Paediatric Immune Thrombocytopenia (ITP)
Lesson Objectives
By the end of this lesson, learners should be able to:
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Define acute and chronic ITP in children and understand the natural history.
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Recognize clinical features of acute vs. chronic ITP.
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Describe differential diagnosis and red flags for serious disease.
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List investigations required to confirm diagnosis and exclude other causes.
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Outline immediate and ongoing management strategies.
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Monitor for complications and when to refer to tertiary care.
Description
Immune Thrombocytopenia (ITP) is an immune-mediated decrease in platelet count, often following viral infection or vaccination.
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Acute ITP (AITP): Platelets <100 × 10⁹/L, often <20 × 10⁹/L; self-limiting; resolves in ~80% within 6 weeks to 6 months.
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Chronic ITP (CITP): Persistent thrombocytopenia beyond 6 months.
Platelet survival is shortened due to autoantibody-mediated destruction, with compensatory increased megakaryocytes in the bone marrow.
Clinical Features — Acute ITP
| Feature | Description |
|---|---|
| Bruising / Purpura / Petechiae | Sudden onset; child otherwise well |
| Mucocutaneous bleeding | Nosebleeds, gum bleeding, prolonged bleeding from minor cuts |
| Recent viral infection / vaccination | Often within 2–3 months prior |
| Absence of organomegaly | No hepatosplenomegaly or lymphadenopathy |
| Red flag signs | Headache, neurological deficits → suspect intracranial bleed; urgent CT head required |
Additional Considerations:
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Look for family history of low platelets, medication exposures, hemarthroses, systemic symptoms (fever, weight loss, bone pain), autoimmune signs, or features suggesting HUS/TTP.
Investigations
| Investigation | Findings / Purpose |
|---|---|
| FBC / Differential / PBS | Isolated thrombocytopenia, platelets normal or large, occasional giant platelets |
| Peripheral smear | Normal RBC/WBC morphology; microcytic hypochromic red cells may indicate iron deficiency |
| Tumor lysis labs | Normal potassium, phosphorus, uric acid, LDH |
| Bone marrow aspiration | Only if atypical features: neutropenia, organomegaly, lymphadenopathy, bone pain |
| Exclusion tests | Rule out HIV, autoimmune conditions, medications, HUS/TTP |
Immediate Treatment — Acute ITP
| Scenario | Treatment |
|---|---|
| Asymptomatic / mild bleeding | Monitor platelet counts, educate family, avoid NSAIDs and contact sports |
| Moderate mucosal bleeding | Prednisolone 2 mg/kg/day (max 120 mg) PO for 5–7 days |
| Significant bleeding (GI, intracranial) | Platelet transfusion + IVIG 0.8–1 g/kg IV for 2 days |
| Mucosal bleeding (adjunct) | Tranexamic acid |
| Follow-up | Monitor FBC and PBS monthly until resolution; most recover within 6 months |
Chronic ITP (CITP) Management
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Avoid NSAIDs and contact sports.
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Investigate autoimmune diseases: ANA, APLA, ACA, LAC; immune deficiencies: HIV, IgG/IgA/IgM.
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Treatment indicated if:
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Platelets <10 × 10⁹/L with repeated mucosal bleeding
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Older girls with menorrhagia
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Diminished quality of life
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Trauma risk or acute neurological signs
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Pharmacological therapy:
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Dexamethasone 0.6 mg/kg/day (max 40 mg)
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If unresponsive: discuss thrombopoietin receptor agonists (eltrombopag), rituximab, or splenectomy for persistent, significant bleeding
Summary
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ITP is an immune-mediated thrombocytopenia with acute and chronic forms.
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Acute ITP usually self-resolves; chronic ITP persists >6 months.
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Key features: sudden bruising, petechiae, mucocutaneous bleeding; absence of organomegaly.
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Investigations: FBC, peripheral smear, exclusion of infections, medications, autoimmune conditions, and bone marrow if atypical.
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Management: mostly observation; corticosteroids or IVIG for moderate/severe bleeding; consider thrombopoietin receptor agonists or splenectomy for chronic cases.