Yersinia enterocolitica

Snapshot

A 2-year-old girl presents to her pediatrician with 1 week of low-grade fevers, initially watery diarrhea which became bloody today, and abdominal pain. Her parents report that when they saw some blood in the diarrhea, they were alarmed and decided to bring her in. On physical exam, the girl has sunken eyes and dry mucous membranes. Her belly is tender to palpation in the right lower quadrant. A bedside abdominal ultrasound shows a normal appendix. A stool sample is sent for studies. Meanwhile, she is given supportive care for treatment.

Introduction

Classification
- Yersinia enterocolitica
  - a nonmotile, gram-negative, facultative intracellular bacillus
    - non-lactose fermenting, oxidase negative, and does not produce H₂S
  - requires iron as an essential growth factor
  - transmitted via ingestion of contaminated foods
    - unpasteurized milk
    - raw pork or seafood
  - causes gastroenteritis and pseudoappendicitis
Epidemiology
- demographics
  - more common in infants and children
- risk factors
  - day-care centers
  - drinking or eating unpasteurized milk products
  - iron overload
    - chronic hemolysis
    - hereditary hemochromatosis
Pathogenesis
- the bacteria invade tissue
  - proliferates in Peyer patches
- produces enterotoxin similar to E. coli heat-stable toxin
Associated conditions
- erythema nodosum
- reactive arthritis
Prognosis
typically self-limited

Presentation

Imaging

Abdominal computed tomography (CT)
- indication
  - suspected appendicitis
- findings
normal appendix

Studies

Differential

Treatment

Management approach
- mainstay of treatment is supportive care
- antibiotics can be used in severe cases or immunocompromised patients
Conservative
- supportive care
  - indication
    - all patients
  - modalities
    - hydration
Medical
- aminoglycosides
  - indication
    - first-line for those who need treatment
- cephalosporins
  - indication
    - second-line
- trimethoprim-sulfamethoxazole
  - indication
second-line

Complications