|MadSci Network: Immunology|
Hi Vera, Well first things first. Don't eat fish! You said that you have a history of serious reactions to fish that you ate, so don't push your luck. Food allergies can be fatal even if you only ate a small bite. The reason is that your immune system has made a type of antibody called IgE that attaches to the food proteins that you have eaten(fish in your case). This type of antibody is often found attached to the surface of a cell called a mast cell. What happens is that when this fish protein becomes attached to this IgE antibody, a reaction is triggered in the mast cell which causes it to release chemicals called histamines and leukotrienes, and these are the things that cause the allergic reaction. You get flushed, your can't breath, your throat swells up, and if you don't get it under control quickly, you can die. What you should know is that your immune system does increase in response with further exposure to the allergic causing substance. Unfortunately there is no way to get rid of the IgE antibodies, and the only thing you can do to avoid another allergic response is not to eat fish. Why do you have these antibodies? Well all of our antibodies are preformed before we are ever exposed to anything. Whenever we become infected by a virus, bacteria, or parasite our immune system tries to match up a preformed antibody with a piece of the invader like a lock and key. Some people make antibodies that just happen to fit with food proteins and that causes all the problems. There are tests to determine if you are allergic to certain substances called the prick skin test, or a blood test called the RAST(radioallergosorbent test). In the first test small amounts of allergins are injected into the skin of the forearm or back. If the person is allergic to these substances a small circle of inflammation occurs called a wheal. In the blood test, you blood tested for the presence of antibodies that react with allergins. I would suggest having your doctor put you in touch with an allergy specialist if you are that concerned about it. And I'll say it one last time, don't eat fish cause it isn't so tasty that it should cost your life. Here are some web sites that may be helpful. Allergy, Asthma, and Immunology Online, Allergist Finder Mark Sullivan
Try the links in the MadSci Library for more information on Immunology.