It manifests itself as darker patches on cheeks, forehead, nose and chin. More than 6 million women are estimated to have melasma. (Men can develop it, but it is rare.) It is more common in people with light brown skin, especially Hispanics and Asians.

Melasma is usually caused by normal hormonal changes in women — during pregnancy or when taking birth control pills or hormone replacement therapy. Because of the way it looks when it usually occurs, melasma is sometimes called the "mask of pregnancy." It can be mild, moderate or severe, depending on how much of your face is discolored and how much darker than normal your skin has become. Melasma may also be associated with the use of certain anti-epileptic drugs.

Melasma only occurs on the areas of your skin that are exposed to the sun. Exposure to the sun, even during normal daily activities, can further darken melasma patches.

Melasma can be embarrassing, especially in a society where appearance is important and valued. Fortunately, treatment is available. Use our Self-Assess Your Skin Tool to help determine if you have melasma, then visit a dermatologist.

Locate a dermatologist in your area today with the DermFinder.