Arthritis, Infectious Tenosynovitis, and Tendon Rupture in a Patient With Rheumatoid Arthritis and Psoriasis

C ompared with monoarticular arthritis, polyarticular arthritis may yield an initially narrower differential diagnosis that focuses on systemic inflammatory conditions, such as rheumatoid arthritis (RA). Approximately 15% to 30% of septic arthritis is polyarticular, of which about 45% is associated with underlying RA.1,2 Regardless of the number of joints involved, septic (infectious) arthritis is a valid consideration given the morbidity and mortality. In a retrospective study in the United Kingdom (UK) between 1982 and 1991, the morbidity and mortality of septic arthritis was 31.6% and 11.5%, respectively, and 16% of the study population had RA. A review of the literature by Dubost and colleagues found that polyarticular septic arthritis (PASA) has a mortality of 31% to 42% compared with 4% to 8% for monoarticular septic arthritis, and RA was present in 67% of the PASA fatalities.1 Rheumatoid arthritis and its treatment predispose patients to septic arthritis. Septic arthritis in the UK general population is 0.42 per 100 patient-years for patients with RA on antitumor necrosis factor therapy.3,4 In a retrospective study in the U.S., the incidence of septic arthritis was 0.40 per 100 patient-years for patients with RA compared with 0.02 per 100 patient-years for patients without RA. Other complications of RA include infectious tenosynovitis and tendon rupture. The incidence and prevalence of infectious tenosynovitis and tendon rupture in RA are not firmly established in the literature. We present a patient with RA and psoriasis who responded initially to acute management for RA but subsequently was diagnosed with culturenegative polyarticular arthritis and infectious tenosynovitis associated with beta hemolytic group G Streptococcus (GGS), a part of Streptococcus milleri (S. milleri). During surgery, he was also found to have bilateral extensor pollicus longus (EPL) tendon rupture. Given the possible morbidity, the authors believe this patient may be of interest to the medical community.