Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
A - Physical examination of 2-mm-wide black longitudinal streak starting at the distal surface of the right thumb. B - Distal dermoscopy highlights a localized thickening of the nail plate with subungual hyperkeratosis at the hyponychium. C - Dorsal plate dermoscopy shows a sharply delimitated longitudinal melanonychia on the dorsal surface of the nail plate
