Allergic Reaction?

Last night I started itching all over my upper back, neck, arms, and face. At first I thought it was just one of the symptoms of my disease, but then this morning the itching was worse and I started getting red blotches/welts all over. I called Stanford around noon and they suggested that I either go to the ER or go into the infussion center as a "sick call." Because it's the weekend, they don't have many doctor's on staff so I would have to wait a while to see a doctor. Fortunately I only waited about an hour before seeing the doctor on call. She thinks I had some type of allergic reaction, because of the way my skin looked. It may have been from the contrast that was used for my PET/CT scan. Although I've never had a reaction to the contrast before, it's not unlikely to eventually develop one. They gave me some Benadryl through IV (which knocked me out right away) and I'm supposed to take some more through the weekend to hopefully clear up the rash.

I was pretty upset about the whole ordeal considering that Saturday's are my only days to do anything fun. We've dedicated Sunday's to working on the house and I'm so exhausted from the long hours at work to do anything on weeknights.