What are the causes of melasma?
Melasma has been considered to arise from pregnancy, oral contraceptives, endocrine dysfunction, genetic factors, medications, nutritional deficiency, hepatic dysfunction, and other factors. The majority of cases appear to be related to pregnancy or oral contraceptives. The infrequency of melasma in postmenopausal women on estrogen replacement suggests that estrogen alone is not the cause. In more recent experience, combination treatment using estrogen plus progestational agents is being used in postmenopausal women, and melasma is being observed in some of these older women who did not have melasma during their pregnancies. Sun exposure would appear to be a stimulating factor in predisposed individuals. Although a few cases within families have been described, melasma should not be considered a hereditary disorder.
