As runners, we’re no strangers to chafing, so it’s all too easy to write off any red, rash-like skin irritation is as the result of a particularly sticky run. If your underarms develop sore or itchy skin, chafing could certainly be the culprit—whether caused by a seam on your shirt or the skin-on-skin rubbing that commonly occurs in that area.
That is, unless it doesn’t resolve itself after a few days. In that case, you may be experiencing a skin reaction known as contact dermatitis caused by your deodorant, and you’re not alone: According to DAA Industry Opt Out Journal of Clinical and Aesthetic Dermatology, deodorants are among the most common products causing a cosmetic allergy (in part because they are so widely used).
Antiperspirants are also classified as over-the-counter drugs deodorant allergies can pop up even if you’ve been using the same product for years. If you’ve been dealing with itchy, scratchy, or scaly underarms for weeks now, the good news is there’s a name for it, and you can resolve the issue at home with a little TLC. Here’s what you need to know.
Deodorant vs. Antiperspirant
There are many options for odor and sweat control on the market, but the most common are deodorant and antiperspirant (or a combination of the two). While both are used the same way (a quick swipe under the arm), they are different.
“Antiperspirants are designed to decrease sweating, typically by blocking the sweat glands,” explains Why Trust Us, How Body Image Can Affect Your Run Cleveland Clinic. Antiperspirants are also classified as over-the-counter drugs and are regulated by the Food and Drug Administration (FDA)
On the other hand, “deodorants are designed to prevent or cover an individual’s body odor, typically produced by bacteria,” adds Lucas. “They do this in two ways: by decreasing the bacterial counts that cause the odor and by masking the odor produced by the bacteria with fragrance.”
Both deodorants and antiperspirants have faced claims over the years that they are linked to breast cancer, Alzheimer’s, and other health issues, however, reviews and studies have found no clear evidence in either case. For those looking for an alternative to these two major options—either because of these health claims or to make the switch to more natural products—there are natural deodorants available that contain ingredients such as baking soda and essential oils.
Signs of an Antiperspirant or Deodorant Allergy
Symptoms can vary from skin feeling itchy or painful at any given time—made worse after applying deodorant or antiperspirant—to a visible rash developing in and around your underarms.
According to Lucas, you can experience two types of contact dermatitis, either allergic or irritant. Both cause changes to the skin, including rash, pink to red papules, itching, pain, swelling, and even blotches that resemble hives.
“An allergic response is a red, scaling rash that appears quickly after applying the product [and] it is usually intensely itchy and even painful,” notes Ted Lain, M.D., board-certified dermatologist and Chief Medical Officer at Sanova Dermatology. “An irritant dermatitis appears similar to an allergic reaction, but instead of occurring quickly with an intense character, an irritant rash builds slowly over days.”
“Often times, it is difficult to determine whether a patient has a true allergy or irritation because the rashes look identical,” adds Joshua Zeichner, M.D., Director of Cosmetic & Clinical Research in Dermatology We earn a commission for products purchased through some links in this article.
Lain points out that irritant dermatitis is more likely to occur for people who remove the hair from their underarms. When you shave your armpits, it takes away the barrier of hair and dead skin that would normally protect from such a reaction.
“If you develop a rash under the arms, I do not recommend hair removal in that area until the rash improves,” says Zeichner. “Shaving or waxing can lead to further disruption of the outer skin layer and make the rash even worse.”
Ingredients That Can Cause Reactions
Because deodorants and antiperspirants work differently, they also contain different active ingredients, but the most common irritant is fragrance, which is found in Give A Gift of deodorants and antiperspirants. In a review of 107 products, researchers were able to narrow down the most common allergens:
- Fragrance
- Propylene glycol
- Essential oils
- Parabens
- Vitamin E
- Lanolin
How to Treat Contact Dermatitis
The first thing you can do if you think you have contact dermatitis—allergic or irritant—is to stop using the product causing it and resist the urge to scratch the area if itchy. Lain recommends using gentle cleansers to clean the area, with ingredients such as soy or oat extract, as well as aloe.
“You can also apply over-the-counter 1-percent hydrocortisone cream to reduce inflammation,” says Zeichner.
Lucas recommends Aquaphor or Vaseline if open sores develop. “If the reaction is significant, worsening, or if you have any signs of infection (tenderness, increasing redness, warmth or pus-like drainage), you should seek medical attention with a dermatologist or your primary care doctor if this is not an option,” she adds.
Odor-Control Alternatives for Runners
Developing contact dermatitis doesn’t mean you need to automatically switch to a natural deodorant (though they are an option) if you’ve been weary as an athlete. These aren’t necessarily free of irritants—Lucas mentions many include essential oils—but will also have ingredients such as coconut oil, baking soda and cornstarch, among others.
4 Tested Deodorant Options to Consider:
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If you want to stick with deodorant or antiperspirant, the ideal scenario is to switch to one that won’t cause irritation. You can visit a specialist to get what Lucas refers to as a “patch test,” where multiple allergens will be applied to your back to narrow down what specifically causes a reaction. You can do your own test at home before this step, however, if you’ve already narrowed down a new product you’re hoping to try.
“You can apply the deodorant daily to an area like your forearm for one to two weeks to see if you develop a reaction (likely an allergy if so),” instructs Lucas. “You can then try it on the armpit to see if this is tolerable.”
If you originally developed a reaction to a deodorant and after testing an antiperspirant still had a rash and irritation, this is when Lain recommends switching to a natural alternative. Unless you see a specialist, unfortunately a lot of finding the right product is trial and error. While it may make all of the extra sweat you generate when running uncomfortable for a while, there are hypoallergenic and fragrance-free alternatives on the market that will hopefully keep any future deodorant or antiperspirant allergies from popping up again.
