Cook Peel (70% Glycolic Acid +40% Trichloroacetic Acid) for Extra-Facial Areas

Abstract

Body peels are the most difficult because of lower density of pilosebaceous units, delayed healing, and scarring. At the same time, most chemicals present reduced epidermal penetration in body sun-exposed areas, compared to facial skin. This chapter illustrates how to properly perform a chemical peel, which is one of the strongest superficial peels for the body, and how to increase its penetration to achieve focal chemoabrasion of melanosis or superficial keratoses. The success of the procedure depends on the artistic hands of the surgeon, patient education, and attention to endpoints for neutralization.

1 Materials

• Degreasing agent: standardized acetone–ethanol (3:1 mixture) or 70% ethanol.

• Applicators: 4 × 4 gauzes (Fig. 6.1).

• Peeling agents : large stock bottles of GA 70% (cosmetic grade) and TCA 40%. Pour the contents of the acids in two different shot glasses or beaker glasses with units of measure. For patients with atrophic skin, the author recommends TCA 30–35% instead of TCA 40% (Fig. 6.2).

• Neutralizing agent : sodium bicarbonate solution 10% in a large glass. Dry disposable soft towels are soaked in this cup and are ready to be used.

• Post-peeling regimen: Vaseline and sunscreen.

Fig. 6.1

Materials. Two shot glasses for soaking 4 × 4 gauzes, folded in half twice. After excess solution is removed from the gauze, the saturated gauze is placed in small bowls (red plastic for glycolic acid and ceramic for TCA). A large glass containing three soft towels is placed in the right side of the picture. These compressed “magic towels” are dry and compressed in individual packages (large container in the back). After each area is done, everything is refilled. Gloves used for neutralization (assistant) are changed after each neutralization to avoid cross-contamination of the neutralizing solution

Fig. 6.2

Application of 40% trichloroacetic acid solution with the dominant hand as soon as 70% glycolic acid solution has been applied with the other hand. Watch uniform layer of solution

2 Methods and Techniques

• Degreasing: the importance of removal of all make-up, sebum, beard, topical anesthetic, and sunscreen before any chemical peel is unquestionable. The physician scrubs the body surface to be treated with semi-soaked gauze pads.

• Peeling solution application: the left hand is used for GA 70% solution and the right hand for TCA 40% solution (the dominant hand for TCA); if the author is left handed, he would change the disposition of the shot glasses and bowls as well in the table. Fold gauzes in half twice, soak, and squeeze to remove excess solution. Place in each bowl one saturated gauze of each solution for every 5% of body surface area. Begin with GA, fast application to cover the whole designated area, throwing away semi-dry gauzes, and changing to a new saturated gauze. As soon as the process is over with GA, start the application of TCA with the dominant hand, starting from the same point and covering exactly the same area, changing the gauzes in the same position.

• Endpoint visualization: the surgeon waits for the endpoint. For higher phototypes, above Fitzpatrick III, due to risk of post-inflammatory hyperpigmentation, in the first session, the endpoint is erythema. For lower phototypes, the endpoint is speckled frosting. Usually, erythema is achieved at 2 min after TCA application, and frosting starts in 3 min. Once the solution is dry, wait at least 3 min before using another application of TCA, which is always less saturated than the first application (Figs. 6.3 and 6.4).

• Focal treatment: if there is a specific goal for the treatment session, for example, to remove actinic keratosis , this waiting time is the time to perform local treatments, such as cryotherapy for hypertrophic keratoses or cotton-tipped applicator peel with 40% TCA with increased pressure and passes, over superficial keratoses, to achieve uniform frosting.

• Neutralization : once the endpoints are achieved, the area treated is dried with a gauze (if still wet) and subsequently neutralized with soft towels saturated in 10% bicarbonate solution by the assistant. Three disposable towels are necessary for each limb, passing all towels at the whole area, starting with the area where there is increased frosting (hot spots) (Fig. 6.5).

