Itch in ethnic populations.

Racial and ethnic differences in the prevalence and clinical characteristics of itch have rarely been studied. The aim of this review is to highlight possible associations between ethnicity and different forms of chronic itch. We provide a current review of the prevalence of different types of itch in ethnic populations. Genetic variation may significantly affect receptors for itch as well as response to anti-pruritic therapies. Primary cutaneous amyloidosis, a type of pruritic dermatosis, is particularly common in Asians and rare in Caucasians and African Americans, and this may relate to a genetic polymorphism in the Interleukin-31 receptor. Pruritus secondary to the use of chloroquine for malaria is a common problem for African patients, but is not commonly reported in other ethnic groups. In patients with primary biliary cirrhosis, pruritus is more common and more severe in African Americans and Hispanics compared with Caucasians. Racial and ethnic differences in itch and its medical care are poorly understood. Research is needed to examine biological, psychosocial, and lifestyle factors that may contribute to these disparities.