Immune thrombocytopenic purpura (peds)

This page is for pediatric patients. For adult patients, see: Immune thrombocytopenic purpura.


  • Also known as immune thrombocytopenia (ITP)
  • Autoantibodies to platelet membrane antigens clear platelets and limit production
  • Can be primary or secondary (medications, systemic illness, infection)
  • Hallmark is isolated thrombocytopenia
  • Primary peak is in early childhood (2-5 years) with a smaller peak in adolescence
  • ITP is a diagnosis of exclusion

Clinical Features

  • Usually well appearing without constitutional symptoms
  • May have a preceding systemic illness
  • May have exposure to recent vaccinations (particularly MMR) or drugs known to cause thrombocytopenia: Heparin, Quinidine, Phenytoin, Sulfa drugs, Valproate and Vancomycin
  • May have bleeding, but this may be absent
    • Most have dry bleeding consisting of petechiae, purpura, and ecchymoses
    • Can see mucosal bleeding
    • Severe or intracranial bleeding are rare

Differential Diagnosis

DDx for ITP.png


Decreased production

Increased platelet destruction or use

Drug Induced

Comparison by Etiology

↓ PLT Yes Yes Yes Yes Yes
↑PT/INR No No No +/- Yes
MAHA No Yes Yes No Yes
↓ Fibrinogen No No No No Yes
Ok to give PLT Yes No No No Yes



  • CBC


  • Platelet count of < 100,000/microL is usually the only finding on a CBC
    • Usually < 30,000/microL.
  • Remainder of the CBC is typically normal, unless there is significant bleeding (Hgb could be low)
  • Peripheral blood smear shows fewer than normal platelets and increased mean platelet volume (due to younger, larger platelets/megakaryocytes)



  • Low-risk patients may be discharged with short-term follow up
  • Moderate to high-risk patients or those with severe bleeding should be admitted

See Also


  • Duncan, Ellen. Immune Thrombocytopenia. PEM GUIDES. 7th edition. NYU Langone Health; 2020: 459-462.