Armpit Rashes

Written by Matt McMillen
Medically Reviewed by Stephanie S. Gardner, MD on April 09, 2025
10 min read

An armpit rash is more common than you might think. Your armpits probably come into contact with more chemicals each day than most other parts of your body. Don’t be surprised if you have an itch or other symptoms there sometimes. But why is it so easy to get a rash in your armpit?

"Armpits provide a warm, moist environment, making them an ideal breeding ground for fungi and bacteria," says Jose Jaller, MD, an assistant professor of dermatology at the University of Miami Miller School of Medicine in Miami.

Chemicals and fragrances from everyday products like soap, deodorant, laundry detergent, fabric softeners, and dryer sheets are often to blame. Even the clothes you wear and the way the skin folds on itself can lead to a skin rash in your armpit. More severe rashes can be painful and a signal of a medical condition. Some may come with boils, pimples, or skin discoloration. 

The color of your armpit rash can depend on your skin tone. In people with lighter skin, armpit rashes tend to be red. Rashes on darker skin may appear purple or simply lighter or darker than the surrounding skin.

If you have an armpit rash, the following are the most likely culprits, with the most common one first.

Contact dermatitis

This happens when the skin in your armpit reacts to harsh ingredients found in certain personal care products. 

"The armpit experiences constant friction – whether from skin rubbing against skin or clothing – which can progressively damage the skin's protective barrier," says Danielle Dubin, MD, an assistant professor of dermatology at the Icahn School of Medicine at Mount Sinai in New York City.

Contact dermatitis can trigger these symptoms:

  • Itching
  • Painful burning or stinging sensations
  • A purple or red appearance to your skin that’s darker than your natural skin tone
  • Discharge of fluid or pus
  • Flaky or scaly skin
  • Blisters or pimples in small, bumpy clusters
  • Swelling of the skin

Deodorant armpit rash

Chemicals in some deodorants can lead to this type of contact dermatitis. "Many deodorants contain fragrances, which are among the most common allergens responsible for contact dermatitis," says Jaller.

Other ingredients also may be to blame, including:

  • Propylene glycol (keeps products moist)
  • Lanolin (softens skin)
  • Parabens (help products last)

Another, though less common, culprit: aluminum.

"While aluminum, found in many antiperspirants, is not a frequent cause of allergic reactions, some individuals may develop a sensitivity to it, leading to irritation and rash," says Jaller.

Yeast infection armpit rash (candidiasis)

This fungal infection starts when a yeast called candida grows in warm, moist places like your armpit. It's a bright red rash that's often very itchy and can show up in patches with pimple-like spots around it. Other signs of a yeast infection may include:

  • A burning sensation
  • Swelling
  • Scaling of the skin
  • Release of clear liquid

Yeast infections often happen in hot, humid areas of your body, like your armpit. Other things that can raise your chances of getting one include:

  • Wearing tight clothes
  • Not keeping your armpits clean
  • Not changing your underclothes often

Certain medical conditions also increase your risk, such as:

  • Pregnancy
  • Overweight/obesity
  • Skin conditions like psoriasis and intertrigo
  • Conditions that weaken your immune system, like HIV, AIDS, and diabetes

Some types of medications also increase your risk of a yeast infection, like:

  • Antibiotics
  • Chemotherapy
  • Drugs that weaken your immune system

Ringworm

Despite its name, ringworm has nothing to do with worms. It gets its name from its look: a round, itchy rash that’s flat, discolored, and bordered by a raised and scaly ring. The rash may look brown on darker skin and red on lighter skin. This rash comes from a fungal infection and spreads easily. You can get it from:

  • Skin contact with someone who has ringworm
  • Contact with an animal that has the fungus
  • Use of objects from a person or animal with ringworm
  • In rare cases, contact with infected soil

Erythrasma

A bacteria called Corynebacterium minutissimum causes this common skin rash. At first, you’ll notice pink, wrinkly patches of skin, which will change over time into brown, scaly patches. The rash usually has no symptoms, but some people have mild itching or burning.

