Evaluation of Dermoscopic Features in Facial Melanosis with Wood Lamp Examination

Abstract

Introduction: Facial melanosis is one of the most common reasons for which patients refer to a dermatologist in Nepal. Objectives: The objective of this study was to evaluate the dermoscopic findings of common facial melanoses and correlate them with findings from Wood lamp examination. Methods: This was a cross-sectional study conducted at the Department of Dermatology and Venereology, Nepal Medical College and Teaching Hospital. We recruited a total of 204 patients from July 2020 to March 2021. The most common diagnosis was melasma (37 patients) followed by melasma with steroid-induced rosacea-like dermatitis (29 patients).  After collecting clinical and demographic data, patients underwent Wood lamp and dermoscopic examination. Results: Dermoscopy of ashy dermatosis and nevus of Ota revealed blue-gray pigmentation forming a curvilinear pattern; café-au-lait macule and nevus spilus revealed a light brown reticular pattern with follicular sparing; and a reticular and hem-like pattern of pigmentation was observed in clofazimine-induced pigmentation, peribuccal pigmentation of Brocq and periorbital pigmentation. The degree of agreement between Wood lamp and dermoscopic findings was found to be statistically significant in melasma (κ = 0.701, P = 0.0001) and melasma with steroid-induced rosacea-like dermatitis (κ = 0.628, P = 0.0001). While the agreement between the two techniques was 100% for epidermal types, it decreased to 44.8% for dermal melasma and 61.5% for dermal melasma with steroid-induced rosacea-like dermatitis. Conclusions: Dermoscopy is useful in assessing facial melanoses. It may be supplemented with Wood lamp examination to increase diagnostic accuracy.