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Skin Allergies: What to Expect from Patch Testing

If you’ve ever suspected that your skincare or household products are causing a rash, patch testing may reveal the specific allergen(s) at the root of the problem. At SkinCare Physicians, Dr. Molly Stout evaluates patients with skin rashes, also known as allergic contact dermatitis, through a structured, week-long patch testing process. Read on to find out how patch testing works to solve the mystery of skin allergies.

Why it’s hard to identify skin allergens

Our immune system, particularly the component housed in our skin, is quite adaptive.  A signature scent you’ve worn for years, could one day cause a dreadful, swollen and itchy red rash. Unlike food allergies, which may trigger an immediate reaction like hives or anaphylaxis, contact allergens provoke a DELAYED hypersensitivity response. This typically appears as an eczema-like rash a few days after exposure, making it very difficult to identify and eliminate the culprit allergen on your own, especially given the myriad of products we are exposed to daily.

Have you ever looked at the back of a shampoo bottle? The list of chemical names is dizzying. At Skincare Physicians, we take the guesswork out of identifying allergens with an extensive panel of 92 allergens to evaluate thoroughly the possibility of an allergic contact dermatitis. We test for fragrances, preservatives, topical medications, metals, and numerous other common chemicals found in skincare, hair care, nail products and household items. Each individual allergen is painlessly applied to the back for 3 days. Throughout the testing week, Dr. Stout and her team meet with you multiple times to support and guide you every step of the way. Once we identify your exact allergen, you will have a clear roadmap to avoid that chemical. You will be able to build a personal “safe list” of products that will not cause your rash.

Step-by-step patch testing week

Patch testing is a structured week-long experience.

• Monday – 92 individual allergen patches are applied and taped to your back. Exercise and showering are strictly forbidden to prevent the allergens to all wash together. While these temporary restrictions may be inconvenient, they are well-worth the insight you’ll gain!
• Wednesday – You come back to SkinCare Physicians for a brief nurse visit to remove the patches and note any initial reactions. A tiny patch of eczema under a specific allergen indicates that your immune system is at odds with the ingredient. Still no exercise and showering.
• Friday – You return to see your dermatologist for your final read and allergic evaluation. It takes about 96 hours for the allergens to fully incubate and interact with your immune system. Any positive reactions will be recorded in your chart. The offending ingredient(s) will also be added to the SkinSAFE account we will create for you and removed from your safe list.

After the week-long testing, the real work begins—going through your personal care products and eliminating items that contain your allergen(s)! The good news? Unlike other chronic skin conditions, allergic contact dermatitis has a straightforward solution: once you eliminate your allergen(s) from your life, the rash disappears without any further treatment.

If you suspect an allergy to a chemical may be at the root of your skin irritation, patch testing offers clarity and a path to relief. Book your patch testing today to continue your journey to healthier, happier skin!

You may also like:

– Patch testing: A crucial tool for dermatologists in assessing allergic contact dermatitis
– Allergic or not to a skin care product? Find out with patch testing