THUMB TUBERCULOSIS: A CASE REPORT

Tuberculosis is caused by Mycobacterium tuberculosis, occurs in about 2 billion people. Approximately 8 million people/year develop the active form.1,2 Tuberculosis in the hand is manifested as osteomyelitis in carpals, metacarpals and phalanges.1 Musculoskeletal tuberculosis occurs, in most cases, through haematogenous dissemination from the primary focus. In immunosuppression circumstances, it is reactivated. METHODS: 47 years old lady, who had underlying pulmonary tuberculosis on anti-TB medications since June 2018, presented to us for swelling over right thumb. Associated with tender, erythematous skin and limited range of motion of right thumb. RESULTS: Plain radiograph demonstrated soft tissue swelling, joint space narrowing, mottled lucency of the proximal phalanx and cystic degenerative changes. MRI shows osteomylities proximal phalanx of right thumb. Patient underwent wound debridement of right thumb, culture and sensitivity shows Mycobacterium tuberculosis infections. Post debridement, range of motion of MCP joint of right thumb was improved and anti-TB medications to restart. DISCUSSIONS: Tuberculosis involvement of the metacarpals and phalanges is a rare presentation of extrapulmonary TB. The radiographic features of osseous tuberculosis are present in conditions such as inflammatory arthritis, pyogenic osteomyelitis, osteopenia, softtissue swelling with minimal periosteal reaction, narrowing of the joint space, cysts in bone adjacent to joints, and subchondral erosions. The gold standard to diagnose is culture of Mycobacterium tuberculosis from bone tissue. Current treatment is a 2 month initial phase of isoniazid, rifampin, pyrazinamide, and ethambutol followed by a 6 to 12 month regimen of isoniazid and rifampin. CONCLUSION: Finger swelling is a rare presenting sign of disseminated tuberculosis. Early biopsy and appropriate microbiologic testing can avoid diagnostic delay. REFERENCES: 1. Malaviya AN, et al. Best Pract Res Clin Rheumatol. 2003;17:319–43. 2. Fortún J, et al. Mycobacterium tuberculosis infection? Medicine. 2010;10:3808–19. DOI: 10.1016/S0304-5412(10)70119-0.