Epidemiology and Clinical Manifestations of Immune Thrombocytopenia

Immune thrombocytopenia (ITP) occurs with an incidence rate of 1.6 to 3.9 per 100,000 patient-years, which increases with age and has a slight female preponderance. ITP is termed acute, persistent or chronic when its duration is <3 months, 3 to 12 months and >12 months, respectively. In this narrative review, we discuss the clinical manifestations of ITP in children and adults. ITP is asymptomatic in some patients; however, when present, bleeding is the most common symptom and can be mild as in petechiae, purpura and epistaxis, or severe and even life threatening in cases of intracranial haemorrhage, and massive gastrointestinal or urinary tract bleeding. A platelet count <10-20 × 10⁹/L, advanced age and prior minor bleeding are risk factors for major bleeding, which is also more common in the months following a new diagnosis of acute ITP. Fatigue and impaired health-related quality of life are also manifestations of ITP that often improve with treatment and improvement in platelet counts. Over long-term follow-up, ITP is also associated with an increased risk of venous and arterial thromboembolism, haematologic malignancy and overall mortality than the general population.