Introduction: Idopathic Thrombocytopenic Purpura (ITP) is a condition with isolated thrombocytopenia and bleeding symptoms in skin and mucous membranes. It is easy to establish the diagnosis, but treatment is controversial, possibly due to different estimates of the risk for serious bleeding. We present the epidemiology and clinical course of ITP during the first 6 months after diagnosis in Danish children diagnosed from 1998-2000.
Materials and methods: The Nordic Society of Paediatric Haematology and Oncology conducted a prospective registration study of children with newly diagnosed ITP from 1998-2000. The study included children < 15 years of age with newly diagnosed, untreated ITP and platelet count (TBC) < 30 x 10(9) /l. Information about bleeding symptoms, TBC, treatment and ITP related episodes was recorded at diagnosis and during the first six months.
Results: Of 109 included children 81% had a short symptom history, 46% a preceding viral infection. At diagnosis 62% had TBC < 10 x 10(9) /l, 41% mucosal bleeding, and 72% received medical treatment. Follow-up was available for 91 children. Sixty seven children with acute ITP had TBC < 150 x 10(9) /l for 11 days (median). Twenty four children suffered chronic ITP, 8 of them had persistent TBC < 20 x 10(9) /l. Insidious onset had a 64% predictive value for chronic ITP. Of the 57 registered ITP-related episodes, 45 occurred in chronic cases, 23 of them in six of the children with persistent TBC < 20 x 10(9) /l.
Conclusion: It is likely that children with newly diagnosed ITP recover quickly, and the risk of serious bleeding is low. A small group of children with persistent severe thrombocytopenia experience significant morbidity.