Epidemiology of melasma in Brazilian patients: a multicenter study.

BACKGROUND: Melasma is an acquired, irregularly patterned, light to dark-brown hypermelanosis, with symmetric distribution mostly over the face. The aim of this study was to evaluate clinical characteristics and factors related to melasma in Brazilian patients. METHODS: This was a cross-sectional, multicenter study performed in Brazil. Investigators examined and questioned 953 patients over 18 years of age on clinical characteristics and other factors related to their melasma. RESULTS: Melasma was more prevalent in women (97.5%) and in Fitzpatrick skin phototypes II (12.8%), III (36.3%), and IV (39.7%). Skin phototypes II and III and family history of melasma had early onset of the disorder when compared with skin phototypes IV, V, and VI (P<0.0001). Similar results were also observed when these same groups were compared with the absence of family history (P<0.0001). Extra-facial melasma was more frequent in postmenopausal women compared with those who were not experiencing menopause (14.2% vs. 3.5%, P<0.0001). CONCLUSIONS: Data suggested that the age of melasma onset are related to skin phototypes and family history. Additionally, extra-facial melasma was more common in menopausal women. This is the first study on the epidemiology of melasma in Brazil involving a large sample of the population. These data can be a source of new relevant research on the cause and development of melasma.