Skin Allergy Testing

Allergic reaction no handWhat is allergic contact dermatitis?
This is a skin reaction that occurs when you touch or contact substances that you are allergic to. Your skin can be itchy, cracked, red, sore, and even bleed. The substances that cause this reaction can be an ingredient in your makeup, aftershave, shampoo, jewelry, medication, and clothing. You may also find these substances at work in your cleaning supplies, paper and ink, medicines, disinfectants, construction materials and rubber products.

What is Patch Testing?
Patch Testing is a reliable, easy way to diagnose allergic contact dermatitis. It is designed to help your doctor find out whether you are allergic to the substances included on the test panels (shown in the table below). The test panels contain 35 different substances known to cause allergic contact dermatitis.

Patch testing chart. Please contact our office for full details.
How does patch testing work?
You wear the panels (on your back or an alternative site) for 2 days. Do not remove the panels unless your doctor tells you to do so. You will return to the office to have the panels removed. Any allergic reactions will be visible on the skin, allowing your doctor to take the first skin reading. A second reading will be done 2-5 days after removal of the patches to help discern allergic reactions from irritant ones. Your patch testing results are typically discussed at this time.

Skin Allergy TestingWhat activities should I avoid while being patch tested?
You must be careful NOT to get the panels or the surrounding skin wet. This can cause the panels to loosen, wash away the test substances or marking ink. To avoid this:

  • Do not wet the panels or the surrounding skin while bathing. Take sponge baths for the first 48 hours and don’t shower until the patches are removed. After the patches have been removed, you will still need to avoid getting the area wet. Avoid scrubbing the test site until the final reading.
  • Avoid getting the panels or the surrounding skin wet while exercising or participating in activities that may cause you to sweat, such as vigorous exercise or sunbathing.

If an area of the test panel does become loose, use hypoallergenic adhesive tape to reattach them to your skin in exactly the same position as before. Apply tape only around the outside edge of the panels.

What should I do if my skin itches or burns while wearing the patch testing?
Itching and burning sensations are common side effects. Try not to scratch the patch test area. Scratching can irritate your skin, and may make the itching worse. It also can affect your doctor’s ability to interpret your skin’s reaction. If the itching or burning becomes severe, you should contact your doctor immediately.

Photo of a positive testWhat reactions will alert my doctor?
At each skin reading, your doctor will carefully examine the test area for signs of an allergic reaction. It may look like a small skin rash with swelling, redness and tiny blisters.

It is very important that you keep all appointments. Your doctor needs to see your skin and check for signs of an allergic reaction in the test area.

When will my patch testing results be known?
Some reactions to the substances on the patch testins appear within a few days, while others can take as long as 10 days to appear. Your doctor will determine how long it will take to complete your test based on your history and symptoms. Your doctor will discuss your results with you during your last appointment.

If I am allergic to a substance on the patch test, what should I do?
If you test positive, your doctor will explain which substance you are allergic to and talk to you about how to avoid contact. Your doctor will provide information about:

  • Where the substance can be found at work and at home;
  • What products are likely to contain this substance;
  • Steps you can take to avoid this substance; and
  • Alternative products you can use that don’t contain this substance.

What does a negative test result mean?
Negative results are very common. If you test negative, you will not have to avoid products that contain the 35 common allergens and allergen mixes included in this patch test However, you still can have other allergies. Although the 35 allergens and allergen mixes included in our patch tests are the most common, there are many more substances that could be causing your symptoms. Some patients need additional tests to determine if they are allergic to less common allergens.

Your doctor may decide that your symptoms are due to an irritant reaction, and talk with you about how to better care for your skin and avoid irritating substances. If your doctor believes your skin’s reaction is due to some other condition, you may be referred to a specialist for further testing and treatment.