What is the next step in managing a patient with mild anisocytosis and potential iron deficiency?

Management of Mild Anisocytosis and Potential Iron Deficiency

The next step in managing a patient with mild anisocytosis and potential iron deficiency is to initiate oral iron supplementation with ferrous sulfate 200 mg three times daily and confirm the diagnosis with serum ferritin testing. 1

Diagnostic Assessment

• The laboratory findings show low MCH (26.1 pg) and low MCHC (30.2 g/dL) with normal MCV (86 fL), suggesting early iron deficiency with anisocytosis 1
• Serum ferritin is the single most powerful test for confirming iron deficiency and should be measured if not already done 1
• A serum ferritin <15 μg/dl is diagnostic of iron deficiency 1
• Other iron studies that may be helpful include transferrin saturation, especially when a false-normal ferritin is suspected 1

Iron Therapy

• All patients with confirmed or suspected iron deficiency should receive iron supplementation to correct anemia and replenish body stores 1
• Ferrous sulfate 200 mg three times daily (providing approximately 65 mg elemental iron per tablet) is the most cost-effective option 1, 2
• Alternative preparations such as ferrous gluconate or ferrous fumarate are equally effective and may be better tolerated in some patients 1
• A liquid preparation may be considered if tablets are not tolerated 1
• Adding ascorbic acid (vitamin C) enhances iron absorption and should be considered when response to therapy is poor 1

Monitoring Response

• Hemoglobin concentration should rise by approximately 2 g/dL after 3-4 weeks of proper iron therapy 1
• A good response to iron therapy (Hb rise ≥10 g/L within a 2-week timeframe) is highly suggestive of absolute iron deficiency, even if initial iron studies were equivocal 1
• Failure to respond is usually due to poor compliance, misdiagnosis, continued blood loss, or malabsorption 1
• Iron therapy should be continued for three months after correction of anemia to adequately replenish iron stores 1

Follow-up

• Once normalized, hemoglobin concentration and red cell indices should be monitored at three-month intervals for one year and then after a further year 1
• Additional oral iron should be given if the hemoglobin or MCV falls below normal (with ferritin estimation in doubtful cases) 1
• Further investigation is only necessary if the hemoglobin and MCV cannot be maintained with iron supplementation 1

Investigation for Underlying Causes

• If iron deficiency is confirmed, investigation for underlying causes should be considered, particularly in men and post-menopausal women 1
• Common causes include gastrointestinal blood loss, malabsorption (particularly celiac disease), poor dietary intake, and NSAID use 1
• Screening for celiac disease should be performed, as it is found in 3-5% of cases of iron deficiency anemia 1
• In men and post-menopausal women, gastroscopy and colonoscopy are generally recommended as first-line GI investigations 1

Special Considerations

• Anisocytosis is often one of the earliest hematological abnormalities in developing iron deficiency, even before significant changes in hemoglobin concentration occur 3
• The combination of anisocytosis with low MCH and MCHC but normal MCV suggests early or developing iron deficiency 3
• Parenteral iron should only be used when there is intolerance to at least two oral preparations or documented non-compliance 1