Fig. 6.3

Endpoint observation at 2 min. Actinic keratoses presented early frosting, which is expected; this patient’s desired endpoint at the first session was erythema, with speckled frosting over hand melanoses with denser frosting over actinic keratoses

Fig. 6.4

Endpoint observation at 4 min after the solution was dry revealed no frosting over hand melanoses and superficial pigmented seborrheic keratoses . This patient’s desired endpoint at first session was erythema, with speckled frosting over hand melanoses with denser frosting over actinic keratoses. Another focal layer of 40% trichloroacetic acid was applied to the melanoses

• Post-peeling regimen: a thick layer of Vaseline is applied to the peeled areas as soon as the desired chemoabrasion endpoints were achieved. The patient is instructed to use broadband sunscreen over the Vaseline layer twice a day if the skin needs to be sun-exposed, otherwise, only Vaseline (Fig. 6.6).

Fig. 6.5

Neutralization with 10% sodium bicarbonate after erythema endpoint was achieved (about 4 min). Three applications of 10% are performed to ensure complete neutralization and removal of the acids

3 Clinical Follow-Up

• There is pain after 2 min of TCA application, which usually lasts until complete frosting or erythema is achieved. Neutralization stops the pain almost instantly.

• The skin becomes dry after about 1 week for limbs and 3 days for the neck and chest. The corneal layer becomes thick and darker after about 10 days, when it starts to peel, very slowly. For the hands and feet, expect about 3–4 weeks for peeling to start, while the shoulders, chest, and neck usually peel after about 2 weeks (Fig. 6.6). It is very important to avoid pulling or scratching the dark peeling skin because it protects deeper layers from light and chemicals. Moisturizing with either Vaseline or fragrance-free hypoallergenic creams is fundamental to avoid fissures.

• Vesicles, blisters, and oozing are not expected; if any of those signs are present during follow-up, diagnosis must be made of either herpes reactivation, bacterial infections, or eczematous reactions.

Fig. 6.6

Two-week follow-up . Pinching the skin reveals the thick corneal layer which will peel in about 2 more weeks. The areas which achieved frosting are darker (melanoses)

4 Before and After (Figs. 6.7, 6.8, 6.9, and 6.10)

Fig. 6.7

Two-week follow- up of Cook’s peel applied to the forearms and hands of a patient with multiple seborrheic keratoses and lentigines. This patient was peeled with 70% glycolic acid followed by 35% trichloroacetic acid with a large feathering area due to phototypes III–IV and concerns of demarcation marks to the arms

Fig. 6.8

Two-month follow-up of Cook’s peel applied to the forearms and hands with 70% glycolic acid followed by 35% trichloroacetic acid of a patient with multiple seborrheic keratoses and lentigines; skin texture improved, superficial actinic keratoses were removed, and most of the melanoses peeled off. The patient was scheduled for a second session after one more month

Fig. 6.9

Before and after 2 months of a single Cook’s peel with 70% glycolic acid, followed by 40% trichloroacetic acid

Fig. 6.10

Before and after 4 months of two Cook’s peels in the dorsal hands with 70% glycolic acid followed by 40% trichloroacetic acid

5 Side Effects, Complications, and Their Management

• Post-inflammatory hyperpigmentation : the most common side effect of chemical peels in general. If erythema endpoint is respected for higher phototypes, this adverse reaction is minimized, along with the results; therefore, multiple treatments are recommended.

• Infection: any oozing or edema must be treated with topical steroids, along with systemic antibiotics, especially in the lower limbs, where erysipelas is not rare. This peel is contraindicated in patients with venous insufficiency or lymphedema.

Tip Box

• Hands-on training mandatory for acquiring the correct technique, as in any peel.

• In patients with atrophic skin or higher phototypes, use 30–35% TCA instead of 40% to minimize the adverse effects of hotspots.

• Understand the limitations of extra-facial resurfacing treatments. Expect multiple treatments with safer interventions.

• Realistic expectations and patience must be taught to every patient undergoing body peels.