Racial variations

Racial variations in skin are reflected in Table 3.1; these have implications for assessment, such as determining lesion colour and in the estimation of UV protection related to the presence of melanin (see Biology of the skin). The most lightly pigmented (European, Chinese and Mexican) skin types have approximately half as much epidermal melanin as the most darkly pigmented (African and Indian) skin types. Research by Alaluf et al. (2002) highlights the analysis of melanosome size, which revealed a significant and progressive variation in size with ethnicity: African skin having the largest melanosomes followed in turn by Indian, Mexican, Chinese and European. Based on these findings, they propose that variation in skin pigmentation is strongly influenced by both the amount and the composition (or colour) of the melanin in the epidermis. Variation in melanosome size may also play a significant role. Further details of the relationship of skin typing to the person’s genetic history and social heritage are given in Leach et al. (1996) and on racial influences on skin disease in Gawkrodger (1998).