"My foot hurts": a flare of rheumatoid arthritis?

A 56-year-old man with a history of rheumatoid arthritis presented with a 2-day history of worsening pain in his left foot. Treatment with high-dose steroids was of no benefit, hence a diagnosis of septic arthritis was considered. However, the patient's condition deteriorated despite empirical antibiotic therapy. Following persistent investigation, the cause was identified as a fastidious Legionella longbeachae infection, and appropriate antibiotic therapy led to complete resolution of the sepsis. This emphasises the importance of considering infections with atypical organisms in patients on immunosuppressive therapy.