Definition of Melasma:

Melasma is a dark skin discoloration found on sun-exposed areas of the face.

Causes, incidence, and risk factors:

Melasma is a very common skin disorder. Though it can affect anyone, young women with brownish skin tones are at greatest risk.

Melasma is often associated with the female hormones estrogen and progesterone. It is especially common in pregnant women, women who are taking oral contraceptives ("the pill"), and women taking hormone replacement therapy during menopause.

Sun exposure is also a strong risk factor for melasma. It is particularly common in tropical climates.