Cutaneous Tuberculosis Presenting as a Chronic Dermatologic Disorder

Cutaneous tuberculosis (CTB) is a rare manifestation of extrapulmonary tuberculosis that is frequently misdiagnosed due to its diverse clinical presentation and resemblance to other dermatological conditions. Tuberculosis verrucosa cutis (TBVC), one clinical manifestation of CTB, poses a particular diagnostic challenge, as lesions are often paucibacillary, resulting in negative culture and PCR results. We present the case of a 73-year-old woman with a 10-year history of recurrent skin lesions on her left hand, initially diagnosed as eczema and exacerbated by topical corticosteroid treatment. Despite repeated negative histopathological stains, mycobacterial cultures. and PCR for Mycobacterium tuberculosis, a strong positive QuantiFERON-TB Gold test established the diagnosis. This case emphasizes the diagnostic utility of interferon-gamma release assays (IGRAs) in paucibacillary forms of CTB. Management was complicated by adverse drug reactions (ADRs) to first-line antituberculosis therapy (HRZE), including myalgias, fatigue, and a pruritic rash attributed to pyrazinamide and rifampin. These agents were discontinued, and the patient was transitioned to an alternative regimen, which resulted in improved tolerability and marked clinical improvement. This case highlights the diagnostic pitfalls and therapeutic challenges in managing TBVC. It underscores the importance of maintaining a high index of clinical suspicion for CTB in chronic, verrucous skin lesions, even in patients without specific TB risk factors. It also emphasizes the need for individualized treatment strategies.