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Allergen Patch Testing

Our Ann Arbor and Plymouth locations offer skin patch testing to help diagnose the specific causes of contact dermatitis, sometimes called eczema. The condition appears as an itchy rash, which is caused by your skin coming into contact with a substance that triggers an allergic reaction. The most common cause of contact dermatitis is poison ivy or oak, but cleaning solutions, cosmetics, perfumes, latex, and even jewelry can produce this type of reaction.

Patch tests don't use needles and can detect delayed allergic reactions, which can take several days to develop. When a patient needs allergy testing at our Ann Arbor practice to determine the cause of a rash, a patch test may be recommended. The test exposes small areas of your skin to extracts of substances that can cause contact dermatitis.

What to Expect

Patients who get patch tests return to our office for a number of scheduled appointments within one week of the initial appointment. On the first day of the testing, a series of small patches that contain specific allergens is placed on the skin. Various patch tests are available. We use the Chemotechnique Diagnostics patch to test for contact dermatitis at Ann Arbor Dermatology.

During a patch test, your skin may be exposed to up to 80 extracts of substances that can cause contact dermatitis. These can include latex, medications, fragrances, preservatives, hair dyes, metals, and resins.

You wear the patches on your back for 48 hours. Avoid bathing (sponge baths are okay) or activities that can produce heavy sweating while wearing the patches. When we remove the patches, we check for any skin irritation that may indicate an allergic reaction.

Common Questions

Is the patch test painful?

Unlike allergy tests that use needles, the patch test is relatively simple and causes no discomfort.

How long will I have to avoid showering or bathing?

We remove the patches after 48 hours. Patients then return to our office 24 to 96 hours later to have the skin checked again. A typical appointment schedule involves coming in on a Monday morning to have the patches applied, returning on a Wednesday to have them removed, and coming back on a Friday to learn the test results.

How is contact dermatitis treated?

The primary treatment for acute contact dermatitis (ACD) is avoiding the substance that causes the reaction. Treating eczema includes some options, such as using prescription steroid creams best-suited for your allergy, applying ointment to help the skin heal, and taking prescription oral medications (e.g., antihistamines and antibiotics.)

It's important to identify the potential allergens that cause contact dermatitis. If you have a rash and are concerned that it's eczema, request a consultation at Ann Arbor Dermatology. Or call our office at (734) 996-8757 (Ann Arbor) or (734) 455-6881 (Plymouth), and one of our knowledgeable staff members will be happy to assist you.

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