What is the management for a patient with severe iron deficiency anemia, microcytic hypochromic anemia, and associated eosinophilia and thrombocytopenia?

Management of Severe Iron Deficiency Anemia with Eosinophilia

This patient requires immediate oral iron supplementation with ferrous sulfate 200 mg three times daily, urgent investigation for parasitic infection given the marked eosinophilia, and comprehensive gastrointestinal evaluation to identify the source of iron loss. 1

Immediate Iron Replacement Therapy

All patients with iron deficiency anemia must receive iron supplementation to correct anemia and replenish body stores. 1

• Start ferrous sulfate 200 mg three times daily (providing approximately 65 mg elemental iron per dose), which is the gold standard, simplest, and most cost-effective treatment 1, 2, 3, 4
• Alternative ferrous salts (ferrous gluconate or ferrous fumarate) are equally effective if ferrous sulfate is not tolerated 1
• Consider adding ascorbic acid to enhance iron absorption if response is poor 1
• Expect hemoglobin to rise by 2 g/dL after 3-4 weeks of treatment 1
• Continue iron supplementation for 3 months after correction of anemia to replenish iron stores 1

Parenteral Iron Considerations

• Reserve intravenous iron only for intolerance to at least two oral preparations or documented non-compliance 1
• Parenteral iron offers no faster hemoglobin rise than oral therapy, is expensive, painful (if intramuscular), and carries risk of anaphylaxis 1

Critical: Address the Eosinophilia

The 26% eosinophilia is highly abnormal and demands immediate investigation for parasitic infection, particularly hookworm or other helminthic infections, which are classic causes of both severe iron deficiency and eosinophilia.

• Obtain stool examination for ova and parasites (multiple samples)
• Consider serologic testing for strongyloides, schistosomiasis, and other helminths depending on geographic exposure
• The combination of severe iron deficiency with marked eosinophilia strongly suggests chronic intestinal blood loss from parasitic infection

Investigate the Underlying Cause

Treatment of the underlying cause is essential to prevent further iron loss. 1

Comprehensive GI Evaluation Required

• Upper GI endoscopy with small bowel biopsy to exclude celiac disease, gastric/duodenal lesions, and assess for parasites 1
• Colonoscopy or barium enema to evaluate for colonic pathology 1
• Both investigations should be performed in 90% of patients with iron deficiency anemia without obvious cause 1

Age-Specific Considerations

• If patient is >45 years: full upper and lower GI investigation is mandatory given increased risk of malignancy 1
• If patient is <45 years: prioritize upper GI endoscopy with small bowel biopsy; consider antiendomysial antibody testing for celiac disease 1

Address the Thrombocytopenia

The thrombocytopenia (assuming you meant 85 × 10⁹/L, not 585) may paradoxically be caused by the severe iron deficiency itself. 5

• Iron deficiency can rarely cause thrombocytopenia rather than the typical thrombocytosis 5
• Platelet count should normalize within 48 hours of starting iron supplementation if iron deficiency is the cause 5
• Bone marrow examination showing increased megakaryocytes may falsely suggest immune thrombocytopenic purpura 5
• Avoid inappropriate corticosteroid therapy; iron supplementation is the correct treatment 5

Monitoring and Follow-Up

• Check hemoglobin at 3-4 weeks: failure to rise by 2 g/dL suggests poor compliance, continued blood loss, malabsorption, or misdiagnosis 1
• Monitor hemoglobin and MCV every 3 months for one year, then annually 1
• Recheck platelet count within 48-72 hours to confirm response to iron 5
• Monitor for resolution of eosinophilia after treating any identified parasitic infection

Common Pitfalls to Avoid

• Do not delay iron supplementation while awaiting investigation results—start immediately 1
• Do not ignore the eosinophilia—this is a critical clue to parasitic infection requiring specific treatment
• Do not assume thrombocytopenia requires separate treatment—it may resolve with iron alone 5
• Do not use parenteral iron as first-line therapy—oral iron is equally effective and safer 1, 3
• Do not stop investigating if initial tests are negative—90% of patients should have comprehensive upper and lower GI evaluation 1