ALLERGY TESTS
What is an allergy?
An allergy occurs when you react to things like pollen or cats that don’t affect most people. If you come into contact with something you are allergic to (called an allergen), you may have symptoms such as itching or sneezing, itchy throat and ears, and hives. This is called an allergic reaction.
Allergy tests
Allergy tests are able to help identify which substances, or allergens, induce allergic reactions. Such tests have the ability to detect characteristic allergy symptoms, such as skin inflammation or elevated levels of IgE in the patient’s blood . These allergy tests are done after controlled exposure to possible allergens.
The Glow Allergy Clinic offers three different tests to best diagnose allergies:
Skin Prick Testing
First, a small amount of possible allergen is placed on the forearm. After this, a medical professional then pricks the patient’s skin in order to introduce the substances into the blood stream. The medical professional will subsequently observe the patient for visible inflammatory responses. Please note that results of this test should only interpreted by an allergy specialist; as positive reactions are not necessarily indicative of allergens. Skin testing is efficient, inexpensive and is often the first test suggested when an allergy is suspected.
What can I expect during a skin test? A number of different allergens will be tested. It takes about 5 to 10 minutes to place the allergens on your skin. They are usually put on the forearm in adults and on the back in children. Then you will wait about 15 minutes to see if a small red lump appears where any of the allergens were placed. The prick or scratch test and intradermal test may hurt slightly. If you are sensitive to any of the allergens, your skin may itch where the allergen was placed.
Blood Testing
Blood tests are suggested in cases where patients suffer from widespread skin conditions, or are taking medication that makes skin testing impractical. In this instance, a blood sample is acquired from the patient after sequential exposure to potential allergens, and analyzed for elevated levels of IgE antibodies. Tests can determine not only the severity of an allergy, but can also help predict future symptom development.
Patch Testing
(please see the following link for nice picture and explanation to be added…https://www.contactdermatitisinstitute.com/pdfs/patch-test-guide.pdf)
Patch testing identifies contact allergens (allergens that induce inflammatory responses via direct contact with the skin). Patch testing involves placing a small quantity of a potential contact allergen on the skin, and then a medical professional would cover the allergen with an adhesive patch. After 48 hours, the patient’s skin would then be examined for a hypersensitivity reaction.. During this test, individuals are advised to avoid exposure to sunlight and any type of ultraviolet (UV) light.
How should I prepare for the test?
Tell your doctor about all medicines you’re taking, including over-the-counter medicines. Don’t take antihistamines for 3 to 7 days before the test. Ask your allergist when to stop taking them. (It’s okay to use nose [nasal] steroid sprays and asthma medicines. They will not interfere with skin tests. Talk to your allergist’s staff before the testing to find out which medications you can continue using.)
Is the test safe?
Very small amounts of allergens are tested on your skin, so skin testing is safe.During the test, the doctor will watch for a possible severe allergic reaction, but it rarely happens.
What do the skin test results mean?
If you’re sensitive to an allergen:
With the prick or scratch test and intradermal test, a small red bump appears on the skin where that allergen was placed, and this area may itch. The larger the bump, the more sensitive you may be to it.
These results are called positive skin tests and mean that you may be allergic to the allergen tested. Even if a skin test shows that you’re allergic to something, you may not react to it when you’re exposed to it later. Your allergist will review your medical history and skin test results to help find out what you’re allergic to. What happens if the skin test shows I have allergies? Your doctor will create a plan for controlling your allergies. This means preventing and treating symptoms.
Take these steps:
Avoid or limit contact with your allergens. For example, if you’re allergic to dust mites, reduce the clutter in your house, which collects dust.
Take medicine to relieve your symptoms. Your allergist may prescribe medicines such as antihistamines, decongestants, nose (nasal) sprays, or eye drops.
Get allergy shots if the allergist says you should. Some people need them when they can’t avoid an allergen. The shots contain a tiny but increasing amount of the allergen you’re sensitive to. Whether given in shot form or under the tongue, immunotherapy involves giving gradually increasing doses of the substance to which you are allergic (also known as your allergen). The small increases over time in the amount of your allergen – things like dust, pollen, mold and pet dander – cause the immune system to become less sensitive to it. That reduces your allergy symptoms when you come across the allergen in the future. Immunotherapy also reduces the inflammation that comes with hay fever and asthma.