Beta haemolytic streptococci and musculoskeletal sepsis in adults

Lancefield group A streptococci (GAS) account for 3-17% cases of septic arthritis, but other beta haemolytic streptococci (BHS) (groups B, C, and G) are being increasingly implicated. Epidemiological evidence suggests that the increase of BHS sepsis in adults is a true increase and not simply a reflection of better reporting. While underlying predisposing disease and old age are common concomitants of BHS sepsis, some subjects with devastating disease have been young and healthy. This is particularly the case for highly virulent M1 serotypes of GAS, where a toxic shock-like syndrome has led to a number of deaths in young adults in the United Kingdom and elsewhere. Musculoskeletal features, such as myalgias, painful swollen limbs, myositis, and fasciitis, are important features of this condition, so that rheumatologists may be involved in management. Group C and G musculoskeletal sepsis remains uncommon, with a high prevalence of underlying predisposing disease, or pre-existing arthritis in the septic joint. Group B BHS septic disease appears to be increasing in incidence. Musculoskeletal sepsis with these organisms usually takes place in subjects with other diseases, but healthy subjects have not been spared. Multiple septic foci and a rapidly destructive arthritis are not uncommon, and a recently described extra-articular feature is potentially blinding metastatic endophthalmitis. Clinicians need to be aware of an apparently increasing incidence of BHS musculoskeletal sepsis in adults so that early identification can lead to aggressive management in these potentially fatal infections.