In vivo reflectance confocal microscopy for the differential diagnosis between vitiligo and nevus depigmentosus.

BACKGROUND Nevus depigmentosus (ND) is frequently confused with vitiligo. Differential diagnosis can be difficult. In vivo reflectance confocal microscopy (RCM) is a noninvasive technique for real-time en face imaging of the superficial layers of the skin down to the superficial dermis with cellular level resolution close to conventional histopathology. In this study, we tried to use this new technology to study the features of the distribution of pigment cells of these two hypopigmentation disorders and then concluded the differential features. METHODS Sixty vitiligo patients and 62 ND patients were enrolled in the study. Three points in each patient (lesional, margin of the lesions and adjacent non- lesional points) were examined with RCM. The gray value of image was quantified using software, and we calculated the relative gray value. RESULTS The RCM image feature was different between vitiligo and ND patients. The differential diagnosis was made based on the following four RCM features: complete absence of pigment cells; the distribution of pigment cells; the margins; and the relative gray value. CONCLUSION RCM can be used as an auxiliary diagnostic tool for the differential diagnosis between vitiligo and ND.