[Case report: suppurative arthritis due to group B Streptococcus in a patient with rheumatoid arthritis]

A 62-year-old woman, who had been diagnosed as having rheumatoid arthritis (RA) with systemic amyloidosis and diabetes mellitus, was admitted to our hospital because of polyarthralgia on October 1, 1987. She had some subcutaneous nodules and rheumatic pleural effusion. Therefore she was treated with 20 milligrams of prednisolone (PSL) daily. On the ninth day after the beginning of steroid therapy, she complained of severe pain and a new swelling in her right knee joint. The knee joint aspirate on arthrocentesis yielded a pure growth of group B Streptococcus (GBS). Blood culture was also positive for GBS. Her suppurative arthritis gradually improved by treatment with penicillin G. However, after the discontinuance of PSL, her pleural effusion deteriorated and she died on January 10, 1988. To our knowledge, there have been no prior reports of group B streptococcal suppurative arthritis complicating RA in Japan.