I thought I would post this on a thread, warnign signs of severe allergic reaction.
One of the things you look out for with a severe allergic reaction is two body systems being involved. Body systems would be skin, respiratory, intestinal or even mind. Let's say you have a child with welts on their skin and is wheezing, for example. That would be a severe reaction and they need to go to the hospital when it involves respiratory, period. Something a little more subtle would be a skin reaction and nausea or stomach pains.
Keep Benadryl on hand, you never know if and when your child could react to something. My daughter has an allergic reaction to something, we thought it was a nut allergy but that was ruled out via scratch test. So, we keep an epi pen on hand and she knows the sign of a reaction.