deep resurfacing is needed only over localized areas such as perioral or periorbital face, a blending medium-depth peel does reduce morbidity and healing time.12 (Fig VII)

Coleman Version Glycolic Acid and Trichloracetic Acid Peel
The combination of glycolic acid 70% and trichloracetic acid 35% is another combined peel designed to improve the efficacy of 35% trichloracetic acid without the risks and complications of higher strength TCA.(21) Chemicals, methodology and techniques are different so that one must have a thorough understanding of this peel and not utilize the methods of the preceding combination peel or the use of trichloracetic acid alone. This combination peel produces less wounding depth than the previous combination peels as demonstrated in histologic studies, but a significantly greater wound level than 35% trichloracetic acid alone. It has also demonstrated the ability to stimulate new collagen production with a comparable Grenz zone to the other medium depth peels.13 Application of the glycolic acid prior to the TCA peel allows for an even debridement of the stratum corneum equal to that obtained with a degreasing procedure and the Jessner's solution.9

In this procedure, no cleansing or degreasing procedure is done. After washing the face with soap and water, 70% glycolic acid is applied directly to the patient's facial skin with a rectal swab and after a strict 2 minute contact period, the solution is removed with tap water. Next, the 35% trichloracetic acid is applied in a sequential pattern with either cotton tip applicators or 4 x 4 inch gauze pads to the entire face. The usual frosting is obtained and cool compresses are placed to alleviate the stinging and burning.

This combination peel has also been found effective in the treatment of actinic keratoses and epidermal growths, Glogau grade II photoaging skin, and pigmentary dyschromias. The same skin preparations are used as well as similar post-operative wound care. Advantages of this peel are that most physicians are already familiar with the use of glycolic acid and its time-dependent action. It is a fairly simple learning curve to add the 35% trichloracetic acid onto this already established chemical peel. Drawbacks may be the uneven nature of glycolic acid peeling and the possibility of accentuating "TCA hot spots." In addition, the use of saline to neutralize the glycolic acid may inhibit some of the absorption of trichloracetic acid for the second part of this combination peel. Though these are theoretical points, in practicality, Dr. Coleman has demonstrated excellent results with this combination medium depth peel.

Other medium depth peels include:
1. Full strength unoccluded phenol peel
2. Pyruvic acid (alpha-keto acid)
3. Jessner's-glycolic acid peel

Eighty-nine percent phenol has the ability to wound through the papillary dermis similar to other peeling strengths discussed. Its disadvantage is inherent in the absorption of phenol with significant cardiac and hepato renal toxicity. For this reason, the other peels discussed have significant advantages.

Pyruvic acid is an alpha-keto acid which is a very potent chemical peeling agent and has been used experimentally for photoaging skin. The rapid dermal penetration has the potential for scarring and side effects and though some results have been demonstrated by Griffin to be excellent, its safety and efficacy has not been well established.14

The Jessner's Solution and Glycolic Acid Peel
This combination peel has been studied by Dr. Larry Moy with the intent of two theoretical advantages.
1. Jessner's solution allows for deeper penetration of the
glycolic acid.
2. The glycolic acid will be a greater stimulant for
collagen regeneration without further exfoliation.
Though this technique is both time-dependent and restricted to visual endpoints, the chances for overtreating are great which may create potential side effects and complications.15

Post-Operative Care and Complications
The four stages of wound healing are apparent after a medium depth chemical peel.16 They include:
1. Inflammation
2. Coagulation
3. Reepithelialization
4. Fibroplasia

At the conclusion of the chemical peel, the inflammatory phase has already begun with a brawny, dusky erythema that will progress over the first twelve hours. With the medium depth peels, the epidermis will begin to separate, creating a leathery, dry, cracking appearance to the epidermis. This is an accentuation of pigmented lesions on the skin as the coagulation phase separates the epidermis, producing serum exudation, crusting and pyoderma. It is during this phase that it is important to use debrident soaks and compresses as well as occlusive salves. These will remove the sloughed necrotic epidermis and prevent the serum exudate from hardening as crust and scab. I prefer the use of 1/4% acetic acid soaks found in the vinegar water preparation (one teaspoon white vinegar, one pint warm water), as it is antibacterial, especially against pseudomonas and gram negatives. In addition, the mildly acidic nature of the solution is physiologic for the healing granulation tissue, mildly debrident, as it will dissolve and cleanse the necrotic material and serum. Occlusive dressings including bland emollients and salves and biosynthetic membranes. For medium depth peeling, I prefer the occlusive salves as these can be monitored carefully day by day for potential complications.

Reepithelialization begins on day three and continues until day seven to ten. Occlusive salves promote faster reepithelialization and less tendency of delayed healing.17 The final stage of fibroplasia continues well beyond the initial closure of the peeled wound and continues with neoangiogenesis and new collagen formation for three or four months. Prolonged erythema may last two to four months in unusual cases of sensitive skin or with contact dermatitis. New collagen formation can continue to improve texture and rhytides for a period up to four months during this last phase of fibroplasia.

Many of the complications seen in peeling can be recognized early on during healing stages. The cosmetic surgeon should be well acquainted with the normal appearance of a healing wound in its time frame for medium depth peeling. Prolongation of the granulation tissue phase beyond one week may indicate delayed wound healing. This could be the result of viral, bacterial or fungal infection, contact irritants interfering with wound healing, or other systemic factors. A red flag should alert the physician that careful investigation and prompt treatment should be instituted to forestall potential irreparable damage that may result in scarring. Thus, it is vitally important to understand the stages of wound healing in reference to medium depth peeling. The physician then can recognize, treat and avoid any and all complications early on.

Long-term care of peeled skin would include sunscreen protection for up to six months along with reinstitution of medical treatment such as low strength hydroxy acid lotions and tretinoin. Re-peeling areas should not be performed for six months from the previous peel. If any erythema or edema persists, the peel should not be performed as the re-injury may create complications. This peel should not be performed on undermined skin such as facelift or flap surgery performed up to six months prior to the peel.18

The evolution of medium depth chemical peeling has changed the face of cosmetic surgery. It has introduced new techniques into the armamateria of the cosmetic surgeon to treat problems that previous have been approached with tools inadequate to obtain the results for moderate photoaging skin or with overly-aggressive treatment using deep peeling agents. The combination peels have provided some of the more popular tools needed to approach a burgeoning population with photoaging skin.