When food is consumed the immune system treats a particular protein in that food as a threat to the body. Immunoglobulin E, or IgE, is an antibody that is produced by the body to attack the food protein (the antigen). Once the antibodies have contact with the antigen it signals an attack on the protein by releasing histamine and other chemicals. These chemicals cause the allergic symptoms. Each type of food has its own proteins. A person may become allergic to one protein or more than one.