Unique features of group B streptococcal arthritis in adults.

Group B streptococci have rarely been reported to cause serious infection in adults and even less frequently to result in septic arthritis. We reviewed our clinical and radiologic experience with septic arthritis and uncovered five cases of infectious arthritis caused by group B streptococci. Unlike previously described patients with monoarthritis and complete recovery, our patients displayed polyarticular involvement. The infection in some cases was aggressive, resulting in destruction of multiple joints. Therefore, the series supports the view that this uncommon pathogen may produce an aggressive polyarthritis with the potential for serious functional damage and permanent morbidity. Culture and identification of a group B streptococcal pathogen and prompt institution of therapy can help avoid these complications.