The rast test for allergy is a test to check for any allergic reactions in a patient. The full form of RAST is 'radioallergosorbent' test. It is sometimes called rast allergy blood test because it involves testing the blood. Rast testing of allergy is extremely accurate.
Skin allergy tests are commonly used to detect a person's allergic reaction to a particular stimulus. Skin testing is not as accurate as maybe sometimes required in a complicated case. Skin testing may not produce a positive result, even though the person is allergic. This happens when the allergen is not properly absorbed into the skin or the concentration is too low. Rast allergy testing is thus used in situations where the doctor wants a specific allergen to be tested. Rast allergy test results are specific and point directly to a particular cause. Rast allergy testing has some more advantages, because it can be done on a patient by removing his or her blood sample for testing without actually introducing the allergen into his or her system. Thus, if the allergy is a severe problem, the patient can continue on medication that subdues the symptoms while the underlying cause is determined by this test.
The rast test allergy method is cost effective. It seeks to check the body's reaction by locating what are known as Immunoglobulin E antibodies. Immunoglobulin E antibodies are specifically present in people who have an immediate response to the allergen. This is often the most dangerous type of allergy as it may trigger a life threatening reaction in the person and can be fatal without adequate emergency medication. The rast test allergy scale measures the quantity of immunoglobulin E antibody specific to that allergen. The higher the level of the antibody, the worse would be the reaction in a person. Some people may have allergen antibodies without displaying any allergic reaction. This is the case in people who have grown out of an allergy or have such a mild reaction that it is often not discernable.
A rast food allergy test can also be performed because a person who is suspected of a particular food allergy will have the immunoglobulin E antibodies present in his or her system. Rast tests allergies in a way that is least harmful or uncomfortable to a patient. Testing can be conducted without the presence of the patient after blood has been drawn. It is particularly safe for this reason as there is no allergen-patient contact at all during the testing phase.