Diagnosis and Management of Pyomyositis

dc.contributor.authorZekri, Sana
dc.creatorAl-Dossari, Ranna
dc.descriptionResearch Appreciation Day Award Winner - 2018 Medical Student Government Association - Best in Third Year Class
dc.description.abstractIntroduction: Pyomyositis is a purulent infection of striated muscle tissue that usually leads to an abscess, commonly due to S. aureus. The pathophysiology is unknown, but is proposed to be due to hematogenous bacterial seeding in muscle bodies. Pyomyositis is typically found in tropic regions, but it is increasingly being recognized in temperate climates, especially in immunocompromised individuals. Patient presentation ranges from afebrile with mildly elevated WBC to frank sepsis. In many reported cases, patients may develop multiple abscesses at different sites. Case Description: A 54-year-old male with a history of COPD presented to the emergency department for worsening right pectoral pain with swelling and skin changes that persisted despite empiric outpatient antibiotic treatment for cellulitis. He reported superficial abrasions to the affected area one week prior to onset of symptoms along with fever, non-productive chronic cough, and red, swollen skin on his right chest. His social history was significant for heavy cigarette and alcohol use, and occasional methamphetamine use. On admission, vital signs were unremarkable, but he soon developed fever and tachycardia. On exam, the right pectoral region and shoulder were erythematous and tender, and noticeably asymmetric. Lab results demonstrated elevated inflammatory markers. Initial ultrasound of the affected area was consistent with cellulitis. A CT scan demonstrated inflammatory stranding of the pectoral muscle but no abscess. The patient was started on broad-spectrum antibiotics; however, his clinical status worsened. A repeat bedside ultrasound performed several days later demonstrated abscess formation. Surgical incision and drainage revealed copious purulence between the pectoralis minor and major muscles. Wound cultures grew methicillin-resistant S. aureus. The patient required repeat incision and drainage before being discharged on oral clindamycin. Discussion: This case highlights the difficulty of detecting tropical pyomyositis in its early stages without strong clinical suspicion, and also points to a possibility that broad-spectrum antibiotics may not effectively treat early pyomyositis before abscess formation is achieved. The role of antibiotics in early tropical pyomyositis, therefore, may be to prevent continued hematogenous spread and subsequent appearance of further lesions, but may not impact progression of disease at the primary site.
dc.titleDiagnosis and Management of Pyomyositis