Today at lunch I decided to try a new food, and while he ate it right up, he soon had the same telltale signs of reactions. The food was a kiwi, which is known to be high in histamine and thus I knew going into it that it was possible he would have a reaction to them.
You can see, if you scroll down to the post two below this one, how peaches-and-cream his complexion normally is. He gets red easily when he plays outside in the heat for any amount of time, but this flushing is different. More pronounced and defined on his skin:
I didn't give him any of his meds since it didn't seem to be bothering him at all. His cheeks stayed flushed for about 30-40 minutes, in which time I made sure he was not acting uncomfortable, gave him lots of cool water to drink, and used a cool cloth to wipe his cheeks gently. I'm not entirely sure if either the drinking water or the cool cloth actually help him feel better, but they made me feel better.