According to the National Institutes of Health, about 6 million women in the United States are estimated to cope with melasma, which has no permanent cure, but can be effectively treated. While hormonal changes and sunshine are the two biggest triggers, those with a genetic predisposition and darker skin are more prone to the condition. People who work around heat for example, such as cooks, may also be prone because of heat's ability to irritate the skin and induce overproduction of pigment.
"Most women who come to me with melasma are dismayed at their appearance," says Morales. "Melasma is not dangerous, but there's no question that it detracts from their quality of life.