Armpit rashes can appear in different ways, for instance, bumpy, smooth, or dry. The causes range from a heat rash to psoriasis, and treatment will depend on the cause.

Some armpit rashes can last a few hours and disappear if an irritant is removed. Others occur with a chronic condition, such as psoriasis, and may come and go for many years.

Some are treatable with home remedies or over-the-counter (OTC) options, while others may need prescription treatment.

Below, find out about 15 possible causes of an underarm rash and what to do about them.

Pictures of armpit rash

Here are some images of some types of rashes that can affect the armpit.

Causes of armpit rashes

Here are 15 possible causes of an armpit rash, but there may be others.

Candida (yeast infection)

Candida or candidiasis is a fungal or yeast infection. It occurs most frequently, and it affects moist areas of skin, such as the underarms.

It can cause:

  • swelling
  • itching
  • scaling
  • red rashes that may appear as gray or purple, depending on your skin tone

Factors that can increase the risk of a Candida infection include:

  • hot climate
  • tight clothing or synthetic fabrics
  • insufficient hygiene
  • having a weakened immune system due to age, a health condition, or a medical treatment

What are some home and natural remedies for candidiasis?

Atopic dermatitis

Also known as eczema, atopic dermatitis can affect the armpits. It happens when a problem with the skin barrier makes the skin more susceptible to irritants and allergens.

The skin becomes inflamed and there may be crusting, itching, and dry scaliness. Patches may ooze fluid.

Scratching can worsen symptoms and cause bleeding. A person with eczema may experience flare-ups at certain times of the year but have no rash at other times.

Seborrheic dermatitis

Seborrheic dermatitis is skin irritation caused partly by the overproduction of sebum, or skin oils. It appears as oily patches of flakes or scales, which may be white or yellow due to the excess oil.

Allergic contact dermatitis

Allergic dermatitis is a type of contact dermatitis that occurs when you come into contact with an allergen.

If a rash appears as an allergic reaction, you may also experience other allergy symptoms, such as hives and swelling.

Irritant contact dermatitis

Another a type of contact dermatitis, irritant contact dermatitis can happen if your skin comes into contact with an irritant.

This could be the fragrance in your deodorant, a new laundry detergent, or the fabric of a shirt.

Deodorant armpit rash

A deodorant rash can result if you’re allergic to any of the ingredients in your deodorant, or if any of these ingredients irritate your skin. It’s a kind of contact dermatitis.

You may notice inflammation, burning, or itchiness. Stopping the use of a deodorant will likely cause the rash to disappear.

What’s a deodorant allergy?

Heat rash (miliaria)

Heat rashes, also known as miliaria, occur when the sweat glands and ducts become blocked, leading to sweat-filled bumps under the skin. It can lead to pain, itching, and inflammation.

Heat rashes usually improve if you move to a cooler area.

Folliculitis

Folliculitis is an infection of a hair follicle, where the hair grows out of the skin. There are various possible causes, but the most common is a bacterial infection.

It can happen if an ingrown hair occurs after shaving. It may result in an inflamed bump, which can be painful. Sweating and scratching can increase the risk of folliculitis.

Inverse psoriasis

Inverse psoriasis is an inflammatory condition and a type of psoriatic disease. It can affect areas in skin folds or where skin meets skin, such as the armpits.

It appears as smooth, clearly defined patches on the skin. It looks red on lighter skin but may look gray, purple, or darker in color on darker skin tones. The skin may also be moist, itchy, and soft to the touch. There may also be fissures and an unpleasant smell.

Which natural remedies can support inverse psoriasis treatment?

Hidradenitis suppurativa

Also called inverse acne, hidradenitis suppurativa (HS) can cause nodules and abscesses to develop under the skin. It often affects the armpits and other areas where skin folds occur.

HS can cause pain, itching, warmth, and an unpleasant smell. There may also be seepage of fluid. Excess sweating may occur around 12–48 hours before a new lesion appears.

Risk factors include having overweight and obesity.

Weight discrimination and health

Although studies often suggest that obesity is a risk factor for certain health conditions, they rarely account for the role weight stigma and discrimination play in health. Discrimination is one of the social determinants of health — the conditions in daily life that affect our health — and it can and does contribute to health inequities.

Weight discrimination in healthcare can prevent people at high body weights from seeking medical care — and those who do may not receive accurate diagnoses or treatment, because doctors may attribute their health concerns solely to their weight.

As a result, any health condition a person may have may be more advanced by the time they receive a diagnosis.

Meanwhile, experiences of weight stigma in daily life, even outside of medical settings, are associated with negative mental and physical health outcomes.

Everyone deserves appropriate and compassionate healthcare. For resources, including a growing directory of weight-inclusive health professionals, you may want to follow the work of the Association for Size Diversity and Health.

Can home remedies help relieve HS?

Acanthosis nigricans

While not a rash as such, acanthosis nigricans causes skin to become darker in color and soft to the touch. It’s usually a symptom of an underlying condition, such as diabetes, obesity, and some autoimmune conditions.

It often affects areas where skin meets skin, such as the armpits.

Intertrigo

Intertrigo is an inflammatory condition that tends to affect areas of softer skin, for example, the armpits, where heat, moisture, and friction occur.

