This 59-year-old woman presented for evaluation of a new area of pigmentation under her great toenail that she had noticed for the first time in the past 2 weeks. It was asymptomatic, and there was no history of trauma. No other toenails have a similar appearance.
Answer: Punch biopsy through nail plateSee the full case at Consultant360
This patient had 2 subungual hematomas. Upon further history, she said that the dark areas under her toenail had appeared after she had taken a long walk. The clinical clue to the diagnosis was the longitudinal streaking and sudden onset, although these lesions are hard to discern. Doing a punch biopsy through the nail plate, taking care not to go too deep, will provide the answer when in doubt. It has been recently reported that using a fecal occult blood test to identify the heme is an easy and effective way to establish the diagnosis of subungual hematoma.
Lee A, Kovich O, Greenspan A, Shan HY. Rapid, cost-effective diagnosis of subungual hematoma. DermPearls. http://dermpearls.com/2011/01/rapid-cost-effective-diagnosis-of-subungua…. Published January 10, 2011. Accessed November 23, 2016.