Pimples aren't fun, no matter where you get them, but there's something incredibly annoying about pimples on your underarms. If you're experiencing pit pimples, Ivy Lee, MD, a board-certified dermatologist based in Pasadena, California, says the first thing you need to know is that these bumps are different from the ones you might get on your face (or the inside of your nose, which might be the second most frustrating place where they pop up).
"When a lot of people experience red or tender bumps in the armpit, they automatically think, 'Well, this looks similar to a pimple on my face, so it must be acne,' and I want to dispel that because often it's not acne," says Dr. Lee. "It can be acne-like, but several different things can cause it."
Experts In This Article
- Ivy Lee, MD, board-certified dermatologist
- Rachel Nazarian, MD, FAAD, board-certified dermatologist at Schweiger Dermatology Group in New York
Keep reading to find out whether those bumps in your armpit are actually pimples or something else entirely.
What causes bumps under my armpits?
There are two main causes behind those pesky bumps under your arms that look (and often feel) like zits—neither of which are technically pimples at all.
Ingrown hairs
First, there are ingrown hairs. "Ingrown hairs happen when the hairs in that armpit area become bent or twisted so that they aren't coming out of the skin properly, which can cause localized inflammation and tenderness," says Dr. Lee. If you've ever had an ingrown elsewhere on your body (and, let's be honest: who among us hasn't?), you're likely somewhat familiar with what these look like.
Generally, you can tell the difference between these types of armpit bumps and run-of-the-mill acne based on what's in the center: A zit will typically have a white or yellow pus-filled center (or, if it's a blackhead, a hard black dot), while an ingrown will show up with slight red coloring and a hair visible beneath the skin. However, the two can look really similar–especially in spots like your armpit, where it can be hard to get a closer look.
Folliculitis
The other main cause of bumps under your arm is folliculitis, which is basically a more intense version of an ingrown hair. "It's a type of inflammation in the hair follicle, and is much more common in the underarms than acne," says Rachel Nazarian, MD, a board-certified dermatologist based in New York City.
Dr. Lee explains that these types of bumps occur when an ingrown hair becomes inflamed due to irritation. "This happens either due to friction from wearing certain clothes that are rubbing in the area or from a localized bacterial infection around the follicles," she says, adding that these can look like "small pimples, cysts, or even boils."
With that in mind, folliculitis can be a bit harder to identify, mainly because it has many of the same common causes as run-of-the-mill acne (Side note: bacteria, which is one of the main culprits behind acne, thrives under your arms also the reason why armpits smell.). "It can mimic acne and appears as red bumps on the skin, often with a whitehead, and surround each hair follicle," says Dr. Nazarian. "The causes tend to overlap between acne and folliculitis. Hormones, oil production, and dead skin cells are thought to play a role in the etiology of folliculitis—and acne also tends to involve the glands and blockage of pores, and can also cause red bumps."
The easiest way to tell the difference between pimples and folliculitis is that pimples tend to occur in clusters, while folliculitis typically appears as a one-off bump.
Other causes of bumps under your arms
If none of these conditions sounds like what you're dealing with, there are a few other reasons why you may be experiencing red spots in your armpits.
"A true cyst may appear in the armpit area, which tends to have a central blackhead—or even an infection, like an abscess—which is exquisitely painful, and worsens each day," says Dr. Nazarian. "Abscesses are single lesions that are filled with pus, may require oral antibiotics, and should be drained. If you're not sure what's going on, or are concerned you have an abscess, I often recommend an evaluation by a board-certified dermatologist."
Additionally, if you're experiencing recurrent, painful breakouts under your arms, it may be due to a condition called hidradenitis suppurativa. Like facial acne, this condition is characterized by microscopic plugs in your pores. But, this is much different than typical pimples—it's an inflammatory medical condition, and you'll want to book an appointment with a board-certified dermatologist to come up with a treatment plan.
What causes armpit bumps?
As you may imagine, an area exposed to a lot of sweat, bacteria, and hair removal is primed for skin conditions to occur, and certain things can increase the risk of them happening.
"Often, improper shaving techniques can cause folliculitis on the armpits by using a dull blade or inadequate lubrication, which puts pressure and tugging on the hair and skin," says Dr. Nazarian. "Compressive undergarments, lack of showering, and poor hygiene habits are also causes—the people most likely to experience folliculitis include active individuals who like working out, but folliculitis can happen to anyone." She adds that certain ingredients found in deodorants and antiperspirants—namely, fragrances and perfumes—can also be somewhat irritating to the delicate skin under your arms.
Your best bet to avoid any type of bumps in your armpits is to keep the area clean (pro tip: use a glycolic acid pad under your arms every once in a while to kill off any bacteria), shave with some sort of shaving gel and a fresh blade, and try to get out of any tight, sweaty clothes as quickly as possible—but more on that below.
