[Persistent fever in a patient with Salmonella typhimurium gonarthritis].

A 65-year-old patient with systemic lupus erythematodes (SLE) developed fever and gonarthritis whilst taking prednisone and hydrochloroquine. Salmonella typhimurium, sensitive to amoxicillin, was grown in cultures of synovial fluid, blood and urine. After high dosages of intravenous amoxicillin, blood cultures and knee punctate became negative, but fever seemingly without a clinical focus persisted. By means of a fluoro-18-deoxyglucose positron emission tomography (FDG-PET) scan, an abscess was located in the left upper leg and successfully treated. In patients with impaired cell-mediated immunity, an extra-intestinal manifestation of Salmonella should be taken into consideration particularly if there appears to be no clinical focus. This may be detected by FDG-PET.