Chemical peels are effective and common treatments for many skin problems such as photoaging, lentigines, melasma, and other pigmentary changes. Different chemical peels act on different depths of the skin layers. Alpha-hydroxy acids such as glycolic acid (GA) 20%-50%, lactic acid (LA) 20%-30%, and mandelic acid (MA) are classified as superficial peeling agents and act on the epidermis, preserving the basal layer. These are all considered safe for all skin types, but MA is considered the safest choice. Salicylic acid (SA) is a beta-hydroxy acid and has been considered to be the safest peel in skin of color.
All of the peeling agents have some side effects, most commonly swelling, crusting, and postinflammatory hyperpigmentation (PIH). Previous studies have suggested that the deeper the peel and the darker the skin tone, the more side effects and complications can be expected, especially PIH. However, the data on how different skin tones fare with different peels is limited, so a recent study examined the frequency and range of side effects associated with superficial chemical peels in ethnically diverse patients.
The retrospective study included 132 patients with skin types III-VI who received a total of 473 chemical peels over a five –year period at a Boston medical center by a single dermatologist. Patients received the peels to treat melasma, PIH, acne, acanthosis, lentigines, and photoaging. The study catalogued side effects that included the development of dyspigmentation, erythema, crusting, or blisters and noted whether they lasted more or less than two weeks.
The results showed that in this population, only a small percentage of treatments (3.8%) resulted in either short or long-term (over 2 weeks) side effects. This is lower than in previous studies on darker skin. The most common effects were prolonged crust (2.3%), PIH (1.9%), and erythema (1.9%) and complications were less frequent when the treatment was done in winter and were more common in skin type VI – average duration was 4.5 weeks.
The authors conclude that based on the data superficial chemical peels are safe in darker skin types and result in few side effects and complications.