How to treat armpit pimples
If you've ruled out cysts and hidradenitis suppurativa, you can usually treat ingrown hair and folliculitis-induced bumps at home. First things first, though, you'll want to keep in mind that the skin under your arms is more sensitive than the skin on your face, so the usual products you rely on for treating acne may be too strong to use in this area.
"Given the anatomy and where the armpit is, which is in the flexural space in that little nook of your body, anything you put onto your armpit skin is going to penetrate the skin much more easily than that on your face," says Dr. Lee. She explains that because the side of your body pushes the ingredients into your skin, it's basically the same as putting saran wrap or a bandage over it.
First, do not try to pop what you think might be a pimple under your arm. Because these bumps probably aren't pimples—and are more likely related to an ingrown hair—picking at them can do much more harm than good. If you aren't careful (or even if you think you are being careful), you risk driving the hair deeper into your skin and making things even harder to treat. You can cause so much irritation that you may even turn a regular ingrown into folliculitis. Instead, dermatologists recommend trying one (or all) of these methods to eliminate an underarm bump.
Use a warm compress
Dr. Lee suggests using a warm compress if you have one bump. "Soak a hand towel in warm water, ring it out, and hold it to that area to hopefully encourage draining of that localized infection," she says. This will help open up the pores under your arms, making it easier for whatever's trapped underneath your skin (whether that's pus, hair, or some combination of the two) to work its way out.
Opt for a gentle cleanser
Keeping your underarms clean is critical in this situation, and given how sensitive the skin is in this area, your usual body wash may not be quite the right choice when you're dealing with irritation. Dr. Nazarian recommends swapping in an anti-inflammatory facial cleanser—like Cetaphil Redness Relieving Foaming Face Wash For Sensitive Skin ($9)—which will whisk away bacteria while also helping to calm your skin.
Try an over-the-counter treatment
If proper cleansing isn't enough to get rid of your armpit bumps, or you have multiple little tender bumps in that area, "then you may want to think about an over-the-counter antibiotic or go to a dermatologist or primary care for a prescription antibiotic gel," says Dr. Lee.
As far as over-the-counter topicals go, she recommends using a formula that's got a low concentration of benzoyl peroxide, ideally between 2 and 5 percent (Dr. Nazarian is a fan of Proactiv's Acne Cleanser ($25), which fits the bill). "Benzoyl peroxide can be irritating, and the last thing you want to do to an already tender area is add an irritant, which is why I usually recommend a lower-strength benzoyl peroxide gel," says Dr. Lee. Use the gel twice a day, and if you don't see any significant improvement after five days, check in with your doctor.
How to prevent armpit pimples
1. Wash up daily
"If it is an ingrown hair or if it is folliculitis that's caused by irritation, then returning to the basics of hygiene is important," says Dr. Lee. Make sure you regularly clean your underarms with gentle soap and water to eliminate any bump-inducing bacteria.
2. Regularly exfoliate
Your skin is constantly creating new cells, and when dead ones build up on the surface, it can contribute to the growth of ingrown hairs (since they can't poke through all the debris) and harbor bacteria that lead to folliculitis. Because of this, Dr. Lee recommends gently exfoliating your underarms on the reg, which helps get rid of this buildup and, in turn, can prevent armpit bumps from popping up. Glycolic acid, a chemically exfoliating alpha-hydroxy acid, is a great ingredient to use on the underarm area, as it melts away dead skin cells while also neutralizing bacteria—which helps prevent bumps and body odor.
3. Ensure hair removal tools are clean
If you're removing hair from your underarms, Dr. Less says to make sure you're using a clean razors (or tweezers, or wax strips, depending on your removal method of choice) so that you're not introducing any new bacteria into the area, which can cause folliculitis. If you're shaving, use a sharp razor to give you a clean shave and help prevent ingrown hairs.
4. Shave in the direction of hair growth
Your mom was right: There are benefits to shaving down instead of up. "When you're shaving, shave in the direction of hair growth, which is very counter-intuitive to what we often do," says Dr. Lee. "Most of the time, we think if we need to get a clean shave, we actually shave against the direction of growth. To prevent ingrown hairs and frictional folliculitis, you need to shave in the direction of hair growth."
Final takeaway
As Dr. Nazarian puts it, "Pimples are actually not the most common reason for getting red bumps in your armpits." Whatever uncomfortable bump you're dealing with under your arms is probably not a pimple at all, so it's important to treat it accordingly. Know what signs to look out for for ingrown hairs and folliculitis, then tweak your routine with a gentle cleanser, an exfoliant, and a benzoyl-peroxide product.
Even if you don't have any "pimple" situation under your arms, make it a point to keep the area clean and change out of tight, sweaty workout clothes as quickly as you can (and maybe lay off the fragrance-ridden deodorants) so that you can prevent one from ever happening.
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Tags: Skin-Care Tips
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