[Pasteurella multocida septic arthritis in a native joint: Management dilemmas in a penicillin-allergic patient]

Pasteurella multocida is a common zoonotic, but it can also lead to invasive forms such as septic arthritis, particularly in immunocompromised patients.

We report a 53-year-old man with well-controlled HIV, who presented with acute wrist arthritis following a cat scratch. He had a documented history of penicillin anaphylaxis, leading clinicians to avoid β-lactam antibiotics in the acute setting in the absence of immediate allergological evaluation. Synovial fluid culture grew P. multocida susceptible to several alternative antibiotics. After failure of doxycycline and intolerance to trimethoprim-sulfamethoxazole, treatment with levofloxacin led to a favorable outcome. The absence of a drainable collection allowed conservative management, with complete recovery after six weeks of antibiotic therapy.

This case highlights the therapeutic challenges of P. multocida arthritis in a penicillin-allergic patient living with well-controlled HIV infection. Despite universal susceptibility to β-lactams, sequential alternative regimens were required due to drug intolerance. The favorable outcome without surgery underscores the importance of individualized antibiotic strategies.