Skin differences, needs, and disorders across global populations.

Accurately determining the incidence and prevalence of dermatologic disease in most large populations has been challenging for reasons ranging from the lack of easily quantifiable tests and measures to imprecision around definitions of race, ethnicity, photo skin type, pigmentation, and population groups. Compounding the problems with these categorizations is the fact that skin disease and skin health are affected not just by inherent risk factors but also by habits and environment. Thus, a fundamental question remains as we evaluate the effects of cultural and environmental factors: do genetic factors account for most of the difference that we see in skin types? Is the primary influence the way the skin mediates the environmental insult of UV radiation or how inflammation is handled? Is melanization the primary characteristic that we should measure and consider? This article will provide an introduction to current knowledge and future directions researchers are taking in differentiating both the biological differences of skin and the clinical manifestations of skin disease among the groups described above. This discussion will be followed by a brief overview of cultural practices and environmental factors that are known to have significant impact on skin disease and a summary of the most common conditions that are encountered worldwide.