Skin gets its color from melanin in its uppermost layer, or epidermis. That melanin is produced by cells called melanocytes. If melanocytes are destroyed or fail to function properly, the body cannot produce melanin, and the skin loses its color. This anomaly does not happen overnight, nor does it happen evenly throughout the body. Vitiligo can occur in three different forms:
- Focal, in which loss of color is limited
- Segmental, in which one side of the body loses color
- Generalized, in which the symptoms are widespread [source: American Vitiligo Research Foundation]
Because lightening of the skin is more noticeable in people with darker complexions, Michael Jackson's case was obvious both to him and to the public. But vitiligo can affect people of any skin tone. Between 0.5 to 1 percent of the world's population has the condition, which affects people of all races and both sexes equally [source: National Vitiligo Foundation]. Symptoms are most likely to begin when a person is in his 20s. The most common starting points for the telltale white patches are above the eyes or on the neck, armpits, elbows, genitalia, hands or knees. Less common signs of vitiligo are premature graying of scalp hair and loss of color in the mucous membranes or retinas [source: American Vitiligo Research Foundation].
While doctors do not know why some people get vitiligo, they theorize that it is an autoimmune disease, a disorder in which the body attacks its own healthy tissue for unknown reasons. Heredity plays a role, although many people with vitiligo do not have a family member with the condition. Doctors believe a combination of genetic, immunologic, neurogenic and environmental factors are at play in many cases [source: American Skin Association]. Some people first report seeing the white patches after severe sunburn (one more reason to always protect your skin by wearing sunscreen), while others believe their vitiligo was triggered by emotional trauma. But is this condition contagious? Read on to find out if you can "catch" vitiligo from someone.