Septic arthritis of the right ankle caused by Staphylococcus aureus infection in a rheumatoid arthritis patient treated with etanercept.

We report on a 65-year-old man with rheumatoid arthritis who developed septic arthritis of the right ankle and was treated with etanercept, low-dosage prednisolone, and salazosulfapyridine for 18 weeks. Staphylococcus aureus was cultured from ankle synovial fluid; hence, etanercept was stopped and cefazolin was administered. The patient responded well to arthroscopic synovectomy and irrigation of the ankle. Etanercept treatment should cease if it leads to septic arthritis and patients should be prescribed systemic antibiotics, with surgical debridement considered.