Irritant contact dermatitis (ICD), a common dermatological disorder, presents the classic signs and symptoms of inflammation: edema, redness and tenderness. It can occur as a result of single exposure to an acute irritant, or when exposure to a less potent irritant is persistent or repeated until signs and symptoms develop over weeks, years or decades.
The severity of symptoms depends on exogenous and endogenous factors. Exogenous factors include the irritant’s chemical and physical properties, and the vehicle and frequencyofapplication. Endogenousfactors have been speculated to be age, sex, pre-existing skin diseases, skin sensitivity, genetic background, and – the subject of this column – race, or in today’s parlance, ethnicity.
Ethnic differences in skin physiology and pathophysiology exist, and so whether ethnicity is, in fact, an endogenous factor affecting ICD is a relevant question, with clinical and practical consequences. Premarket testing of topical products such as soaps, detergents, perfumes and cosmetics (an ever-expanding global market), risk assessment for occupational hazards, and subject-inclusion requirements for product safety studies might benefi t from knowledge about ethnic differences. Ethnic predisposition to ICD has been studied by comparing the irritant responses of blacks and Asians to those of whites as a benchmark. We review these studies to evaluate if ethnic differences in susceptibility to ICD do exist.