Características clínicas del Púrpura Trombocitopénico Inmune: revisión de 52 casos

background: inmune thrombocytopenic purpura (itp) is usually self-limited, but may have a chronic evolution when persisting more than 6 months (10-20% cases). its treatment is controversial and few national data is available. objective: to obtain knowledge on clinical and laboratory characteristics of itp, its relationship with chronic evolution and treatment. patients and methods: retrospective study that includes patients with diagnosis of itp between march 1998 and february 2003 at luis calvo mackenna children's hospital. we registered at diagnosis: sex, age, symptoms and treatment strategy. platelet count (pc) was done at diagnosis, between day 15-60 and after 6 months. fisher test and odds ratio were calculated. results: median age was 4,4 years (0,7-16,1), initial pc was ￡ 20 000/mm3 in 37/52 cases. no cerebral bleeding was found. observation strategy was used in 34/52 cases, steroids in 17/52 cases and steroids + inmunoglobulin in 1 case. the 6-months follow up was completed in 48/52 cases; 11 patients had a chronic evolution. we found an association with pc day 15 ￡ 20 000/mm3 (p = 0,01 or = 9 ic95% 1,26-80,16) and pc day 60 ￡ 50 000/mm3 (p = 0,0000003 or = 124 ic95% 7,77-4951,52). conclusions: most of our patients were successfully managed with the observation strategy. 23% cases had a chronic evolution and pc day 15 ￡ 20 000/mm3 and pc day 60 ￡ 50 000/mm3 are considered risk factors