Immune thrombocytopenic purpura (peds)
Background
- 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
Differential Diagnosis
- See image
Workup
- 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)
Management
- Consult pediatric hematologist
- Avoid activity that could increase risk of trauma
- Avoid NSAIDs and anticoagulants
- Therapy is based on degree of bleeding
- Low-risk bleeding: Watchful waiting
- Moderate to high-risk bleeding: IVIG or RhoGAM if significant bleeding or if preparing for procedure
- Severe bleeding, non-life threatening: Platelet transfusion if needed. Methylprednisolone, IVIG and/or RhoGAM for up to 4 days. Possibly Romiplostim (thrombopoietin receptor agonist) or TXA.
- Life threatening bleeding: Platelet transfusion, methylprednisolone x 3-4 days, IVIG x 1-3 days.
Disposition
- 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
References
Duncan, Ellen. Immune Thrombocytopenia. PEM GUIDES. 7th edition. NYU Langone Health; 2020: 459-462.