What is the best management approach for a 19-year-old female with iron deficiency anemia, celiac disease, and recent blood transfusion, currently on oral iron supplementation?

Management of Iron Deficiency Anemia in a 19-Year-Old with Celiac Disease

This patient requires immediate escalation to intravenous iron therapy given her severe iron deficiency (iron saturation 5%, ferritin 15 ng/mL), recent transfusion requirement, and underlying celiac disease with malabsorption, as oral iron supplementation has clearly failed despite ongoing use. 1, 2

Immediate Treatment Recommendation

Switch from oral to intravenous iron immediately because:

• Iron saturation of 5% represents severe iron depletion requiring aggressive repletion 2
• Celiac disease with active malabsorption makes oral iron absorption unpredictable and often inadequate, even with adherence to a gluten-free diet 1, 3
• Recent transfusion requirement (hemoglobin <6 g/dL) indicates transfusion-dependent iron deficiency anemia, which is an absolute indication for IV iron 1
• Current hemoglobin of 10.3 g/dL with ongoing oral supplementation demonstrates failure of oral therapy 2

Preferred IV Iron Formulation

Use ferric carboxymaltose (500-1000 mg single doses over 15 minutes) as the preferred IV iron preparation because it can replace the entire iron deficit in 1-2 infusions rather than requiring multiple visits 1, 2. Alternatively, iron dextran can be given as a total dose infusion in a single session, though it carries a slightly higher (but still rare at 0.6-0.7%) risk of anaphylaxis 1, 2.

Avoid iron sucrose as it requires multiple visits with maximum 200 mg per infusion, making it impractical for severe deficiency 1.

Concurrent Celiac Disease Management

Verify strict adherence to gluten-free diet as this is essential for restoring duodenal absorption capacity 1, 2. However, do not delay IV iron while waiting for mucosal healing, as normalization can take 6 months to 2 years and this patient needs immediate repletion 3.

Up to 20% of celiac patients remain iron deficient despite strict gluten avoidance, making IV iron particularly important in this population 1.

Investigation of Ongoing Blood Loss

While treating with IV iron, evaluate for additional sources of blood loss beyond malabsorption:

• Assess menstrual blood loss using pictorial blood loss assessment charts (80% sensitivity/specificity for menorrhagia) 1, 2
• The presence of schistocytes and helmet cells on her smear is concerning and warrants hematology consultation to exclude microangiopathic hemolytic anemia or other hemolytic processes contributing to her anemia 2
• Upper endoscopy is NOT routinely indicated in a 19-year-old premenopausal woman with known celiac disease unless she has upper GI symptoms or alarm features 1
• Colonoscopy is NOT indicated unless she has rectal bleeding, strong family history of colorectal cancer, or persistent anemia after iron repletion and correction of menstrual losses 1

Monitoring Protocol

Check hemoglobin 4 weeks after IV iron administration, expecting a rise of approximately 2 g/dL 2. If hemoglobin fails to rise appropriately:

• Reassess for ongoing blood loss (particularly given the schistocytes on smear) 2
• Verify gluten-free diet adherence 1, 2
• Consider hematology referral for the abnormal red cell morphology 2

Once hemoglobin normalizes, monitor every 3 months for the first year, then annually 1, 2.

Why Oral Iron Has Failed and Should Be Discontinued

Oral iron absorption is severely impaired in celiac disease, particularly with active villous atrophy, making it ineffective for severe deficiency 1, 3. The fact that she required transfusion this winter despite being on oral supplementation proves oral therapy is insufficient 1, 2.

Ferrous sulfate absorption is limited in active celiac disease and unpredictable even on a gluten-free diet 3. While adding vitamin C (500 mg) can enhance absorption, this strategy is inadequate when iron saturation is 5% and recent transfusion was required 1, 2.

Critical Pitfalls to Avoid

• Do not continue oral iron indefinitely without response - this patient has already demonstrated failure of oral therapy with her transfusion requirement 2
• Do not delay IV iron while pursuing extensive GI investigation in a young premenopausal woman with known celiac disease 1
• Do not overlook the schistocytes and helmet cells - these require hematology evaluation as they may indicate a concurrent hemolytic process 2
• Do not assume celiac disease alone explains everything - her marked red cell fragmentation (schistocytes, helmet cells, acanthocytes) is unusual for uncomplicated iron deficiency and warrants further investigation 2
• Resuscitation facilities must be available when administering IV iron due to rare but serious anaphylaxis risk 1, 2

Expected Outcome

With appropriate IV iron therapy and strict gluten-free diet adherence, hemoglobin should normalize within 3-4 months 1, 2. Iron stores should fully replenish within 6 months, though celiac patients may take longer 3. If anemia persists beyond 6 months despite IV iron and gluten-free diet, reassess for ongoing blood loss and consider the significance of her abnormal red cell morphology 2.