Etiology, Investigations, and Differential Diagnosis of Microcytic Hypochromic Anemia

Introduction

Microcytic hypochromic anemia is characterized by red blood cells that are smaller than normal and have reduced hemoglobin content. It is primarily caused by iron deficiency, thalassemia, or anemia of chronic disease.

Etiology

• Iron Deficiency Anemia (IDA): Caused by insufficient dietary iron intake, malabsorption (e.g., celiac disease), or chronic blood loss (e.g., gastrointestinal bleeding).
• Thalassemia: A group of inherited hemoglobin disorders resulting in defective hemoglobin synthesis.
• Anemia of Chronic Disease (ACD): Occurs due to chronic inflammation, malignancies, or infections that affect iron metabolism.

Investigations

A systematic approach to diagnosis includes:

• Complete Blood Count (CBC): Identifies microcytic hypochromic red blood cells.
• Serum Iron Studies: Determines iron levels, total iron-binding capacity (TIBC), and ferritin levels.
• Hemoglobin Electrophoresis: Essential for diagnosing thalassemia.
• Bone Marrow Examination: Used in complex cases to assess iron storage and erythropoiesis.

Differential Diagnosis

Iron Deficiency Anemia vs. Thalassemia vs. Anemia of Chronic Disease

Feature	Iron Deficiency Anemia	Thalassemia	Anemia of Chronic Disease
Serum Iron	Low	Normal/High	Low
TIBC	High	Normal	Low
Ferritin	Low	Normal/High	Normal/High
Hemoglobin Electrophoresis	Normal	Abnormal	Normal

Conclusion

Accurate diagnosis of microcytic hypochromic anemia is essential for appropriate management. Understanding the differences between iron deficiency anemia, thalassemia, and anemia of chronic disease ensures targeted therapy.