• Superficial peels

For superficial peels, patients who belong to Glogau classification for photoaging types I and II are most appropriate (Box 7.2). Severe photodamage with resultant hyperkeratosis and parakeratosis creates a barrier to peel penetration and will minimize the effect of any peeling agent. This can make using only a superficial peeling agent almost totally ineffective. It is therefore recommended that a retinoid be used to pretreat the area and increase the penetration of the peel. With regards to sun-reactive skin types, Fitzpatrick types IV, V, and VI are most prone to developing postinflammatory hyperpigmentation (Table 7.2). Pretreatment with tretinoin and hydroquinone may minimize this effect and can be particularly helpful in type IV, where the hyperpigmentation may be the most noticeable compared to their normal skin tone. Topical ascorbic acid has also been used as a priming agent and has been found to be beneficial in decreasing pigmentation. Soliman et al (2007) reported a significant improvement in melasma patients who were pretreated with topical 5% ascorbic acid prior to a superficial peel with 20% TCA. With adequate patient education, patients with darker complexions can safely undergo superficial peels without risk of permanent color change as hyperpigmentation fades over time and with treatment. Oily, thickened, sebaceous skin may lead to uneven and less effective superficial peeling. Peel response may be improved with the use of pretreatment tretinoin on a daily basis combined with alpha-hydroxy acids (10–20%) used as a daily cream, lotion or gel. In addition, a more vigorous skin preparation may be used to enhance peel absorption. In contrast, there are patients, usually women, who have paper-thin skin with a translucent quality. These patients are at an increased risk for conversion to a medium-depth peel with superficial peeling agents and should have their skin preparation and skin pretreatment performed cautiously. Other patients who deserve caution are those with seborrhea and other types of dermatitis (retinoid, etc.) Inflammation in the skin is known to enhance uptake of the peel solution and result in a deeper than expected peel.

Table 7.2 Fitzpatrick’s classification of sun-reactive skin types

* Asian Indian, Oriental, Hispanic, or light African descent, for example

• Medium-depth peels

Medium-depth peels are most appropriate for patients with moderate to advanced photodamage (Glogau types II and III). Those with Glogau classification II will achieve the most significant benefit. Patients with Fitzpatrick skin types III, IV, V, and VI are at an increased risk for postinflammatory hyperpigmentation and should be pretreated accordingly for prevention. As with superficial peels, sebaceous quality, skin thickness, and inflammation should be taken into account and treated accordingly to foster more even peel absorption and optimal clinical response, as well as to avoid complications. Patients with rosacea should be warned that they may develop persistent erythema postpeel, and pretreatment for rosacea may be helpful in preventing this occurrence.

• Contraindications

In addition to choosing the right patient with reasonable expectations for the procedure, complications may be avoided by excluding patients under certain circumstances. Relative contraindications for chemical peels include the use of isotretinoin (should be off it for at least 6–12 months), a history of radiation to the region (ablating adnexal structures), active herpes simplex or bacterial infection, history of hypertrophic scar formation, and a rhytidectomy or brow lift in the previous 3 months. With regards to brow lift and rhytidectomy, while waiting 3 months for resurfacing has traditionally been recommended, a publication by Alster et al (2004) described 34 patients who underwent combination carbon dioxide (CO₂) or erbium:yttrium-aluminum-garnet (Er:YAG) laser skin resurfacing and surgical lifting procedures (S-lift rhytidectomy, blepharoplasty, and brow lift). The effects were found to be no different than those in patients undergoing the laser-only procedure. An article by Herbig et al (2009) suggests that the same may be true for chemical peel resurfacing. They reported performing 27 face and/or neck lifts with SMAS plication or SMAS-ectomy along with full face chemical peels and noted no hypertrophic scarring. Certain facial surgical procedures utilizing a skin or muscle flap may still compromise vascular supply to the tissue and result in delayed healing following medium-depth peels. Patients with a history of herpes simplex virus infection should be pretreated with an oral antiviral agent, which is continued until reepithelialization occurs.

