What is Allergy Patch Testing?
Patch testing checks to see whether a particular substance is causing an allergic skin irritation, also known as contact dermatitis, by applying allergens to patches and then placed on your skin. The skin on your back may be exposed to up to 36 extracts of substances that can cause contact dermatitis including latex, medications, fragrances, preservatives, hair dyes, chemicals, and resins.
You will wear the patches applied by your allergist, most likely on your back, for 2-3 days. During this time you should not remove the panels unless your allergist tells you to do so. After 2-3 days, you will return to your provider’s office to have the panels removed.
Irritated skin at the patch site may indicate an allergy; however, your allergist will need to see you again for a second reading 1-5 days after the patches are removed to ensure an accurate diagnosis. Your allergist will discuss the results of your patch test at this time. They will inform you of substances that you should avoid and ways that you can prevent future contact with that substance.
Affiliated Dermatology also offers a skin test on the back with 80 antigens that provide results within 60 minutes.
What is Allergic Contact Dermatitis?
This is a skin reaction that occurs when you touch or come in close contact with substances to which you are allergic. Your skin can become itchy, cracked, red, sore and may even bleed. The substances that cause this reaction are referred to as allergens and can be an ingredient in your shampoo, soap, makeup, aftershave, jewelry, medication or your clothing. You may also have a reaction to an allergen in your workplace because allergens are common in cleaning supplies, paper and ink, disinfectants, construction materials, and rubber products.
How to Know What is Causing My Allergy?
Your allergist may give you a patch test to identify potential allergens. Patch testing is a reliable, safe, and easy way to diagnose the cause of your specific allergic contact dermatitis. Your allergist will apply a panel or series of panels containing allergens to your body. Each chamber will contain a different allergen, and each panel can contain up to 12 individual chambers.
FAQs on Allergy Patch Testing
What should I do if my skin itches or burns while wearing the patch tests? Itching and burning sensations are common side effects. Try not to scratch the patch test area as it can irritate your skin and may make the itching worse. It can also decrease the ability to interpret your test results. If the itching and burning become severe, contact your provider immediately.
What should I do if my patch starts to come off? Your allergist probably will have applied tape or covering over your test panels. If, however, the panel becomes loose, you can use a hypoallergenic tape to reattach it to your skin. Apply the tape only around the outside edge of the panels.
Can I shower? You should minimize your exposure to water. If your allergist has used a water-resistant covering, s/he will let you know if you can shower. Even after the patches are removed, you will need to limit showering and avoid scrubbing the test site until after the final reading.
Can I go to the gym? Depending on the type of panel applied, you may be able to go to the gym for a light workout. Some patch test materials are water and sweat-resistant. Your provider will determine what’s best for your specific tests.
What will a positive reaction look like? Your allergist will review your results when the patches are removed. Positive reactions range from a small skin rash with a little swelling to red, blistered skin.
How long will this testing take? Usually, your patches will remain in place for 2 days. After this time, your allergist will remove them and will set an appointment for you to return in 1-5 days. Most reactions occur within this period; however, some reactions can take as long as 10 days to appear. Your allergist will be able to tell you how long it will likely take to complete your testing based on your history and symptoms.
What if my results are negative? Negative results are common. Patch testing helps to narrow the potential allergens that are causing your reaction. If you test negative on the initial testing, your allergist may test you again using another set of allergens. This process of elimination will continue until your specific allergens are identified with 35 of the most common allergens causing 80% of all allergic contact dermatitis.
Request an Appointment
For more information or to schedule an appointment at one of our several dermatology offices in Arizona, please contact us by calling (480) 556-0446 or leaving us a message with the contact form below.