[Streptococcus pyogenes pyomyositis of the piriformis muscle in a child].

Acute pyomyositis is a suppurative infection of the skeletal muscle. Staphylococcus aureus is the most frequent etiological agent. Cases produced by Streptococcus pyogenes are uncommon. The most usual locations are quadriceps, buttocks and iliopsoas. The involvement of the piriformis muscle is very exceptional. We present the case of a previously healthy 8-year-old male who was admitted to our hospital for acute pyomyositis caused by Streptococcus pyogenes located in the piriformis muscle. Early diagnosis and prompt initiation of antibiotic treatment allowed the conservative management of the condition, and surgery was not necessary. The evolution was satisfactory without sequels.