• Making up the solution

Concentrations of 10–25% TCA are typically used for superficial peels, though in some patients, concentrations of 35% may be necessary for superficial peeling, depending on factors such as actinic damage, sebaceous quality of the skin, and epidermal thickness. TCA may be acquired from a local pharmacy with a basic knowledge in compounding. TCA solutions are compounded in a weight to volume preparation. To make a 25% preparation, use 25 g of TCA USP (BP) crystals, dissolve in a small amount of water and add water to make a total volume of 100 mL. TCA is stable at room temperature or refrigerated and is not light sensitive and may be stored accordingly. Aqueous TCA solution has a shelf life of 6 months.

• Skin preparation and application

As with other light peels, the method of skin preparation and peel application may affect peel depth and must be uniform. Greater pressure and repeated rubbing increase peel depth. Applicator types have been categorized according to peel amount with sable brushes giving deeper peeling than gauze or cotton-tipped applicators. This is probably due to a larger volume of peel solution applied. The skin is prepped prior to peeling to promote more even peeling by removal of superficial stratum corneum, sebaceous and sweat gland secretions. It has been shown that rubbing alcohol, chlorhexidine gluconate and acetone are equally efficacious in the prepeel skin preparation. It is helpful to break the area to be prepped into units. If using 2″ × 2″ (5 cm²) cotton gauze, one might typically use one 2″ × 2″ for each of the following areas on the face: forehead (sometimes subdivided into two to four units depending on the size), cheeks (one each), chin, nose and upper lip. As with application of the peeling agent, skin preparation should be categorized as either a ‘wipe’ in a unidirectional motion or a ‘scrub’ with bidirectional motion and greater friction. Vigorous scrubs are used in the setting of sebaceous skin or advanced photoaging. For younger patients, patients with active inflammation as in acne or seborrhea, or in patients with thin, translucent skin, a wipe is sufficient preparation. A more vigorous prep can lead to conversion of the peel from a superficial peel to a medium-depth peel. The timing of the prep should be noted, and most fall around 2 minutes.

When applying the peeling agent, as in the skin prepping, it is helpful to divide the area to be peeled into units with one gauze used per unit. This will help quantify the amount of peel used per unit. A 2″ × 2″ gauze is submerged and wrung out (small metal cups may be used to contain the peel agent being used, as other materials will corrode over time) and with a wiping or scrubbing motion (depending on the patient) the peel is performed. All variables should be documented in the chart including the type of prep, time of prep, peel agent, unit areas (number and type of applicators), pressure of application (scrub vs wipe). It is often useful to have the patient keep a log of their peeling so as to help guide the physician in planning their next peel. The patient should record the type of flakes (small white, large brown), the areas of peeling and the extent of peeling. In addition, if a less than expected or deeper than expected peel occurs, documentation is clear on how the peel was performed. The end point of a superficial peel with TCA is speckled white frost. Once this is noted, cool water gauze compresses are placed over the areas peeled for patient comfort. The cool water compresses are used for symptomatic relief and to eliminate any possible pooling from the solution. Once the peel solution is applied, absorption occurs and cannot be neutralized by additional base application. After a few minutes, the patient may rinse off the area peeled with cool water splashes until tingling or burning subsides (Table 7.3).

Table 7.3 Skin preparation

• Postpeel advice to patients

Patients should be instructed that the skin may be pink initially, feel tight, peel in 2 to 3 days and continue peeling for up to 1 week. It should also be clear that no scrubbing is to be performed at home, and the patient must resist the urge to pick, peel or scratch. They may resume moisturizer use after 4 hours, after soaks, and as needed. In previous studies, occlusion with ointment vehicle was shown to enhance medium-depth peel necrosis when applied after 4 hours rather than immediately after application of the peel. Swelling can be improved by sleeping with the head elevated and using cool compresses for 15–30 minutes several times daily. Direct sunlight should be avoided for at least 3 weeks after the peel. Patients should resume their prepeel regimen of a retinoid and alpha-hydroxy acid lotion when their skin is healed, which is usually by 5 to 7 days postpeel. Alpha-hydroxy acids are typically dispensed starting at a lower concentration (8%), with a gradual increase in concentration, depending on the patient’s tolerance, up to 20% lotion. When indicated, as in the treatment of melasma or in the prophylaxis of those at risk for postinflammatory hyperpigmentation, hydroquinone may also be started at that time (Table 7.4).

