Children are ten times more likely than adults to have food allergies. Some researchers believe that as a person's gastrointestinal system develops, it gets better at blocking the absorption of components that trigger food allergies. Over time, children typically outgrow allergies to cow's milk, eggs, wheat, and soybean products. However, allergies to peanuts, tree nuts, fish, and shellfish can be lifelong. And some children will outgrow one allergy only to develop another.