Hip pain and fever: when it's not a septic joint, what's next?

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.

Pyomyositis in Children

Primary pyomyositis in children is prevalent in the tropics and increasingly being recognised from temperate regions. Staphylococcus aureus remains the principle causative organism worldwide, while proportion of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is on rise. Commonly involved groups are around the pelvis and lower limbs. Clinical presentation depends on the stage of disease, most commonly a child presenting with limping with fever. Early diagnosis and management are crucial. The investigation of choice is MRI scan. Appropriate antibiotic treatment should be instituted at the earliest opportunity along with drainage. Majority of patients show excellent and complete recovery with no long-term complications once treatment is started early. A high level of awareness and suspicion of this condition is warranted from all paediatric clinicians.