Rheumatologic Perspective on Persistent Right-Hand Tenosynovitis Secondary to Mycobacterium marinum Infection.

Background: Rheumatologic conditions share many symptoms with infectious processes. The immunosuppressive therapies used in rheumatology unfavorably impact any underlying infection. Nontuberculous mycobacteria (NTM) are difficult to grow in culture media and may affect the musculoskeletal system, developing manifestations that may imitate rheumatic inflammatory arthritis. For this reason, surgical debridement and biopsy culture are essential in cases where suspicion remains high.

Case presentation: We present the case of a patient with progressively worsening right-hand tenosynovitis who was evaluated for rheumatic conditions given initial negative synovial tissue biopsy cultures. He was finally diagnosed with Mycobacterium marinum infectious tenosynovitis after repeated surgical debridement.

Conclusions: Our case reinforces the vital role of history gathering in establishing diagnoses and underscores the value of clinical suspicion in patients unresponsive to standard treatment for inflammatory arthritis. Tissue biopsy with culture for acid-fast bacilli is crucial for accurate diagnosis in NTM infection, which may imitate rheumatic inflammatory arthritis. Physicians should be keenly aware of this fastidious, indolent organism in the setting of persistent localized tenosynovitis.