I'm familiar with peanut allergies. I have a son who can die within minutes from swollowing minute particles of peanut. However, he has never reacted to atmospheric exposure to peanuts.
Many people with the allergy do. Some react to traces in the air. Some of the kids collapse from touching something that was touched by someone with traces of peanut butter on their hands.
However, someday Jesse will probably react to atmospheric exposure. In the meantime, he is living a normal life, only scrutinizing what he eats.
It's a tough thing for a kid to have to deal with something like that. My prayers to him.