Alteration of Racial Differences in Melanosome Distribution in Human Epidermis after Exposure to Ultraviolet Light

CAREFUL studies of human epidermis have revealed that there is no significant difference between the number of melanocytes in the various racial groups, although there are regional differences in the population density of DOPA-positive melanocytes in various areas of the body (for example, on the forehead, 2,310 mm^?2; abdomen, 800 mm^?2; and back, 1,100 mm^?2)¹. These differences in the number of melanocytes may explain the colour differences in various areas of the body, but the colour of skin in the various races is apparently due to variations in the number of melanin granules, or melanosomes, in the melanocytes and in the epidermal keratinocytes, as well as to the degree of melanization of the individual melanosomes.