Coinfection of Pulmonary Tuberculosis and Borderline Lepromatous Leprosy Complicated by Reversal Reaction.

Tuberculosis (TB) and leprosy are major mycobacterial infections in Indonesia, but coinfection is rare. We describe a 57-year-old male with pulmonary TB and borderline lepromatous leprosy complicated by reversal reaction. He also had type 2 diabetes mellitus and oral candidiasis. TB was confirmed by GeneXpert MTB/RIF, rifampicin-sensitive sputum culture, and chest radiography, showing right suprahilar infiltrates. Leprosy was diagnosed by slit skin smear positive for Mycobacterium leprae. During the 6th month of multidrug therapy (MDT), he developed reversal reaction with fever, painful erythematous plaques, and sensory loss. Management included systemic corticosteroids, continuation of MDT without rifampicin, anti-TB drugs, and supportive care. Clinical improvement was observed after treatment modification. This case highlights the complex immunological interplay between M. leprae and Mycobacterium tuberculosis, therapeutic challenges of drug interactions, and the importance of multidisciplinary management.