• Preparation for medium-depth peeling

In preparation for a medium-depth peel, the use of sunscreens, exfoliant cleansers (5–10% glycolic acid, for example), topical retinoid, bleaching agents, and antiviral medications are usually used. A sunscreen with activity in the range of both UVA and UVB (preferably a sunblock such as titanium dioxide or zinc oxide) is required in those at risk for postinflammatory hyperpigmentation (Fitzpatrick skin types III–VI). As with the retinoid, this should be started as soon as possible before the peel. In our practice, the use of daily sunscreen is routinely recommended to all patients. Exfoliant cleansers or moisturizers, such as glycolic acid preparations, while enhancing the uptake and uniformity of the peel are typically added after the patient has tolerated a few weeks of retinoid use. If added together, patients with sensitive skin often cannot tolerate the combination. If patients tolerate daily retinoid use, a glycolic acid cleanser or moisturizer can then be added. A retinoid, typically tretinoin 0.02%–0.1% cream, is prescribed for use as soon as possible before starting the peel. Tretinoin has been shown to accelerate healing after TCA peels in addition to being associated with earlier, more intense and more uniform frosting. These effects were appreciated after just 14 days of daily retinoid use. Bleaching agents such as hydroquinone 4–8% are begun 6 weeks prior to medium-depth peel in patients with Fitzpatrick skin type III, IV, V, or VI. In skin types I and II we do not routinely use pretreatment with a bleaching agent. We like to start only one topical product at a time with patients, and we choose retinoids first. Most patients will be in for their peel before another product is started. Although many people pretreat medium-depth chemical peel patients with bleaching agents, recent evidence of the effects of pretreatment with these agents on the incidence of hyperpigmentation following CO₂ laser resurfacing demonstrated no significant difference in the incidence of hyperpigmentation between those who received pretreatment and those who did not. Skin types I, II, and III were represented. Should hyperpigmentation develop in these patients, treatment may begin and routinely is effective.

In the authors’ experience, on the day of the procedure, a mild sedative can be given (lorazepam, for example) or an oral analgesic to increase the pain threshold. If the patient has a history of herpes infection, valacyclovir (1 g) is given 1 hour prior to the procedure and daily for 5 days or until reepithelialized. Patients are also given prednisone to begin on the day of the procedure (40 mg for 2 days, 20 mg daily for 3 days, then stop) to minimize postpeel edema.

• Solid CO₂ and 35% TCA (Brody combination)

In 1986, Brody published his use of solid CO₂ ice plus 35% TCA for medium-depth peels. Solid CO₂ creates epidermal injury without risk of deeper dermal freeze and subsequent hypopigmentation or scarring. A skin prep of povidone iodine, alcohol wipe and an acetone scrub is performed for 3 minutes. Areas noted to require deeper peel are marked to receive heavier CO₂ freeze (deeper rhytides around the mouth, melolabial and glabella furrows, crow’s feet, thickened actinic keratoses or epidermal lesions, and rims of acne scars). A block of CO₂ is broken to a shape to fit the hand and applied to the skin with varying pressure. Friction is diminished by the dipping of the CO₂ block in a 3:1 solution of acetone to alcohol. Mild pressure (3–5 seconds), moderate pressure (5–8 seconds), and hard pressure (8–15 seconds) are applied as warranted. The skin is wiped dry followed by 35% TCA peel. Dr. Brody treats the most sensitive areas first (the eyelids, nose, cheeks, perioral region, followed by the forehead). Following the peel, cool ice packs wrapped in paper towels are used for 5 minutes and followed by an emollient. Disadvantages to this technique include the difficulties in maintaining and storing solid CO₂ and the variability of technique-dependent results. Advantages are a reported greater improvement compared to other combinations in the treatment of thicker epidermal lesions and acne scarring.

