The spectrum of group A streptococcal joint pathology in the acute care setting.

Objectives: Group A streptococcus (GAS) is a frequent cause of pediatric musculoskeletal infections including septic arthritis, acute rheumatic fever (ARF), and a more benign arthritis called post-streptococcal reactive arthritis. Children with painful joints are frequently evaluated in the acute care setting, and because the presentation of each of these entities is similar, the diagnosis can be difficult to make. Five cases of children with GAS arthridities are presented to demonstrate the spectrum of GAS-associated joint pathologies encountered in the acute care setting and also to discuss how GAS laboratory tests may assist in the evaluation and management of children presenting with a painful joint.
Methods: Five cases of GAS-associated joint pathology are presented. Evaluation of these patients was conducted using a diagnostic algorithm derived from a literature review of post-streptococcal reactive arthritis and ARF, as well as the current clinical practice guideline for the diagnosis and treatment of septic arthritis.
Results: The 5 cases presented include 1 case of transient synovitis, 2 cases of inflammatory synovitis, 1 case of septic arthritis, and 1 case of ARF.
Conclusions: Determining the cause of joint pain in the acute care setting is challenging. The addition of the GAS laboratory tests to a diagnostic algorithm based on clinical examination and monitoring systemic inflammation can help to identify patients with ARF and septic arthritis in the acute care setting. In addition, GAS-specific laboratory tests may help to identify cases of nonseptic, non-ARF GAS joint pathology.