What to Recommend Before Patch Testing

Patch testing is an incredibly helpful tool for identifying allergens in patients with allergic contact dermatitis. However, patch testing may not be feasible or necessary for every patient. Rajani Katta, MD, shared her recommendations for these patients at the 2019 Fall Society of Dermatology Physician Assistants Conference in Scottsdale, AZ.

Dr Katta is a clinical professor of dermatology at McGovern Medical School of the University of Texas Health Science Center in Houston, TX. She was the director for the Contact Dermatitis Clinic at Baylor for 17 years and now has her own private practice for contact dermatitis.

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Dr Katta said she asks patients about their skin care routine and what products they use on their, face, hair, and body. It is not enough to just tell patients to stop using certain products, said Dr Katta, adding that she is very specific with what she recommends. "Early on I was not as specific," she said. "However, there are so many options available now that is can be very difficult for patients to find one that does not have their allergen." She has lists of products patients can use on her website and updates this list every year.

One reason it can be difficult for patients to find a product without allergens is because there is no legal definition for hypoallergenic. These products can still have allergens, and sometimes they even have more, said Dr Katta. Fragrance-free is also another confusing term because a product can contain fragrances as long as it is not used as one, she added. Patients will think a product that is labeled all natural, hypoallergenic, and/or fragrance free is safe, added Dr Katta, but these can still contain known allergens. In addition, Dr Katta stated she rarely recommended baby products because these are sometimes worse.

Nickel is still the number one allergen and can be leached out by sweating, said Dr Katta. After nickel, the top 15 allergens include fragrances and other preservatives. There is a difference between no fragrance labeling and fragrance-free labelling, Dr Katta said, and there are at least 127 fragrance additives.

No product is nonallergenic, she said. When she selects “least allergenic” products to recommend to patients, she looks for she looks for ones that have fewer than 50 allergens. It is important to recognize that less allergenic options are not nonallergenic, she said, and to discuss this with patients as every product has some type of allergen. A lot of patients will do better if they follow these recommendations, she said.

For patients with eyelid dermatitis, Dr Katta considers what the patient applies to or near the eyes, including hair products, what could be transferred from their hands, and airborne allergens, such as essential oils from diffusers. Nickel particles or chemicals from nail polish can be transferred to the eyes, she noted, adding that patient’s metal eyeglass could also cause eyelid dermatitis.

For these patients, Dr Katta has them stop their traditional skin care products, any makeup they use and makeup wipes, soap, remove and stop using nail polish, such as acrylic, shellac, and gel, and stop eyedrops. She also noted that providers should consider patient’s metal eyeglass frames as a potential trigger.

For patients with eyelid dermatitis, she recommended Albolene, less allergenic cleansers, moisturizers, and hair care products. She also encouraged patients who wear glasses to use plastic eyewear.

To treat the inflammation, she recommends cortizone 10 (1% hydrocortisone ointment), which can be used on the eyelids twice daily for no more than 7 days. Protopic ointment can also be used, she noted. She told providers to be careful with Tobradex because it can cross react with neomycin.

If a patient has a history of atopic dermatitis, an allergen can trigger eyelid dermatitis, she said. Allergic contact dermatitis is a delayed reaction mediated by T cells which can take 24 to 72 hours or longer to present following allergen exposure, she added.

Similar to eyelid dermatitis, Dr Katta has patients with facial dermatitis stop skin care, makeup, and hair care. She also recommends they use a different sunscreen and asks them about anything that could be transferred from their hands to their face.

She recommends gentle cleansers, such as Albolene, Aveeno baby cleaning wipes, Neutrogena ultra-gentle hydrating cleansers. Dr Katta said she gives patients handouts with all the information they need on what products to use and avoid, which are also available on her website. In addition, she has patients stop using Dove bar soap and any natural or botanical soaps from Whole Foods.

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Among men with facial dermatitis, Dr Katta asks them about their aftershave, shaving gel, sunscreens, as well as the products their wife uses, noting that she has seen a few patients who have transfer contact dermatitis. Patients will also try over-the-counter products first, such as neomycin or mycitracin.

While she hardly sees patients with allergies to parabens, she does include products without parabens on her list for those who may be strongly against using them due to concerns about endocrine disruption.

For patients with hand eczema, she recommends they stop skin care, using Bath and Body Works, antibiotics, wipes, using leather and rubber gloves, as well as GoJo soaps if they work as mechanics or in industrial settings. If patients have an infection, she prescribes oral antibiotics. In addition, she noted that about 50% of topical steroids used to treat dermatitis contain propylene glycol and recommended providers consider this when treating patients with allergic contact dermatitis.

Dr Katta recommended using cashier vinyl gloves for nonmedical workers. She also suggested double gloving and using white cotton liners, as well as heavy duty cotton or canvas gloves. All medical personal need patch testing, she said. In addition, she recommended Avagard fragrance free hand sanitizers, manufactured by 3M.

For generalized dermatitis, Dr Katta said to consider clothing in addition to skin and body care products. She recommended less allergenic products, fragrance free laundry detergent, and steroids. Formaldehyde and formaldehyde preservatives are in both skin care products and clothing, she said. halobetasol propionate cream has formaldehyde, as well as other creams and ointments, she added.

Some patients with recalcitrant atopic dermatitis may have allergic contact dermatitis, said Dr Katta. She suggested keeping an open mind with patients who may need systemic therapy and consider the possibility they have allergic contact dermatitis and possibly an allergy to steroids.

Dr Katta shared a list of steroids she used for patients with steroid allergies, which is not available on her website:

• Cortizone 10
• Protopic ointment
• Desonide ointment
• Triamcinolone 0.1% generic as long as it does not contain propylene glycol (Dr Katta said she wrote this instruction on the prescription)
• Desoximetasone 0.05% ointment 0.25% if provider is not sure if the dermatitis is caused by the active steroid or an ingredient
• Halog ointment

The creams she recommended include were Locoid Lipocream and Cloderm Cream. All bets are off with generics, said Dr Katta, because they are not necessarily formulated in the same way as the branded version.

Cheilitis can be caused by allergens to balsam of pero, which is found in flavoring, some foods, and in lip balm, she said. She also recommended providers ask patients about any crowns, bridges, and fillings because sensitizers used in acrylic nails are also used in fillings.

Allergic reactions to clothing, caused by dyes and formaldehyde resin, can present as generalized dermatitis in atypical locations, noted Dr Katta, especially in areas of high friction and sweating, such as the thighs. Blue and black clothing often contains these allergens, notably workout clothing (sports bars, leggings, etc) and uniforms. Patients with allergic contact dermatitis caused by clothing can wear items made from 100% silk, denim, and polyester, said Dr Katta, as well as lighter colors.

At the end of her presentation, Dr Katta recommended providers go to the Allergic Contact Dermatitis Society website for more information and http://www.doctorkatta.com/.

—Melissa Weiss

Reference

Katta R. Before the patch test: What to recommend and avoid in suspected allergic contact dermatitis. Presented at: 2019 Fall Society of Dermatology Physician Assistants Conference; November 22, 2019; Scottsdale, AZ.