Clinical scenario: Thalassemia | deferoxamine | pain abdomen | vomiting |bloody diarrhea
A 10-year-old boy with transfusion-dependent β-thalassemia major is receiving regular packed red cell transfusions and subcutaneous deferoxamine for iron chelation. He presents with a 4-day history of fever, severe abdominal pain, vomiting, and bloody diarrhea. Examination reveals dehydration, diffuse abdominal tenderness, and splenomegaly.
Investigations:
- Hemoglobin: 8.4 g/dL
- WBC count: 18.5 × 10⁹/L
- CRP: 145 mg/L
- Blood cultures are pending.
Which of the following organisms is the most likely cause of his illness?
A. Campylobacter jejuni
B. Escherichia coli O157:H7
C. Salmonella Typhi
D. Shigella sonnei
E. Yersinia enterocolitica
Correct answer & Explanation:
Correct Answer: E. Yersinia enterocolitica
Explanation
Children with thalassemia major who have iron overload and are receiving deferoxamine are particularly susceptible to Yersinia enterocolitica infection.
Deferoxamine acts as a siderophore, providing iron that enhances the growth of Yersinia. Infection may present with:
- Fever
- Abdominal pain (often mimicking appendicitis)
- Enterocolitis with diarrhea (sometimes bloody)
- Bacteremia or sepsis in severe cases
Management includes:
- Prompt antibiotics active against Yersinia
- Temporary discontinuation of deferoxamine during active infection
- Supportive care
Why the other options are incorrect
A. Campylobacter jejuni
- A common cause of bacterial gastroenteritis but has no specific association with thalassemia or deferoxamine therapy.
B. Escherichia coli O157:H7
- Causes hemorrhagic colitis and hemolytic uremic syndrome but is not linked to iron chelation.
C. Salmonella Typhi
- Causes enteric fever rather than the characteristic deferoxamine-associated enterocolitis.
D. Shigella sonnei
- Causes dysentery but has no specific relationship with iron overload or deferoxamine.
High-yield pearl
Yersinia enterocolitica is the classic gastrointestinal pathogen associated with transfusion-dependent thalassemia patients receiving deferoxamine. In a child with iron overload who develops fever and abdominal pain while on deferoxamine, Yersinia infection should be suspected, and deferoxamine should be withheld until the infection has resolved.
