males; about 10% of patients with melasma are men.Common, especially among persons with constitutive brown skin color who are taking contraceptive regimens and who live in sunny areas.Pregnancy causes melasma.Melasma has recently been appearing in menopausal women as a result of regimens for prevention of osteoporosis using a combination of estrogens and progesterone;The pigmentation usually evolves quite rapidly over weeks, particularly after exposure to sunlight.Completely macular hyperpigmentation of the face, the hue and intensity depending largely on the skin phototype of the patientMost often symmetric.Lesions have serrated, irregular and geographic borders.Two-thirds on the central part of the face: cheeks, forehead, nose, upper lip, and chin; a smaller percentage on the malar or mandibular areas of the face and occasionally the dorsa of the forearms.May disappear spontaneously over a period of months after delivery or after cessation of contraceptive hormones.Melasma may or may not return with each subsequent pregnancy.Treatment with hydroquinone can lead to a permanent loss of melanocytes with the development of a disfiguring spotty leukoderma.Prevention: opaque sunblock containing titanium dioxide and/or zinc oxide.Even the potent transparent sunscreens (with high SPF) are completely ineffective in blocking visible radiation">