Clinical Scenario:
A 22-month-old boy is brought to the pediatric clinic because of progressive pallor and poor appetite for 3 months. He drinks approximately 1.2 liters of whole cow’s milk daily and refuses most solid foods. His growth is normal. Examination reveals conjunctival pallor without hepatosplenomegaly or lymphadenopathy.
Laboratory investigations show:
- Hemoglobin: 8.4 g/dL
- MCV: 65 fL
- RDW: Increased
- Reticulocyte count: Low
What is the most likely diagnosis?
A. β-thalassemia trait
B. Iron deficiency anemia
C. Anemia of chronic disease
D. Sideroblastic anemia
E. Hereditary spherocytosis
Correct answer & Explanation:
Correct Answer: B. Iron deficiency anemia
Explanation
This toddler has the classic presentation of iron deficiency anemia (IDA). Excessive cow’s milk intake (>500 mL/day after 12 months of age) is a major risk factor because it is low in iron and displaces iron-rich complementary foods from the diet.
The laboratory findings support iron deficiency:
- Low hemoglobin
- Low MCV (microcytic anemia)
- Increased RDW (anisocytosis)
- Low reticulocyte count
Why the other options are incorrect
A. β-thalassemia trait
Usually causes marked microcytosis with a normal RDW and a relatively high RBC count. A dietary history of excessive cow’s milk strongly favors iron deficiency.
B. Iron deficiency anemia
Correct. The dietary history and laboratory findings are characteristic of IDA.
C. Anemia of chronic disease
Usually occurs in children with chronic inflammatory or systemic illnesses and is more often normocytic or mildly microcytic.
D. Sideroblastic anemia
A rare cause of microcytic anemia and is not associated with excessive cow’s milk intake.
E. Hereditary spherocytosis
Typically presents with hemolytic anemia, jaundice, splenomegaly, and spherocytes on the peripheral smear rather than microcytic anemia.
Learning Point
In toddlers, excessive cow’s milk intake is the most common dietary risk factor for iron deficiency anemia. Cow’s milk is a poor source of iron and can reduce the intake of iron-rich complementary foods. According to pediatric recommendations, cow’s milk intake should generally be limited to <500 mL/day after 12 months of age.
