Food intolerance is a problem in the digestive system.
food allergy
Who among us hasn’t been tormented by the itch after a mosquito bite? This is due to the histamine release at the offending site.
On my recent flight to New York City, an attendant announced that a passenger had a severe peanut allergy. If any of us had brought food containing peanuts, it was requested that we put it away for the entire flight.
Peanut allergies range from inconvenient to potentially fatal. The cause is unknown, but it is likely to involve a combination of immunogenetic and environmental factors.