Erythrasma is a long-lasting infection, common in warm and humid climates. These things increase your risk of infection: 

  • Too much sweating
  • Older age
  • Obesity
  • Diabetes
  • Weakened immune system

Folliculitis

This is an infection or inflammation of hair follicles, the tiny pockets in the top layers of your skin where hair grows. You have over a million hair follicles on your head and about 5 million on your body, including in your armpits. Folliculitis can be mild to severe. The more serious it is, the more likely it is to cause hair loss and scarring.

There are different types of folliculitis, including:

  • Bacterial folliculitis, which is usually due to the bacteria Staphylococcus aureus (staph). Such infections can lead to painful, pus-filled boils and to carbuncles, which are clusters of boils.
  • Hot tub folliculitis, which happens when pseudomonas bacteria infect your skin. These bacteria live in hot tubs, heated pools, and water slides that don’t have enough chlorine or the correct pH balance.
  • Razor bumps, which happen when hairs grow into the skin. You can get this if you shave too close. A more severe form is an infection of the hair follicle with large, red pustules. This condition can clog your pores.

Other conditions that less commonly cause a rash in the armpit include:

Armpit eczema

Atopic dermatitis (AD) is a long-lasting type of eczema that can appear in your armpits. When it does, people often call it armpit eczema. 

What causes AD remains unknown. It's been linked to specific genes, an overactive immune system, and a variety of triggers that can cause an allergic reaction and lead to symptoms like itchy, swollen skin. These include:

  • Sweat
  • Wearing scratchy clothing
  • Humidity and temperature changes
  • Fragrances in deodorants and other products
  • A harsh skin care routine
  • Stress

Seborrheic dermatitis

This common skin condition causes a discolored, scaly rash and dry, flaky skin. It usually shows up on oily areas of your body, like your scalp, forehead, nose, mouth, and eyes. It can also affect the back of your head and neck, as well as your chest.

It may also spread to other parts of your body, including the folds of skin of your armpits. You may feel pain, tenderness, itching, and burning when this happens.

Inverse psoriasis

This is a type of psoriasis, a long-term autoimmune disease that affects the skin. Experts don’t know what triggers this immune reaction. 

It causes a shiny, smooth rash in skin folds, like your armpits. The rash can look red, brown, or purple, and may feel a bit wet. It usually itches, and scratching can lead to an infection.

Like armpit eczema, inverse psoriasis can flare up due to certain triggers. These can be different for each person, but common ones include:

  • Skin injuries from cuts, scrapes, or surgery
  • Stress
  • Infections like strep (the same bacteria behind strep throat)
  • Some medications for high blood pressure or mental health conditions

Acanthosis nigricans

This condition causes dark, thickened, and velvety patches to form in areas where your skin folds and creases. This includes the armpits, as well as the neck and groin.

"Unlike traditional rashes, it lacks redness and can be so subtle that patients may not immediately notice the changes," says Dubin. "Its gradual onset makes early detection challenging."

The darkened patches of skin may be itchy and have skin tags (small fleshy growths). You may also notice a bad smell from the patches. Acanthosis nigricans isn’t harmful and can be treated, but it may be a sign of another health problem, like diabetes or prediabetes. In rare cases, it could be a sign of cancer.

Intertrigo

This rash happens in warm, moist skin folds. When the skin rubs together, it causes friction, which leads to irritation and swelling. The result is a red or reddish-brown rash that can itch, burn, sting, or hurt. If not treated, it can cause more problems, such as:

  • Skin that feels raw
  • Cracked skin
  • Bleeding or oozing
  • Crusty or scaly skin

Intertrigo can lead to an infection, with symptoms like a bad smell and painful, pus-filled bumps.

Hidradenitis suppurativa 

This is a long-lasting inflammatory condition of the skin. Though also called acne inversa, it is not a type of acne. It isn't contagious, and it is not an infection.

"Hidradenitis suppurativa is more than a typical rash," says Dubin. "It presents as painful, deep bumps that drain pus and can cause significant scarring." These bumps, or boils, form when the disease attacks the hair follicles in areas where your skin folds, including the armpits. 

 Armpit heat rash 

These rashes happen when sweat gets trapped under your skin. They can affect anyone, from babies to adults. They’re common in hot, humid weather and usually show up where skin folds, like your armpits. Most of the time, armpit heat rashes go away once your skin cools down. But you should still see a doctor to be sure.

