Pernicious Anemia

• Pernicious Anemia 


  A type of megaloblastic anemia associated with Vitamin B12 deficiency.
• Vitamin needed in synthesis of DNA and myelin: B12
• Gastrectomy and resection of ileum can be a cause of pernicious anemia due to the lack of intrinsic factor necessary for B12 absorption
• Pernicious anemia can also be found in pregnancy due to low intake and malabsorption disorders
• Best source of B12: Meat
• Substance abuse cause of Pernicious Anemia: Alcoholism
• Decreased intrinsic factor production by the parietal cells of the stomach causes decreased vitamin b12 absorption. Vitamin b12 has to bind with intrinsic factor so that it can be absorbed in the small intestine (ileum)
• Diagnostic Test: Pernicious Anemia

  Lab test:

  • decreased hemoglobin
  • decreased hematocrit
  • large RBCs
• Diagnostic Test: Pernicious Anemia

  Schilling's Test - most definitive test
• Diagnostic Test: Pernicious Anemia

  Schilling's Test

  • The test involves administration of a small amount of radioactive B12 orally and 24-hour urine collection to measure uptake. Decreased excretion of vitamin b12 in the urine supports the diagnosis of pernicious anemia.
• Normal Schilling’s Test: >10% B12 in urine
• Pernicious Anemia Schilling’s Test: <10% B12 in urine
• Pernicious Anemia: Clinical Manifestations

  • "beefy" red, inflamed tongue - pathognomonic sign
  • Neuro involvement: paresthesia, lack of balance
  • jaundice due to faulty erythropoiesis
• Pernicious Anemia: Management

  Monthly vitamin B12 IM for life

  • oral vitamin B12 cannot be absorbed because of inadequate intrinsic factors.