Racial differences in skin pathophysiology.

Racial differences in skin function occur and may be responsible for differences in skin reactivity in physiologic and pathologic conditions. This article reviews the main racial anatomic and physiologic differences as well as mechanisms of irritation, sensitization, and drug absorption reported in the recent literature. Racial differences in transcutaneous penetration of chemicals and drug absorption have been described. Decreased transcutaneous penetration has been reported in black persons. In contrast, conflicting findings have been reported concerning some aspects of irritation and sensitization. Decreased erythematous reactions have been found in pigmented skin, whereas white persons have a stronger resistance to water barrier damage. Regional variation in skin function is more evident in fair skin because of the modifying effects of long-term UV exposure.