Process of Elimination

After having slept on it, I think I figured out what caused Henry's breakout. I bought some new rice chips yesterday, they are wheat and gluten free so I didn't think of them last night. They are rice and sesame. Sesame is the only strange thing from yesterday.
I googled sesame allergy this morning and it turns out that in countries where sesame is a more common part of their cuisine, it is included in the list of top allergenic foods. (The US list is: dairy, wheat, soy, eggs, peanuts, tree nuts, fish and shellfish.) In Israel, where they eat a lot of sesame, it is the number 2 cause of anaphlyatic shock in children. Fortunately, I ate the chips not Henry!!! Judging by how bad his reaction is from my eating them, it is certain that he would have a serious reaction were he to eat sesame himself.