• 70% Glycolic acid and 35% TCA (Coleman combination)

This peel combination gives similar peel depth as that achieved with degreasing and Jessner’s solution prior to TCA 35% peel. The patient should wash the face with a gentle soap and water, but no further cleansing or degreasing is performed prior to application of 70% glycolic acid. The 70% unbuffered glycolic acid is applied easily with a large cotton swab or 2″ × 2″ gauze with a strict 2-minute contact period. After 2 minutes, the areas are rinsed with cool tap water. A 35% TCA peel follows. Disadvantages of this combination are more related to the nature of glycolic acid in that abraded or inflamed areas of the skin tend to take up glycolic acid and allow penetration to a medium-depth peel from that alone more commonly than the alternative pretreatments prior to 35% TCA. Nevertheless, this combination is effective and most physicians are already familiar with glycolic acid, improving the ease of use.

• Jessner’s solution and 35% TCA (Monheit combination)

This peel combination uses Jessner’s solution (14 g resorcinol, 14 g salicylic acid, 14 g 85% lactic acid, with ethanol added to create a total volume of 100 mL). With Jessner’s solution as a pretreatment keratolytic, the epidermal barrier is altered prior to TCA peeling to help create a more rapid and uniform uptake. Jessner’s solution is compounded in a weight to volume manner, as described above. It has a shelf life of over 1 year but may develop yellow coloration when exposed to both light and air.

In preparation for the Jessner’s peel, a vigorous scrub with acetone is performed for 2 minutes. As in the superficial peel with TCA, it is helpful to divide the areas of the face to be treated into units (forehead, cheeks – each with one 2″ × 2″ gauze – chin, nose, and upper lip). The forehead may be broken down into 2 to 4 units depending on the size. One 2″ × 2″ gauze should be used for each unit. The scrub should be complete in its removal of sebaceous and sweat gland secretions and debris. Excessive scale and superficial stratum corneum are also removed with the acetone scrub. Particularly sebaceous regions such as the hairline, the glabella, the nose, temples, and upper lip should be noted to have complete degreasing before proceeding. For hypertrophic actinic keratoses, curettage may be performed to the hyperkeratosis prior to peel application to facilitate peel absorption. In Monheit’s description of the peel, he also adds a gentle scrub prior to acetone with Ingasam (Septisol, Vestal Laboratories, St. Louis, Mo.) with 4″ × 4″ (10 cm²) gauze pads and water with subsequent rinsing, drying and repeated twice.

After preparation, Jessner’s solution is applied to each of the facial units with a 2″ × 2″ gauze for each unit. One or two coats may be used to create an endpoint of a speckled white frost and mild, uniform erythema (Fig. 7.3A). If necessary, a Wood’s lamp may be used to verify even application as the salicylic acid component in Jessner’s peel solution is fluorescent under the Wood’s lamp. Even application is important as it will affect the uptake of the TCA peel solution to follow. After the Jessner’s peel, cool water compresses may be placed to provide symptomatic treatment of mild burning and heat. It is recommended to wait at least 5 minutes before application of TCA following Jessner’s peel preparation.

Figure 7.3 (A) Speckled white frost following Jessner’s solution peel in preparation for 35% TCA medium-depth peel; (B) even, white frost with a background erythema following application of 35% TCA medium-depth peel

During that time, one may wish to apply a topical anesthetic (i.e., EMLA-lidocaine 2.5% and prilocaine 2.5%) to the area prior to TCA application, which will make the procedure more tolerable for the patient.

• Glycolic acid 70% gel and 35–40% TCA (Cook total body peel)

This peel combination has been used to treat nonfacial skin. It has been reported by Cook et al (2001) to be effective in the treatment of the neck, chest, arms, hands, legs, back, abdomen and balding scalp. In our practice we use this method to treat photodamaged arms (i.e., lentigos, actinic keratoses and solar purpura). When performing this combination, it is important to use glycolic acid 70% gel rather than solution. The glycolic gel acts as a barrier when combined with the TCA in order to prevent excessive penetration and potential scarring.

