Yersinia pseudotuberculosis-Associated Myositis

Area of Science:

• Microbiology
• Infectious Diseases
• Pediatrics

Background:

• Yersinia pseudotuberculosis (Y. pstb.) is a Gram-negative bacterium causing gastrointestinal infections like enterocolitis.
• While reactive arthritis is a known complication, myositis is an exceptionally rare sequela.

Observation:

• A five-year-old boy presented with fever, abdominal pain, and leg pain progressing to severe muscle weakness and inability to walk.
• Laboratory tests revealed elevated inflammatory markers, and stool cultures confirmed Y. pseudotuberculosis infection.
• MRI demonstrated muscle inflammation indicative of myositis.

Findings:

• The patient experienced rapid improvement with conservative management, including rest and acetaminophen, without antibiotic intervention.
• He remained asymptomatic 13 years post-infection, suggesting a favorable long-term prognosis.
• This case documents the extremely rare occurrence of myositis following Y. pseudotuberculosis infection.

Implications:

• The findings suggest a potential post-infectious, immune-mediated mechanism for myositis development after Y. pseudotuberculosis.
• Clinicians should consider myositis in the differential diagnosis for children with muscle weakness following Y. pseudotuberculosis infection.
• Conservative treatment approaches may be sufficient for managing this rare complication.