Posterior reversible encephalopathy syndrome (PRES) is a clinical-radiographic diagnosis that can be visualized as symmetric posterior white matter vasogenic edema in the occipital and parietal lobes that arises as a consequence of endothelial damage in vulnerable vasculature. PRES can present clinically as visual changes, headaches, seizures, and altered mental status. Although most cases of PRES have been described in the setting of hypertension, a rare subset has developed in the setting of blood transfusion in chronic anemia.

Here, we present the first case of an adult male who developed PRES following a blood transfusion. The patient is a 69-year-old caucasian male who had an acute exacerbation of chronic anemia and went on to develop PRES following the transfusion of three units of packed red blood cells. 

21 total cases of PRES following a blood-transfusion have been documented. 20 of these cases are reported in females and 1 in an adolescent male. In the setting of chronic anemia correction in patients with identifiable risk factors (i.e., hypoalbuminemia or metabolic acidosis), care should be taken to transfuse blood products over long periods of time with close monitoring of hemoglobin levels to mitigate the risk of developing PRES. In patients with PRES, early identification and discontinuation of inciting factors are critical to a favorable prognosis.