Childhood chronic immune thrombocytopenic purpura: unresolved issues.

Chronic immune thrombocytopenic purpura (ITP), defined as a platelet count of below 150 x 109/L persisting for more than 6 months from onset of illness, occurs in approximately 20% to 25% of children with acute-onset ITP. A small subset of these patients (approximately 5%) will manifest symptomatic, severe thrombocytopenia (platelet counts <20 x 109/L) at 1 year or longer following diagnosis, and may require splenectomy. Complete/partial response rates following splenectomy in children with primary chronic ITP are of the order of 70% to 75%; response rates are lower in children with secondary ITP and those with complex autoimmune cytopenias (e.g., Evans syndrome). Laparoscopic splenectomy is increasingly preferred over open splenectomy. Patients should be immunized with the pneumococcal, Haemophilus type b and meningococcal vaccines before splenectomy; the duration of postsplenectomy antibiotic prophylaxis using penicillin or an equivalent antibiotic is controversial but should be at least until 5 years of age and for a minimum of 1 year postsplenectomy. Some experts advocate life-long antibiotic prophylaxis. Treatment of postsplenectomy failures is a challenge; partial/complete remission rates are low, and multimodality therapy may be more efficacious than monotherapy. The presence of an accessory spleen should be sought and removal considered if present. The role of newer treatment modalities such as anti-CD 20 remains to be established.