There is no pretreatment with local anesthetic or sedative needed for this procedure. The area is cleansed with water and a mild cleanser as we do not use an acetone scrub prior to performing this peel. As described above, it is helpful to divide the area being treated into units (i.e., 3 segments per forearm), each of which will be treated with one 2″ × 2″ gauze. The 70% glycolic acid gel (glycogel) is applied to the treatment area and the TCA 35–40% is immediately applied to the same area with the 2″ × 2″ gauze. It is important to apply an even coat to the area prior to applying the TCA 35–40%, in order to ensure uniform penetration of the TCA in the treatment area. A uniform white speckled frosting and mild erythema is expected. The 70% glycolic acid gel should be neutralized within 2 minutes to prevent excessive penetration of the agents. Either 10% sodium bicarbonate solution or water soaked gauze is used for neutralization.

• 35% TCA peel

As mentioned previously, our practice is to premedicate patients for medium-depth peels with lorazepam (Ativan) or an oral analgesic. We have found that even with no oral analgesic or antianxiety agent the peel is well tolerated if, after the application of the Jessner’s solution or glycolic acid peel prior to the medium-depth peel, a topical anesthetic is generously applied (EMLA, lidocaine 2.5% and prilocaine 2.5%) and left in place for 15 minutes. The topical anesthetic is wiped clean and dry with moistened gauze. (This step is performed between the superficial peel and the medium-depth peel.)

After the face is completely dry, 35% TCA is used to perform the medium-depth peel. It is helpful to use a small container to dip cotton tips or gauze into for better control of the amount of solution. Again, the face is broken into units and TCA is painted evenly using unidirectional strokes. Either cotton tips or 2″ × 2″ gauze may be used. Excess peel solution should be gently wrung from the cotton against the side of the container to avoid dripping of solution into the eyes or onto the neck. Typically, the units are the forehead (sometimes subdivided into 2–4 units depending on the size), the cheeks and temples (each getting one 2″ × 2″ gauze), the chin, the upper lip, and nose. After application, contiguous white frost begins to appear within 30 seconds and matures over 2 to 3 minutes. The degree of frost should be evaluated and documented after this time elapse (Table 7.5). Level II frosting is desired for most medium-depth peels and is characterized by an even, white-coated frost with background erythema (Fig. 7.3B). It is important to treat cautiously areas prone to scar, such as the zygomatic arch, bony prominences of the jaw, and the chin. In addition, the eyelids should be treated cautiously and achieve at most, a level II frost. Level III frost may be appropriate for thickened, keratotic lesions, heavy actinic damage or significantly thickened skin. Skip areas may be retreated lightly after evaluating initial frost. Thickened actinic keratoses or epidermal lesions will not take peel solution evenly and often need cotton-tipped reapplication with vigorous rubbing for peel penetration. Feathering is important around the brows, into the hairline, around the neck and onto the vermilion border to minimize lines of demarcation of peeled and nonpeeled areas. As frost develops, cool, wet compresses should be placed over all areas peeled.

Table 7.5 Frosting grading system

For eyelid peeling, an assistant should place dry cotton tips at both medial and lateral canthi to absorb tearing, which may draw peel solution into the eyes through capillary action. The cotton tips are also used to place gentle traction on the eyelids during the peeling to help with even application. Using a semidry cotton tip (pressed against the edge of the metal container to drain any excess peel solution), the eyelids are painted gently within 2 to 3 mm of the lid margin. If the treatment is the patient’s first, TCA 25% is often used in place of 35% as this strength is often all that is necessary for medium-depth peel and level II frosting of the eyelids. The eyes should be closed, and some authors recommend head elevation to 30 degrees in order to reduce the risk of the peeling agent getting into the eyes. Cool water compresses are applied immediately following peel application for the eyelids. Care should be taken that the water compresses are not soaked and cause dripping water, as this could carry small amounts of peel solution into the eyes inadvertently.

Helpful hints from other authors (Monheit) include stretching wrinkled skin to allow for penetration of the peel solution into folds as well as painting oral rhytides with the wooden end of the cotton tip. It is not recommended to aggressively treat deep furrows as they will not improve.

