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.
Causes of Vitiligo
Vitiligo appears to be an autoimmune disorder in which immune cells attack melanocytes, the cells that produce pigment; why this happens is not yet known. Vitiligo runs in some families; can appear at any age; affects both sexes equally; and affects people of every skin color. There is also some correlation between vitiligo and three other autoimmune diseases: pernicious anemia, hyperthyroidism and Addison's disease.
Diagnosis of Vitiligo
In most cases, vitiligo is diagnosed by simple physical examination, but, in some cases, an ultraviolet light called Wood's light is used. Wood's light provides a definitive diagnosis because it illuminates only skin affected by vitiligo. At times, a skin biopsy is taken to make sure the depigmentation does not have another cause. If another medical issue is suspected, blood tests may be administered to check the patient's levels of various hormones, especially thyroid hormone, and of vitamin B12.
Treatment of Vitiligo
Vitiligo is a very difficult disorder to treat. In most cases, patients just live with it, using sunblock to protect white patches from sunburn and/or makeup to camouflage them. Although it used to be believed that melanin was the only agent protecting the body from sun damage, vitiligo has shown that that is not the case; some patients suffer severe sunburn on vitiligo patches and others do not. In all cases, however, it is important for patients with vitiligo to use sunblock.
There are several treatments for vitiligo that are used with varying degrees of success. They include the following:
- Phototherapy (medical exposure to ultraviolet light)
- Topical drugs (to increase skin sensitivity to light)
- Topical corticosteroids
- Topical immunosuppressants
- Autologous skin grafts from pigmented areas
- Medical tattooing (micropigmentation)
Other treatments are being used experimentally. One involves the transplantation of melanocytes grown from a patient's healthy cells to the area affected with vitiligo.