Post-transfusion purpura: a rare and life-threatening aetiology of thrombocytopenia.

We present a middle-aged man with history of lung adenocarcinoma, who was admitted with massive haemoptysis secondary to severe thrombocytopenia. Two weeks prior he was started on enoxaparin for a newly diagnosed pulmonary embolus and at that time required blood transfusions for anaemia. Our initial diagnosis was heparin-induced thrombocytopenia. His platelet count, however, did not improve despite receiving argatroban and platelet transfusions. Hence, we suspected post-transfusion purpura (PTP) and started him on intravenous immunoglobulin which brought his platelet count to normal levels. The serotonin-release assay was negative and platelet-antibody test was positive confirming PTP as our diagnosis. The patient eventually was transferred to hospice care because of the advanced stage lung cancer and died of respiratory failure.