[Polyarticular septic arthritis: analysis of 19 cases]

Polyarticular septic arthritis accounts for 15% of all septic arthritis, but there are few references in the literature. We describe characteristics of patients with polyarticular septic arthritis in a rheumatology service.

Retrospective analysis of patients with septic arthritis involving more than one joint. Only patients with positive culture of synovial fluid were included. Clinical, analytical and radiological variables are reviewed.

19 patients (14 male) had a polyarticular infection. Mean age was 55 years. Mean time from onset to diagnosis was 6 days. The knee was the most commonly involved joint, followed by ankle. The mean number of joints involved per patient was 3. Risk factors included diabetes, chronic renal or hepatic disease, gout and rheumatoid arthritis. Most commonly isolated agents were S. aureus (47%) and S. agalactiae (21%). Blood cultures were positive in 52,6% and 15.8% had septic shock. Scintygraphic bone scan showed a polyarticular uptake. Mean duration of antibiotic therapy was 46±27 days. Clinical outcome was good in 52,6%, complicated in 26%, and mortality rate was 15.8% (3 cases). Joint debridement was performed in 21%.

Multiple joint involvement does not exclude the diagnosis of septic arthritis. Inflammatory arthritis is an important risk factor. S. aureus in the main infectious agent. The morbidity and mortality of this condition are important, so we need to maintain a high index of suspicion for the condition.