[Two cases of pneumococcal septic arthritis complicating rheumatoid arthritis].

It is reported that most of the causative organisms of suppurative arthritis complicating rheumatoid arthritis (RA) is Staphylococcus aureus and that Streptococcus pneumoniae is rare, representing less than 5% of cases of suppurative arthritis complicating RA. We here report two cases of pneumococcal septic arthritis complicating RA. Both were female, and 68 and 64 years old, respectively. They had active, long-standing RA with destructed changes. Infected joints included both knees (case 1) and right knee (case 2). Pain and loss of motion in the septic joints were prominent. On admission, the physical examination showed severe redness, swelling and tenderness of the septic joints and the range of motion of those was markedly decreased. The radiograph of affected joints showed stage III. Laboratory data showed markedly elevated ESR of 127 mm/hr (case 1) and 142 mm/hr (case 2) and C-reactive protein of 49.91 mg/dl (case 1) and 30.36 mg/dl (case 2). Aspirate of the left knee of case 1 showed numerous neutrophils. Cultures of the joint fluid grew S. pneumoniae. Grossly purulent material was aspirated from the right knee of case 2 and cultures also grew S. pneumoniae. They were started on intravenous antibiotics with a good response and the function of involved joints returned to preseptic condition. The source of infection on case 1 was presumed to be otitis media because she had discharge from left ear concurrently with the exacerbation of joint symptoms. Case 2 had productive cough and cultures of sputum also disclosed S. pneumoniae when pain of right knee joint developed. The suggested source of infection was upper respiratory tract.(ABSTRACT TRUNCATED AT 250 WORDS)