FAQs About Skin Patch Allergy Testing For Contact Dermatitis

If you've been dealing with itchy, red, irritated skin that your doctor believes may be contact dermatitis, then you might be sent to an allergist for skin patch testing. This type of allergy test is meant to identify the substances you're allergic to. Then, you can know what to avoid and how to ease the symptoms of your contact dermatitis, going forward. As your skin patch test appointment approaches, you may find you have some of the following questions.

How is the test conducted?

A skin patch test is usually done in your allergist's office. They'll begin by drawing a grid on your skin. Usually, this is done on your back, but sometimes it may be done on your upper arm. The allergist will then apply a different potential allergen to each square within the grid. For instance, they may apply sodium lauryl sulfate to one square, pineapple extract to another square, and so forth. You'll then need to wait a while as the allergist observes your skin and how it reacts to the various substances. Some of the squares may show irritation, and others may not. If there's a reaction in a certain square, that means you're allergic to the substance that was applied to that square of skin.

What happens if you have a severe reaction?

Most people do not have a severe reaction, beyond skin irritation, during a skin patch test. Your doctor won't conduct this test on you if they think there's a significant chance of you reacting really severely. With that being said, there is always some risk of a patient going into anaphylactic shock or experiencing another sort of serious reaction to the skin patch test. This is why the test is done in an allergist's office. If you do react, the allergist can quickly give you a shot of adrenaline to counteract the reaction. They can also administer any antihistamines you might use.

How long will your skin be itchy after the test?

Obviously, if your skin patch test does detect an allergy, you'll have some itchiness and redness in the test area. The good news is that this should not last long with the treatment your doctor gives you afterward. They should give you an antihistamine cream to apply. In some cases, they may even give you a shot of antihistamines to speed up your recovery.

If you struggle with contact dermatitis, a skin patch test can determine what's causing your symptoms, allowing you to finally enjoy relief. Although this test is pretty common and relatively safe, it's normal to have some concerns. If you have additional concerns that were not addressed here, reach out to your allergist.