3 TYPES OF IGE SKIN TESTS
Skin Scratch Test – This is the most common method, where we scratch the outer layer of your skin to insert the allergen. The test itself takes 10 minutes and has a 15-minute wait time for a reaction to occur.
Skin Injection Test – This is another great option, particularly if you are being tested for sensitivity to insect bites or penicillin. The timing is approximately the same as that of the scratch test.
Patch Test – This is a less common method, where we place allergen-filled patches onto your skin. The test requires 2 visits with a wait time of 48 hours.
Blood tests are used for people that are unable to have a skin test performed on them due to sensitivity. Even though a blood test is less sensitive than skin tests.
It is possible for people to have a positive reaction to a skin test but have a negative reaction to a blood test. The most common blood test performed is called an enzyme-linked immunosorbent assay (ELISA, EIA) What this test does is measure the blood level of a type of antibody called Immunoglobulin E or IgE, That the body may produce in response to a certain allergen. IgE levels are often higher in people with allergies and/or asthma.
There are two other tests that a lab may perform which are called Radioallergosorbent Testing (RAST) or an Immunoassay Capture Test (ImminoCAP, UniCAP or PharmaciaCAP)
CHALLENGE ALLERGY TEST
This is when a small amount of an allergen is inhaled or taken by mouth. This type of allergy testing is performed when there is potential for a food or medication allergy. For this type of test to take place, it is important that the patient is supervised by a physician with specialized training and experience.