Thrombocytopenia and ITP

Thanks to Connie for presenting the case of an elderly woman who presented with petechial bleeding, found to have a platelet count of 15, with work up revealing possible Evans’ Syndrome as well as bladder cancer!

Clinical Pearls

  • Think of thrombocytopenia as a problem with platelet production, platelet destruction, sequestration, or lab problem.
  • ITP is a diagnosis of exclusion. It can be a primary process due to autoimmune platelet destruction, or triggered by an associated condition (secondary ITP).
  • Remember that decadron is superior to prednisone in treatment of ITP based on this meta-analysis.
  • TPO mimetics are best as a last resort and more useful in maintenance of remission rather than inducing remission.

Thrombocytopenia DDx

  • Decreased production
    • Aplastic anemia
    • MDS
    • Drugs
    • Alcohol
    • Cirrhosis
    • Leukemia
    • Severe megaloblastic anemia (folate/B12 deficiency)
    • Myelofibrosis
    • Granulomas
    • Solid malignancy mets to the bone
  • Increased destruction
    • Immune mediated
      • Primary ITP
      • Secondary
        • Infection: HIV
        • Rheum d/o: SLE, APLS
        • Lymphoproliferative process: CLL, lymphomas
        • Drugs
        • Post-transfusion purpura (alloimmune process)
    • Non-immune mediated
      • MAHA (DIC, HUS/TTP)
      • Plavix
      • Vasculitis
      • HELLP
      • Infections: sepsis, CMV, EBV, malaria, rickettsia, ehrlichiosis, dengue, Hanta virus, etc.
      • CVVH
  • Sequestration due to hypersplenism
  • Pseudo-thrombocytopenia: clumping due to EDTA anticoagulated tubes (confirm by request blood draw in citrate coated tubes)

Thrombocytopenia work up

  • Good history and review of meds, infections, prior history of autoimmune disorders
  • Check CBC, coags and peripheral smear!
    • Spherocytes ⇒ AIHA, hypersplenism
    • Schistocytes ⇒ MAHA
    • Pancytopenia ⇒ aplastic anemia, MDS, leukemias, etc.

Immune Thrombocytopenic Purpura (ITP)

Check out our thorough post on this topic here.

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