Cool compresses do not neutralize TCA, but rather provide symptomatic relief of the burning pain experienced by patients immediately upon application of the peel. This subsides and becomes comfortable over a period of 5 to 10 minutes of cool compress application and resolves completely within 15 to 20 minutes, by the time of discharge. An emollient, such as Aquaphor healing ointment, is applied immediately following the peel. By discharge, most of the frost will have turned to a brawny, shiny appearance.

Patients may expect the skin to feel tight with swelling, particularly around the eyes. We have found that with prednisone prescribed as described above, this is greatly reduced. Aquaphor is reapplied frequently over the 4 days following the peel and serves to promote faster reepithelialization. After 24 hours, the patient may shower. The face may be cleaned twice daily with a gentle cleanser. As the epidermis separates, the tight, dry, ‘cracked pottery’ appearance gives way to peeling and serous exudates with crusting may occur. Patients are instructed not to pick or peel the skin, though careful trimming with clean, sharp scissors is allowed. Reepithelialization typically begins on the 3rd day and continues up to 10 days postpeel. On the 5th day, a moisturizing cream may be applied to any dry areas as needed. After the skin has healed (sometimes this takes up to 10 days), a green toner may be applied to cover the new, slightly erythematous skin, with make-up over this toner. Redness fades to pink over the course of the 1st week and will gradually continue to fade to complete resolution over the course of 2 to 3 weeks. In rare cases, erythema may last up to 4 months and may be accompanied by pruritus, burning, stinging, and a change in skin texture, in which case potential etiologies, including rosacea, systemic lupus erythematosus, atopy, eczema, allergic or irritant contact dermatitis (retinoid, glycolic acid or other), should be considered. This may be treated with mild topical steroids such as desonide cream or westcort ointment depending on the intensity of erythema, up to 3 × daily, with weaning over 2 to 3 weeks as symptoms resolve. It is recommended that patients avoid direct sunlight and wind with sun exposure for 6 to 8 weeks after peeling to help prevent postinflammatory hyperpigmentation. In addition, a sunscreen with both UVA and UVB coverage should be applied daily (Fig. 7.4).

Figure 7.4 (A) Patient with photodamage before TCA peel; (B) 1 day after 35% TCA peel; (C) 2 days after 35% TCA peel; (D) 3 days after 35% TCA peel; (E) 6 days after 35% TCA peel; (F) 9 days after 35% TCA peel. Note improvement in overall color and texture

Most patients note considerable improvement in color and texture of their skin as well as a reduction in fine lines. Patients may have continued improvement in their skin texture over the next 6 months to a year as collagen remodeling occurs. We explain to patients getting a medium-depth peel that they may benefit from another medium-depth peel in 1 to 3 years. Delayed healing with the granulation tissue phase lasting more than 1 week should be an indication to the physician to investigate the possibility of a complicating viral, bacterial or fungal infection, contact irritant exposure, or other systemic reason for poor wound healing. If patients develop pain during the healing process, they are instructed to call immediately as this can be a harbinger of the onset of a herpes outbreak. As discussed earlier, any patient with a history of herpes ‘fever blisters’ receives prophylactic treatment with valacyclovir (1 g the day prior to procedure and for 5 days thereafter or until reepithelialized). Candidiasis is an infrequent complication and seen much more commonly after CO₂ laser resurfacing. Some authors (Monheit) recommend 0.25% acetic acid soaks (1 tablespoon white vinegar in 1 pint warm water; 15 mL in 500 mL) 4 × daily for the first 24 hours. This is felt to help prevent secondary bacterial infections (gram-negative) in addition to providing mild debridement of necrotic material and serous crust.

Pretreatment topical therapies are restarted after 2 to 3 weeks, including tretinoin or an alternative retinoid, and alpha hydroxy acids or glycolic acid creams. Patients should be warned that their skin may be more sensitive than usual. If hyperpigmentation is noted, hydroquinone 4% cream or an alternative prescription-strength bleaching agent is started immediately. A second medium-depth peel should be performed no sooner than 6 months from the previous peel, though most patients do not need additional peeling for a year or more, particularly if they stay on a good skin care regimen that includes broad-spectrum sunscreen.