Melasma is a common skin condition in which patches of skin on the face darken. Typically, the affected areas are the cheeks, bridge of the nose, forehead or upper lip. The dark patches are often symmetrical. Melasma can occur in anyone, but is much more frequently found among women, especially women who are pregnant when it is called chloasma, and is sometimes referred to as the “pregnancy mask.” Although not a painful or dangerous problem, melasma can be very distressing emotionally because of its alteration of the appearance. Melasma is not always a permanent condition. It may disappear in a woman several months after she gives birth, but may reoccur after unprotected exposure to the sun.

While the precise cause of melasma is unknown, certain individuals have a genetic predisposition to developing this condition and it more frequently occurs in people with brown skin. There is also a clear correlation between female hormones and melasma, since not only are pregnant women more susceptible but so are women on birth control or hormone replacement therapy. Sun exposure makes the development of melasma more likely, so women in tropical climates are more prone to the condition.