The scoop on allergens – A Canadian dermatologist shares the facts

We seem to hear about allergies a lot these days. Parents live in fear of nuts. Your next door neighbour follows a strict diet because she’s intolerant to pretty much everything that tastes good. And your dentist won’t see you if you’re wearing perfume.

Sure, you can look online and find a wealth of information about all kinds of allergies. But sorting fact from fiction? Not so simple. We spoke to one of our experts to help clear the fog—on skin allergies at least.

Meet Dr. Joel DeKoven, a Consultant Dermatologist and Associate Professor in the Department of Medicine at the University of Toronto. He’s a specialist in diagnosing and managing Allergic Contact Dermatitis—skin allergies.

What is a skin allergy?

Let’s start with the basics. Some things irritate your skin; like wearing a wool sweater. It can be scratchy and uncomfortable, but take it off, and problem solved. An allergy involves your immune system reacting to something that is harmless to other people. Your body protects itself by triggering lymphocytes, which attack what your body sees as an invader.

A skin allergy usually presents itself as redness, oozing skin, bubbles or blisters, scaly skin, usually with itching. These symptoms may appear on parts of your body that haven’t come in contact with the offending product. Take hair dye, for example. You might first react around your hairline, and on your face, but you may end up with a blotchy rash on other parts of your body too. So, don’t discount a certain product just because it didn’t touch your elbow!

Anyone can have skin allergies, but right now, there aren’t any firm numbers on how many people are affected. “While we don’t have studies in North America that can tell us definitively that the number of skin allergy sufferers is on the rise, I can tell you that allergies to certain products are on the increase,” shared Dr. DeKoven. “My colleagues and I recently published a study that shows that allergies are increasing to chemicals found in shellac nail polish and artificial gel nails as well as some preservatives used in products to keep them fresh.”[1]

What should you do if you think you are suffering from a skin allergy?

If your reaction is quite severe, for example you’re very itchy or swollen, you’ll want to see a doctor right away to alleviate your symptoms. “People with severe allergies can end up in the emergency room,” says Dr. DeKoven. Once you’ve dealt with the initial reaction, see your family physician. He or she will likely refer you to a dermatologist to help you identify the allergen and give you advice on what products may contain it.

The most common allergens

Dr. DeKoven and several of his colleagues across North America have been tracking skin allergens for years. While these allergens are in products that people use every day, for most, they are harmless. But, if you’re trying to figure out what you may have reacted to, this list is a good start.

You’ll find nickel in some costume jewelry, and it turns up in things like belt buckles, watch bands, and the arms of spectacles.

This is a big one. Fragrance is added to many products like shampoo, cleansers, moisturizes, sunscreens, deodorant, household cleansers, and of course, perfume.

Many lotions, creams and shampoos contain preservatives to keep them fresh and guard against bacteria. The most common are methylisothiazolinone, methylchlorothiazolinone, and formaldehyde.

These cleaning agents are found in hair products, shampoos, cleansers, and body washes, for example.

Paraphenylenediamine (PPD)
Many hair dyes contain this chemical which can cause a severe reaction in some people. You should always follow the package instructions when using hair dye.

Allergic reactions to hydroxyethyl methacrylate are on the rise. You’ll find them in artificial gel nails, nail extensions and in shellac nail polish. “This one is not well known. Even some dermatologists don’t know that nail shellac can contain methacrylates,” says Dr. DeKoven.

Topical corticosteroids
Surprisingly, some products that many of us use to treat minor skin conditions like rashes, insect bites, and scrapes—those that contain antibiotic ingredients like neomycin or bacitracin—have also been among the top five allergens for years.

Dr. DeKoven’s advice? “If you’re concerned about a specific product that you’re using, try a repeat open application test. Put a small sample of the product on your arm just below the crease at the elbow and leave it on your skin. Do this twice a day for two weeks to see if the product causes a rash at the site of the test application.”

Tips and Hints

Dr. DeKoven has a lot of experience, and has come across all kinds of issues when helping his patients identify allergens. Here are some of the things he’s learned along the way.

Follow the KISS (Keep it simple, smarty) principle
If you’re trying to work out what you might be allergic to, cut back on the number of products you use. “Sometimes I see patients that are using 35 products a day. They could cover the kitchen table with the products they use in a month,” says Dr. DeKoven. “It’s usually much higher for women than men. And the number often surprises people.”

Read the label
“When in doubt, always go with the package information,” advises Dr. DeKoven. “A manufacturer can change the formulation of a product at any time.” He once saw a patient who appeared to be reacting to her shampoo. The ingredients listed online seemed fine. However, when the patient brought in the package, the ingredient list was different, and the offending allergen was indeed present.

Watch for hidden ingredients
In Canada, many manufacturers list fragrance as ‘parfum’, even in the English ingredient list. “Usually, this potential allergen is included as the last item on the list, but not always. That makes it easy to miss, even when you’re looking for it.”

Even products that look the same can be different
The ingredients of a product may vary depending on where it’s manufactured. “There’s a popular skin cream that I know – if it’s in a metal container, it’s made in Germany. If it’s plastic, it’s made in Mexico and it has a different list of ingredients,” says Dr. DeKoven. “They’re the same brand, and look identical, but they’re not.”

Natural is not allergen free
Many people believe that natural products are automatically safer for your skin. This isn’t always the case. “The example I always use is poison ivy. Completely natural,” says Dr. DeKoven. “But you certainly don’t want it on your skin.” Another allergenic natural product is tea tree oil.

Beware of the boyfriend allergy
One of Dr. DeKoven’s patients was convinced that she was allergic to her boyfriend because she would break out in a rash within six hours of being close to him. It turned out that she was allergic—to a preservative that was in his favourite moisturizing lotion. This situation even has a name: Consort Dermatitis. Relationship ending? Dr. DeKoven won’t tell!

So, there you have it: skin allergies 101. Thanks to Dr. DeKoven for sharing his knowledge. If you are concerned about an issue with your skin, you should consult a family physician or dermatologist.

[1] Dermatitis, October 2016. North American Contact Dermatitis Group Patch Test Results: 2013-2014.

The information in this article has been reviewed by a certified dermatologist.