My doctor was well aware of my past allergic reaction to contrast dye. So he gave me a 1 prednisone at 9pm then 3am then 9 am again and benadryl at the same times. But non the less I have been sick since the scan. Even ended up in ER next day because my temp went to 95.2 and my cheeks were ruby red. Felt they they were on fire and surprise surprise. The ER said I had a delayed reaction to the contrast dye. Friday the 8th of April I had the dye and today the 11th my cheeks still red and feel like they are on fire doctor told me. Not his fault probably something else that caused it. Which I highly doubt! but either way felt a little better reading what you wrote.ty