New triggers for contact dermatitis in adults and kids

With a practice almost exclusively devoted to allergic contact dermatitis, Rajani Katta, clinical professor of dermatology, at McGovern Medical School, UTHealth, Houston, Texas, often picks up on new trends in products causing allergic reactions. One of the latest is allergies related to all-natural products, in particular deodorants containing essential oils. She spoke to colleagues on the topic Saturday at the Society for Pediatric Dermatology Annual Meeting in Austin, Texas.

“I have seen a number of allergic reactions to those essential oils that are used in deodorants,” she says, and these can be a particular issue in women who shave their underarms, she adds.

“That causes an impairment of the skin barrier and makes you more likely to develop an allergic reaction,” Dr. Katta says.

She has also seen a rising number of cases of allergies to the flavored lip balms that currently are popular with teenage girls and young women who like to experiment with different products and flavours.

“A lot of my patients just simply don’t realize that you can become allergic to those flavorings,” Dr. Katta says.

Often it will be a vicious circle, the patient will experience some inflammation, think they have chapped lips, and apply more lip balm, and the problem gets worse. While patch testing can determine the specific allergen, she says, it can be difficult for patients to then find flavored lip balm products excluding that specific allergen because U.S. labelling laws do not require the manufacturer to break down the specific constituents of flavorings since they are considered a trade secret.

Patients often also do not realize that they can become allergic to their clothing, and if it happens they presume it is the fabric that is the culprit, Dr. Katta says. More often it is the dye; particularly darker dyes, such as black and blue.

Allergies are more likely to occur with clothing that is tight, made of a synthetic material (because dyes leech out more easily) and where friction and sweating is involved. Workout clothing, such as tight leggings, yoga pants and sports bras, and school sports kit, meet all those criteria, she says. If the item is a uniform that cannot be swapped for something else, wearing barrier clothing such as a white tee shirt underneath can help.

Sneakers without socks create similarly ripe conditions for sensitization of feet exposed to the chemicals in rubber cement pulled out through friction and sweating. If the wearer becomes allergic to the rubber cement which holds the shoes together, their feet can end up covered in blisters.

The craze among children for creating slime from recipes they find online is an increasingly common prompt for contact dermatitis. Many recipes contain craft glue, which turns out to contain methylisothiazolinone – a chemical used in many personal care products like body washes, shampoos and hair gels.

The fact that methylisothiazolinone is used in so many craft glues came as a surprise, Dr. Katta says.

“Once you are sensitized to this chemical, the next time you are exposed to it via your hand soap, you can develop an allergic reaction. It is a real issue for some children,” she says.

She recommends that children with eczema or sensitive skin, or any cuts or scrapes which can act as a portal for sensitizing skin, wear gloves when making slime.