Dermoscopic features of nail matrix nevus (NMN) in adults and children: A comparative analysis.

BACKGROUND: Nail matrix nevus (NMN) is one cause of longitudinal melanonychia. The typical dermoscopic patterns of NMNs are well established. However, little is known about how the dermoscopic characteristics of NMNs differ between adults and children. OBJECTIVE: We sought to compare the dermoscopic characteristics of NMNs between adults and children. METHODS: We retrospectively reviewed the medical records of patients in whom NMN was diagnosed between 2005 and 2014. RESULTS: The dermoscopic findings of 58 NMNs from 56 children and 35 NMNs from 34 adults were analyzed. Pigmentation tended to be broader in children, without statistical significance (P = .062). Moreover, NMNs in children were darker and multicolored (P < .001). Pseudo-Hutchinson sign (P = .004), triangular sign (P = .001), and dots/globules (P = .004) were detected more commonly in children. An irregular pattern and Hutchinson sign were also found more frequently in children, without statistical significance (P = .071 and P = .249, respectively). LIMITATIONS: This was a retrospective study in a tertiary-level hospital. CONCLUSION: The dermoscopic findings showed that NMNs have more melanoma-associated features in children than in adults.