What Is It?
Vitiligo consists of white patches of skin that are caused by the loss of melanin, the pigment that is a major contributor to skin. Melanin is produced by special cells called melanocytes, which are destroyed in people who have vitiligo. The cause of vitiligo is not known but evidence strongly suggests that vitiligo is an autoimmune disorder, in which the body's immune system mistakenly targets and injures these specific cells.
Vitiligo can cause minor changes or extensive changes in the skin. In some people, it may be hardly noticeable, while in others it is obvious. In dark-skinned people the vitiligo patches are obvious since they contrast with normal skin. Light-skinned people may have fewer cosmetic concerns, but patches without pigment can become obvious in the summer because unaffected skin tans while vitiligo skin does not tan.