Pyomyositis due to Streptococcus pneumoniae.

Pyomyositis is an unusual but potentially serious disease in children. Staphylococcus aureus is the most commonly implicated pathogen, but pneumococcal pyomyositis is very rare. Clinical diagnosis of pyomyositis can be difficult often mimicking septic arthritis of the hip or appendicitis. We report a 12-year-old male with pyomyositis caused by Streptococcus pneumoniae who presented with fever and severe right hip and abdominal pain. Magnetic resonance imaging of the right hip revealed the diagnosis of pyomyositis. Blood cultures grew Streptococcus pneumoniae, sensitive to penicillin, ceftriaxone, and clindamycin. He was successfully treated with a 3-week course of clindamycin. Early recognition, appropriate antibiotic therapy, and if indicated, drainage of the muscle abscess is critical to reduce morbidity and mortality.