TOPICAL RETINOIC ACID (TRETINOIN) FOR MELASMA IN BLACK PATIENTS - A VEHICLE-CONTROLLED CLINICAL-TRIAL

Background and Design: Melasma is an acquired, masklike, facial hyperp igmentation. The pathogenesis and treatment of melasma in black (Afric an-American) patients is poorly understood. We investigated the effica cy of topical 0.1% all-trans-retinoic acid (tretinoin) in the treatmen t of melasma in black patients. Twenty-eight of 30 black patients with melasma completed a 10-month, randomized, vehicle-controlled clinical trial in which they applied either 0.1% tretinoin or vehicle cream da ily to the entire face. They were evaluated clinically (using our Mela sma Area and Severity Index), colorimetrically, and histologically. Re sults: After 40 weeks, there was a 32% improvement in the Melasma Area and Severity Index score in the tretinoin treatment group compared wi th a 10% improvement in the vehicle group. Colorimetric measurements s howed lightening of melasma after 40 weeks of tretinoin treatment vs v ehicle. Lightening of melasma, as determined clinically, correlated we ll with colorimetric measurements. Histologic examination of involved skin revealed a significant decrease in epidermal pigmentation in the tretinoin group compared with the vehicle group. Side effects were lim ited to a mild ''retinoid dermatitis'' occurring in 67% of tretinoin-t reated patients. Among the patients in this study in comparison with c omparably recruited white patients, melasma was reported to have begun at a later age and was more likely to be in a malar distribution. Con clusions: This controlled study demonstrates that topical 0.1% tretino in lightens melasma in black patients, with only mild side effects.