Primary Cutaneous Tuberculosis Misdiagnosed as a Deep Mycotic Infection

Primary cutaneous tuberculosis (PCTB) is a relatively uncommon presentation, particularly in immunocompetent subjects and its diagnosis may be delayed, as it resembles many other skin infections.

The authors reported a case of PCTB in a 41-year-old Iranian female who presented with a 2 × 5 cm, erythematous swollen skin lesion over the dorsal aspect of the finger that had been diagnosed as a bacterial infection; after admission, the diagnosis of tuberculosis was also masked by a positive polymerase chain reaction for deep mycoses which resulted in a delay in treatment and several months of morbidity. The mycobacterial infection was confirmed by a positive culture for M. tuberculosis and the patient responded well to the anti-TB treatment.

A diagnosis of PCTB should be kept in mind in all patients who present with a chronic skin infection (especially nodular, ulcerated, and purulent lesions) with no response to initial antibacterial therapy.