Multifocal Musculoskeletal Invasive Group A Streptococcal Infection in Previously Healthy Children

Background: Multifocal musculoskeletal invasive group A streptococcal (iGAS) infection is a severe and infrequently reported presentation in children. We describe 2 previously healthy pediatric patients with multifocal musculoskeletal iGAS infection and compare their presentations with previously reported pediatric cases. Methods: We describe 2 previously healthy pediatric patients from a single center with multifocal musculoskeletal iGAS infection. We additionally performed a focused review of previously published pediatric reports of multifocal musculoskeletal iGAS infection in PubMed using terms including “group A Streptococcus,” “Streptococcus pyogenes,” “multifocal,” “musculoskeletal,” “pyomyositis,” “septic arthritis” and “child”/“pediatric.” We included English-language pediatric case reports describing multifocal musculoskeletal or soft-tissue GAS infection and excluded reports without clear multifocal involvement. Finally, we compare these cases to highlight common presenting features, management challenges and practical diagnostic considerations. Results: The first case involved an 18-month-old boy who presented with fever and multifocal soft-tissue swellings with overlying erythema after mild upper respiratory tract symptoms. The involved soft-tissue sites were notable for fluctuations in clinical appearance over a short period. Initial imaging was unremarkable; however, repeat imaging later revealed a right trapezius abscess that required incision and drainage, with clinical improvement postoperatively. The second case involved a 12-year-old boy who presented with fever, altered mental status and hemodynamic instability after ankle pain. His course was complicated by bilateral upper-extremity pyomyositis with compartment syndrome, requiring fasciotomies with continued hemodynamic instability postoperatively and multifocal septic arthritis requiring multiple washout procedures and presumed septic embolic central nervous system lesions. Review of previously reported pediatric cases suggests that multifocal musculoskeletal iGAS often follows nonspecific antecedent symptoms, may involve multiple extremities or deep soft tissues, and frequently requires operative source control. Conclusions: These cases highlight that multifocal iGAS can occur in otherwise healthy children, may initially mimic inflammatory or post-viral conditions, and should prompt early inpatient management, serial clinical reassessment, repeat imaging when indicated and timely surgical consultation.