What is happening in the body when one has a food allergy?
When someone has an allergy the immune system produces an allergy antibody that we call IgE, in response to a particular protein. Once IgE is produced, it circulates in the body until it encounters allergy cells. When the IgE encounters those cells, it attaches to them. Then the antibody waits like a guard watching for that particular protein.
Let's say an individual produces IgE antibody to egg. When that sensitive individual eats egg again, the egg protein will be absorbed and when it encounters the IgE specific for egg protein, the two join together. When that happens, the allergy cells release a variety of chemicals that can cause the signs and symptoms of an allergic reaction.
When do food allergies first appear?
Food allergy can begin at any point in life, but most commonly it begins in the first three years of life.
What foods are children commonly allergic to?
The most common foods include egg, cows' milk, wheat, peanuts, soy and tree nuts. So that's a list of six foods that account for about 95 percent of reactions in children.
What kinds of reactions do people with food allergy have?
One of the important characteristics of reactions in food allergy is that the reaction typically occurs within minutes and always within one to two hours after eating the food. Another characteristic is that reactions occur each and every time that particular food is ingested.