Surgical Pearl: Dermoscopy of the free edge of the nail to determine the level of nail plate pigmentation and the location of its probable origin in the proximal or distal nail matrix

Abstract

N ail pigmentation (melanonychia) is a common problem in dermatological practice. For the management of nail pigmentations, it is important to know the exact anatomic location of the pathologic feature (proximal or distal nail matrix). This enables the surgeon to choose the correct biopsy site and the adequate surgical technique. For the patient this is important because biopsy of the proximal nail matrix is much more likely to result in a permanent nail dystrophy. On the other hand, a biopsy specimen up to 3 mm in size taken from the distal part of the nail matrix usually does not affect nail growth. It is currently possible to identify the origin of nail pigmentation by using Fontana-Masson staining of a nail plate clipping specimen. This is the standard technique, which is relatively expensive and most important does not provide the answer immediately