What is the treatment for microcytic hypochromic anemia with low Mean Corpuscular Volume (MCV) and Mean Corpuscular Hemoglobin (MCH)?

Treatment for Microcytic Hypochromic Anemia with Low MCV and MCH

Oral iron supplementation is the first-line treatment for microcytic hypochromic anemia with low MCV and MCH, which is most commonly caused by iron deficiency anemia (IDA). 1

Diagnostic Confirmation

Before initiating treatment, confirm iron deficiency with:

• Serum ferritin (most specific test for iron deficiency)
  • <15 μg/L indicates absent iron stores
  • <30 μg/L indicates low body iron stores 2
• Additional iron studies if false-normal ferritin is suspected:
  • Transferrin saturation <30% helps confirm iron deficiency 1
  • Elevated red cell distribution width (RDW >14%) 1

Note: Ferritin is an acute phase protein and may appear normal in iron deficiency with concurrent inflammation 2

Treatment Protocol

First-Line: Oral Iron Therapy

• Dosage: One tablet daily of ferrous sulfate, fumarate, or gluconate 1
• Duration: Continue for 3 months after hemoglobin normalizes to replenish iron stores 1
• Monitoring:
  • Check hemoglobin weekly until stable, then every 2-4 weeks
  • Monitor ferritin and transferrin saturation monthly during initial treatment 1
  • A good response (Hb rise ≥10 g/L within 2 weeks) confirms iron deficiency 2

Second-Line: Intravenous Iron

Consider IV iron (e.g., ferric carboxymaltose) for patients with:

• Intolerance to oral iron
• Poor absorption
• Chronic inflammatory conditions
• Ongoing blood loss 1

Treatment Targets

• Ferritin >100 ng/mL
• Transferrin saturation >20% 1

Differential Diagnosis Considerations

Microcytic hypochromic anemia can also be caused by:

1. Thalassemia trait

   • Very low MCV (<70 fl)
   • Normal RDW (≤14%)
   • Normal ferritin
   • Normal transferrin saturation
   • Normal/high RBC count 1

2. Anemia of chronic disease

   • Low/normal MCV
   • Normal/slightly elevated RDW
   • Normal/high ferritin
   • Low transferrin saturation 1

3. Sideroblastic anemia 3

Follow-up and Monitoring

• Monitor hemoglobin and red cell indices every three months for one year, then after another year
• Provide additional iron if hemoglobin or MCV falls below normal
• Further investigation is only necessary if hemoglobin and MCV cannot be maintained with iron therapy 1

Important Considerations

• GI investigation is essential in all patients with confirmed unexplained IDA, as approximately one-third of men and postmenopausal women have underlying pathological abnormalities 1
• In pregnant women, infants, and elderly patients, iron requirements are higher 1
• Exercise recommendations should be tailored based on anemia severity:
  • Regular moderate exercise is generally safe for mild anemia (Hb >10 g/dL)
  • Limited activity until anemia improves for severe anemia (Hb <8 g/dL) 1

Common Pitfalls to Avoid

• Accepting dietary history as the sole cause of IDA without GI investigation
• Misinterpreting ferritin levels in the presence of inflammation
• Inadequate duration of iron therapy
• Deferring iron replacement while awaiting investigations 1