Evaluation of the relationship between clinicoepidemiological features of melasma and the level of involvement on wood's lamp Examination

Melasma is a common acquired hyperpigmentation disorder often appearing on the face of young women. Melasma is classified into four groups based on Wood’s lamp examination: epidermal, dermal, mixed, and indeterminate. The goal of this study was to evaluate the relationship between clinicoepidemiological characteristics of melasma and the level of involvement under Wood’s lamp examination. In a cross sectional study, 50 melasma patients who were visited at the dermatology clinic of Imam Reza Hospital from March 2010 to September 2011 were studied. The level of melasma involvement in all patients was determined using a Wood’s lamp, and the patients’ information such as age, occupation, location of melasma, marital status, pregnancy, oral contraceptive pill consumption and Fitzpatrick skin type was collected in a questionnaire. In single patients, dermal involvement and in married patients, epidermal involvement was more common. Involvement was more frequently dermal in jobs with exposure to sun and more epidermal in indoor jobs. In the malar region, epidermal involvement was more common. In patients with a history of pregnancy, epidermal involvement was more prevalent as well, while in the participants without a history of pregnancy, dermal involvement was more frequent. In the pregnant patients with melasma, epidermal involvement was more frequent. In patients without a family history of melasma, epidermal involvement was more frequently observed than the other two levels of involvement. Based on the findings of this study, melasma in cases with the involvement of the malar region, starting in pregnancy, in patients without a family history of melasma, and in the individuals who have indoor occupations is most likely to be epidermal and may have a better response to treatment. On the other hand, melasma in single persons and in those who have outdoor occupations and are exposed to sun light is mostly dermal with a worse response to treatment according to previous studies.