Vitiligo is a skin condition characterized by loss of pigmentation. It can occur at any age and effects about 1% of the population. There is a positive family history and about 25% of the cases. The cause is unknown. The pigment cells (melanocytes) die and are not replaced. It may be associated with autoimmune diseases such as hyperthyroidism and hypothyroidism. The disease is disfiguring in people with dark skin.