The efficacy and tolerability of single-agent chemical peeling for the treatment for melasma in patients with skin of color was supported by study data published in the Journal of Cosmetic Dermatology. In a meta-analysis of 13 studies, trichloroacetic acid and Jessner’s solution emerged as the most efficacious single-agent chemical peels for melasma in patients with dark skin.
Although chemical peels are frequently used to treat melasma, the risk for postinflammatory hyperpigmentation is increased in patients with dark skin. To further investigate and efficacy and safety of single-agent chemical peels in patients with pigmented skin, investigators conducted a systematic review and meta-analysis of the current literature. The Medline, SCOPUS, Web of Science, Google Scholar, and Cochrane databases were searched from inception through September 2020 for studies of chemical peeling treatment of melasma. Eligible studies enrolled patients with Fitzpatrick skin type III-VI and reported the relative efficacy and safety of 2 or more of the following chemical peelings agents: alpha-hydroxy acids, beta-hydroxy acids, Jessner’s solution, retinoic acid, or trichloroacetic acid. Only randomized controlled trials or prospective observational studies were included. Outcomes of interest included melasma area and severity index (MASI) score and incidence of adverse events.
The meta-analysis included data from 10 randomized controlled trials and 3 prospective comparative studies. The most frequently examined chemical peeling agent was glycolic acid, which was compared with trichloroacetic acid (n=5 studies), tretinoin (n=1), topical nanosome vitamin C iontophoresis (n=1), and amino fruit acid (n=1). In addition, 2 studies compared hydroquinone with trichloroacetic acid peel or Jessner’s solution peel or azelaic acid; 2 studies compared Jessner’s solution with salicylic acid and lactic acid; and 1 study compared tretinoin with vehicle cream.
The overall effect estimates favored trichloroacetic acid peel over topical hydroquinone in terms of MASI change from baseline (mean difference [MD], -5.30; 95% confidence interval [CI], -6.41 to -4.19; P <.001). Jessner’s solution also outperformed hydroquinone by this metric (MD, −3.20; 95% CI, −5.35 to −1.05; P =.004). No significant differences were observed between azelaic acid peel and topical hydroquinone. In addition, in the studies that compared glycolic acid with other chemical peels, no significant differences in MASI change were observed. No studies reported rate of melasma recurrence. Between-study heterogeneity was high for efficacy estimates.
Overall side-effect profiles were comparable in chemical peel agents. However, higher risk for erythema was observed in the trichloroacetic acid peel groups compared with the glycolic acid peel groups (risk ratio, -0.18; 95% confidence interval [CI], -0.30 to -0.071; P =.002). Risk for hyperpigmentation was similar for trichloroacetic acid peel and glycolic acid peel. The most common adverse event with Jessner’s solution was discomfort.
The primary limitation of this analysis was between-study heterogeneity, which may have affected the reliability of effect sizes. Also, no studies reported the long-term impact of chemical peeling on melasma recurrence.
Results from this meta-analysis identify trichloroacetic acid and Jessner’s solution as particularly effective modalities for melasma treatment in dark skin, the study authors believe. Side effects were mild in nature, although trichloroacetic acid was associated with higher risk for erythema compared with glycolic acid. “[C]hemical peelings are effective as single agents for management of melasma in patients with darker skin types, with the use of topicals as maintenance treatment,” investigators wrote. “[However], further well-designed trials are still needed.”
Dorgham NA, Hegazy RA, Sharobim AK, Dorgham DA. Efficacy and tolerability of chemical peeling as a single agent for melasma in dark-skinned patients: a systematic review and meta-analysis of comparative trials [published online September 18, 2020]. J Cosmet Dermatol. doi: 10.1111/jocd.13725