Parvo or Hives?

A couple of hours ago as we were getting in the car to go to VBS Dane's face started looking flushed. By the time we got there (15 mins later) his whole face had very red sploches all over it and the left side looked swollen, but he was feeling just fine. When VBS was over Tonii took him over to his sister's house. Where better to take him than the house of a pediatrician and a dermatologist?! They think that he either has parvo or (and I think this is more likely) a hives reaction to food coloring. My kids very rarely get anything artificial or fake colorful. I mean I don't even buy juice on a regular basis. Today, for some strange reason, I let Dane have 2 Capri Sun drinks (that is like unheard of for me to do) and a bowl of Fruit Loops for a snack in the afternoon. He has never even had Fruit Loops before, we just bought them this week because they were on sale. In fact, he is so unfamiliar with them that he calls them Fruit "Lips", which I just got such a kick out of. We gave him some Benadryl and we'll see how he is in the morning.