Management of Microcytic Hypochromic Anemia

Diagnostic Approach

The American College of Physicians recommends measuring serum ferritin, transferrin saturation, and iron binding capacity to determine if iron deficiency is the underlying cause of microcytic hypochromic anemia in a 65-year-old woman 1
Serum ferritin is the most specific test for iron deficiency, with levels <15 μg/L indicating absent iron stores and <30 μg/L indicating low body iron stores 1
A ferritin cut-off of 45 μg/L provides optimal sensitivity and specificity for iron deficiency in clinical practice 1
Transferrin saturation (TSAT) should be evaluated as it is more sensitive for detecting iron deficiency than hemoglobin concentration alone 1
The combination of low MCV and elevated RDW strongly suggests iron deficiency anemia rather than thalassemia 1

The American College of Physicians recommends first-line treatment with oral iron supplementation with ferrous sulfate 324 mg (65 mg elemental iron) daily to three times daily for at least three months after correction of anemia 1
Alternative formulations include ferrous gluconate and ferrous fumarate if ferrous sulfate is not tolerated 2
Adding ascorbic acid can enhance iron absorption 1
A good response to iron therapy is defined as a hemoglobin rise ≥10 g/L within a 2-week timeframe, which confirms iron deficiency 2

In a 65-year-old woman with iron deficiency anemia, gastrointestinal blood loss must be ruled out as the underlying cause 1
Upper and lower gastrointestinal endoscopy should be performed to exclude malignancy, especially in this age group 1
If initial iron studies do not confirm iron deficiency, consider other causes of microcytic anemia, such as anemia of chronic disease 3
Sideroblastic anemia should be considered if ferritin is normal/high with abnormal iron studies 4
Genetic disorders of iron metabolism should be considered in patients with microcytic anemia 5

Monitor hemoglobin concentration and red cell indices at three-monthly intervals for one year and then after a further year 1
Provide additional oral iron if hemoglobin or MCV falls below normal 1
For patients who fail to respond to oral iron therapy, consider intravenous iron if there is malabsorption 2
Evaluation for other causes of microcytic anemia should be considered in patients who fail to respond to oral iron therapy 2
Bone marrow examination should be considered if sideroblastic anemia is suspected 5

In patients with refractory microcytic anemia despite adequate iron supplementation, genetic testing should be considered 1, 5
For X-linked sideroblastic anemia, a trial of pyridoxine (vitamin B6) at 50-200 mg daily initially may be effective 5
Avoid overlooking combined deficiencies, such as iron deficiency coexisting with B12 or folate deficiency 2
For patients with genetic disorders affecting iron metabolism, treatment may include oral iron supplementation, erythropoietin, or erythrocyte transfusions based on individual needs 2