The dermoscopic characteristics of melasma in relation to different skin phototypes, distribution patterns and wood lamp findings: a cross-sectional study of 236 melasma lesions.

Melasma is an acquired, pigmentary disorder characterized by the appearance of brown to bluish-gray patches with well-demarcated or ill-defined borders, most commonly on the face. This challenging hyperpigmentation disorder is generally observed in women; sun exposure, pregnancy, oral contraceptive use, genetic influences and chemical agents are some etiopathogenetic factors. Even though readily diagnosed by clinical examination; dermoscopy, Wood lamp findings and histopathology may also help the clinicians to confirm the diagnosis and to disclose the features of the melasma such as melanin depth and melasma type. In our study, we aimed to investigate the dermoscopic properties of facial melasma in accordance with different skin phototypes, age, distribution patterns, presence of other facial dermatoses, etiological factors and wood lamb findings. In the present cross-sectional study, patients clinically diagnosed with facial melasma in a secondary care hospital were included. Demographical data, personal history, distribution patterns of the melasma, dermoscopic features, Wood lamp examination findings, the presence of any other facial dermatosis, possible underlying risk factors and skin phototypes were determined. One hundred fifty nine patients with a total number of 236 melasmas with variable distribution patterns were included. The mean age was 37.91 years, whereas the mean age at the onset of the melasma was 32.43 years. One hundred thirty three participants were females, whereas 26 were males. The most prevalent risk factors of melasma were exposure to UV light (62.2%), pregnancy (50.6%) and genetic predisposition (43.6%). The most common melasma localization was cheek (43.6%) followed by T zone (33.1%). The most common dermoscopic findings were brown reticular pseudonetwork (73.3%), increased vascularity and telangiectasia (51.7%) and brown clods (33.1%). Brown reticular pseudonetwork was present at a higher rate in patients with skin phototype V compared to the ones with skin phototype II (p = 0.033). Our study shows that dermoscopic findings of melasma may differ across different skin phototypes, melasma localizations, possible associated risk factors and age.