Vitiligo (vit-ill-eye-go) is a pigmentation disorder in which pigmentation is lost by the melanocytes (cells that make pigment) in the skin. As a result, white patches of skin appear on different parts of the body. The hair that grows in areas affected by vitiligo may turn white.
The cause of vitiligo is not known, but doctors and researchers have different theories. One theory is that people develop antibodies that destroy the melanocytes in their own bodies. Another theory is that melanocytes destroy themselves. Finally, some people have reported that a single event such as sunburn or emotional distress triggered vitiligo; however, these events have not been scientifically proven to cause the disorder.
About 1 to 2 percent of the world's population, or 40 to 50 million people, are affected by vitiligo. In the United States, 2 to 5 million people have the disorder. Ninety-five percent of people who have vitiligo develop it before their 40th birthday. The disorder affects all races and both sexes equally.
Vitiligo seems to be more common in people with certain autoimmune diseases (diseases in which a person's immune system reacts against the body's own organs or tissues). These autoimmune diseases include hyperthyroidism (an overactive thyroid gland), adrenocortical insufficiency (the adrenal gland does not produce enough of the hormone called corticosteroid), alopecia areata (patches of baldness), and pernicious anemia (a low level of red blood cells caused by failure of the body to absorb vitamin B12). Scientists do not know the reason for the association between vitiligo and these autoimmune diseases. However, most people with vitiligo have no other autoimmune disease.
Vitiligo may also be hereditary; that is, it can run in families. Children whose parents have the disorder are more likely to develop vitiligo. However, most children will not get vitiligo even if a parent has it, and most people with vitiligo do not have a family history of the disorder.
Vitiligo generally appears in one of three patterns. In one pattern (focal pattern), the depigmentation is limited to one or only a few areas. Some people develop depigmented patches on only one side of their bodies (segmental pattern). But for most people who have vitiligo, depigmentation occurs on different parts of the body (generalized pattern). In addition to white patches on the skin, people with vitiligo may have premature graying of the scalp hair, eyelashes, eyebrows, and beard. People with dark skin may notice a loss of color inside their mouths.
There is no way to predict if vitiligo will spread. For some people, the depigmented patches do not spread. The disorder is usually progressive, however, and over time the white patches will spread to other areas of the body. For some people, vitiligo spreads slowly, over many years. For other people, spreading occurs rapidly. Some people have reported additional depigmentation following periods of physical or emotional stress.
If a doctor suspects that a person has vitiligo, he or she usually begins by asking the person about his or her medical history. Important factors in a person's medical history are a family history of vitiligo; a rash, sunburn, or other skin trauma at the site of vitiligo 2 to 3 months before depigmentation started; stress or physical illness; and premature graying of the hair (before age 35). In addition, the doctor will need to know whether the patient or anyone in the patient's family has had any autoimmune diseases and whether the patient is very sensitive to the sun.
No testing is necessary to diagnose vitiligo. Examination is sufficient to confirm its presence.