Iron Deficiency Anemia

Overview

• Most common cause of anemia worldwide.
• Causes:
  • Developing world: Nutritional deficiency.
  • Developed world: Acute blood loss (e.g., GI bleeding, peptic ulcer disease).
• Populations at risk:
  • Females (menstruation).
  • Children (decreased intake, high demand for growth).

Causes of Iron Deficiency Anemia

• Decreased Supply:
  • Nutritional deficiency.
  • Malabsorption (e.g., celiac disease, post-gastric surgery).
  • Prematurity, poverty, old age, strict vegan diet.
• Increased Demand:
  • Pregnancy, lactation, growth.
• Loss:
  • Blood loss (e.g., peptic ulcer disease, Meckel's diverticulum, hookworm infection, colon cancer).
  • Intravascular hemolysis (e.g., microangiopathic hemolytic anemia).

Pathophysiology

• Hemoglobin consists of heme (iron + protoporphyrin) and globin.
• Iron deficiency leads to decreased heme and hemoglobin.
• Red blood cells (RBCs) become smaller (microcytic anemia).
• Increased central pallor in RBCs due to leftover protoporphyrin.

Clinical Features

• Pale, tired, angina, weak, irritable, exercise intolerance.
• Associated conditions:
  • Plummer-Vinson syndrome.
  • Glossitis, cheilitis.
  • Restless leg syndrome.
  • Koilonychia (spoon-shaped nails).
  • Beeturia, pica (craving for ice).

Diagnostic Tests

• Lab Results:
  • Low hemoglobin and hematocrit.
  • Low MCV, MCH, MCHC.
  • Low reticulocytes.
  • Usually normal white blood cells.
  • Platelets may be slightly increased.
• Iron Studies:
  • Decreased serum iron and ferritin.
  • Increased total iron-binding capacity (TIBC).
  • Decreased percent saturation.
  • Increased soluble transferrin receptor.
• Bone Marrow Biopsy:
  • Depleted iron stores (painful procedure, not commonly done).
• Alternative Diagnosis:
  • Trial of iron supplementation and monitoring for improvement.

Treatment

• Oral Ferrous Sulfate:
  • Side effects: diarrhea, constipation, black stool (guaiac negative).
• Intramuscular/Intravenous Iron:
  • Side effect: risk of anaphylaxis (especially with dextran).
• Address underlying causes (e.g., ongoing blood loss, malabsorption issues).

Important Considerations

• Ferritin is an acute phase reactant; may be elevated with concurrent inflammation.
• Distinguish between iron deficiency anemia and anemia of chronic disease.
• In cases of hookworm infection, white blood cell count may be affected.
• Resistant cases often involve celiac disease.

Summary

• Iron deficiency anemia is characterized by low iron leading to small, pale RBCs and is diagnosed primarily through iron studies and clinical improvement with iron therapy.
• Treatment focuses on correcting iron levels and addressing underlying causes.

---

Please subscribe for more updates on new videos covering related topics.