(See also Overview of Skin Pigment.)
Vitiligo is a loss of melanocytes that causes patches of skin to turn white.
Vitiligo affects up to 2% of people.
The cause of vitiligo is unknown, but it is a disorder of skin pigmentation that may involve an attack by the immune system on the cells that produce the skin pigment melanin (melanocytes). Vitiligo tends to run in families, or people may spontaneously develop it. Vitiligo may occur with certain other diseases. Vitiligo is associated with autoimmune disorders (when the body attacks its own tissues), thyroid disease being the most common. It is most strongly associated with an overactive thyroid (hyperthyroidism, particularly when caused by Graves disease) and an underactive thyroid (hypothyroidism, particularly when caused by Hashimoto thyroiditis). People with diabetes, Addison disease, and pernicious anemia also are somewhat more likely to develop vitiligo. However, the relationship between these disorders and vitiligo is unclear and may be coincidental.
Occasionally, vitiligo occurs after physical injury to the skin, for example, as a response to a chemical burn or sunburn. People may also notice vitiligo is triggered by an episode of emotional stress.
Vitiligo may cause considerable psychologic distress, especially in dark-skinned people.
In some people, one or two well-defined patches of vitiligo appear. In other people, patches appear over a large part of the body. Rarely, vitiligo occurs over most of the skin surface. The changes are most striking in people with darker skin. Commonly affected areas are the face, fingers and toes, wrists, elbows, knees, hands, shins, ankles, armpits, anus and genital area, navel, and nipples. The affected skin is extremely prone to sunburn. The areas of skin affected by vitiligo also produce white hair because melanocytes are lost from the hair follicles.
Vitiligo is recognized by its typical appearance. A Wood light examination is often done to help distinguish vitiligo from other causes of lightened skin. Other tests, including skin biopsies, are rarely necessary.
No cure is known for vitiligo, although skin color may return spontaneously. Treatment may be helpful. All affected areas of skin are at risk of severe sunburn and should be protected from the sun with clothing and sunscreen (see Prevention of Sunburn).
Small patches sometimes darken (repigment) when treated with strong corticosteroid creams. Drugs such as tacrolimus or pimecrolimus may be applied to patches on the face or groin, where strong corticosteroid creams may cause side effects. Calcipotriene (also called calcipotriol), which is a form of vitamin D, blended with betamethasone (a corticosteroid cream), can be effective and is more effective than either cream used alone. Some people simply use bronzers, skin stains, or makeup to darken the area.
Because many people still have a few melanocytes in the patches of vitiligo, exposure to ultraviolet (UV) light in a doctor’s office (phototherapy) restimulates pigment production in more than half of them (see Phototherapy). In particular, psoralens (drugs that make the skin more sensitive to light) combined with UVA light (PUVA) or narrowband UVB light treatment without psoralens can be given. However, phototherapy takes months to years to be effective and may need to be continued indefinitely. Doctors rarely use lasers on some people who have small patches that do not respond to corticosteroid creams.
Areas that do not respond to phototherapy may be treated with various skin-grafting techniques and even transplantation of melanocytes grown from unaffected areas of the person’s skin. Tattooing is especially useful for areas where it is difficult to restimulate pigment production (such as the nipples, lips, and fingertips).
Some people who have very large areas of vitiligo sometimes prefer to bleach the pigment out of the unaffected skin to achieve an even color. Bleaching is done with repeated applications of a strong hydroquinone cream to the skin for weeks to years. The cream can be extremely irritating. The effects of bleaching (such as permanent loss of pigment) are irreversible.