Vitiligo ( /ˌvɪtɨˈlaɪɡoʊ/) is a condition that causes depigmentation of sections of skin. It occurs when melanocytes, the cells responsible for skin pigmentation, die or are unable to function. The cause of vitiligo is unknown, but research suggests that it may arise from autoimmune, genetic, oxidative stress, neural, or viral causes. The incidence worldwide is less than 1%. The most common form is non-segmental vitiligo, which tends to appear in symmetric patches, sometimes over large areas of the body.
The most notable symptom of vitiligo is depigmentation of patches of skin that occurs on the extremities. Although patches are initially small, they often enlarge and change shape. When skin lesions occur, they are most prominent on the face, hands and wrists. Depigmentation is particularly noticeable around body orifices, such as the mouth, eyes, nostrils, genitalia and umbilicus. Some lesions have hyperpigmentation around the edges. Patients who are stigmatised for their condition may experience depression and similar mood disorders.