post-transfusion purpura
Last reviewed 01/2018
This occurs when individuals lacking the PLA-1 antigen are transfused with blood containing PLA-1 positive platelets. It is uncommon as only 2-3% of the population are PLA-1 negative.
Thrombocytopenia - often severe - occurs 5 - 14 days after transfusion. Clinically, presentation is with bruising and petechiae.
Often the patient has been sensitised by a previous transfusion or by pregnancy.
The thrombocytopenia usually resolves within a month.
Recovery may be hastened by treatment with immunoglobulin.