Vitiligo is a skin condition caused by progressive depigmentation; it presents as white patches on the skin. Although any part of the body can be affected, vitiligo is usually found on the face, elbows, knees, hands, feet, genitals and upper thighs. When the scalp is affected, the hair growing on the vitiligo patch is white. Vitiligo can also affect the chin or eyelid, in which case the lashes or beard become white. The texture of the depigmented skin is not altered and the condition is not painful, although the affected skin may be much more sensitive to the sun.
Vitiligo affects both sides of the body equally, often symmetrically, and the borders of the white patches are irregular but well-defined. White patches may appear gradually or suddenly. Vitiligo is not uncommon, affecting between one-half and one percent of the population. While not serious medically, it can cause emotional distress for the sufferer because of how it makes the skin look.