An allergic reaction is triggered when the body feels threatened by some external stimuli, in this case certain types of foods-items. The body sees them as intruders and the immune system reacts by pumping out antibodies in defence. Release of protective chemicals is one part of that defence and results in a runny nose, itchiness in eyes or hands, hives, and sometimes, inability to breathe. Most foods that trigger allergic reactions have a protein common in them, that results in the releasing of the antibody known as ‘Immunoglobulin E’, that humans developed in the first place, as a protection against parasites.