Approximately 2 to 4 percent of children have allergic reactions to food. Food allergies occur when the body sees a food as harmful and causes the immune system to release massive amounts of a chemical called histamine, which triggers the allergic reaction. According to the American Academy of Allergy, Asthma and Immunology, symptoms of an allergic reaction can include:
Symptoms typically occur anywhere from a few minutes to two hours after the allergen is consumed. Food allergies occur most often in infants and children, but they can appear at any age and develop suddenly to foods that were previously eaten without any reaction. Eight foods cause 90 percent of the food allergy reactions in children, according to the Food Allergy and Anaphylaxis Network. These are:
Children often outgrow allergies to eggs, milk, and soy, but allergies to peanuts, tree nuts, fish, and shellfish usually last into adulthood.