By Gary M. White, MD

Onychoclavus or subungual corn

Onychoclavus (or subungual corn) represents a hyperkeratotic response of the skin to repeated pressure/trauma between the distal nail and the underlying tissue or bone. An X-ray to rule out an exostosis may be indicated.


A very painful, hyperkeratotic papule in the distal subungual zone is characteristic of this type of corn.


The nail should be trimmed and the corn pared. To prevent recurrence, the footwear may be changed and bony lesions (if present) removed.


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