Staphylococcus aureus Bacteremia With Disseminated Multiple Foci and Pyomyositis in an Immunocompetent Patient: A Case Report.

Pyomyositis is an uncommon primary infection of skeletal muscle resulting in muscle inflammation followed by pus formation. Pyomyositis is typically caused by Staphylococcus aureus (S. aureus), and most cases are associated with skin penetration and/or immunosuppressive conditions in tropical or even temperate climates. We report a previously healthy, immunocompetent 44-year-old man who presented with fever and right lower back pain. He had received an analgesic injection for his back pain 12 days prior to this visit. His clinical course was further complicated by the coexistence of multiple muscular abscesses, renal infarction, and septic arthritis of the right shoulder. He underwent computed tomography-guided drainage of the abscess. The abscess and blood cultures were positive for methicillin-susceptible S. aureus. The patient responded well to prolonged treatment with cefazolin and cephalexin and was discharged 12 weeks after initial admission.