What is the diagnosis and treatment for a patient with anemia?

Diagnosis and Management of Microcytic Anemia

The CBC results show a microcytic anemia with low hemoglobin (12.0 g/dL), low hematocrit (35.0%), and low RBC count (3.66 x10^6/uL), which most likely represents iron deficiency anemia requiring oral iron supplementation as first-line treatment. 1

Diagnostic Classification

The laboratory values provided show:

• Hemoglobin: 12.0 g/dL (low)
• Hematocrit: 35.0% (low)
• RBC count: 3.66 x10^6/uL (low)

These values indicate a mild anemia that appears to be microcytic based on the pattern of low RBC count with proportionally lower hemoglobin and hematocrit. While MCV is not explicitly provided, the pattern is consistent with microcytic anemia, which is most commonly caused by:

1. Iron deficiency anemia
2. Thalassemia
3. Anemia of chronic disease
4. Sideroblastic anemia 2

Initial Workup

The following tests should be ordered to confirm the diagnosis:

• Complete iron studies including serum ferritin, total iron binding capacity (TIBC), and transferrin saturation 1
• Reticulocyte count to determine if the anemia is due to decreased production or increased destruction/loss 1
• If iron deficiency is confirmed, further evaluation for the cause of iron deficiency is warranted, including:
  • Stool guaiac test for occult GI bleeding
  • Menstrual history in females
  • Nutritional assessment 1

Treatment Approach

First-line Treatment

• Oral iron supplementation with ferrous sulfate 324 mg (65 mg elemental iron) taken 1-3 times daily between meals 1, 3
• Continue treatment for 2-3 months after hemoglobin normalizes to replenish iron stores 1
• Monitor response with repeat CBC after 4 weeks of therapy 1

Alternative Treatments

• For patients with intolerance to oral iron, poor absorption, or severe anemia (Hb <10 g/dL), intravenous iron may be indicated 1
• If anemia is severe (Hb <7 g/dL) or patient is symptomatic with hemodynamic instability, red blood cell transfusion may be considered 4

Special Considerations

Mixed Anemias

• Consider testing for vitamin B12 and folate deficiency if MCV is normal or elevated, as mixed nutritional deficiencies can occur 4, 1
• In patients with chronic inflammatory conditions, serum ferritin may be falsely elevated despite iron deficiency; in this context, ferritin up to 100 μg/L may still be consistent with iron deficiency 1

Refractory Anemia

• If no response to iron therapy after 4 weeks, consider:
  • Medication adherence issues
  • Ongoing blood loss
  • Incorrect diagnosis
  • Malabsorption
  • Anemia of chronic disease 1

Common Pitfalls

• Failing to identify the underlying cause of iron deficiency can lead to recurrence 1
• Premature discontinuation of iron therapy before replenishing stores can result in relapse 1
• Misdiagnosing anemia of chronic disease as iron deficiency (check inflammatory markers) 1
• Overlooking mixed anemias, particularly in elderly patients 1, 5

Follow-up

• Repeat CBC after 4 weeks of iron therapy to assess response 1
• If hemoglobin improves, continue iron for a total of 2-3 months after normalization 1
• If no improvement, reassess diagnosis and consider alternative causes or treatments 1

The most important step is to confirm iron deficiency with appropriate laboratory testing and to identify and address the underlying cause while initiating iron replacement therapy.