I had a blood transfusion three weeks ago. When i came home that everning i had red, hot, itchy skin from my neck/face down to my thighs. I took my Niaspan at the hosptial before the blood transfusion and after i came home. Is there any correlation between the transfusion and Niaspan, or could i be having a side effect from just the transfusion? The doctor does not seem to think it is the from the transfusion, as any side effects would have occured at the time of the transfusion within fifteen minutes. Any help would be appreciated.