An allergy is an excessive reaction of the body's immune system against a perceived threat. The human immune system is designed to attack objects that are perceived to be threatening to the health of the individual. In some cases, particularly in those individuals who have hyper sensitive immune systems, the system begins to attack an object that is not harmful to the body, but becomes harmful because of the allergic reaction to it. This could be something ingested, like food, or something that is airborne or something that has come into contact with the skin of the individual. Allergic reactions range from mild rashes to much more serious reactions that may even include anaphylactic shock which can cause serious medical complications and, if not treated as an emergency, lead to death. Allergies that cause more serious reactions can be controlled if the person is aware of the allergy and the allergen that causes the reaction. Control can be exercised in the form of avoidance of the allergen as well as by carrying emergency anti-histamine medication to reduce the effects of the reaction to the allergen. It is thus prudent to have an allergy test done in order to establish your allergic response to various substances.
Allergy testing may be done as a precautionary study by someone who is likely to be exposed to a new environment that has several different possible allergens. It may also be conducted on an individual who has a history of allergies and allergic reactions. Serum allergy testing is the study of the person's allergic response using a blood sample, also known as, serum sample. This technique is an in-vitro technique which means that it is done in a laboratory and is outside the body of the individual. This is particularly helpful as it avoids the effects that the allergen will have on an allergic person if testing is done directly on the individual. Laboratory testing is also extremely accurate as each allergen can be introduced to one sample of the blood. The drawback of such testing is the time that it takes to test a sample. Skin prick testing provides results faster than blood testing in some cases.
The most common blood test for allergies is the RAST test which uses radioactive particles introduced into a blood sample. These particles then interact with the immune cells in the blood stream to show whether the particular allergen is causing a reaction or not.
Submitted by N on May 10, 2010 at 03:30