Hereditary spherocytosis HS

• Facts:
  Autosomal dominant, EXTRAvascular hemolytic anemia
  MC hereditary hemolytic anemia in white population
  RBC membrane spectrin gene defect
  RBCs get trapped in red pulp of spleen, undergo hemolysis
• History / PE:
  Positive family history
  Pallor, jaundice
  Splenomegaly
• Diagnosis:
  Peripheral smear shows spherocytes with central pallor
  Osmotic fragility test
  Positive COOBS' test
  Pigmented gallstones (calcium bilirubinate)
  Elevated reticulocyte count, indirect bilirubin, serum LDH
• Treatment:
  Folic acid supplementation
  Splenectomy
• Complications:
  Acute cholecystitis (from bilirubin gallstones)
• Notes:
  Post splenectomy, patients require anti-pneumococcal, Haemophilius, and menigococcal vaccines
  
  Additionally, daily oral penicillin prophylaxis for 3-5 years afterwards
• Differential Diagnosis:
  1) Autoimmune hemolytic anemia (negative family history)
  2) Paroxysmal nocturnal hemoglobinuria (intravascualr hemolysis)