The skin condition characterized by white patches caused by loss of pigment is vitiligo. It occurs when areas of skin lose melanin, the pigment responsible for much of the skin’s color, producing pale or completely depigmented patches.
Vitiligo is generally described as a chronic autoimmune disorder, although its precise cause is not fully understood. Genetic susceptibility may interact with environmental factors, and some people develop new patches after skin injury or other triggers. The patches can appear anywhere, but the face, hands, wrists, and areas around the eyes and mouth are common sites.
The most common form, nonsegmental vitiligo, often affects matching areas on both sides of the body and may expand over time. Segmental vitiligo usually follows a more localized distribution. Vitiligo is not contagious and is not the same as albinism, a usually inherited condition involving reduced melanin throughout the body.
Historical descriptions of white-spot disorders were sometimes confused with leprosy, leading to stigma. Modern care may include camouflage makeup, topical medicines, corticosteroids, and light therapy. Depigmented skin is also more vulnerable to sunburn, so sun protection is important.