Broadcast: Thursday 06 April 2006 09:00 PM |
There is a lot of inaccurate information about allergies - none more so than the tests you can access through high street stores, certain complementary practitioners and mail order.
Diagnosis
There is a lot of inaccurate information about allergies - none more so than the tests you can access through high street stores, certain complementary practitioners and mail order.
There are only two tests that currently have any scientific validity in allergy diagnosis. They both measure the same 'marker' of allergy, known as 'specific IgE to individual allergens'.
Skin-prick test
In this preferred method, a drop of a standardised preparation solution containing one allergen is applied to the inner forearm and pricked into the surface of the skin. If the patient is allergic to that allergen, it will react with a specific antibody present under the skin within 15 minutes, causing a small itchy weal and red area. This is measured and will disappear quite quickly.
ImmunoCAP or RAST blood test
The allergens are put into a test tube containing a small amount of the patient's blood. The reaction with any matching specific antibodies happens within the tube and is interpreted by a machine.
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