Wow.  It sounds as though it could have been psychosomatic... but then again, in a child with a known allergy, I wouldn't discount the possibility, by any means.  Not if there was cooking of the protein happening in the vicinity, for sure.

My 13 year old daughter outgrew her peanut and egg allergy by age 3 or 4. (only reaction to pb was at 1 years old with rash around mouth when she had pb-happened 3 times, but living in foreign country.Doctors never mentioned food allergy) When my son became allergic 6 years ago, she stopped eating peanut butter, but loved M&M's. Whenever she was eating them she would get a horrible stomach ache so I said she shouldn't have them anymore. We were going to have her blood tested for allergies from this. Well, today at school they are making some kind of peanut butter cookies in the classroom next to hers. She said the smell was very strong. She started getting light headed, headache and said she couldn't breath all the way. The teacher sent her to the nurse where she got better. Do you think this was just nerves or panic attack? I had her SPT at 8 and she had NKA! The nurse didn't call me either which I will call them about tomorrow.