Vitiligo is a skin disease characterized by a loss of pigmentation; pale, whitish lesions develop as melanocytes, the skin cells that produce the pigment melanin, are destroyed. The loss may be limited to a few spots or may be extensive; in severe cases, all pigment cells are lost. Hair in vitiliginous areas usually is white. The cause is unknown, although genetic factors are believed to play a role. There also are indications that vitiligo is an autoimmune diseaseÑthat is, one in which the immune system forms antibodies that attack the body's own tissues, in this case, the melanocytes.
Vitiligo is not harmful to general health. In fair-skinned people, lesions may be barely visible, but they are pronounced in dark-skinned individuals. Cosmetics or temporary dyes can be applied to the lesions so that they blend with the normal skin. Some patients undertake repigmentation therapy, which generally involves taking psoralen compounds, followed by exposure to ultraviolent light. Although this process is lengthy and sometimes produces unpleasant side effects, it is successful in about 65 percent of cases. An alternative is depigmentation therapy, in which pigment cells in unaffected areas are destroyed by applying a cream containing monobenzone. This procedure may be suggested for patients with vitilgo over more than half the body surface.