Multi-drug Resistant Tuberculous Osteomyelitis of the First Carpometacarpal Joint Presenting as Unmasking Immune Reconstitution Inflammatory Syndrome.

Tuberculosis (TB) is an important cause of significant morbidity and mortality, particularly in patients living with human immunodeficiency virus (HIV ) infections. The co-infection of TB and HIV coinfection is further complicated by a relatively higher frequency of extra-pulmonary TB and upsurge of drug resistance. Musculoskeletal TB is a relatively less common form of extrapulmonary TB; involvement of carpometacarpal joint as an initial manifestation is even rarer. We herein present a retro positive patient who presented with low-grade fever, constitutional features and swelling of the base of the left thumb. On evaluation, he was found to have axillary and inguinal lymphadenopathy with lytic destruction of carpometacarpal joint as well as D10-D11 vertebrae. Fine needle aspiration (FNA) of synovial fluid was negative for tuberculosis but geneXpert from FNA of axillary node revealed Mycobacterium tuberculosis with rifampicin resistance. This case highlights the rarity of carpometacarpal joint involvement in TB as the initial manifestation and the importance of meticulous search of alternative sites for sampling in difficult situations such as osteoarticular TB. It also highlights the rising prevalence of drug-resistant TB and a definitive need for microbiological diagnosis wherever feasible.