When you get a rash under your armpit such as redness, itching, or flaking skin after applying deodorant or antiperspirant, it’s a sign that you might be allergic to something in the product.

Most adults are in the habit of swiping deodorant or antiperspirant under their arms as a part of their daily hygiene routine.

Both deodorant and antiperspirant products are meant to keep your body smelling fresh, even as your body temperature rises and you begin to sweat.

Since most deodorants and antiperspirants have similar active ingredients, it’s possible that almost all of these products can cause an allergy or sensitivity.

This article will help you figure out if you are allergic to your deodorant and give you tips for treating this kind of allergy.

Deodorant is a product that soaks up and masks the odor of your sweat.

Antiperspirant is a product that stops you from sweating.

When people refer to a “deodorant allergy,” they could mean an allergy or sensitivity to either of these products.

A deodorant allergy is a type of contact dermatitis that is triggered by ingredients in deodorant or antiperspirant products. This type of allergy can cause:

  • redness
  • inflamed skin
  • hives
  • itching

You can develop a sensitivity or allergy to your deodorant even if you’ve been using the same product for years. Sometimes, cosmetic companies change their formulas without alerting the consumer, introducing a new ingredient that you may have already been sensitive to.

It’s also possible to develop a new allergy to an ingredient in your go-to product.

According to the Food and Drug Administration (FDA), four categories of deodorant ingredients can trigger allergies and irritation. They are:

  • aluminum
  • fragrances
  • preservatives
  • dyes

In a 2011 study, 25 percent of people who showed an allergy to cosmetic fragrance were triggered by deodorant fragrance ingredients.

Different types of alcohol are considered fragrance ingredients and can also trigger allergies.

Preservatives in deodorant can also trigger an allergic rash or irritation. Parabens are a type of preservative that was once included in many personal care products. Most deodorant companies have removed parabens from their formulas, but there are still some that include parabens.

Metals in your cosmetic products can trigger an allergic reaction. One of the ingredients that’s used to stop you from sweating is aluminum. Research has linked contact dermatitis with this type of aluminum exposure.

Dyes used to add to or change the color of your deodorant product may also be the culprit.

Symptoms of a deodorant allergy may include:

  • itchy, red patches under your arms
  • inflammation and swelling
  • scaling and flaking skin where the deodorant has been applied
  • underarm blisters or hives
  • lumps or cysts under your armpit

It can be hard to pin down whether your deodorant is what’s causing your allergic reaction.

Since deodorant and antiperspirant products are allowed to simply list “fragrance” or “parfum” on their ingredient label, it can be hard to tell if it’s any one of the many fragrance ingredients that’s triggering your reaction.

Your doctor or allergy specialist can help you confirm what type of reaction you’re having and what’s causing it.

If you have symptoms of a deodorant allergy, your doctor can use a patch test to confirm your diagnosis.

There are so many alternatives to deodorant with allergens, with more seeming to pop up every day.

“Natural” deodorant options use ingredients like essential oils, baking soda, and cornstarch to keep your underarms dry.

Be careful, though, as people can develop allergies to products labeled as “natural.”

Some of these “hypoallergenic” deodorants are more effective than others. Everyone’s body is different, so you may need to try a few brands before you find the natural deodorant formula that works for you.

If you have sensitive skin, it’s possible that you will experience symptoms of itching and redness even with some of the natural deodorant products that are on the market.

Some people find that they are more comfortable skipping deodorant completely or only using it for special circumstances.

People lived for thousands of years before they could drop by the supermarket to buy deodorant, so going without it isn’t going to hurt your health.

There’s nothing wrong with a little sweat — in fact, it’s good for you.

After an initial “armpit detox,” during which your body will recalibrate the bacteria that live under your arms, you may find that you don’t notice a particularly strong or offensive smell coming from your armpits.

Some people use a few drops of a natural antibacterial substance under their arms to keep them feeling fresh. One example is tea tree oil diluted with a carrier oil, like almond oil.

When you’re experiencing an allergic reaction from your deodorant, your first priority might be symptom relief.

An over-the-counter topical antihistamine, such as diphenhydramine (Benadryl), can be applied to soothe burning, itching skin.

If symptoms persist or the rash is especially painful, your doctor may prescribe a prescription-strength topical cream.

Home remedies such as cold compresses, an oatmeal bath, and calamine lotion may also help symptoms of itching and inflammation.

Going forward, you should identify and try to avoid the allergen. This could be as simple as switching deodorants. It might involve a visit to your doctor to figure out which ingredient is causing your reaction.

How to find relief when you have a skin rash or allergy

There are a few tried-and-true home remedies that can help you find relief when you have an allergic reaction. These home remedies include:

  • applying pure aloe vera
  • using tea tree oil, diluted with coconut oil
  • applying baking soda paste
  • bathing in Epsom salt
  • applying cold compresses
  • taking an oatmeal bath
  • applying calamine lotion

Having an allergic reaction to your deodorant isn’t uncommon. It also isn’t usually a medical emergency.

Self-treatment with home remedies, switching products, and identifying your allergy trigger might be enough to ensure that you don’t have to deal with symptoms of this type of allergy again.

If your symptoms persist even after switching deodorants, consider calling your doctor and asking for a referral to an allergy specialist.

If your allergic reaction symptoms result in cracked, bleeding skin under your arms, yellow discharge at the site of your rash, or a fever, seek emergency medical help right away to make sure you don’t have an infection.