Anal tuberculosis complicating anti-TNFα therapy

Area of Science:

• Immunology
• Infectious Diseases
• Dermatology

Background:

• Anti-tumour necrosis factor (anti-TNF) therapy, including adalimumab, is used for psoriatic arthritis.
• Patients on anti-TNF therapy are at increased risk of infections, including tuberculosis.
• Psoriatic arthritis patients on adalimumab may present with unusual infections.

Observation:

• A 42-year-old man on adalimumab for psoriatic arthritis developed a chronic anal ulcer.
• Chest X-ray revealed a lung infiltrate, despite the absence of pulmonary symptoms.
• Initial biopsies of the anal ulcer were negative for Mycobacterium tuberculosis.

Findings:

• Despite negative initial tests, Mycobacterium tuberculosis was cultured from a second biopsy of the anal ulcer.
• The patient was diagnosed with disseminated tuberculosis.
• Treatment with a four-drug antituberculosis regimen and discontinuation of adalimumab led to complete ulcer resolution.

Implications:

• This case highlights the importance of considering tuberculosis in patients on anti-TNF therapy presenting with non-healing ulcers.
• Early microbiological diagnosis is critical for effective management of opportunistic infections.
• Re-evaluation of immunosuppressive therapy is necessary in the context of active tuberculosis.