Nonhealing vegetating plaque on the finger: tuberculosis verrucosa cutis.

Tuberculosis verrucosa cutis is an uncommon form of tuberculosis that typically presents as a chronic warty plaque. It develops in individuals with moderate to high immunity to Mycobacterium tuberculosis due to inoculation of an open wound. We present the case of a Somali man born in the United Kingdom who presented with a nonhealing ulcer on the right hand of 10 years' duration. The patient was diagnosed with tuberculosis verrucosa cutis based on clinical suspicion, which was confirmed by several investigations including strongly positive results of a Mantoux test, IFN-gamma release assay, typical histology on skin biopsy, and polymerase chain reaction (PCR) analysis positive for mycobacterial DNA. Treatment with quadruple antituberculous therapy produced rapid resolution of the ulcer. This unusual condition often is overlooked in the differential diagnosis of nonhealing ulcers, yet it has an excellent prognosis with treatment. A high index of suspicion is required.