Synopsis
Diagnose immune platelet destruction by exclusion, grade bleeding rather than count alone, treat critical haemorrhage immediately, and choose observation, corticosteroid, immunoglobulin or durable second-line therapy collaboratively.
- ITP is an acquired immune thrombocytopenia caused by increased platelet destruction and impaired production, diagnosed after excluding alternative causes of an isolated low count.
- Confirm true thrombocytopenia with repeat count and film; platelet clumping, schistocytes, blasts, dysplasia and additional cytopenias argue for another pathway.
- Bleeding risk relates to count, but age, previous bleeding, anticoagulants, hypertension, falls, infection and procedure plans substantially modify it.
Key red flags
Severe headache, vomiting, focal neurology, seizure or reduced consciousness with profound thrombocytopenia needs immediate imaging and rescue therapy.
Investigation priorities
Confirm isolated genuine thrombocytopenia and exclude fragments or blasts.
Management branches
True thrombocytopenia is found without immediate major bleeding.
- Review film, previous counts, medicines, alcohol, infection, vaccines, pregnancy, autoimmune symptoms, lymph nodes and spleen and assess bleeding systematically.
- Exclude pseudothrombocytopenia, TMA, DIC, liver disease, marrow failure, HIV, hepatitis C and drug or heparin causes from the phenotype.
Key medicines
DexamethasoneA common adult initial regimen is 40 mg orally once daily for 4 days, sometimes repeated under haematology guidance; use a lower or alternative plan when toxicity risk dictates.
Intravenous immunoglobulinHaematology commonly uses 1 g/kg intravenously for one or two days, or an equivalent divided regimen, when a rapid temporary platelet rise is needed.