A 79 year old female presents the day after the New York Marathon, complaining of a painful R big toe. She wore old sneakers to run the race, her 50th marathon, and feels that her toe may have rubbed up against the toe box of the shoe.

How can this be managed in the ED?

A subungual hematoma is the presence of blood under the nail, usually due to localized trauma. Disruption of the blood vessels of the nail bed without fracture of the nail results in accumulation of blood under the nail, which can be very painful. Subungual blood remains liquid enough to be removed using some gentle expression up to 36 hours post-injury.

Trephination (placing a small hole in the nail to drain the blood underneath) without nail removal is fully adequate for most injuries, including nails with hematoma over essentially 100% of the nail surface.

Various tools for this purpose include a heated paper clip, electric nail drill, electrocautery, 18-gauge needle, or scalpel.  After drainage, instruct patients to soak the affected finger in warm water containing antibacterial soap two to three times a day for 7 days and to follow basic wound-care principles.

Nail removal is necessary only if there is significant nail bed injury and an unstable fingertip. Subungual hematomas covering more than half of the nail bed have been associated with a 60% chance of nail bed laceration. This increases to 95% if there is an associated distal phalanx fracture. Distal tuft or phalanx fractures are associated with approximately 50% of nail bed injuries, so imaging of the involved digit(s) is needed. Nail plate deformity permanently affecting nail growth is the most common complication resulting from inadequate treatment.

Various studies have shown mixed responses with removal of the nail for full evaluation and treatment of underlying nail bed lacerations, so current recommendations are to remove the nail and repair the nail bed only if there is a broken nail or the nail bed is disrupted.