Most melasma occurs in women; however, 10% of cases affect men. The cause of melasma remains unknown but is believed to be due to an increase in the production of cells which release the pigment melanin, resulting in darkening of the skin. Because melasma is so common and has a very characteristic appearance the diagnosis of melasma is made by the physician in most cases by just looking at the skin.
The condition is universal and seen in all cultures and ethnicities; however it is far more commonly seen in people with darker skin tones including those of Asian, Hispanic, Latin, Indian, Middle Eastern, Mediterranean and North African descent. Individuals with these backgrounds have higher levels of melanin in their skin and a tendency to tan. There often is a family history of melasma. Individuals with fair skin may experience a lighter shade of melasma which is not always recognized.
There are multiple factors which are thought to trigger melasma including some cosmetics, birth control pills, hormone therapy, drugs that cause sun sensitivity, certain ant-seizure medications and sun exposure. In addition, melasma is very common during pregnancy and after childbirth. Pregnancy related melasma is referred to as chloasma or the “mask of pregnancy”.