Your body’s immune system is designed to defend you against possibly toxic substance such as bacteria, viruses, and other toxins. In a normal person this perfectly working system will remove toxic substances from the body so they cannot harm the rest of the body’s organs. The cause of food allergies is not well understood as of yet, but what is known is that the immune system of an allergic person malfunctions and over reacts to what would be for anybody else a normally harmless food.

The immune system can react to any food but the most common foods are milk, eggs, peanuts, soy, shellfish, fish, tree nuts, and wheat.  When a person eats these foods the immune system sees them as toxic invaders and mounts an attack on the proteins in these foods. The immune system response is to produce what is called antibodies, specifically immunoglobulin E or IgE.

The first time this food is consumed it likely will not cause an allergic reaction because the immune system will create these antibodies as a result of the initial exposure. These antibodies will then attach themselves to special cells that are called mast cells. This is a preventative measure on the part of the immune system which will keep these antibodies as a defense for any future invasions of the “toxic” substance.

The next time a person eats the food that the immune system rejected as toxic it will be ready for it. The food proteins will attach themselves to the antibodies on the mast cells, causing the mast cells to release a number of chemicals one of which is histamine in an effort to protect the body.

Histamine is what causes allergic symptoms, causing inflammation, swelling and itching. Histamine is also directly responsible for hives making hives the best indicator of allergies since the presence of hives indicates there is histamine running lose in the body.