A Case of Septic Arthritis of Shoulder Joint Due to Streptococcus anginosus Following Dental Treatment

Abstract

Septic arthritis is classified in acute rheumatologic emergencies and prompt diagnosis and treatment is critical for prognosis since the infection may lead to permanent destruction. Etiology varies due to routes of infection and host factors. Gram positive cocci are responsible in most of the cases (75-80 %) but in case of immune supression, elderly patients, intravenous drug usage and iatrogenic cases, Gram negative bacilli may also be involved. S.anginosus group are non-motile, facultative anaerobe and catalase-negative Gram-positive cocci that are recognized as normal flora of the human oral cavity and gastrointestinal tract. The unique characteristic of the S.anginosus group that sets these streptococci apart from other pathogenic streptococci is their ability to cause abscesses and should be considered as true pathogens when isolated. Infections vary from dental abscesses, gingivitis and other periodontal infections to deep neck infections, metastatic lung, liver, intra-abdominal and brain abscesses. In the literature soft tissue infections, septic arthritis and osteomyelitis are very rarely reported. In this case report we present a case of septic arthritis due to S.anginosus in an otherwise immunocompetant 64 year old woman that presented with pain and swelling of the left shoulder one month after a dental treatment. The sinoviyal fluid analyses revealed a WBC count of 26,000/ mm3 with 82 % polymorphonuclear leukocytes with a negative Gram stain. The patient was started on ampirical intravenous treatment with piperacilin-tazobactam and daptomycine. At the fourth day, the synovial fluid culture results yielded S.anginosus, then piperacilin-tazobactam was stopped and daptomycine continued till the 14th day. The patient was discharged with oral amoxiciline-clavulanic acid 1 gr/day for 14 days. After two weeks the therapy was stopped due to clinical improvement.