Vaccination associated thrombocytopenic purpura in children

Patients who presented with purpura and blood platelets < 30 x 10(9)/1 within 1 month after vaccination were collected from a population based material of 506 consecutive pediatric patients with newly diagnosed ITP. Of the 35 such patients, 24 had thrombocytopenia after MMR vaccination giving an estimated ITP risk of approximately 1 in 30,000 MMR inoculations. Symptoms of the 35 patients were nearly always acute. Thrombocytopenia disappeared within a month in 74% of the study patients and lasted longer than 6 months in only 10%. Bleeding episodes were uncommon during the follow-up period. We conclude that the incidence of symptomatic thrombocytopenia after vaccinations is much lower than that after respective natural infections and that the outcome in most cases is excellent. (c) 2006 Elsevier Ltd. All rights reserved.