About 32 million Americans have food allergies. Food allergies can develop at any time, even to a food that you’ve safely eaten before. They tend to first appear in young children, but about 15 percent of individuals with food allergies are diagnosed as adults. Some children may outgrow certain food allergies as they get older but many food allergies are lifelong.
Food allergies occur when the body’s immune system sees a harmless food protein (an allergen) as an invader. The allergen triggers a chain reaction within your body and symptoms usually develop within a few minutes to two hours after eating a food. Symptoms can affect different parts of the body and can be mild (few hives, itching) to very severe (trouble breathing), potentially life-threatening.