[Refractory idiopathic thrombocytopenic purpura following influenza vaccination].

A 79-year-old man was admitted to our hospital due to generalized petechiae. Four days before onset, the patient had been administered an influenza vaccine. The platelet count, which was 13.6x10(4)/microl before vaccination, decreased to 0.4x10(4)/microl. Although he received various treatments, such as high-dose immunoglobulin therapy, prednisolone, and splenectomy, they were ineffective. Three weeks after CyA administration, the platelet count began to increase. Eighty days after administration, it reached 3.0-5.0x10(4)/microl. Thrombocytopenia after influenza vaccination is rare, and no refractory case has been previously reported.