Obturator internus pyomyositis presenting as a pararectal abscess

Area of Science:

• Pediatric infectious diseases
• Musculoskeletal imaging
• Surgical pathology

Background:

• Limp and hip pain in children can present diagnostic challenges.
• Primary pyomyositis, particularly of the obturator internus, is rare in pediatric populations.
• Septic arthritis is a common differential diagnosis for pediatric hip pain and limp.

Purpose of the Study:

• To describe the clinical presentation and diagnostic findings of primary obturator internus pyomyositis in children.
• To emphasize the importance of advanced imaging in diagnosing unusual causes of pediatric hip pain.
• To highlight the successful management and recovery from this rare condition.

Main Methods:

• Case report of two pediatric patients presenting with fever, hip pain, and limp.
• Initial clinical diagnosis considered septic arthritis of the hip.
• Magnetic Resonance Imaging (MRI) utilized to identify pararectal abscesses.
• Surgical incision and drainage performed for abscess management.
• Microbiological culture of abscess pus for pathogen identification.

Main Results:

• Both patients presented with fever, hip pain, and a limp.
• MRI revealed pararectal abscesses, distinct from septic arthritis.
• Staphylococcus aureus was identified as the causative pathogen in both cases.
• Both children experienced a full recovery following incision, drainage, and antibiotic treatment.

Conclusions:

• Primary pyomyositis of the obturator internus muscle is an uncommon cause of pediatric hip pain and limp.
• Early and accurate diagnosis through imaging, particularly MRI, is crucial for appropriate management.
• Prompt surgical intervention and targeted antibiotic therapy lead to favorable outcomes in these cases.