There are different types of armpit heat rash. Some cause tiny, clear blisters, while others lead to red, itchy bumps or blisters filled with pus.

Other causes of armpit rashes

Armpit rashes can also sometimes be caused by:

Impetigo. This is a bacterial skin infection that mostly affects kids between 2 and 5 years old, but older kids and adults can get it too. It can show up in many parts of your body. The rash usually starts as red bumps that turn into blisters. These may itch and hurt a little when touched. As the blisters break open, they often form a yellow, honey-like crust on the skin.

Cutaneous lymphoma. This is a type of cancer that involves your immune cells. It’s also called skin lymphoma. It usually affects T cells, which help protect against infections. But it can also involve B cells, which create antibodies. You might see dry, red patches on your skin. It can turn into thick, hard patches that itch and create sores, usually on the face, buttocks, and skin folds.

The symptoms of your armpit rash depend on its cause. Common armpit rash symptoms include:

  • Redness or other discoloration
  • Itching
  • Burning
  • Bumpy, raised skin
  • Blistering
  • Flaking skin

Itchy armpit rash

Itching is one of the most common symptoms of an underarm rash, but what causes the itch?

"Itching is often a result of underlying inflammation in the affected area," says Dubin, who points to the following common culprits:

  • Fragrance and chemicals in products like deodorants, soaps, or laundry detergents
  • Skin irritation from rubbing, tight clothes, or exposure to strong chemicals
  • Bacterial or fungal infections
  • Hot or humid weather

Armpit rash that burns

A burning sensation is another common symptom of an armpit rash. It’s usually a sign that your rash is getting worse, says Dubin.

"When inflammation becomes severe, the initial itchy sensation can escalate to a more intense burning feeling," she says.

The right treatment for your armpit rash depends on what caused it. Often, says Jaller, the trigger is a personal care product like deodorant, soap, or laundry detergent. You might use the same product for months, or even years, and suddenly get irritation or an allergic reaction.

"If someone develops a rash or even just itchiness, a good first step is to switch to hypoallergenic, fragrance-free products," says Jaller. "Start by changing your deodorant, since it’s often the main culprit. If symptoms continue, consider also switching your body wash, laundry detergent, and fabric softener."

To help with irritation, Jaller also recommends that you wear loose, breathable clothes and make sure your armpits stay clean and dry.

You can also "apply a gentle, unscented moisturizer to soothe the skin," says Dubin. An over-the-counter hydrocortisone cream may help. "If the rash appears scaly, an over-the-counter antifungal cream may also be beneficial," she says.

See your doctor if you notice any of the following:

  • Intense pain that’s worse than the usual burning
  • Pus or unusual discharge
  • Fever
  • Rash spreading quickly
  • Swollen lymph nodes nearby

Many of the things you can do to relieve your armpit rash also can help you to prevent future rashes, says Jaller. For example, if you're prone to rashes, try a deodorant with gentle ingredients and no scent. Other things you can do include:

  • Wear loose clothing that allows moisture to escape to help keep your armpit area dry and cool.
  • Use drying powders and antiperspirants to keep your armpits dry and help prevent yeast infections.

You can’t prevent all armpit rashes. Conditions like eczema, inverse psoriasis, and seborrheic dermatitis don’t have clear causes you can avoid. But you can still identify triggers and stay away from them to keep your symptoms at bay.

Your armpit provides the perfect setting for a rash: It’s warm, moist, and has skin folds that can trap bacteria and fungi. It’s also regularly exposed to chemicals that can cause a rash, like fragrances in deodorant, soap, and laundry detergent. Most rashes are not serious. But if you have very bad symptoms, such as intense burning or a rash that’s getting worse, see your doctor.

What does a fungal underarm rash look like?

You’ll see a bright red, patchy rash in the folds of your armpit. Pimply spots may appear around the rash. You might also have swelling and scaly skin.

What does a deodorant rash look like?

The rash will turn your skin reddish or purple. Your skin may swell as well as flake or become scaly. Blisters or pimples may form and leak fluid or pus. 

What does lymphoma armpit rash look like?

This rash often starts with patches of dry, red skin. This can turn into thick, hard patches. You may also have have small bumps. It can lead to erythroderma, a serious condition where most of your skin becomes red and scaly.