- Agents: Yersinia enterocolitica (more common in diarrhea) and Y. pseudotuberculosis. Gram negative bacilli.
- Risk population: It mainly affects children < 4 years.
- Seasonality: Greater incidence in cold climates (autumn and winter). The bacteria multiplies at refrigeration temperatures (4°C).
- Transmission: Fecal-oral. Contaminated food (raw/undercooked pork, unpasteurized milk), contaminated water, contact with pets, or preparation of pig intestines (chitterlings).
Infants and Preschoolers (< 5 years)
Classic presentation of gastroenteritis that is usually longer than the viral one (lasts 1-3 weeks).
- Watery diarrhea, often with mucus or blood (up to 25% of cases).
- Fever (usually low grade).
- Colicky abdominal pain.
Schoolchildren and Adolescents
Pseudoappendicular syndrome:
- Intense pain in the Right Iliac Fossa (RIF).
- Fever and leukocytosis.
- Secondary to mesenteric adenitis o terminal ileitis.
- CRUCIAL Differential in Emergencies with acute appendicitis. There may be signs of focal peritoneal irritation.
Laboratory
- Gastrointestinal Panel PCR: Fast, sensitive and specific. It is the method of choice in emergencies if available.
- Coproculture: Notify the laboratory. Requires special media (CIN agar) or prolonged cold enrichment.
- Blood cultures: Only if there is suspicion of sepsis (immunosuppressed, iron overload).
Image (Ultrasound)
Vital to differentiate from the appendiceal condition in older children. Findings:
- Normal appendix (compressible, < 6mm).
- Enlarged mesenteric lymph nodes (>8 mm short axis).
- Thickening of the wall of the terminal ileum or cecum.
Golden rule in emergencies:
In the vast majority of cases of uncomplicated Yersinia gastroenteritis, the condition is self-limited and Does NOT require antibiotics. The pillar is rehydration.
Antibiotic therapy indications:
- Infants under 3 months.
- Sepsis / Bacteremia.
- Immunodeficiencies.
- Iron overload (e.g. sickle cell disease, use of deferoxamine). Yersinias are siderophilous.
- Severe extraintestinal involvement.
Treatment Options (If indicated):
| Drug | Pediatric Dosage | Via |
|---|---|---|
| Cotrimoxazole (TMP/SMX) | 8-10 mg/kg/day (TMP) in 2 doses | OV/IV |
| Cefotaxime (Severe symptoms/sepsis) |
150-200 mg/kg/day div. every 6-8h | IV |
| Ciprofloxacin (Alternative, older children) |
20-30 mg/kg/day in 2 doses | OV/IV |
They may appear 1 to 3 weeks after the gastrointestinal episode, mediated by immunological mechanisms (especially HLA-B27 positive in older adults/adolescents):
Reactive Arthritis
Polyarticular, not purulent.
Erythema nodosum
Painful pretibial nodules.
Rare: Bacteremia, meningitis or liver/splenic abscesses (suspect in immunosuppressed or iron overload).