Food Allergy A true food allergy has little to do with digestion– instead, it’s an immune system response. Your body treats the food like a foreign invader, and manufactures antibodies to fight it. Any contact with the food–even touching it or kissing someone who has recently eaten it–can trigger allergic responses such as hives, asthma, vomiting, swelling, and so on. What Can Happen? While a food intolerance can be a painful nuisance, a true food allergy can be deadly. If you are severely allergic to peanuts, for example, eating only half a peanut can lead to asphyxiation and death. While only one or two percent of adults have true food allergies, about five percent of children do, usually outgrowing them by around age four. That’s why parents should be especially cautious–and especially observant–when introducing new foods to their toddlers.