A Meta-analysis to Investigate the Relation Between Fitzpatrick Skin Types and Tolerability of Adapalene-Benzoyl Peroxide Topical Gel in Subjects with Mild or Moderate Acne.

The overall goal of acne management for all patients is to select treatments that effectively address as many pathogenic factors as possible while minimizing side effects. Acne therapy in darker skin patients presents unique challenges due to differences in the risk of postinflammatory hyperpigmentation, which may develop in response to acne itself or to irritation secondary to treatment. One combination treatment currently available is a gel formulation containing a retinoid (adapalene 0.1%) in fixed combination with an antimicrobial (benzoyl peroxide 2.5%). Results from three randomized, double-blind, vehicle-controlled, clinical trials of adapalene-benzoyl peroxide were combined in a retrospective meta-analysis that included 909 patients treated for 12 weeks and assessed at each visit for erythema, scaling, dryness, and stinging/burning. Only Week 1 results were included in the meta-analysis because the worst severity of cutaneous irritation was found to occur at this timepoint in all three trials. For each study, and for the meta-analysis, comparisons were made using the Cochran-Mantel-Haenszel test. There were no statistically significant differences in dryness, scaling, and stinging/burning with adapalene-benzoyl peroxide treatment when subjects with Fitzpatrick skin types I to III were compared to subjects with Fitzpatrick skin types IV to VI (P=NS). Erythema assessments were statistically different based on skin types, as subjects with Fitzpatrick skin types IV to VI were rated as having "none" more often than those with Fitzpatrick skin types I to III (P<0.001). This could be due to the difficulty in visualizing erythema in patients with darker skin types, mainly Fitzpatrick skin types VI. Acne patients with Fitzpatrick skin types IV to VI were not found to be more susceptible to cutaneous irritation from treatment with the adapalene-benzoyl peroxide gel than patients with Fitzpatrick skin types I to III.