Pyomyositis in children and adolescents: report of 12 cases and review of the literature.

Pyomyositis initially was observed more commonly in the developing world but now is reported with increasing frequency in the United States. The presentation is nonspecific and the differential diagnoses are many. We found the clinical history, laboratory findings, and response to treatment similar to those observed in different areas of the world. Magnetic resonance imaging (MRI) with gadolinium injection, in addition to helping to make the diagnosis, may help differentiate between early and late stages that help guide treatment. Coexisting bone changes (58%) may represent either the sensitivity of MRI to reactive inflammatory changes or the presence of a coexisting osteomyelitis. All patients responded to antibiotics and drainage if abscesses were present. Although the optimal duration of antibiotic therapy remains unclear, a shorter course should be considered in patients with a good clinical response, even when MRI shows nonspecific bony abnormalities. Percutaneous drainage was successful in five cases and may represent an alternative to the traditional surgical approach.