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What Causes Armpit Pimples + How To Deal, From Derms

October 7, 2022
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Have you ever had a red bump that's so ambiguous you can't tell if it's a pimple, an ingrown hair, or something else entirely? Playing dermatologist at home isn't easy—especially when a mysterious bump occurs in an odd place. One prime example: armpit pimples.  

If you've never spotted a red bump under your arm, consider yourself lucky. These pesky bumps can be difficult to name and even more challenging to work around with a razor. Luckily, we asked derms for the 101 on armpit pimples so you can be bump-free stat. 

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What are armpit pimples? 

A true pimple on the armpit is like any other breakout—it's made up of dead skin cells, oil, and bacteria clumping together in a sticky glob, clogging the pore. This, alongside some inflammation, will result in a red, angry pimple. 

While zits like these can certainly appear under the arms (and anywhere else you have pores), there's a plethora of other bumps that are more likely taking up space in your armpit. A few of these include: 

  • Folliculitis: "The most common cause of acne-like bumps in the underarm area is folliculitis1, which is an inflammation and sometimes infection around the hair follicles," board-certified dermatologist Hadley King, M.D., tells mbg. This can present as small red bumps or larger nodules. 
  • Dermatitis: "Dermatitis, which may result from irritation or skin allergies, can occur in the underarm and may appear as red, flaky patches or associated with red bumps," board-certified dermatologist Marisa Garshick, M.D., FAAD, explains. 
  • Hidradenitis suppurativa (aka acne inversa): "This is a chronic skin condition characterized by inflamed and swollen bumps and nodules that are typically painful and can drain fluid or pus," King says. "The underlying mechanism is believed to involve a dysfunction of apocrine sweat glands, and genetics play a significant role," she explains. 
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Causes.

The armpit is a unique place—it's practically an ecosystem in and of itself. Because of that, it has some area-specific triggers that may be causing those little red bumps:

  • Hair removal: "Waxing and shaving can also trigger pimple-like bumps because the sensitive skin in this area is easily irritated and inflamed after hair removal," King says. 
  • Pore-clogging deodorant: If you're experiencing underarm pimples after switching your deodorant, it's probably the new product. "Underarm care may contribute to red bumps, which may be traditional pimples depending on if the products used in the underarm cause clogged pores," Garshick says. 
  • Fragrance: No matter the source of the fragrance (natural, synthetic, a blend of both), some people are simply sensitive to the addition. "Fragrance is a common cause of dermatitis, and I recommend choosing a fragrance-free deodorant and antiperspirant whenever possible," board-certified dermatologist Rebecca Marcus, M.D., FAAD, explains. If you can handle fragranced options, feel free to keep using them. But if you find that you're breaking out, consider switching to unscented options.
  • Sweat buildup: While sweating under your arms is pretty much unavoidable, you can use an antiperspirant (yes, antiperspirant is different from deodorant), if you believe the sweat is causing your underarm breakouts, Garshick says. We believe that natural, aluminum- and baking-soda-free deodorants are the best options, but we also know that everybody's needs are different. If you find they don't work for you, then antiperspirant may be the way to go.
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Prevention tips.

Let it be known—prevention is the route of least resistance when it comes to armpit pimples. There's no need to treat problems you don't have, after all. Here, a few rapid fire tips to keep in your back pocket: 

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Treatments.

If you already have an armpit pimple, there are a few expert-approved methods of treating it. While some face products may work as well, you should be mindful that you're dealing with very different skin.

"The skin in the underarm is thin, and because it is a skin fold, the skin rubs against itself and forms an area of occlusion, which can lead to irritation and friction," Garshick says. Here, a few safe treatment options:

1.

Spot treatments with BHAs.

"An OTC [over-the-counter] topical spot treatment containing salicylic acid may be helpful," Marcus suggests. Salicylic acid is in a class of exfoliator called BHAs or beta-hydroxy acids. Salicylic acid is particularly beneficial for acne-prone skin2, due to its ability to break through oil and dead skin. Plus, it's antibacterial

If you're on the hunt for a grade-A choice, this First Aid Beauty Fab Pharma BHA Acne Spot Treatment Gel is a winner. While it will work wonders for the underarm area, you can keep it on hand for breakouts that pop up anywhere. 

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2.

Professional hair removal. 

"If ingrown hairs are the problem, the most definitive solution is getting rid of the hair," King says. Laser hair removal is a great option for those prone to ingrowns, especially if it's causing you discomfort or pain. 

It is important to note that laser hair removal is a pricey procedure, and it's not a realistic option for everyone. But don't worry, there are plenty more budget-friendly products out there to help prevent and treat these bumps—here are a few to get you started

3.

See a dermatologist. 

"Before treating an armpit pimple, it's important to confirm that it is, in fact, a pimple, and not something else," King says. One person who will know the answer to this tricky question: your derm. 

Especially if you're prone to breakouts outside of the underarms as well—whether it be on the face, back, neck, chest, etc.—then a prescription-grade product may work better than OTC options. 

Can your armpits detox?

If you frequent the clean beauty space, you may have heard of an "armpit detox." Some people believe that the transitional stage of switching from an antiperspirant to a natural deodorant will cause the skin to "detox," essentially purging all impurities. This tends to include an increase in sweat and odor. To be frank, there's no research to back up this claim. 

However, if you have recently switched to a natural deodorant, then you will most likely experience an increase in sweat given the lack of aluminum—the ingredient that blocks the sweat from coming out of your pores. This increase in sweat can lead to more armpit pimples, Garshick explains, but only for some individuals.

If you want to use a natural deodorant but fear the increased sweat, just know it varies for everyone, and it might not be a problem for you. If it is, you can always do a quick pit-wash midday if you're worried about sweat buildup. 

The takeaway.

It's not easy to identify a random red bump on the skin, especially if it's in a particularly odd area like the underarms. Armpit pimples can occur due to sweat and bacteria buildup, but red bumps in this spot can also be an ingrown hair, folliculitis, or dermatitis. There's a long list of potential causes, but even more ways to prevent these from popping up again and again. Getting rid of these bumps could be as easy as finding a trusty razor that's designed for sensitive skin—here are our top picks if you're on the hunt. 

Hannah Frye
Hannah Frye
mbg Assistant Beauty Editor

Hannah Frye is the Assistant Beauty Editor at mindbodygreen. She has a B.S. in journalism and a minor in women’s, gender, and queer studies from California Polytechnic State University, San Luis Obispo. Hannah has written across lifestyle sections including health, wellness, sustainability, personal development, and more. She previously interned for Almost 30, a top-rated health and wellness podcast. In her current role, Hannah reports on the latest beauty trends, holistic skincare approaches, must-have makeup products, and inclusivity in the beauty industry. She currently lives in New York City.