601f9fde_Adverse_Transfusion_Reactions__Definition
[Type of Reaction] Post-transfusion purpura (usually occurs > 1 week after transfusion) [Symptoms] • Precipitous fall in platelet count • Generalized purpura [Definition] 
Abrupt onset of severe thrombocytopenia an average of 9 days post transfusion (range 1-24 days)
Adverse Transfusion Reactions
Definition