Nail matrix nevi in children: a prospective study.

Longitudal melanonychia (LM) is not common in children even in dark skinned individuals and its evaluation is difficult. LM can be caused by melanocytic hyperplasia, which occurs in the context of a nevus or melanoma and manifests dermoscopically with a brown pigmented band, or by melanocytic activation presenting with grey pigmentation. The typical dermoscopic feature of a nail matrix nevus (NMN) is the presence of regular lines on a brown background, whereas nail melanoma usually manifests with Hutchinson sign, variation of the color and width of the bands, particularly a triangular shape, and disruption of the nail plate.4 We conducted a prospective study to evaluate the clinical and dermoscopic characteristics and the evolution of LM in children.