Acne vulgaris (acne) is the most common dermatologic condition in black patients.1,2 However, among outpatient visits, racial disparities exist in both the likelihood of seeing a dermatologist and being treated.3 Black patients are less likely to visit a dermatologist or receive any acne medication. Acne in black skin is frequently associated with postinflammatory hyperpigmentation (PIH), an important consideration in treatment choice and maintenance.
There is a paucity of clinical studies that specifically evaluate acne treatment in this patient population. An 8-week, vehicle-controlled study with tretinoin cream 0.025% in 27 black patients with acne reported notable decreases in papules, pustules, and hyperpigmented macules in 83% of patients treated with tretinoin compared to only 13% receiving vehicle.4 However, irritation and inflammation were problematic. An open-label study of adapalene gel 0.1% in 65 black South Africans also demonstrated significant improvement in inflammatory and noninflammatory lesions and PIH (P<.01), with seemingly better tolerability.5,6 A meta-analysis of 5 randomized studies from the United States and Europe (N=655) compared the efficacy and safety of adapalene gel 0.1% in black (n=46) and white patients.7 There was no significant difference in percentage reduction in comedonal (44%) or total (42%) lesion counts. The percentage reduction in inflammatory lesion counts (53%) was significantly greater in black patients (P=.012). Tolerability also was better; black patients experienced significantly less erythema and scaling (P<.001 and P=.026, respectively), though erythema can be underestimated in darker skin tones because of the masking effects of melanin.5,7 Dryness was more common, though a smaller percentage of black patients reported moderate or severe dryness compared to white patients (7% vs 18%).7
Black patients also are less likely to receive combination therapy, and again clinical data are limited.3 A more recent subgroup analysis evaluated the safety and efficacy of adapalene 0.1%–benzoyl peroxide 2.5% gel in black patients with moderate acne from 3 studies (n=238 out of a total of 3855 patients).8 Similar results were obtained as in the overall study populations, with 64.3% and 48.5% reductions in inflammatory and noninflammatory lesion counts, respectively, at week 12. The most common treatment-related adverse event (AE) in both treatment groups was dry skin (11.3%).8
Extensive clinical data in a predominantly white population have shown that topical retinoids (eg, tretinoin, adapalene, tazarotene) are highly effective in treating acne, and they are recommended as the cornerstone of topical therapy.9 However, there is a common perception that they are primarily effective in comedonal acne10 and that their use is associated with notable cutaneous irritation.11,12 Several attempts have been made to alleviate the tolerability issue using novel delivery systems. A new lotion formulation of tretinoin recently was developed and leveraged polymeric emulsion technology with the aim to improve both efficacy and tolerability of tretinoin. Herein, we performed a post hoc analysis of 2 large phase 3 clinical studies13 in patients with moderate or severe acne treated with tretinoin lotion 0.05% to evaluate its safety and tolerability in a black population.
We conducted a post hoc analysis of 2 identical multicenter, randomized, double-blind, vehicle-controlled, parallel-group clinical studies13 in black patients with moderate or severe acne. Protocols received approval from the appropriate institutional review board for each center before patient enrollment, and the studies were conducted in accordance with the Declaration of Helsinki and Good Clinical Practice as well as in compliance with local regulatory requirements. All patients were informed of the study details and provided written consent before entering the studies.
Patients were enrolled with an evaluator global severity score (EGSS) of 3 (moderate) or 4 (severe). Participants were randomized (1:1) to receive tretinoin lotion 0.05% or vehicle applied to the face once daily for 12 weeks.