Allergic Contact Dermatitis: Maintaining Our Armor in 2022

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Allergic contact dermatitis burden many people, but it is important for patients to know why and how they may limit their risk.

The skin functions as armor, protecting human beings from harmful outside elements and ensuring a level of safety and comfort for the body. Allergic reactions are natural responses to these harmful elements invading bodies.

Despite the existence of harmful elements threatening to invade the skin that remain outside of an individual's control, there are certain elements that are admitted into the skin. These elements can often result in allergic reactions that can severely affect a person's daily lives, and their existence is widely unknown by the greater public.

There have been a number of major product recall decisions made by the US Food and Drug Administration (FDA) in recent years, including sunscreen products in aerosol cans and dry shampoo products. These decisions are part of the ongoing discovery of harmful elements found in everyday products of which most remain unaware.

While these actions by the FDA were taken due to the existence of harmful carcinogens such as benzene, they still highlight the fact that many products first approved for widespread use may in fact not undergo the same amount of regulation that food or drugs undergo.

Many harmful elements may come from personal care products (PCPs), which can contribute to the breakdown of our skin’s overall defenses. Allergic reactions to elements found in PCPs are not to be taken lightly. PCPs may, in fact, end up contributing to inflammation and allergies such as the common reaction known as contact dermatitis.

It is well-known that allergic contact dermatitis is a problem for many people, but it is important for patients to know why it is so impactful, what contact dermatitis’ relationship is with PCPs, and how they may be able to prevent and be on the lookout for it.

The What, Where, and When of Allergic Contact Dermatitis

Allergic contact dermatitis takes the form of a red, itchy rash with an often unknown cause, often resulting from exposure to a particular chemical or compound.

This itchy rash can be found at the allergen’s point of contact, usually pink or red, potentially flat or raised, and it may even result in blisters. Often those who suffer from the condition are custodians, mechanics, healthcare workers, or hairstylists.

The condition may end up lasting for up to 4 weeks, even if allergens or irritants have been removed and cleaned off. Cases of allergic contact dermatitis can result in visible symptoms within hours post-exposure, but it may even be 1 to 7 days before it presents for patients.

Most commonly, dermatologists will treat the contact dermatitis with hydrocortisone or other steroids, though they first should rule out psoriasis as a possible alternative. If the rash from the condition is found to be widespread, either injectable or oral corticosteroids may be prescribed.

Personal Care Products and Contact Dermatitis

Whether browsing through social media or wandering through health and beauty aisles of drug and department stores, people may instinctively hunt for products to make their skin and hair feel healthy.

They should, however, purchase these products with caution and an acute awareness of potential drawbacks, despite vague labels such as ‘natural’ or ‘clear.’ The FDA describes one branch of PCPs as cosmetics such as makeup, moisturizers, perfume, lipsticks, fingernail polishes, and shampoos. Crucially, these are not subjected to the FDA’s premarket approval authority.

Peter A. Young, MPAS, and colleagues from the Department of Dermatology at Stanford University, published a recent study regarding the prevalence of contact allergens in PCPs.

“Skincare products are not food and they’re not drugs, and so they’re not really regulated by the Food and Drug Administration in our country,” Young said. “Because of that, companies can put a lot of things on the label that aren’t necessarily subject to a rigorous screening process or a rigorous governing process.”

Young and colleagues collected data on products sold at Whole Foods Market, Target, and Walgreens, and used the Contact Allergy Management Program (CAMP) database to assess the PCPs labeled as natural.

They identified a total of 73 unique allergens on component lists of these 1555 PCPs, appearing 7487 times in total. The investigators pointed out that manufacturers often would list botanical extracts—which are major causes of contact dermatitis and photosensitization—by their Latin names, causing confusion for customers.

“I have, pretty frequently, patients that complain of skin issues, irritation, redness, rashes,” Young said in an HCPLive interview. “And when we discuss the possible triggers or causes, then they’re very confident the trigger or cause could not be related to the products that they use on their skin because they only use ‘natural’ skincare products.”

Some of the more common allergens contained in these natural-labeled products were identified by Young as being tea tree oil or carmine, the latter of which is a red dye used in lipstick made up of crushed insects.

Another study published this year by a team of Harvard Medical School and Massachusetts General Hospital researchers identified that pediatric allergic contact dermatitis is driven most by fragrances, metals, and preservations have driven the rate of pediatric allergy contact dermatitis.

The most common allergen among all 3 groups assessed from ages 0 to 17 in their research was hydroperoxides of linalool, commonly found in fragrances, hygiene products, and cosmetics.

Some other common allergens identified in the study were fragrance mix I and benzoyl peroxide, the latter of which is used in a great many skincare products designed to treat acne.

The main takeaway from these major studies is that allergens can be found in products of all kinds, including those labeled as natural. They are frequently the cause of contact dermatitis breakouts and spreading awareness of their ubiquity is essential to ensuring the health and wellness of patients.

Ways to Defend Against Allergens

When considering how to advise patients on how to repair their skin barrier and defend against allergens, keeping skincare regimens to a minimum and becoming aware of common allergen ingredients is a positive first step.

Products such as chemical exfoliants can be more gentle on the skin than physical exfoliants such as scrubs, although they should not be applied once a week for dry or sensitive skin, according to a recent article by the New York Times.

The same article cited the need for those with skin allergies to protect and rebuild their skin’s barrier, known as the acid mantle. The acid mantle is a protective layer on the skin made up of natural oils, sweat, and amino acids. Too many harsh exfoliants or alkaline washes may promote allergic reactions and inflammation.

Another step that can be taken to prevent too much exposure to allergens is patch-testing, which patients may be able to request. Patch testing is a key way to prevent constant breakouts of contact dermatitis, and can both help identify allergens and prevent misdiagnosis.

“I think atopic dermatitis often gets misdiagnosed as allergic contact dermatitis,” said Karan Lal, DO, the Affiliated Dermatology Scottsdale director of pediatric dermatology and cosmetic surgery. Lal is also the social media chair for the Society for Pediatric Dermatology.

“I think it's very easy at the moment in the clinic to get a label of atopic dermatitis for somebody because they have a dry, scaly, rash,” Lal described in an HCPLive interview. “It's itchy without being worked up. So oftentimes, they get referrals for what it's a topic term not responding to certain agents or medications, and they haven't been adequately patch-tested.”

A professor of dermatopharmacology at the University of Zurich has authored research into the acid mantle and concluded with a suggestion that patients avoid products with a pH >7, as this will promote a healthy pH balance on the epidermis.

Certain products containing elements such as petrolatum, glycerin, and hyaluronic acid may also promote protection of the skin barrier and allow the skin to maintain its moisture. Nevertheless, given the danger of allergens contained in skincare products, this step alone should not be taken without the others.

It is evident that the growing public interest in skincare products, especially through social media, has promoted a larger discussion about the positive and negative aspects of so many products designed for skin. This can be considered a positive outcome, provided the discussion leads to a more cautious approach to promoting skin health.

Allergic contact dermatitis is one possible outcome from the use of personal care products, but as recent reports on sunscreen and dry shampoo recalls have demonstrated, the risks are high when products are applied without caution.

In the years to come, further research into skin phenotyping, more public awareness of patch testing and hidden allergens, and a greater understanding of the FDA’s regulatory measures, may promote better skin health and fewer skin allergies.