A 10-month-old boy is brought to clinic for evaluation of decreased activity. The patient has been progressively tired over the past few weeks. He normally is able to crawl and pull up to a stand, but lately he is so tired that he prefers to sit still. The boy is primarily breastfed and eats some pureed fruits. He has 6 or 7 wet diapers and 3 soft stools per day. He has no known medical conditions or prior hospitalizations. The patient lives with his parents and 3-year-old sister, none of whom have chronic medical conditions. His parents are originally from Ghana and moved to the United States 4 years ago. Temperature is 36.7 C (98 F) and pulse is 100/min. Examination shows mild conjunctival pallor. The lungs are clear to auscultation. A 2/6 systolic murmur is auscultated over the precordium. The abdomen is soft and nontender, and bowel sounds are present. Laboratory results are as follows: Which of the following is the most likely cause of this child's anemia?

Question

A 10-month-old boy is brought to clinic for evaluation of decreased activity.  The patient has been progressively tired over the past few weeks.  He normally is able to crawl and pull up to a stand, but lately he is so tired that he prefers to sit still.  The boy is primarily breastfed and eats some pureed fruits.  He has 6 or 7 wet diapers and 3 soft stools per day.  He has no known medical conditions or prior hospitalizations.  The patient lives with his parents and 3-year-old sister, none of whom have chronic medical conditions.  His parents are originally from Ghana and moved to the United States 4 years ago.  Temperature is 36.7 C (98 F) and pulse is 100/min.  Examination shows mild conjunctival pallor.  The lungs are clear to auscultation.  A 2/6 systolic murmur is auscultated over the precordium.  The abdomen is soft and nontender, and bowel sounds are present.  Laboratory results are as follows:  Which of the following is the most likely cause of this child's anemia?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c166_73f9_8f63_130e4de7bc87_MD0005_00 Iron deficiency is the most common cause of anemia in infants in the United States. It is typically due to inadequate dietary iron, as in breastfed infants age >6 months who do not eat enough iron-rich foods or any infant who drinks cow's milk before age 1 year. Premature infants are also at increased risk due to inadequate iron stores. Most children with iron deficiency are asymptomatic; however, if symptomatic, the most common findings are lethargy, irritability, pallor, and a systolic flow murmur, as seen in this patient. Severe anemia can cause cardiomegaly and tachypnea. Classic laboratory findings include hemoglobin <11 g/dL, often accompanied by low mean corpuscular volume (MCV), elevated red blood cell (RBC) distribution width, and a low RBC count. A Mentzer index (MCV/RBC) >13 is also suggestive of iron deficiency and can help differentiate it from thalassemia; in this patient, the Mentzer index is 65/3.5 = 18.6. Alpha and beta thalassemias are also microcytic but characterized by a Mentzer index <13 (Choices C and D). Although breastfeeding is recommended for at least the first year of life, iron-fortified cereals, pureed meats, and foods rich in vitamin C (to enhance iron absorption) should be introduced around age 6 months. In addition to iron-rich foods, this patient will also require oral iron therapy to replenish iron stores. (Choice B) Chronic lead ingestion causes normocytic, hemolytic anemia. This patient with a low MCV and poor dietary iron intake is more likely to have iron deficiency anemia. (Choice E) Glucose-6-phosphate dehydrogenase deficiency is an X-linked disorder that may be asymptomatic until exposure to oxidant medications or substances causes acute hemolytic anemia. Acute hemolytic anemia is typically characterized by a normal MCV. In addition, this patient's history is suggestive of a chronic, gradual process rather than an acute event. Educational objective: Iron deficiency anemia is common in infancy and is characterized by hemoglobin <11 g/dL, low mean corpuscular volume, and Mentzer index >13. Although breast milk provides sufficient iron for the first few months of life, introducing iron-rich foods (eg, pureed meats) around age 6 months is necessary to prevent iron deficiency. References: Iron deficiency anemia in predominantly breastfed young children. (http://www.ncbi.nlm.nih.gov/pubmed/24953965) Diagnosis and prevention of iron deficiency and iron-deficiency anemia in infants and young children (0-3 years of age). (http://www.ncbi.nlm.nih.gov/pubmed/20923825) Timing of the introduction of complementary foods in infancy: a randomized controlled trial. (http://www.ncbi.nlm.nih.gov/pubmed/23147979)

A 10-Month-Old Boy Is Brought to Clinic for Evaluation of Decreased