Streptococcal pyomyositis of the psoas: case reports and review.

We present two unusual cases of pyomyositis of the psoas muscle caused by Group A beta-hemolytic streptococcus (GABHS) in children presenting with fever, emesis and leg pain. Pyomyositis secondary to GABHS is rare in children and cases involving the psoas muscle have not been previously reported. In our discussion, we review the epidemiology, presentation, diagnosis and treatment of GABHS psoas myositis in comparison with staphylococcal pyomyositis. Prompt recognition of the signs and symptoms of GABHS psoas pyomyositis is essential for treatment of this life-threatening infection.