A dermatologist examines skin for contact dermatitis.

Expert Diagnosis for Hard-to-Identify Skin Reactions

When an unexplained itchy rash appears on your skin, it can be uncomfortable. Rashes can form hours or even days after contact with an allergen, making it hard to know what caused it. We help you identify what is triggering your skin reaction and help you find relief from itchy rashes.

Our doctors are members of the North American Contact Dermatitis Group, leading the way in skin allergy research and treatment. Whether you’ve recently discovered your rash or you have been dealing with it for years, we can help you uncover what’s triggering your skin reaction so that you can find relief.

What is contact dermatitis?

Contact dermatitis is a condition in which certain substances that touch your skin cause allergic or irritant reactions. The allergic reaction can create an itchy rash that may last for as long as you are in contact with your allergen. Contact dermatitis can develop any time in your life, no matter your age or if you have not had a rash before. It is even possible to eventually develop an allergy that can cause contact dermatitis from something you’ve safely had contact with for months or years.

What are symptoms of contact dermatitis?

Possible symptoms of contact dermatitis include:

Dry, cracked skin
Intense itching or burning
Oozing, weeping or crusting fluid
Redness, swelling or dark discoloration
Small fluid-filled bumps or blisters

How is contact dermatitis treated?

Allergic contact dermatitis is most effectively treated by allergen avoidance or simply staying away from known allergens that might cause another outbreak. For people with identified allergies, we will provide you with custom recommendations for products to remove from your routine, as well as safe products to replace the ones causing your contact dermatitis.

Typically, an allergy that causes allergic contact dermatitis lasts a long time. It might even last your whole life. However, by avoiding known allergens, you can also avoid the rashes.

Should your patch test come back negative, our team will then work with you to discuss next steps for figuring out your diagnosis. It may mean that instead of dealing with an allergy, you might have a different non-allergic rash, which we also diagnose and treat.

Screening & Diagnostics

What is patch testing?

Patch testing is the test used to diagnose a skin condition called allergic contact dermatitis.

How does patch testing work?

Patch testing takes place over about a week, requiring multiple visits. The patch test is different from prick or scratch testing for dust, pollen and pet dander.

Your first appointment is a consultation with us to review your medical and allergy history, examine your rash and discuss the details of our patch testing.
Then, we will apply the patches to your back. Each patch contains a series of potential skin allergens. These patches are taped onto your back without needles, pricking or scratching. We recommend that you wear loose, dark, old clothing to avoid any possible staining from the markers we use to carefully map out the where to place the patches on your back.
The patches are then removed after two days, but at this point it is still too early to know the final results because some reactions might take the full week to develop.
After two to three more days, our team will then examine your back to check for positive patch test results. Then we review the results and your treatment plan with you.

What will be tested?

We test for any allergens that might be found in any product that touches your skin including skincare, cosmetics, clothing, accessories, medical devices and household/workplace products. Potential allergens we screen for include:

Adhesives, glues
Clothing dyes
Fragrances
Hair dyes
Metals
Nail polishes
Plants, botanicals, essential oils
Preservatives
Rubber ingredients
Topical medications (including active and inactive ingredients)

However, your patch test panel will be customized based on the features of your rash and any suspected allergens from your exposure history.

Frequently Asked Questions

Is patch testing safe?

Patch testing is a very safe form of allergy testing. The main side effect from patch testing is itching on your back. If you do have a positive reaction, the site may look like a mosquito bite on your back and can temporarily leave your skin looking discolored. Patch testing should not cause any scarring or permanent changes to your skin, even if you have a positive reaction.

Does patch testing diagnose food allergies?

The patch test is not a food allergy test. It is very uncommon for dermatitis to be caused by a food allergy, making food allergy testing not useful in examining most cases of mystery skin rashes.

Are there restrictions during patch testing?

Patients undergoing patch testing need to keep their back completely dry from the first visit until the last visit four to five days later. This means no bathing, showering or doing anything that makes you sweat, including exercise. However, you can sponge bathe, carefully wash your hair over the sink and drive while the patches are on. You can also go to work and do light work (desk work). You will need to avoid any excessive actions that might make the patches come unstuck like running, lifting, stretching or bending.

We do not usually perform patch testing on people who are pregnant or breastfeeding unless it is an urgent situation.

Our team will discuss with you any medications that might affect your test results.

Do I need a referral for patch testing?

The majority of our patients are referred to us by their dermatologist or allergist. You can also make an appointment on your own by calling (323) 442-6200.

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