[Primary thrombocytopenic purpura in infants under 3 months of age].

The analysis concerns 14 cases of idiopathic thrombocytopenic purpura among infants from 1 to 3 months old, studied at the Servicio de Pediatría del Hospital San Juan de Dios (Santiago), between 1971 and the first trimester of 1978. In none of them an apparent cause of thrombocytopenia has been found, reason why we called them primary. The very good evolution, the laboratory findings and the history of catarrhal symptoms very recently or developing when illness started leads us to assume that they would suffer from a pathogen similar to the acute ITP. The existence of some clinical differences with acute ITP, as major incidence of anemia, the splenomegaly and the purpura characteristics, could be explained by the age of our patients, but not because they present different disease. The existence of some clinical differences with acute ITP, as major incidence of anemia, the splenomegaly and the purpura characteristics, could be explained by the age of our patients, but not because they present different disease. The increase of the incidence of ITP amongst infants, specially during the first trimester of life, is being emphasized. We suggest that this fact could be due to the presence of new strains of virus.