Loss of normal pigment from patches of skin, most commonly occurring on the face and hands
People who have vitiligo have irregular patches of pale skin caused by the loss of melanin, the pigment that gives the skin its colour. The disorder is more obvious in people with dark skin.
In about half of all cases, vitiligo develops before the age of 20. It does not cause physical discomfort, but some people become distressed by the discoloured appearance of their skin.
It is thought that vitiligo is an autoimmune disorder in which the antibodies produced by the body react against its own tissues. In this condition, antibodies destroy the cells in the skin that produce melanin. About 1 in 3 people with vitiligo has a family history of the condition. About the same proportion also have another type of autoimmune disorder, such as pernicious anaemia (see Megaloblastic anaemia), diabetes mellitus, or autoimmune thyroiditis.
The loss of skin colour is gradual, occurring over several months or even years. The symptoms include:
Depigmented skin patches that may occur on any part of the body but most commonly the face and hands.
In some cases, white hair on affected areas of skin due to loss of pigment from the hair follicles.
In most people with vitiligo, the depigmented patches of skin are distributed symmetrically over the body.
The diagnosis is usually obvious, but your doctor may arrange for a skin test to exclude pityriasis versicolor, a fungal infection that may produce discoloured patches of skin. Blood tests may be done to make sure you do not have another autoimmune disorder.
In mild vitiligo, the discoloured areas can be hidden with cosmetics. No other treatment is needed. The affected areas cannot tan so you should avoid exposure to the sun and use a sunblock in direct sunlight (see Safety in the sun). Phototherapy using ultraviolet light can help but takes several months to work. Before treatment, you may be given psoralen, a drug to increase the skin’s sensitivity to light. Other possible treatments include topical corticosteroids; topical immunomodulators (drugs that affect the activity of the immune system) such as tacrolimus; the vitamin D derivative calcipotriol (see Vitamins); and pseudocatalase, a substance that affects hydrogen peroxide metabolism, which is often abnormal in people with vitiligo.
Occasionally, people may lose the pigment from large areas. In these cases, the rest of the skin may be bleached so that the overall colour of the skin appears more even.
There is no cure for vitiligo. In some cases, treatment may slow down or even reverse pigmentation loss but the response to treatment varies from person to person, and the depigmented patches may continue to enlarge slowly despite treatment. However, a minority of affected people regain their natural skin colour spontaneously.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.