Point-of-care ultrasound differentiates pyomyositis from cellulitis

Area of Science:

• Emergency Medicine
• Infectious Diseases
• Musculoskeletal Imaging

Background:

• Pyomyositis (PM) is a primary skeletal muscle infection, frequently presenting with abscess formation.
• Patients with PM often have underlying risk factors or are immunocompromised, complicating diagnosis.
• Delayed diagnosis of pyomyositis can lead to significant morbidity and prolonged treatment courses.

Observation:

• A case is presented of a patient with acute right thigh pain, swelling, erythema, and fever.
• The patient lacked typical predisposing factors for pyomyositis.
• Point-of-care ultrasound (POCUS) demonstrated significant muscle edema and subcutaneous emphysema, crucially without overlying cellulitis.

Findings:

• POCUS identified key features suggestive of pyomyositis.
• The ultrasound findings facilitated an earlier diagnosis compared to typical presentations.
• Early diagnosis directly influenced prompt management decisions in the emergency department.

Implications:

• Point-of-care ultrasound is a valuable tool for the early detection of pyomyositis, even in atypical cases.
• Integrating POCUS into emergency department workflows can improve diagnostic accuracy and timeliness for musculoskeletal infections.
• This case highlights the utility of POCUS in resource-limited settings or when advanced imaging is not immediately available.