Diagnostic applications of nail clippings.

"Nail clipping is a simple technique for diagnosis of several nail unit dermatoses. This article summarizes the practical approach, utility, and histologic findings of a nail clipping in evaluation of onychomycosis, nail unit psoriasis, onychomatricoma, subungual hematoma, melanonychia, and nail cosmetics, and the forensic applications of this easily obtained specimen. It reviews important considerations in optimizing specimen collection, processing methods, and efficacy of special stains in several clinical contexts. Readers will develop a greater understanding and ease of application of this indispensable procedure in assessing nail unit dermatoses."