What is the best course of action for a patient with iron deficiency anemia, recent leukocytosis, gastrointestinal symptoms, and now reactive lymphocytes, who is also being managed for high cholesterol?

Management of Iron Deficiency Anemia with Reactive Lymphocytes and GI Symptoms

Start oral ferrous sulfate 200 mg once daily immediately while pursuing urgent gastrointestinal evaluation, as the reactive lymphocytes likely represent a benign response to infection or inflammation rather than a contraindication to iron therapy. 1

Understanding Reactive Lymphocytes in This Context

Reactive lymphocytes are typically a benign finding indicating viral infection, inflammatory conditions, or immune stimulation—none of which contraindicate iron replacement therapy. 1 The presence of reactive lymphocytes does not alter the management algorithm for iron deficiency anemia with GI symptoms, which requires both immediate iron replacement and investigation for the underlying bleeding source.

Immediate Iron Replacement

Begin oral ferrous sulfate 324 mg tablets (65 mg elemental iron) once daily without waiting for endoscopic results. 1, 2

• Add vitamin C 500 mg with each iron dose to enhance absorption 1
• Once-daily dosing is preferred over multiple daily doses for better tolerance and similar absorption 1
• Continue therapy for 3 months after hemoglobin normalizes to fully replenish iron stores 1, 3
• Expect hemoglobin to increase by approximately 2 g/dL after 3-4 weeks of treatment 4

Urgent Gastrointestinal Investigation

Perform upper endoscopy with mandatory small bowel biopsies regardless of mucosal appearance, as 2-3% of iron deficiency anemia patients have celiac disease. 1, 3

• Upper endoscopy identifies a bleeding source in 30-50% of cases 3
• Do not stop investigation after finding a single upper GI lesion—proceed to colonoscopy because dual pathology (lesions in both upper and lower GI tract) occurs in 10-15% of patients 3, 4
• Stop NSAIDs immediately if the patient is taking them, as these are common culprits for occult GI bleeding 3

Complete colonoscopy is mandatory even if upper endoscopy reveals a lesion, unless carcinoma or celiac disease is found. 1, 3

Addressing the Leukocytosis and Reactive Lymphocytes

The recent leukocytosis with reactive lymphocytes suggests:

• Viral infection (most common cause of reactive lymphocytes)
• Inflammatory response to underlying GI pathology
• Immune stimulation from chronic disease

These findings do not delay or contraindicate iron therapy or GI investigation. 1 However, if leukocytosis persists or worsens, consider hematology consultation to exclude lymphoproliferative disorders, though this should not delay management of the iron deficiency anemia.

Cholesterol Management Consideration

Continue statin therapy as prescribed—there is no interaction between iron supplementation and cholesterol medications. 2

When to Switch to Intravenous Iron

Use IV iron if any of the following occur: 1

• Intolerance to oral iron (GI side effects like nausea, constipation, diarrhea) 1, 2
• Ferritin levels fail to improve after 3-4 weeks of oral therapy 1
• Active inflammatory bowel disease is discovered (compromises oral iron absorption) 1
• Celiac disease is diagnosed and oral iron fails despite gluten-free diet 1

Choose single or two-infusion IV iron formulations over those requiring multiple infusions. 1 True anaphylaxis to IV iron is very rare; most reactions are complement activation-related pseudo-allergy (infusion reactions). 1

Monitoring Protocol

• Check hemoglobin every 3-4 weeks initially to confirm response 3, 4
• If no improvement after 4 weeks, evaluate for non-adherence, malabsorption, or ongoing blood loss 4
• Monitor hemoglobin and iron indices every 3 months for the first year after correction 4

Critical Pitfalls to Avoid

• Never assume dietary deficiency alone explains the anemia—full GI investigation is mandatory even with positive dietary history 3
• Never stop at finding peptic ulcer, erosions, or esophagitis on upper endoscopy—these should not be accepted as the sole cause until colonoscopy is completed 1
• Do not delay iron therapy waiting for endoscopy results—start immediately 3
• Avoid taking iron within 2 hours of tetracycline antibiotics if prescribed 2

Further Investigation (If Initial Workup Negative)

Small bowel evaluation with capsule endoscopy is NOT routinely needed unless the patient becomes transfusion-dependent, has persistent visible blood loss, or fails to respond to iron therapy after 6 months despite appropriate treatment. 3, 4