Idiopathic Thrombocytopenic Purpura (ITP)

  • AKA Autoimmune Thrombocytopenic Purpura
  • Acute or gradual onset of petechiae or ecchymoses in skin and mucous membranes
  • Epistaxis and conjunctival hemorrhage common
  • Melena hematemesis and menorrhagia
  • Non-palpable spleen (97%) - although splenectomy is a treatment
  • Mechanism
    • IgG autoantibodies coat platelets and triggers splenic clearance
    • Bleeding occurs when platelets <50.000/mm3
    • Serious hemorrhage <10.000
    • Intracranial hemorrhage <2.000
  • Exams
    • Bleeding time prolonged; coagulation time normal
    • Bone marrow increased megakaryocytes
  • Chronic Variant
    • More in adult females, cyclical associated with H. pylori and varicella in adults
  • Acute variant
    • Children
    • Follows viral illness in 50% (parvo B19)
    • Most resolve spontaneously
  • Treatment
    • Corticosteroids
    • Splenectomy
    • IVIg
    • IV anti-D (anti-Rho), danazol, rituximab, other immunosuppressive agents