Skin Allergy Testing: Patch
Skin allergies could lead to skin conditions – find out if you have any skin allergies by scheduling a test.
One test, many answers
If you suspect you may be having allergic reactions on your skin, you could easily find out the answer with a skin patch test. One simple test could determine if you are allergic to many substances such as latex, medications, fragrances, preservatives, hair dyes, metals, and resins.
Who is eligible for a skin allergy test?
Skin tests are reliable for diagnosing allergies to airborne substances, such as pollen, pet dander, and dust mites. If you suspect you are allergic to those substances, this test is for you. Information from skin allergy tests can also help your doctors develop an allergy treatment plan that includes allergen avoidance.
This test is also great for finding allergies with delayed reactions. In some cases, however, you can be ineligible for a patch allergy test. The test involves exposing you to a little bit of the allergen and seeing if your skin reacts. This means that you may experience an intense allergic reaction, or have side effects.
In order to manage the risk of this test, you are not eligible if you have a pre-existing condition that would make an allergic reaction worse. You may not be eligible if:
You’ve had a severe allergic reaction before. If you have had a severe reaction prior, you may be sensitive to certain substances that even the tiny amounts used in skin tests could trigger a life-threatening reaction (anaphylaxis).
You take medications that could interfere with results. Some antihistamines, many antidepressants, and some heartburn medications can do this.
If you have certain skin conditions. If you have eczema or psoriasis that covers a large portion of skin on your arms or back, your conditions cover the usual testing sites. Another condition called dermatographism can cause unreliable test results.
What can you expect from a patch skin test?
During this test, your skin is exposed to suspected allergy-causing substances (allergens) and is then observed for signs of an allergic reaction. Not all reactions occur quickly, some can develop over a period of several days. The reaction time depends on what is being tested for.
No needles here! Your doctor will expose your skin to multiple allergens via patches that are pressed onto the skin.
Setting you up with the patches in our office only takes 20-40 minutes in the office. You will return 48 hour later to take the patches off to read the results, and your final follow up will be 4-7 days later.
After the test is administered, you will wear the patches on your arm or back for 48 hours. Avoid anything that could cause the patch to fall off, such as bathing or activities that create a lot of sweat.
Your doctor is looking for something called contact dermatitis, which will appear as skin inflammation. They will examine where your skin is irritated, and will determine which substances you’re allergic to.
Set yourself up for success
There are many factors that go into getting an accurate result. The better you prepare for your test, the more accurate the result, and the less chance of unwanted side effects. Your doctor will make sure this is the right test for you by asking about your medical history, and possibly performing a physical examination. Answer their questions thoroughly to determine if allergies run in your family and if an allergic reaction is most likely causing your symptoms.
There are always risks and side effects. If you are allergic to any of the substances, your skill will be irritated. Swelling, light pain, redness, and itching are possible. Rarely, allergy skin tests can produce a severe, immediate allergic reaction, so it’s important to have skin tests performed at an office where appropriate emergency equipment and medications are available.
Why you may avoid this test
Skin tests are generally safe for adults and children of all ages, including infants. In certain circumstances, though, skin tests aren’t recommended. Your doctor may advise against skin testing if you:
Have ever had a severe allergic reaction.
Take medications that could interfere with test results.
Have certain skin conditions like eczema or psoriasis.
Your skin is allergic to some substances – what now?
You may receive the answers you were looking for from this test alone. You may also need further testing, however, depending on the initial reason you took the test. Skin patch tests cannot be used to detect every possible skin irritant.
There’s also always the risk of a false positive or a false negative. You may react differently to the same test performed on different occasions. Or you may react positively to a substance during a test but not react to it in everyday life.
You and your doctor will review all the data and consider all of your personal factors when making your treatment plan. If you test positive, next steps could include a lifestyle change, medications, or further testing.
