A nationwide survey of newly diagnosed childhood idiopathic thrombocytopenic purpura in Japan.

Background: We evaluated the clinical pictures, outcome for childhood idiopathic thrombocytopenic purpura (ITP) and the trends of the choice of management for childhood ITP in Japan.

Method: Every year, questionnaires were sent to all institutions that employ the active members of the Japanese Society of Pediatric Hematology. The questionnaires included age, sex, date of diagnosis, platelet count at diagnosis, the presence or absence of antecedent infection, hemorrhagic symptoms, initial management, and the outcome of all patients newly diagnosed with ITP.

Results: A total of 986 newly diagnosed as ITP patients were reported between January 2000 and December 2005. The occurrence of ITP peaked in boys less than 1 year of age, and at 1 year of age in girls. The male-to-female ratio was 1.24:1. Wet purpura was observed in more than half of the patients with platelet counts of <10,000/microL. The initial treatment varied among the patients with different platelet counts at diagnosis; most of the patients with platelet counts <20,000/microL received intravenous immunoglobulin or oral corticosteroids. Conversely, cases without any aggressive treatment increased to a larger degree in patients with > or =20,000/microL of platelet.

Conclusions: These findings indicate that overall compliance to the Japanese guideline is considered to be relatively good in Japan.