Intracranial haemorrhage in idiopathic thrombocytopenic purpura. Paediatric Haematology Forum of the British Society for Haematology.

A UK survey was carried out to discover the frequency, circumstances, and outcome of intracranial haemorrhage (ICH) complicating idiopathic thrombocytopenic purpura (ITP) of childhood. A questionnaire was circulated through the membership of the UK Paediatric Haematology Forum, and thence to local paediatricians and haematologists. It sought information on any child with ITP who had had an ICH during the 20 year period to January 1994. Fourteen instances were discovered, seven before 1984 and seven after. Six children survived the event with minimal or no sequelae, four without craniotomy. An immediately precipitating cause was noted in four; two had arteriovenous malformations and two suffered head injuries. The event occurred over two weeks from diagnosis in seven cases and over two months in five. All children were profoundly thrombocytopenic at the time of their intracranial bleed. By calculation the 14 children would have represented some 0.1% of the total with ITP during the period under review. ICH in childhood ITP may have a precipitating cause and is not necessarily fatal. There is no period of maximum risk, and it can occur at any time during the course of the illness when the platelet count is less than 10-15 x 10(9)/l. It is an extremely rare event and previous estimates of its incidence may have been too high.