What are food allergies?
The role of the immune system is to keep infectious microorganisms, such as certain bacteria, viruses, and fungi, out of the body, and to destroy any infectious microorganisms that do invade the body. Allergies are the result of an inappropriate response to a harmless substance (such as a type of food, pollen etc). In an allergic animal, the immune system overreacts to the substance and mounts an immune response against it.