Rash Under Breast: What Causes It and How to Treat It? (Including Prevention Tips)



A rash under the breast is a common irritation that many women experience. Though it can be embarrassing, there are ways to treat and prevent this skin condition. Here are some things you need to know about rashes under the breast.

What Causes Rash Under the Breasts and How to Treat It?

Various things can cause underboob rash. The common causes of underboob rashes include:

Allergic Reaction

It may be caused by chemical irritants in your bra such as nickel in metal bras and latex in rubber bras. You can also develop rashes due to allergies to your laundry detergent and fabric softeners. To treat rash due to allergy, you can stop wearing your bra or switch to a hypoallergenic bra. You can also use a mild cleanser and cool water to wash the area instead of using soap.


This type of rash under the breast is caused by a yeast infection called candidiasis. It usually occurs in moist areas including armpits, groin, skin folds around the anus, skin between breasts, and underneath collarbones. Treatment for candidiasis includes antifungal medications, particularly clotrimazole or terbinafine. It is also good to wear loose clothing and wash the area with cool water and dry it thoroughly. If you are pregnant or have a weakened immune system, you may need antifungal pills to treat the rash.

Autoimmune Diseases

Autoimmune disorders can cause a rash under the breast that itches severely. The rash tends to appear as an irregularly shaped, red patch that may be raised or flat.

It may cause scales or blisters at the rash site and is more likely to occur in women than men—especially after age 50.

The treatment for this type of rash includes corticosteroid creams and oral medications. If the rash doesn’t respond to corticosteroid treatment, your doctor may prescribe a medication called immunomodulators.


Psoriasis is a skin condition that causes an itchy, scaly rash under the breast. It can occur on the scalp, elbows, knees, and under the breast. Treatment includes oral, topical, and phototherapy medications. Your doctor can also prescribe steroid creams for your rash. You may need to use the creams for several months before you see results.


Scabies is an insect bite infection causing severe itching and rash under the breast. The rash may also appear as small bumps, blisters, or red patches. Treatment includes topical medications such as permethrin, benzyl benzoate, crotamiton, and lindane. Oral medications such as ivermectin or spinosad may also be used.


A rash under the breast may be a symptom of inflammatory breast cancer. In inflammatory breast cancer, the immune system cells in your body start attacking normal cells in your breast. This results in a red, warm rash that is often painful and itchy.

Inflammatory breast cancer may also cause enlarged lymph nodes in the underarm, as well as redness and warmth of the breast.

The only way to diagnose inflammatory breast cancer is by performing a biopsy.

Heat Rash

Heat rash usually occurs when sweat glands become blocked causing sweat to get trapped under the skin. They may combine with bacteria or fungi to cause chronic skin conditions.

You can prevent heat rash by wearing loose-fitting clothing and a hat or scarf to keep the sun off your skin. You should also drink plenty of water and stay in cool or air-conditioned areas.

The treatment for heat rash includes over-the-counter antihistamines, keeping cool, and avoiding heat exposure.

Your doctor may also recommend topical ointments such as neomycin. If the rash is severe, the doctor may prescribe a corticosteroid cream.

Yeast infection

Skin yeast infections caused by “Candida” are the most common cause of chronic rashes under the breast. The infection can lead to thick, white patches on the skin that are either smooth or bumpy. Treatment includes antifungal creams, ointments, or oral medications. You can also avoid wearing tight clothing that traps moisture on your skin.

Pregnancy Breast Rash

Pregnancy rash is a common condition caused by an increase in hormones that causes the skin to become more sensitive. This results in red, itchy, or bumpy rashes.

Some women may develop a red rash with watery blisters that cover the skin under the breasts. It usually occurs in the second trimester. Treatment includes not scratching the area to prevent infection, sunscreen if you go outside, and wearing cotton clothing. Your doctor may also prescribe an antihistamine, corticosteroid cream, or oral antibiotics.


Hyperhidrosis is a condition causing excessive sweating usually in the armpits, groin, or hands. The red rash may appear as small bumps. Treatment may include antiperspirants, botox injections, selective nerve inhibitors, or iontophoresis.


This common skin condition causes an itchy rash under the breast and possibly red, scaly patches. If you have very sensitive skin, your skin may react to contact with detergents or irritants such as soaps or shampoos.

To treat rash due to eczema, you need to apply topical creams containing hydrocortisone on the rash. You can also use cool compresses with crushed ice for 15 minutes several times a day. If the rash is severe, your doctor may prescribe an oral corticosteroid and hydrocortisone cream.


Mastitis is caused by an infection of the breast tissue. It may also cause a small, hard lump under the affected breast.

The cause of mastitis is usually a bacterial infection entering the breast through a cracked nipple. But it can also be caused by an injury, surgery, or a clogged milk duct.

The symptoms of mastitis include redness, warmth, pain, and a lump under the breast. The area may also feel tender to touch. You may also have flu-like symptoms such as muscle aches, headache, fever, chills, fatigue, and a fast heart rate. Treatment includes drinking lots of fluids, using a hot or cold compress on the area, and taking over-the-counter pain and prescription medications such as aspirin or ibuprofen. Your doctor will also prescribe antibiotics to kill the bacteria causing the infection.

When Should I See a Doctor for Rash Under My Breasts?

Rashes on the breast can be caused by a variety of factors and range from minor to severe. If you’re experiencing any of these symptoms along with the rash, you should contact your doctor:

  • Nausea
  • Open sores that appear oozing or bleeding
  • Redness that spreads out from the rash
  • Burning sensation of skin
  • Blisters on the skin that turn into scabs
  • Unusual smell
  • Tenderness or pain in the breast area
  • Increased body temperature
  • Fever

Rash Under Breast Prevention Tips

To prevent rashes under the breasts, you should:

  • Maintain good hygiene. Wash your under-breast area with mild soap and water during bath or shower, twice daily.
  • Use an unscented lotion under the breast to keep the skin moist and flexible.
  • Wear cotton clothes that allow sweat to evaporate easily.
  • Don’t wear tight or close-fitting clothing.
  • Avoid stress.
  • Wash your bras with mild soap and water after every wearing. Don’t wear a bra two days in a row.
  • Apply a layer of topical hydrocortisone cream under the breast area before applying your usual skincare products.

Related Questions:

Is Hydrocortisone Cream Good for Intertrigo?

Hydrocortisone cream is effective in the treatment of intertrigo. However, it may not always be advised to use this for an extended period as it can cause skin thinning. Avoid this cream if you have a fungal infection because it may worsen the condition. It is advisable to take a small amount of the medicine on your skin and wait for 48 hours to see if you are experiencing any side effects prior to using it.

Is Vaseline Good for Intertrigo?

Vaseline is one of the best treatments for intertrigo. You can apply it to relieve your itching and burning rash under your breast. If you find it greasy, use a moisturizing lotion on your affected skin after applying it.

What Happens if Intertrigo Goes Untreated?

If you don’t get treatment for intertrigo, it can lead to secondary bacterial infections which can be more severe in nature. It is also likely to spread and can become more difficult to treat.


Breast rash is mostly caused by irritation or allergic reactions, but in some cases, it can be a sign of infection. When you have an under-breast rash, it’s best to see your doctor and get a proper diagnosis.