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Pyomyositis
From WikEM
Contents
Background
- Primary bacterial infection of skeletal muscle
- Also known as myositis tropicans, more common in tropical settings
- Temperate climates in immune compromised patients
- Mainly disease of children, age 2-5 most common
Pathophysiology
- Transient bacteremia after blunt trauma to muscle group, or vigorous exercise[1]
- Most commonly Staph aureus, followed by Strep pyogenes, pneumococcus, neisseria, haemophilus, yersinia, pseudomonas, klebsiella, and E. coli
Risk Factors
Clinical Features
More commonly affects proximal lower extremity muscles
First stage
- Localized muscle pain, low grade fevers, vague complaints[2]
- Localized muscle inflammation without abscess
Second stage
- Worsening pain, muscle swelling, fever, abscess formation
Third stage
- Infection dissemination
- Septic shock
Differential Diagnosis
Skin and Soft Tissue Infection
Look-A-Likes
Evaluation
- CBC
- Chem 10
- PT/PTT
- CK
- Lactate
- CT extremity with contrast
- Ultrasound
- MRI, study of choice
- Surgical exploration is gold standard
Management
- IV antibiotics alone for first stage
- Vancomycin 15-20mg/kg IV q24 hr, ceftriaxone 1g IV q24 hr, clindamycin 600mg IV q8 hr
- Surgical debridement plus antibiotics for abscess
- IV fluids, pressors, airway management, rapid debridement for septic shock
Disposition
- Admit
