What is a food allergy?
At the most basic level, a food allergy is an abnormal response to food.
The body’s immune system reacts to the food as though it were a threat. The most common type of immune reaction is when the body produces a specific type of antibody called immunoglobulin E (IgE).
When IgE binds to the molecules in a food, an allergic response is triggered. The response varies in magnitude from very mild to severe. Anaphylaxis can cause death, so some reactions can be very serious.
If you have a food allergy, it is important to know what that allergy is as specifically as possible and what the possible reactions may be. Working closely with your healthcare provider or allergist will help answer these questions.
First exposure to allergen preps the body
The first time a person is exposed to the food, no symptoms will occur. But plenty is happening inside the body, preparing for the next exposure.
It is at this time that the body creates specific IgE antibodies to that allergen. They circulate throughout the body and attach to mast cells and basophils.
Mast cells are found in all body tissues, especially the nose, throat, lungs, skin and gastrointestinal tract. Basophils are in the blood and also in tissues that become inflamed during an allergic response.
Second exposure triggers reaction
During the second exposure, the body is ready. The food allergens bind to the IgE antibodies spread throughout the body. The binding then signals the release of massive amounts of histamine.
There will be various symptoms depending on where the histamines are released and in what quantity.
An allergic response can happen in minutes or hours. It can come from ingesting, inhaling or even absorbing the allergen through the skin.