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Vitiligo, a disorder that occurs in at least 1 percent of the population of all races and both sexes, interferes with the distribution of pigment (melanin) in the skin. It leads to areas of skin that lack the normal pigmentation so that areas of white skin are surrounded by normally colored skin or even a surrounding border of increased pigmentation. In whites, it may be more prominent in summer when normal skin becomes darker due to sun exposure. The depigmented areas are particularly at risk of sunburn and may require the protection of a sun block.
Vitiligo may begin at any age but most commonly occurs between the ages of 20 to 30 years. It may appear anywhere on the body but is common on the extremities where it may be symmetrical. Heredity may play a role in this condition as well as autoimmune mechanisms that damage the melanin-producing cells (melanocytes) in the skin of the involved areas. In some people, there may be spontaneous repigmentation of the affected skin, particularly in skin with hair. Treatment may be as simple as using cosmetic agents that color or stain the skin or involve use of medications (psoralens) that sensitize the skin to the tanning effects of ultraviolet light (PUVA). However, there is increasing concern that excess ultraviolet exposure, including PUVA therapy, is a major factor in the reported increase in the incidence of melanoma.