A person may start to notice itching, burning, tingling, and pain. An area of inflammation may then develop, and there may be cracking or crusting of the skin and weeping of fluid.

It’s more common among those with diabetes and obesity, especially if they’re living in a warm and humid environment.

What’s the difference between psoriasis and intertrigo?

Ringworm

Ringworm, or tinea corporis, is a fungal skin infection. It can be contagious, but it won’t affect everyone. Children and people with a weakened immune system are more likely to develop ringworm.

It involves an itchy rash that starts as a circle that’s red, grayish, purple, or darker than the surrounding skin, and becomes ring-shaped as the center clears.

Heat, humidity, and fitted clothing can increase your risk of ringworm.

Cutaneous lymphoma

A type of T-cell lymphoma, this is a rare type of non-Hodgkin’s lymphoma, a form of cancer. It can cause bumps, papules, and other growths to appear on the skin. It happens when the immune system isn’t able to defend the skin from fungal and other infections.

Cancer treatments

Chemotherapy, stem cell therapy, and other cancer treatments can cause rashes of various sorts. There may be itching, burning, pain, and blistering, changes in skin color and texture, and other symptoms.

Radiation therapy can cause skin changes in the area where the person receives treatment.

Is it a sexually transmitted infection (STI)?

Some sexually transmitted infections (STIs) can cause a rash anywhere in the body, although not necessarily in the armpits.

Syphilis, for instance, can cause a rash anywhere on the body in the secondary stage. It may appear within 6 months of primary stage sores disappearing, or it might appear while the sores are still healing.

HIV can also cause a rash, either during the acute phase or in the long term, as the immune system finds it harder to fight infections. HIV medications can also cause a rash.

Medical treatment

If a rash gets worse or doesn’t go away, you may need medical treatment. The recommendations will vary widely, depending on the underlying cause.

OTC anti-itch creams, such as hydrocortisone cream, may reduce inflammation.

Antihistamines can help manage itching.

A doctor may also recommend an antifungal or antibacterial cream, if an infection is present. Treatment for a Candida infection, for example, may be with lotions containing clotrimazole, nystatin, or ketoconazole.

Psoriasis, HS, or lymphoma will need more extensive medical attention. A doctor may perform a skin biopsy test to help identify the cause of a rash.

If you need help finding a primary care doctor or dermatologist, you can browse doctors in your area through the Healthline FindCare tool.

Home remedies

Here are some tips for managing a rash at home.

  • Eliminate or swap any irritants, such as deodorants, scented soaps, or washing detergent.
  • Avoid shaving until the rash heals, if you have ingrown hairs.
  • Wear loose, cotton clothing that leaves space for air to flow under the arms.
  • Stay in a cool environment, as far as possible.
  • Take a warm (but not hot) bath with colloidal oatmeal.
  • Apply unscented moisturizers to soothe dry skin or eczema.
  • Use calamine lotion or cool compresses to soothe discomfort.
  • Use antichafing powders to prevent friction and absorb humidity.
  • Avoid scratching, which may make symptoms worse.
  • Manage stress, for instance, through relaxation techniques.
  • Try products containing essential oils, such as lavender or tea tree.

Preventing armpit rashes

Tips for preventing a rash include the following:

  • Shower regularly and ensure you dry under the arms fully before getting dressed.
  • Use mild skin care and laundry products.
  • Wear loose, cotton clothing that allows your armpit to breathe.
  • Stay in a cool environment.
  • Ask a pharmacist about antichafing powders.
  • Ensure your diet contains vitamins, minerals, and antioxidants to help boost your immune system.
  • Try to manage your weight, as excess skin body fat and skin folds can increase the risk of an armpit rash.
  • Seek medical advice if you can’t identify the cause of a rash or if it worsens or persists.
  • Follow any treatment plan for psoriasis or other underlying conditions.

Frequently asked questions

Frequently asked questions

Should I be worried about a rash in my armpit?

A rash under the armpit can happen for many reasons, from wearing clothes that are too tight to an autoimmune condition, such as psoriasis. If lifestyle changes don’t help, consider seeking medical advice.

What should I put on my armpit rash?

OTC creams can often resolve an infection or soothe discomfort. If a chronic condition is causing an armpit rash, you may need to seek medical attention. Otherwise, changing your deodorant, soap, or laundry detergent might help, but this depends on the cause.

What does armpit dermatitis look like?

Atopic dermatitis, or eczema, can cause itching and inflammation. The skin may be red, gray, purple, or darker in color, depending on your skin tone. The skin may also crust over, and there may be oozing of fluid.

How do I know if my armpit rash is fungal?

If you see swelling, itching, scaling, or a red, gray, or purple rash, you may have candida. A circular rash could be ringworm. That said, only a doctor can tell you what is causing the rash.

Is it common to have eczema in the armpits?

Eczema can appear anywhere on the body. Atopic dermatitis specifically can often show up in body folds, including the armpits.

Summary

Armpit rashes can happen for many reasons. Living in a warm, humid environment, wearing tight clothes made of synthetic fabrics, and having a weakened immune system, diabetes, or obesity can often increase the risk.

Sometimes, changing a deodorant or moving to a cooler space may stop the rash. If a rash persists or symptoms are severe, consider seeing a doctor, as it may be a symptom of an underlying condition.