A rash under your breast may commonly be caused by warm temperatures, friction, or excess moisture. Sometimes, bacterial and fungal infections, eczema, allergic reactions, and other skin conditions may be the cause.
A rash under your breast usually looks red, inflamed, and irritated. Depending on what kind of rash you have, you might experience:
- Raised, bumpy areas
- Red, “angry” looking skin
- Scaly, rough, and inflamed skin
- Hives, which look like raised welts
- Skin that’s warm to the touch
- A burning, itching feeling
A rash under your breast may be due to several conditions that cause similar symptoms.
Heat, Moisture, and Friction
It’s common to develop rashes under areas of the skin that trap heat and where you might sweat or experience friction, like under your breasts. These rashes may be more common if:
- You have large breasts
- You’re in a warmer climate
- You sweat often
- You wear tight clothing
Eczema
Eczema is a skin condition that can be very itchy, causing dry skin, rashes, inflammation, scaly patches, and swelling. It may flare up if you encounter triggers such as changing temperatures, humidity, scented products, and certain fabrics.
Fungal Infections
It’s possible to have a fungal infection known as a yeast infection under your breast. Fungal infections occur when a fungus that naturally occurs on your skin, like Candida, grows too much, which can happen in warm, moist folds. Symptoms of a yeast infection include a rash that is very red, itchy, and irritated.
Bacterial Infections
A bacterial infection of the breast may be caused by bacteria called Staphylococcus aureus, which grow normally on your skin. An infection occurs when too much of this bacteria grows on or within your breast. Many of these breast infections occur during breastfeeding.
You may have symptoms like swelling, pain, and reddish lumps or streaks on your breast. You may also experience fever and flu-like symptoms when you have a bacterial breast infection inside your breast. If this happens, it’s important to visit a healthcare provider.
Allergic Reactions
An allergic reaction can cause hives, which look like red welts on your skin. These can be found anywhere on the body, including under your breasts. Hives can be itchy and tend to turn white when you touch them.
Many things can trigger hives, including food, viral infections, bug bites, heat or cold exposure, antibiotics, and certain plants.
Inflammatory Breast Cancer
A rare form of breast cancer called inflammatory breast cancer can cause a rash on and under your breast. Symptoms include redness and swelling of the breast and skin that looks bruised or bumpy, like an orange peel. You may also experience burning, tenderness, and a nipple that’s turned inward.
Other Possible Causes
Several other skin conditions may cause a rash under your breast, including:
- Inverse psoriasis: A type of psoriasis that occurs in the folds of the skin, such as under the breast
- Poison ivy: A rash caused by exposure to the oil found on poison ivy plants
- Shingles: A painful, blistering rash that occurs when the chickenpox virus becomes active again
- Ringworm: A fungal infection that causes scaly, ring-shaped rashes
- Scabies: A parasitic infection that can cause very itchy, blistering rashes
If your rash doesn’t go away on its own in a few days, or if it’s itchy and making it hard for you to sleep or function, consider seeing a healthcare provider. Rashes can usually be treated with medications and at-home care.
There are times when you should visit a healthcare provider right away for a rash under your breast. These include if you:
- Have signs of a serious allergic reaction, such as trouble breathing, tightness in your throat or chest, fainting, or loss of consciousness
- Have signs of a serious infection, such as a fever or a breast that’s very warm to the touch
- Have signs of inflammatory breast cancer, such as a breast rash coupled with a breast lump, swelling, or skin that resembles the texture of an orange peel
Your treatment options may depend on the cause of your rash. A healthcare provider will help you determine what treatment is right for you, which may include:
- Antibiotics for an infection inside your breast
- Antimicrobial treatments that you apply to your skin as a cream or ointment for a mild bacterial infection on your skin
- Antifungal cream for a yeast infection
- Topical corticosteroid cream for inflammation of the skin
- Antiperspirant under your breasts to reduce sweating and moisture
- Home remedies to reduce moisture under your breasts, like wiping with towels, to help your skin heal
You may not always be able to prevent a rash under your breast, depending on the cause, but some approaches may make them less likely to happen. Here are some general tips:
- Keep the skin under your breasts as dry as possible, and wipe away moisture that builds up.
- Stay cool as much as possible, including staying in air-conditioned rooms during periods of extreme heat.
- Dry yourself well after bathing or swimming.
- Wear loose-fitting clothing.
- If you breastfeed, let your baby nurse frequently to prevent your breasts from becoming too full.
- Consider using a drying powder or deodorant under your breasts.
- Avoid known allergy and eczema triggers.
Most breast rashes don’t cause complications, but they are possible in rare cases. If you have a severe or untreated breast infection during breastfeeding, you may develop an abscess, which may need to be drained.
Some breast infections can also develop into a painful skin infection called cellulitis, which a healthcare provider can treat with antibiotics. Untreated and severe allergy attacks can result in death if not promptly treated.
Finally, though rare, inflammatory breast cancer progresses quickly and can be life-threatening.
Most rashes under the breast occur when the skin becomes irritated due to heat and moisture or due to eczema, allergies, fungal infections, and bacterial infections. You can often treat a rash under your breast with medications or by reducing moisture, staying out of the heat, and wearing looser clothing.
