Age and score were main prognostic factors. Infants <1 year of age are a special group with a brief course and very high recovery rate that are not influenced by other prognostic factors. Definition of groups based on age and scoring could be useful to establish differential management guidelines. The cut-off value to define chronic ITP should be changed to 12 months.

Two hundred thirty of 696 evaluable children were identified as having chronic idiopathic thrombocytopenic purpura (ITP). Splenectomy was performed in 30 (13%), achieving remission in 22 (73%). Favorable response was associated to higher initial platelet count. Spontaneous remission was achieved by 53/200 non-splenectomized patients (26.5%), up to 10 years from diagnosis. More than half of them recovered between 6th and 12th month from diagnosis. The recovery rate was significantly higher (P=0.03) in children aged<9 years (31.2%) than in older children (14.6%). No reliable factor predictive of response in individual cases is still available.

Interferon therapy induces a significant increase of platelet count and seems to be a valid alternative therapy to attempt the achievement of prolonged remission in refractory ITP, to defer splenectomy in younger children, or to improve platelet count before planned splenectomy.