A rash under your breast can be caused by a number of things. Generally, they fall into four categories: infections, allergies, autoimmune disorders, and cancer.
The warm, moist skin under breasts is an ideal breeding ground for bacterial, fungal, and yeast infections.
Candidiasis is caused by the same yeasts, or fungi, that cause vaginal yeast infections, oral thrush infections, and diaper rash. These fungal infections are often seen in babies, people with illnesses that affect their immune system, and in people who are taking antibiotics.
Candida yeasts thrive in the moist, warm environment under the breasts. They cause a rash that often develops uncomfortable blisters and small cracks. Like many other rashes, candidiasis can be very itchy.
Antifungal creams are used to treat candidiasis. If the infection is more widespread, your doctor may prescribe antifungal medications to be taken by mouth. It’s also important to keep your skin dry.
Ringworm has nothing to do with worms. It’s one of several types of fungal infections called tinea. Fungi are microscopic, single-cell organisms that are in the air, soil, water, animals, and people.
The types of fungi that cause ringworm and related skin conditions such as athlete’s foot and jock itch, are parasites that feed on dead keratin, the protein that makes up your skin, nails, and hair. Ringworm appears as round, red patches of skin with a distinctive red ring.
Ringworm is highly contagious and often spreads via shared towels, sheets, and showers. You can even get it from your pets.
Over-the-counter or prescription antifungal creams are effective in treating ringworm.
Mastitis is an infection of the breast that‘s common to women who are breastfeeding, although women who aren’t breastfeeding can get it as well. Small cracks in the nipple can be an entry point for bacteria. Clogged milk ducts can also become infected.
Untreated, mastitis can lead to the formation of painful, pus-filled abscesses in your breast, so it’s important to contact your doctor.
Antibiotics are normally prescribed to treat the infection. Warm compresses applied to the breast several times a day also help relieve discomfort. You’ll want to rest and drink lots of fluid to speed healing. If you’re breastfeeding, feed your baby more frequently and empty the affected breast fully.
Hives are an allergic response to a range of substances, including:
- insect stings
Hives are red or, more rarely, skin-colored bumps that can itch violently. If you press on hives, they will blanch, turning white. Hives can occur on any part of your body.
Hives are usually treated with antihistamines. These drugs block histamines, the natural chemical in your skin that causes the hives. You may also use cold compresses and topical preparations such as cortisone creams or calamine lotion.
If you get hives regularly, your doctor may recommend that you see an allergist. An allergist will determine what substances you’re allergic to so you can avoid the allergens in the future.
There are a few different autoimmune disorders that may cause a rash under your breast. Autoimmune disorders are chronic conditions that cannot be cured, but you can treat the symptoms.
Patches of inflamed red or reddish-gray skin that itch severely are signs of eczema, or atopic dermatitis. Eczema can develop small, fluid-filled bumps that ooze and crust over.
Over time, your skin can dry out and be prone to irritation and itching before it flares up again.
Eczema can be found anywhere on your body. It’s seen most commonly on the:
- behind the knees
- inner surface of the elbow
There’s no cure for eczema. It can be controlled by keeping your skin moisturized with fragrance-free moisturizers and by using cortisone creams or gels to control the itching. Eczema symptoms may be made worse by:
- harsh soaps and detergents
Inverse psoriasis is a less common form of psoriasis, a chronic disease of the immune system. It’s characterized by smooth, red patches of skin in the folds of the body. The condition is often seen under the breasts, the armpits, and the groin area. Inverse psoriasis doesn’t usually have the flaky skin plaques associated with other types of psoriasis.
Steroid creams and gels are the first-line treatment for inverse psoriasis. Increasingly, skin medications that suppress the immune system are being used for more severe cases.
Hyperhidrosis is a condition in which your body’s sweat glands produce more sweat than is needed to cool the body. All that perspiration is a welcome mat for germs that cause infections. The cause of hyperhidrosis is unknown, but it tends to run in families.
Antiperspirants may be used under the breasts. In fact, there are also body antiperspirants made for this purpose and some are even available in powder form. If they don’t do the job, your doctor may prescribe a more powerful antiperspirant. Botox injections and the removal of sweat glands via laser or traditional surgery are options for severe cases.
A rare, inherited disorder, Hailey-Hailey disease is characterized by a persistent, blistering rash that may be found:
- under the breasts
- on the neck
- between the buttocks
- in the arm pits and groin
The rash tends to come and go spontaneously. Over time, the skin can become tough and dry, and may develop painful cracks.
Hailey-Hailey disease is often treated with corticosteroid cream or ointment, and antibiotics. More stubborn cases may be treated with oral corticosteroids or antibiotics, photodynamic light therapy, or laser therapy.
If you have Hailey-Hailey disease, your doctor will advise you to avoid situations that make you sweat, such as not wearing heavy clothing that doesn’t breathe and not exerting yourself too much in hot weather.
Inflammatory breast cancer is a very rare form of rapidly spreading cancer. Symptoms include:
- pink or red skin discoloration
- pitted skin often described as looking like an orange peel
- pimple-like rash
- an inverted nipple that points inward rather than outward
Although this type of breast cancer is rare, it’s important to see your doctor promptly if you have these symptoms.
A combination of chemotherapy, surgery, and radiation therapy is the standard treatment for inflammatory breast cancer.
Heat rash, properly called miliaria, occurs when your sweat glands become blocked and sweat can’t be excreted through the pores. Instead, the sweat pools under your skin, causing inflammation and a rash.
The best treatment is to cool off. Heat rash happens mainly when you sweat more than normal because of heat and humidity. Heat rash usually clears up without treatment.
See a doctor
You should contact your doctor if:
- you have a chronic disease or compromised immune system
- you develop a fever, nausea, or vomiting
- the rash is extremely painful
- you see no improvement after using self-help measures for several days
- the rash has open sores that don’t heal
- you have symptoms of inflammatory breast cancer, such as red, pitted skin and an inverted nipple
A rash under the breast is rarely anything more than an annoyance that causes discomfort. By identifying the underlying cause of the rash and treating it accordingly, most rashes heal within a couple of weeks.
Tips for relief
There are some things you can do to help treat symptoms of a rash.
- Skip wearing your bra as much as possible until the rash clears up.
- When you do wear a bra, make sure it fits without binding. Avoid underwire bras.
- Some women find it helpful to wear bra liners or mini pads to absorb moisture under the breasts.
- Wear loose-fitting clothes made of fabrics that breathe, such as cotton and linen.
- Use unscented soaps, lotions, and moisturizers.
- Apply a cool compress to the affected area.
- Calamine lotion can help reduce itching.
- Drying powders such as Gold Bond Extra and Lady Monkey Butt help prevent rashes. Corn starch is popular as a powder, but can make some rashes worse, especially if they’re cause by a yeast infection.