Subungual Haematoma

Crush injuries of lesser severity may cause subungual haematoma. A small nail bed laceration with resultant bleeding occurs, which cannot drain from an intact nail. These can be excruciatingly painful. Painful subungual haematomas should be drained to relieve both pain and pressure.

It has previously been recommended that larger subungual haematomas involving 25-50% of the visible nail require nail removal for examination of the nail bed and repair, however, prospective studies comparing simple haematoma decompression versus nail plate removal and formal nail bed repair have shown no notable difference in outcome.

Small subungual haematomas can be relieved by simply decompressing through a drain hole in the nail by needle trephining using a hot paper clip or battery-powered cautery.

In the ED, if the nail plate is still adherent to the nail bed and not displaced out of the nail fold, regardless of the size of the subungual haematoma, conservative treatment is recommended. In this situation the haematoma may be drained, but the nail need not be removed for nail bed repair.