Management of Microcytic Hypochromic Anemia in a 54-Year-Old Male
Start oral iron supplementation with ferrous sulfate 200 mg three times daily immediately while completing the diagnostic workup, as this patient's presentation strongly suggests iron deficiency anemia. 1, 2
Immediate Diagnostic Workup
Measure serum ferritin first—it is the most specific test for iron deficiency, with levels <30 μg/L indicating low body iron stores, though a cutoff of 45 μg/L provides optimal sensitivity and specificity in practice. 1, 3, 2
Check transferrin saturation (TSAT) simultaneously, as it is more sensitive for detecting iron deficiency than hemoglobin alone, with TSAT <16-20% confirming iron deficiency. 1, 3, 2
Measure C-reactive protein (CRP) because ferritin can be falsely elevated by inflammation—in the presence of inflammation, ferritin up to 100 μg/L may still indicate iron deficiency. 4, 1
Check red cell distribution width (RDW)—the combination of low MCV with RDW >14.0% strongly suggests iron deficiency anemia, while RDW ≤14.0% points toward thalassemia minor. 1, 3
Obtain reticulocyte count to assess bone marrow response—low or normal reticulocytes indicate deficiency states, while elevated reticulocytes suggest hemolysis. 4, 5
Critical Investigation for Underlying Cause
In a 54-year-old male with iron deficiency anemia, gastrointestinal blood loss is the most common cause and must be investigated—this warrants fast-track GI referral for both upper endoscopy and colonoscopy. 1
Upper GI endoscopy with small bowel biopsies should be performed to rule out celiac disease (present in 2-3% of iron deficiency anemia patients), H. pylori infection, and upper GI malignancy. 1
Colonoscopy is essential to exclude colonic cancer, polyps, and angiodysplasia, particularly in this age group. 1
Screen for celiac disease with tissue transglutaminase antibodies if malabsorption is suspected. 1
Treatment Protocol
Begin ferrous sulfate 200 mg (65 mg elemental iron) three times daily for at least three months after correction of anemia to replenish iron stores. 1, 3, 2
Add ascorbic acid (vitamin C) to enhance iron absorption. 1, 3, 2
Alternative formulations include ferrous gluconate or ferrous fumarate if ferrous sulfate causes intolerable gastrointestinal side effects. 1, 2
A good response is defined as hemoglobin rise ≥10 g/L within 2 weeks—this confirms iron deficiency as the diagnosis. 1, 3, 2
Management of Treatment Failure
If the patient fails to respond to oral iron within 2-4 weeks, consider the following in order:
Non-compliance with medication—the most common cause of treatment failure. 1
Ongoing blood loss exceeding replacement capacity—requires more aggressive investigation. 1, 6
Malabsorption disorders (celiac disease, H. pylori, autoimmune atrophic gastritis)—switch to intravenous iron with expected hemoglobin increase of at least 2 g/dL within 4 weeks. 1, 2
Consider rare genetic disorders only if: 1
- Remarkably low TSAT with low-to-normal ferritin (suggests IRIDA)
- Family history of refractory anemia
- Extreme microcytosis (MCV <70 fL)
- Failure to respond to both oral and intravenous iron
Monitoring and Follow-up
Monitor hemoglobin concentration and red cell indices at three-monthly intervals for one year, then after a further year. 1, 3, 2
Expect hemoglobin increase of at least 2 g/dL within 4 weeks of starting treatment. 1, 2
Provide additional oral iron if hemoglobin or MCV falls below normal during follow-up. 1, 3, 2
Critical Pitfalls to Avoid
Do not assume all microcytic anemia is iron deficiency—anemia of chronic disease, thalassemia, and sideroblastic anemia require different management. 1
Do not use ferritin alone in inflammatory states, as it can be falsely elevated—always add TSAT to the workup. 1
Do not overlook combined deficiencies—iron deficiency can coexist with B12 or folate deficiency, recognizable by elevated RDW. 1, 3
Never skip investigation of the underlying cause in adult males—occult gastrointestinal malignancy must be excluded. 1, 3
Differential Diagnosis Considerations
If iron studies are normal or ferritin is elevated despite microcytosis:
Order hemoglobin electrophoresis if MCV is disproportionately low relative to degree of anemia or if the patient has appropriate ethnic background (Mediterranean, African, Southeast Asian descent). 1
Consider anemia of chronic disease if TSAT <20% with ferritin >100 μg/L and inflammatory markers are present. 1
Consider genetic disorders of iron metabolism (IRIDA) if remarkably low TSAT with low-to-normal ferritin and failure to respond to oral iron. 1