A 2-year-old boy is brought to clinic by his parents for a routine well-child visit. He has no known medical conditions and is growing and developing appropriately. The patient is starting to put words into short sentences and sleeps well at night. His diet consists mostly of cheese and yogurt. He drinks approximately five 8-oz cups (1183 mL) of whole cow's milk each day. Two months ago, the patient's family moved from Greece to the United States. He has no allergies and immunizations are up to date. Height and weight are at the 25th percentile. Temperature is 36.7 C (98.1 F). The conjunctivae and mucous membranes are pale. The lungs are clear to auscultation bilaterally. Cardiac examination reveals tachycardia and a 2/6 systolic murmur along the left upper sternal border. Complete blood count is as follows: Which of the following additional findings is most likely to be present in this patient?

Question

A 2-year-old boy is brought to clinic by his parents for a routine well-child visit.  He has no known medical conditions and is growing and developing appropriately.  The patient is starting to put words into short sentences and sleeps well at night.  His diet consists mostly of cheese and yogurt.  He drinks approximately five 8-oz cups (1183 mL) of whole cow's milk each day.  Two months ago, the patient's family moved from Greece to the United States.  He has no allergies and immunizations are up to date.  Height and weight are at the 25th percentile.  Temperature is 36.7 C (98.1 F).  The conjunctivae and mucous membranes are pale.  The lungs are clear to auscultation bilaterally.  Cardiac examination reveals tachycardia and a 2/6 systolic murmur along the left upper sternal border.  Complete blood count is as follows:  Which of the following additional findings is most likely to be present in this patient?

Quizplus · Accepted Answer

11ec25c8_d6a5_0b16_bc81_257fefa28733_MD0003_00 This patient's microcytic anemia and excessive cow's milk intake are concerning for iron deficiency anemia (IDA). Cow's milk has low iron content. In addition, the bioavailability of that iron is poor because the calcium and caseinophosphopeptide found in cow's milk interfere with intestinal absorption of dietary iron. Also, consuming large volumes of cow's milk replaces the normal intake of iron-rich foods. For these reasons, children who consume >24 oz/day are especially at risk for IDA. Although severe IDA can impair neurocognitive development, most children are asymptomatic and have age-appropriate skills (as seen in this patient). Tachycardia and a flow murmur may be present because cardiac output increases to compensate for the reduced oxygen-carrying capacity of iron-deficient red blood cells (RBCs). Inadequate iron stores in the bone marrow lead to a low erythrocyte count and the production of hypochromic RBCs with a low mean corpuscular volume. However, RBC distribution width (size variability) is elevated because the amount of iron available for RBC synthesis varies throughout the day. (Choice A) Beta thalassemias are common in patients of Mediterranean ancestry and present with microcytic anemia, abnormal hemoglobin electrophoresis, low RBC distribution width, and normal/elevated erythrocyte count. Although this patient is from Greece, his dietary history and low erythrocyte count make IDA more likely. (Choice B) Mean corpuscular hemoglobin concentration is a measure of the hemoglobin concentration of each RBC. It is decreased in IDA and thalassemia and elevated in hereditary spherocytosis due to loss of RBC surface area. (Choice D) Increased indirect bilirubin levels are seen in hemolytic anemia due to increased RBC turnover; patients with IDA have normal bilirubin levels. (Choice E) Nucleated RBCs are immature RBCs found in the bone marrow. The presence of these RBCs in the blood indicates significant marrow stress (eg, severe hemolysis, myelofibrosis). Nucleated RBCs (Choice F) Total iron-binding capacity (TIBC) directly measures the iron bound by transferrin and indirectly measures transferrin levels. Anemia of chronic disease has a low TIBC and normocytic or microcytic anemia. In IDA, upregulated transferrin production and lower serum iron result in increased TIBC. Educational objective: Excessive cow's milk consumption (>24 oz/day) commonly causes microcytic, iron deficiency anemia with a low erythrocyte count and elevated red blood cell distribution width. References: Iron deficiency and other types of anemia in infants and children. (http://www.ncbi.nlm.nih.gov/pubmed/26926814)

A 2-Year-Old Boy Is Brought to Clinic by His Parents