Successful diagnosis and management of tuberculosis verrucosa cutis using antituberculosis therapy trial approach

Tuberculosis verrucosa cutis is a paucibacillary form of cutaneous tuberculosis that often occurs in sensitized immunocompetent individuals due to exogenous reinfection. The diagnosis is often difficult because the clinical features are often not typical and acid-fast staining test often shows negative results. Therapeutic trial with antituberculosis therapy is justified if there is strong clinical suspicion in which diagnosis can be made based on the therapeutic response. We report a 46-year-old male with erythematous verrucous plaque on the right knee and crusted erythematous plaque on the left dorsal foot that had been present for 20 years. There were neither history of previous trauma nor tuberculosis treatment. Histopathology, culture, polymerase chain reaction (PCR), Mantoux test, and chest radiograph were negative for cutaneous tuberculosis. Gamma release interferon assay showed positive result. The patient was given category 1 antituberculosis treatment and showed improvement after three weeks. Treatment was continued for 6 months and the lesion significantly regressed.