Posttraumatic Retronychia of the Foot with Clinical and Ultrasound Correlation.

Retronychia, the posterior embedding of the nail bed into the proximal nail fold, can be a complex clinical dermatologic diagnosis that may mimic other inflammatory ungual diseases or tumors of the nail. It has been related to a history of severe systemic conditions that secondarily affect the nail matrix and is commonly associated with onychomadesis. We present a case of retronychia of the foot with a purely traumatic origin, nonconcomitant with onychomadesis, that was diagnosed by color Doppler ultrasound in a long-time practitioner of martial arts who was otherwise healthy.