Types of Pediatric Anemia and Management
Classification by Mean Corpuscular Volume (MCV)
Pediatric anemia is classified by MCV into three categories: microcytic (most common), normocytic, and macrocytic, with iron deficiency anemia being the predominant cause in children worldwide. 1, 2
Microcytic Anemia (Low MCV)
Iron Deficiency Anemia (Most Common)
Iron deficiency anemia is the most widespread, preventable, and treatable cause of anemia in children, affecting over 269 million children globally. 3, 1
Diagnostic Approach
- Confirm anemia with repeat hemoglobin/hematocrit before initiating treatment 4, 5
- In non-acutely ill children with positive screening, make a presumptive diagnosis and begin treatment immediately 4, 5
- Serum ferritin ≤15 μg/L confirms iron deficiency 4, 5
Treatment Protocol
- Prescribe 3 mg/kg per day of elemental iron (ferrous sulfate preferred) administered between meals for optimal absorption 4, 5
- Ferrous sulfate is preferred over other iron salts because it is most cost-effective and provides known amounts of elemental iron 5
- Avoid administering iron with meals or milk, as food reduces absorption by up to 50% 5
- Continue treatment for 2-3 months after hemoglobin normalizes to replenish iron stores 4, 5
Age-Specific Dosing
- Infants <12 months: 1 mg/kg/day iron drops for breastfed infants with insufficient dietary iron 5
- Preterm/low birthweight infants: 2-4 mg/kg/day iron drops (maximum 15 mg/day) from 1 month until 12 months 5
- School-age children (5-12 years): One 60-mg iron tablet daily plus dietary counseling 5
- Adolescent boys (12-18 years): Two 60-mg iron tablets daily plus dietary counseling 5
Monitoring Response
- Repeat hemoglobin/hematocrit at 4 weeks to assess treatment response 4, 5
- An increase of ≥1 g/dL in hemoglobin or ≥3% in hematocrit confirms diagnosis and adequate response 4, 5
Dietary Counseling (Critical Component)
- Limit cow's milk intake to maximum 24 ounces daily, as excessive milk consumption is a major contributor to iron deficiency 4, 6, 5
- Introduce iron-fortified cereals (two or more servings daily starting at 4-6 months) 5
- Add vitamin C-rich foods with meals to enhance iron absorption 4, 5
- For infants, use only iron-fortified formula if not breastfeeding; avoid cow's milk, goat's milk, and soy milk until age 12 months 5
Management of Non-Responsive Cases
- If no response after 4 weeks, measure serum ferritin: ≤15 μg/L confirms iron deficiency, while >15 μg/L suggests alternative diagnosis 4
- Obtain MCV and red cell distribution width (RDW) to evaluate other causes 4
- Consider reticulocyte count as marker of bone marrow response 4
- Evaluate for poor adherence, incorrect administration (taking with food/milk), or alternative diagnoses 5
Severe Anemia Management
- Even with hemoglobin as low as 1.1-1.2 g/dL, oral iron supplementation remains first-line treatment in hemodynamically stable children 4, 3
- Blood transfusion is reserved exclusively for hemodynamically unstable patients with tachycardia, hypotension, or heart failure 4
- IV iron therapy is highly effective for severe cases with complications like reversible cardiomyopathy or gut involvement 3
Other Causes of Microcytic Anemia
- Thalassemia: Genetic hemoglobin disorder requiring hematology referral 2
- Lead poisoning: Screen in high-risk populations 2
Normocytic Anemia (Normal MCV)
Normocytic anemia is classified by reticulocyte count: high reticulocyte count indicates hemolysis, while low reticulocyte count suggests bone marrow suppression. 1, 2
High Reticulocyte Count (Hemolysis)
- Hemoglobinopathies (sickle cell disease, detected on newborn screening) 1
- Membrane defects (hereditary spherocytosis) 2
- Enzymopathies (G6PD deficiency) 2
- Immune-mediated hemolysis 2
Low Reticulocyte Count (Bone Marrow Suppression)
- Anemia of chronic disease (infections, inflammatory conditions) 1, 2
- Bone marrow failure syndromes (require urgent hematology referral) 1
- Transient erythroblastopenia of childhood 2
Any diagnosed bone marrow suppression requires critical pediatric hematology referral. 1
Macrocytic Anemia (High MCV)
Macrocytic anemia is less common in children and typically results from nutritional deficiencies or poor absorption of vitamin B12 or folate. 1, 2
Causes
Treatment of Folate Deficiency
- Folic acid is effective for megaloblastic anemias due to folate deficiency (tropical/nontropical sprue, nutritional deficiency, pregnancy, infancy, childhood) 7
- Usual therapeutic dose: up to 1 mg daily for adults and children regardless of age 7
- Doses >0.1 mg should not be used unless vitamin B12 deficiency has been ruled out or is being adequately treated 7
- Maintenance dose after clinical improvement: 0.1 mg for infants, up to 0.3 mg for children <4 years, 0.4 mg for children ≥4 years and adults 7
Critical Pitfalls to Avoid
- Do not administer iron with meals or milk—this significantly decreases absorption by up to 50% 4, 5
- Do not discontinue iron treatment prematurely—continue for 2-3 months after hemoglobin normalizes to replenish stores 4, 5
- Do not overlook dietary counseling—failure to address excessive milk intake (>24 oz daily) or poor iron-rich food introduction leads to rapid recurrence 4, 6
- Do not transfuse hemodynamically stable patients—even with hemoglobin as low as 1.1 g/dL, oral/IV iron is first-line if stable 4, 3
- Do not use iron polysaccharide complex—it is more expensive, no better tolerated, and may be less effective than ferrous sulfate 5
- Do not add ascorbic acid supplements—they do not improve ferrous iron absorption 5
- Do not use folic acid doses >0.1 mg without ruling out vitamin B12 deficiency—this can mask B12 deficiency and worsen neurologic complications 7
Screening Recommendations
- Screen all children at 9-12 months, repeat at 15-18 months, then annually ages 2-5 years if from low-income families, WIC-eligible, migrant populations, or recently arrived refugees 6
- Screen children with documented risk factors: low-iron diet, excessive milk intake, poverty, special healthcare needs 6
Long-Term Consequences of Untreated Anemia
Iron deficiency anemia in infants causes neurodevelopmental delays, decreased motor activity, impaired social interaction, and reduced attention span that may persist beyond school age if not fully reversed. 4
Special Populations: Chronic Kidney Disease
- Anemia management in children with CKD is understudied, with no RCTs examining effects of ESA and iron on hard clinical outcomes in pediatric patients 8
- Newer iron agents (ferric pyrophosphate, ferric citrate) may be efficacious in children, but more data needed 8
- HIF-PHI agents are not yet studied in pediatric CKD patients but are planned 8