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Contact Dermatitis

Contact dermatitis is a type of skin rash caused by touching an irritant or something you’re allergic to. It causes redness, itching and small bumps. The best way to pinpoint the cause of your contact dermatitis is through a process called patch testing.

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Dermatology care with a personal touch

Sometimes your skin can have a love-hate relationship with your favorite products. Does your favorite cologne, smartwatch wristband or laundry detergent leave your skin bumpy and irritated? Even if you’ve been using the same products for years without any problems, you can still develop contact dermatitis.

So when you’re puzzled over what exactly irritates your skin, turn to our dermatologists to help understand the cause and how to treat it.

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Contact dermatitis is the rash that appears when the skin comes into contact with something it finds irritating, also known as an allergy trigger. Though the rash can appear right away, it usually takes a couple of days to develop and can last for several weeks to months.



Patch testing is a non-invasive allergy test that checks for allergic reactions to products like: 

  • Dyes
  • Fragrances
  • Metals
  • Plants
  • Preservatives
  • Rubber
  • Sunscreens
  • Topical medications

We recommend talking with your doctor to learn whether patch testing is the right move for you. Once your doctor gives you the green light, they can set expectations and answer any questions you may have about the process. Please note that we don't recommend patch testing while you're pregnant or nursing.

During patch testing, we'll place about 80–100 or more patches with different potential allergens on your skin for 48 hours. Patch testing typically requires 3 office visits in 1 week. Your schedule may look like the following:

  1. Monday: Your doctor will place the patches on your skin.
  2. Wednesday: Time to remove the patches.
  3. Friday: Learn about your results and counseling options.

How to prepare for patch testing

Follow these rules leading up to your patch test: 

  • Avoid tanning or phototherapy treatments for 2 weeks before your patch test.
  • Don't receive any steroid injections or start any new pills to treat your contact dermatitis. The exceptions to this rule are that you can continue taking antihistamines and steroid injections for your joints.

Do's and don'ts: the week of patch testing

What's OK to do the week of patch testingWhat to avoid doing the week of patch testing
  • Taking up to 2 pills twice a day of antihistamines like Benadryl®, Zyrtec®, Allegra®, and Claritin® to help with itching
  • Applying an ice pack over your clothes for 5–10 minutes for relief
  • Wearing loose clothing will be most comfortable
  • Showering before your test (with lukewarm water, if your doctor uses plastic tape)
  • Taking sponge baths and washing your hair in the sink
  • Applying topical steroids and lotions on parts of your body that aren't being tested
  • Applying products like lotions, oils or toners before your test
  • Showering, if your doctor uses paper tape
  • Swimming 
  • Exercising or sweat-inducing activities 

What to expect after patch testing

We'll need your help the week following patch testing by letting us know if you experience any new or delayed reactions. Be sure to snap pictures of your reactions to share with your doctor. Your doctor will keep a detailed log of your skin's story. We'll be sure to share your results with your referring physician.



We can explore wellness plans that are uniquely yours. It may take several months for your contact dermatitis to clear up with treatments. One of the most helpful things you can do for your health is avoiding contact with your known allergy triggers.

You may be able to join a clinical trial where you gain access to therapies not available anywhere else while also giving back to others living with the same conditions. Participating in a clinical trial is a very generous move. And when our dermatologists can learn more from you, they can learn more for the greater good.

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