A Young Female With Borderline Lepromatous Leprosy and Tuberculous Lymphadenitis: A Rare Coinfection

In Bangladesh, tuberculosis and leprosy are endemic mycobacterial diseases; however, co-infection is rarely seen. Our patient had a high-grade fever, symmetrical polyarthritis, polymorphous erythematous lesions, widespread lymphadenopathy, peripheral neuropathy, bilaterally thickened ulnar nerves, and claw hands. A lymph node biopsy revealed tuberculosis having acid-fast bacilli with caseating epithelioid histiocytic granuloma. Cutaneous lesions and sural nerve biopsies indicated borderline lepromatous leprosy. Fite-Faraco stain showed the presence of lepra bacilli in the biopsied sural nerve. Mantoux test showed 15 mm induration in 72 hours. Nerve conduction study (NCS) showed severe sensory-motor polyneuropathy (axonal) of all four limbs. Prednisolone and thalidomide for severe type-2 lepra response and category-01 antituberculosis medication and multidrug therapy for multibacillary leprosy improved the patient's condition. Bacille Calmette-Guérin (BCG) vaccination in the community might protect against tuberculosis and leprosy, thus reducing such coinfection. However, reduced cell-mediated immunity might promote latent tuberculosis reactivation or super-infection in individuals with multi-bacilli illnesses.