TIL that not all food allergies induce anaphylaxis or produce immediate symptoms - a certain class of allergic reaction called "Non-IgE-mediated food allergy" causes symptoms similar instead to food poisoning, often not for several hours after a meal has been eaten
https://www.rch.org.au/uploadedFiles/Main/Content/allergy/Non%20IgE%20Food%20Allergy.pdf
https://www.reddit.com/r/todayilearned/comments/15o4jsa/til_that_not_all_food_allergies_induce/