Polyarticular septic arthritis.

Seven adult patients with nongonococcal polyarticular septic arthritis are presented with a literature review of the clinical features of polyarticular bacterial infection. Polyarticular septic arthritis occurred in 19% of reported cases of septic arthritis in adults. Similar to monoarticular disease, the knee was the most commonly affected joint, and Staphylococcus aureus was the most frequently isolated microorganism. Pneumococcus, group G streptococcus, and Hemophilus influenzae had an increased association with polyarticular infection. Five of our 7 patients had underlying rheumatic diseases and the immediate mortality rate was 57%. Review of the literature yielded an overall mortality of 23% for polyarticular septic arthritis compared to the 9% mortality of septic arthritis in general. The subset of patients with polyarticular infection superimposed on rheumatoid arthritis had a mortality rate of 56%.