Patient consultation and selection

When evaluating the patient for the peeling procedure, an extensive medical history should be taken. The patient must be questioned with regard to general health status, medication, allergies, smoking, previous cosmetic procedures, recurrent herpetic outbreaks, and keloid formation, for example. There are almost no absolute contraindications for superficial peels. Deeper procedures require stable patients, both physically and mentally, being able and willing to precisely and obediently follow all post-procedural instructions. Pregnant and lactating patients are always excluded. Darker phenotypes can be peeled after discussing the benefits of the peeling procedure against the risk of post‑inflammatory hyperpigmentation. Any pre-existing cardiac condition should be cleared with the patient’s treating cardiologist before carrying out a phenol peel. The concept of oral isotretinoin being an exclusion criteria for chemical peels has been recently challenged3.

Pre-peel skin preparation is usually advised using retinoic acid and melanin inhibitors.

Superficial peels

Superficial peels are used to refresh the skin, to improve its texture and tone, and to assist in treating active acne and superficial dyschromia4. Serial procedures are usually required to achieve these goals and a combination with home-care products is recommended. Owing to their superficial action, these peels are usually appropriate for all skin phototypes5.

A single treatment with a superficial agent may induce gentle and visible skin exfoliation, but this will not occur in every patient and is not a necessary phase for the achievement of the full beneficial effect of the peel. However, some patients feel disappointed after a peeling procedure with no peel.

Light chemical peel solutions include 70% glycolic acid, Jessner’s solution (resorcinol, lactic acid, and salicylic acid in ethanol), trichloroacetic acid (TCA) 10–15%, salicylic acid 20–30%, and combination peels. The ideal candidate for a superficial peel is someone with mild skin damage and dyschromia, who is seeking minimal recovery time and is willing to go through a serial treatment regimen to achieve the desired results. Superficial peels do not affect wrinkles or deep pigmentations.

Alpha-hydroxy acid peels

Glycolic acid has the smallest molecular weight of all alpha-hydroxy acids (AHAs), penetrates the skin easily, and is therefore the most common AHA used. Glycolic acid peels are commercially available as free acids, partially neutralised (higher pH), buffered or esterified solutions. The application of the solution is performed after defatting of the skin using q-tips, gauze pads or brash. The skin is covered with a thin layer of the product, and neutralisation is performed once the skin achieves uniform erythema. If frosting is observed in any particular area before full-face erythema appears, then immediate neutralisation is performed at this site. It is recommended to begin with a low concentration of the acid (20–30%), and to increase its concentration and application time during the subsequent sessions. The treatment schedule includes a monthly peeling session with topical glycolic acid, and home-care products range from 8–15% concentrations.

Salicylic acid peels

Figure 1. A patient treated with salicylic acid 25% peel. Precipitation of the salicylic acid on the skin appears similar to frosting

Figure 1. A patient treated with salicylic acid 25% peel. Precipitation of the salicylic acid on the skin appears similar to frosting

Salicylic acid is a beta-hydroxyl acid. It is well known in dermatology owing to its keratolytic properties. Its exfoliative activity on the epidermis is almost devoid of associated inflammation; therefore, this agent can be safely used on skin types that are prone to develop post-inflammatory hyperpigmentation (PIH)6. Salicylic acid peels are preferred by some practitioners over other superficial peels in cases of acne and PIH7.

The formulations of salicylic acid used for the peeling are 20% or 30% in ethanol, or 50% in ointment.

The treatment regimen includes six peels 2–4 weeks apart. After cleansing and defatting of the skin, the solution is applied using a cotton-tipped applicator or gauze sponge. The patient will usually experience a burning sensation. A white precipitate of the salicylic acid appears after 1 minute and this should not be confused with a real frosting (Figure 1). The solution can be washed or left on the face for longer periods.

Salicylism or salicylic acid intoxication is a rare complication of salicylic acid applied to large areas of the body, and is not related to the peeling of small areas, such as the facial skin8.