Causes of secondary ITP or non-IT in children misdiagnosed with primary ITP. Infection: HIV, n = 5; Chagas disease, n = 1; herpes zoster, n = 1; no information, n = 47. Autoimmunity: systemic lupus erythematosus, n = 16; Evans syndrome, n = 11; autoimmune lymphoproliferative syndrome, n = 2; autoimmune bicytopenia (thrombocytopenia and neutropenia), n = 5; mixed connective tissue disease, n = 2; diabetes mellitus type 1, n = 1; scleroderma, n = 1; no information, n = 4. Malignancy: myelodysplastic syndrome, n = 3; Hodgkin lymphoma, n = 1; myeloproliferative disease, n = 2; no information, n = 1. Immunodeficiency: DiGeorge syndrome, n = 1; primary chronic granulomatous disease, n = 1; not determined, n = 2.