The chronic skin disease of Vitiligo affects about 1-2% of the world’s population. In this disease, the pigment or color making cells in the skin, called melanocytes, are destroyed and the mucous membranes (such as the tissue inside the mouth and nose) and the eyemay also be affected. As a result, smooth, milky white or light pink patches in the middle of normally pigmented skin appear. The hair may also turn white/grey that grows in areas affected by Vitiligo and on the scalp. There are several arguments suggesting that Vitiligo is a genetically dependent disease, thus genetics play a large role in defining who might get affected by it.
Genetic studies have demonstrated that certain genes are crucial for the development of Vitiligo. This disease is said to be caused by inheritance of multiple causal genes simultaneously, possibly in different combinations in different people, plus exposure to environmental risk factors or triggers that are not yet known. Phenols, and stress whether emotional or physical, are suspected to be environmental triggers, but research continues into these and other possibilities.
Vitiligo also tends to occur more often with certain other autoimmune diseases, such as hyper- or hypo-thyroidism (an over- or under-active thyroid gland), adrenocortical insufficiency (underproduction of corticosteroid hormone by the adrenal gland), rheumatoid arthritis, type 1 diabetes, psoriasis, systemic lupus erythematosus, and pernicious anemia (subnormal red blood cell level caused by inability to absorb vitamin B12). This suggests that these different autoimmune diseases probably share at least some predisposing genetic or environmental causal factors, although these mostly remain unknown.
Vitiligo affects both genders and all races, but is more noticeable in people with darker skin. It can start at any age but about half of those with Vitiligo develop it before the age of 20, and about 95% before age 40.