摘要：Melasma is a common, acquired facial skin disorder, mostly involving sun-exposed areas like cheeks, forehead and upper lip. Melasma occurs in both sexes, although almost 90 percent of the affected are women. It is more common in darker skin types (Fitzpatrick skin types IV to VI) especially Hispanics/Latinos, Asians and African-Americans. The onset of the melasma is at puberty or later, with exception of darker skin types, who tend to develop this problem in the first decade of life. The etiology is still unknown, although there are a number of triggering factors related to the onset of melasma. The most important are sun-exposure and genetic factors in both sexes, while hormonal activity has more important role in females. In addition, stress and some cosmetic products and drugs containing phototoxic agents can cause outbreaks of this condition. Melasma should be treated using monotherapies or combination of therapy, mainly fixed triple or dual combinations containing hydroquinone, tretinoin, corticosteroids or azelaic acid. Modified Kligman’s formula is also very effective. Above mentioned therapy regimens in combination with UVA and UVB blocking sunscreens are mostly effective in epidermal melasma. Discontinuation of the use of birth control pills, scented cosmetic products, and phototoxic drugs coupled with UV protection are also benefitial in clearing of melasma. Alternative treatment including chemical peels and glicolic acid, seem to have the best result as a second line treatment after bleaching creams. Laser treatments show limited efficacy and should rarely be used in the treatment of melasma. Combining topical agents like hydroquinone, tretinoin and a corticosteroid in addition to sun avoidance, regular use of sunscreen throughout the year and patient education is the best treatment in this difficult to treat condition.
