Vitiligo/Pigmentary Disorders
In general, pigmentary disorders (melasma, hyperpigmentation, hypopigmentation and depigmentation) are areas on the skin that are too dark or too light in color relative to the rest of the skin. The brown color, or pigment, in the skin comes from melanin, a brown to black “bio-molecule” that is made by melanocytes. Melanocytes are one type of cell that resides in the skin. The melanocytes make the melanin pigment and then distribute the pigment to the other skin cells to give the skin a brownish hue. A suntan is caused when sunlight stimulates the melanocytes to make and distribute more pigment. Whenever there are abnormalities in the melanocytes or in the amount of pigment they make, it can cause a pigment disorder. For example, in vitiligo, the skin turns white (becomes depigmented) because there are no melanocytes in the skin in that area. In the case of melasma, the melanocytes have been stimulated, often by hormones, to produce more pigment in specific areas of the skin. (Melanomas are a cancer of melanocytes.)
The treatment of pigmentary disorders usually involves reversal or minimization of the melanocyte abnormalities that are the source of the problem. Stimulating re-growth of melanocytes in the case of vitiligo or decreasing pigment production in melasma, for instance. Diverse therapies from light or laser therapies to bleaching creams are available to treat pigment disorders.
