[Paravertebral pyomyositis in childhood following closed injury].

Pyomyositis is an acute bacterial infection that affects striated muscle and is generally accompanied by the formation of an abscess. In most cases, the microorganism involved is Staphylococcus aureus. Clinical findings are characterized by pain, swelling and muscular edema, together with variable general symptoms. Complications include arthritis, osteomyelitis and even septic shock with a mortality of 1.8%. We report the case of an 8-year-old boy who sustained a closed lumbar injury on banging his shoulder while he was playing on a trampoline and who developed paravertebral pyomyositis complicated by sepsis. S. aureus was isolated in the blood culture. The boy subsequently developed a perivertebral abscess and finally contiguous osteomyelitis in the L3 spinous process. The patient received treatment with vancomycin and metronidazole for 6 weeks followed by cloxacillin therapy for 2 weeks (a total of 8 weeks of intravenous antibiotic therapy). Physical examination 3 months after discharge revealed no abnormalities. The possibility of pyomyositis should be borne in mind, especially in children with fever, localized muscular pain and a history of accidental or sports injuries. Early diagnosis and treatment are important to reduce the risk of possibly fatal complications.