Childhood acute immune thrombocytopenic purpura: 20 years later.

Childhood acute immune thrombocytopenic purpura (ITP) is a typically benign, self-limiting illness usually occurring after an infectious disease. Most affected children have platelet counts < 20 x 10 (9)/L at presentation and are at small, but definite risk for an intracranial hemorrhage. This feared complication occurs in < 1% of all children with acute ITP. There is consensus that a bone marrow aspirate should be performed in children with acute ITP and atypical features (e.g., hepatosplenomegaly), and most physicians continue to recommend this investigation before corticosteroids are administered. Issues such as hospitalization versus observation at home, and treatment versus no treatment continue to be debated; there is consensus, however, that children with extreme thrombocytopenia (platelet counts < 10 x 10 (9)/L) and/or clinically significant hemorrhage merit treatment with a regimen known to rapidly increase the circulating platelet count. Candidate regimens include high-dose intravenous (IV)/oral corticosteroids (>/= 4 mg/kg/day of prednisone or an equivalent corticosteroid preparation), IV immunoglobulin (IG; 0.8 to 1.0 g/kg once) or IV anti-D (75 microg/kg once) for Rhesus-positive patients. For those rare children with organ- or life-threatening hemorrhage (e.g., intracranial hemorrhage) multimodality therapy including platelet transfusion, IV high-dose methylprednisone (30 mg/kg, maximum 1 g) and IVIG (1 g/kg) is indicated with consideration of emergency splenectomy. Future prospective trials should include outcome measures other than the platelet count alone (e.g., bleeding scores) and health-related quality-of-life assessments. Key questions that remain to be addressed in children with acute ITP include the need for bone marrow aspiration in typical cases if corticosteroid therapy is planned, the role of hospitalization, and most important, the unresolved issue of treatment versus no treatment, especially in patients with typical features and mild clinical bleeding symptoms.