SEPTIC ARTHRITIS IN PATIENTS WITH RHEUMAT OID-ARTHRITIS - A REVIEW OF24 CASES AND OF THE MEDICAL LITERATURE

Twenty-four cases of septic arthritis in rheumatoid arthritis patients were compared with 99 cases of septic arthritis in patients without r heumatoid arthritis. In addition, 238 previously published cases of se ptic arthritis with rheumatoid arthritis were analyzed. Fifteen percen t of our patients with septic arthritis had rheumatoid arthritis, whic h was typically of long duration (mean 15 years), erosive, and seropos itive. Fifty-four per cent (28% in the literature) and 9% of patients with and without rheumatoid arthritis, respectively, had pyarthrosis o f multiple joints. The knee represented one-third of infected joints a nd the elbows and wrists were more often infected in patients with tha n without rheumatoid arthritis. S. aureus was recovered in 80% versus only 60% of patients with and without rheumatoid arthritis, respective ly. The source of sepsis was often a skin lesion, in particular at the foot, emphasizing the need for early orthopedic treatment of deformit ies responsible for skin lesions. Monoarticular infection was more lik ely to be due to an intraarticular injection. Mortality rate was 17% i n patients with rheumatoid arthritis (23% in the literature) versus 7% in patients without rheumatoid arthritis. Staphylococcal infection an d infection of multiple joints were associated with higher mortality r ates (35% and 49%, respectively). The mortality rate in polyarticular infections has failed to decline over the last 35 years. Initial failu re to distinguish septic arthritis from an exacerbation of rheumatoid arthritis contributes to the high mortality rate. The diagnosis of sep tic arthritis rests on a high index of suspicion. Septic arthritis can not be ruled out based on absence of local inflammation, fever, or hyp erleukocytosis or on presence of inflammation of multiple joints. Join t fluid specimens should routinely be sent to the microbiological labo ratory and should be inoculated in blood culture bottles at the least suspicion.