Allergy testing is a procedure carried out by a trained allergy specialist to check if your body shows an allergic response to a specific known substance.
An allergy exists when the body’s immune system shows an unexpected reaction to something in the environment.
Allergies can prove to be minor inconveniences to potentially life-threatening, which makes it important to know what substances you are allergic to.
The allergens can be quite common and may seem quite harmless, such as pollen which causes symptoms such as a running nose, sneezing, itchy and watery sinuses, along blocked sinuses.
Allergy skin tests can be done on the skin, the blood, or an elimination diet.
Let’s look at allergy skin tests in detail:
What Are Allergy Skin Tests?
Skin tests for allergy are quite common and are used to identify several allergens.
It can help test for airborne, contact, and food-borne allergens by checking for changes and reactions in skin cells.
There are three types of allergy skin tests, and an allergy specialist is likely to try all of them to get a proper look at the body’s reactions to allergens.
Let’s look at all of them in turn:
Scratch Test
A doctor is likely to start allergy skin tests with a scratch test.
The test uses an allergen placed in a liquid that is spread onto the skin using a tool that also punctures the skin slightly to let the allergen move inside.
The exposure is followed by thorough monitoring to see how the skin reacts.
An allergy is deduced if there is localized redness, swelling, itchiness, and elevation on the exposed part of the skin.
Intradermal Test
If the scratch test is not conclusive, your doctor may follow up with an intradermal test.
The test follows the same principle as a scratch test, however, the liquid with the allergen is injected into the dermis layer of the skin.
This is followed by monitoring to check for any reactions.
Patch Test
Patch tests are longer than scratch and intradermal tests. They include applying patches with the allergen on different parts of the body.
The patches remain on the body when you leave your doctor’s office.
They are first monitored 48 hours after application, and then at 72 and 96 hours as well.
How to Prepare for Allergy Skin Tests?
A doctor is likely to ask about your family and medical history before conducting the procedure.
They will ask you to stop taking the following medications:
Antihistamines
Medicine for heartburn treatment
Anti-IgE monoclonal antibodies for the treatment of asthma
Tricyclic antidepressants
Benzodiazepines
Allergy skin tests may cause itching, redness, and mild swelling.
They can also cause small bumps to appear on the skin, with these symptoms lasting for a few hours to a few days.
Strong allergic reactions are rare but need immediate medical attention as they can be life-threatening.
