Tuberculous pyomyositis in a rheumatoid arthritis patient treated with anakinra

Area of Science:

• Infectious Diseases
• Rheumatology
• Immunology

Background:

• Musculoskeletal tuberculosis (TB) is uncommon, accounting for 3% of TB cases.
• Tuberculous pyomyositis is a rare manifestation, typically seen in immunocompromised individuals or those with comorbidities.
• Rheumatoid arthritis (RA) patients on immunosuppressive therapy, including steroids and biologics like anakinra, are at increased risk for opportunistic infections.

Observation:

• An 85-year-old Caucasian patient with RA, treated with steroids and anakinra, presented with fever and localized hip and thigh inflammation (redness, swelling, induration).
• Ultrasound-guided aspiration of thigh fluid revealed Mycobacterium TB via PCR and culture.
• Bronchoscopy also identified Mycobacterium TB in bronchoalveolar lavage fluid.

Findings:

• The patient was diagnosed with tuberculous pyomyositis.
• The diagnosis was confirmed by positive PCR and cultures from both the thigh fluid collection and bronchoalveolar lavage.
• Treatment with anti-TB medication led to the amelioration of inflammatory symptoms in the hip and thigh.

Implications:

• This case represents the first reported instance of tuberculous pyomyositis in a rheumatoid arthritis patient treated with anakinra.
• It underscores the importance of considering rare infections like TB in immunocompromised patients presenting with localized inflammation.
• The findings highlight the need for vigilance in diagnosing and managing tuberculous pyomyositis, especially in patients with autoimmune diseases on advanced therapies.