melasma is an acquired light- or dark-brown hyperpigmentation that occurs in the exposed areas, most often on the face, and results from exposure to sun-light; may be associated with pregnancy, with ingestion of contraceptive hormones, or possible with certain medications such as diphenhylhydantoin, or may be unknown cause.

The pigmentation usually evolves quite rapidly over weeks, particularly after exposure to sunlight.

Melama may disappear spontaneously over a period of months after delivery or after cessation of contraceptive hormones. Topical treatment of hydroquinone cream or combination with topical tretinoin or glycolic acid are effective.It is essential that the patient use, every morning, a sunblock containing titanium dioxide or zinc oxide.