Primary Bacterial Gluteal Pyomyositis: A Rare Disease in Temperate Climates Presenting as Suspected Septic Arthritis of the Hip.

BACKGROUND: In nations with temperate climates, primary polymyositis is a rare, life-threatening bacterial infection that can mimic various clinical diseases depending on the area involved, leading to delayed diagnosis and management. CASE REPORT: We describe a young postpartum woman who presented to the emergency department with hip pain that was initially suspected to be caused by septic arthritis. However, hip arthrocentesis was negative, and a magnetic resonance imaging scan revealed extensive pyomyositis of the gluteal muscles. She underwent surgical debridement and was given parenteral antibiotics with good clinical recovery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: We emphasize that cases of pyomyositis in temperate countries are often diagnosed late and therefore delay life- and potentially limb-saving treatment. For patients who present with hip and thigh pain and clinical features of sepsis, pyomyositis should be considered in the differential diagnosis and an early magnetic resonance imaging scan should be performed to confirm the diagnosis and reduce the high morbidity and mortality associated with this emerging disease.