Why Do I Have a Rash on My Breast?

Medically Reviewed by Poonam Sachdev on August 27, 2024
8 min read

If your breast looks red or swollen, there’s no need to panic. A tender area or rash on your breast often signals a common problem such as an infection. In other cases, it's a symptom of a common, treatable skin condition.

Rarely, a rash and soreness can be signs of inflammatory breast cancer, a form of the disease that can grow quickly, often in weeks or months.

Here’s how you can tell what's going on.

Infection

Infection of breast tissue, also called mastitis, is most common in people who are nursing. It can happen when milk gets trapped in your breast. You might also get it if something clogs one of your milk ducts or bacteria gets into your breast through a cracked nipple.

Mastitis often happens within the first 6 to 12 weeks after you give birth, but sometimes you can get it even when you're not breastfeeding.

If you have mastitis, your symptoms may come on without warning. Common signs include:

  • Tender, warm, or swollen breasts
  • A red patch of skin, often in a wedge shape
  • Pain or burning when you breastfeed
  • A fever of 101 F or higher
  • Chills

Skin conditions

Several common skin conditions can cause a rash anywhere on your skin, including on or under your breasts. They include:

Hives. These itchy welts on your skin often result from an allergy. They can be red or skin-colored, depending on your complexion.

Psoriasis. It causes scaly, itchy patches of skin. They show up when your immune system goes haywire and attacks your body.

Scabies. Bites from the human itch mite cause this condition. The bites form a line of little bumps on your skin and get really itchy at night.

Shingles. This shows up as painful, itchy blisters. It results from the same virus that causes chickenpox.

Intertrigo. This is the name for what happens when the skin under your breast rubs together too much, trapping moisture and creating friction. It may cause a smelly rash under your breast. Besides a red or brown rash, your skin may swell and itch.

Yeast infection under the breast. Intertrigo allows the candida fungus that lives on your skin to grow too much, leading to an itchy rash where skin touches skin. You can use an over-the-counter antifungal cream for a yeast infection under the breast. Or your doctor can prescribe a stronger one.

Nipple eczema. It can lead to a rash around one or both of your nipples. The skin around them may get dry and scaly, or you could have a rash that feels moist to the touch. You may notice a burning feeling if you’re nursing. Nipple eczema often affects people about 5-6 months after giving birth.

Ancanthosis nigracans. This rare condition may cause black or brown spots under your breast. The spots may feel velvety. They may itch and sometimes smell bad. It’s not serious, but it can be a sign of prediabetes. So see your doctor if you have these symptoms. 

Heat rash under the breast. You can get this type of rash when sweat lingers on your skin or if you have a blocked sweat gland. It may feel prickly, mildly itchy, and may hurt a little. You might notice groups of little bumps that look like pimples.

A couple of types of cancer can cause rash-like symptoms on your breasts

Inflammatory breast cancer symptoms result from a buildup of fluid in your breast. Many people don’t feel a lump. Instead, you may notice a rash that looks like an insect bite.

You could also have:

  • Itching that doesn’t go away
  • A nipple that goes inward or gets flat
  • Swelling and redness that affect at least a third of your breast
  • Pink, purple-red, or bruised skin
  • Skin that looks ridged or pitted like an orange peel
  • A sudden increase in breast size
  • Breast tenderness or a "heavy" feeling
  • Swollen lymph nodes under your arm or near your collarbone

Paget’s disease is a rare skin disorder that’s often linked to breast cancer in the tissues behind your nipple. It can cause a red, scaly rash. You could also have discharge or bleeding from your nipple.

What do breast cancer rashes look like?

An inflammatory breast cancer rash doesn’t look the same in everyone who has it. Sometimes it doesn’t even look like a rash.

You might see a rash that looks like red spots on your breast. On some skin tones, it can look dark or purple. 

But in some cases, you might just notice that the pores on the skin of your breasts look larger due to swelling. Or you might see redness or discoloration.

A rash caused by Paget’s disease usually looks like eczema on one of your nipples. The skin may look flaky or crusty, and you may notice oozing. 

Sometimes it looks like a small sore, or you might see inflamed, scaly patches of skin that resemble psoriasis. The rash might extend out to the aureole, the patch of darker skin that surrounds your nipples.

You may notice rashes on your breasts and other parts of your body during pregnancy, mostly because of the hormonal changes happening in your body. 

Pruritic urticarial papules and plaques of pregnancy (PUPPP)

This condition, also known as polymorphic eruption of pregnancy (PEP), can cause you to develop a rash on your breast during pregnancy. The rashes from PUPPP often start from the belly and can spread to other parts of your body, including your breasts. The rash may look pink, red, or the same color as your skin, depending on your skin tone. The itching from the rash may be too uncomfortable, affecting your daily functioning and sleep. 

PUPPP often affects first-time pregnant people during the last trimester of pregnancy. It’s unlikely to happen again in later pregnancies.

No one knows why it happens, but it could be due to different things that come with pregnancy, such as hormonal changes and your belly growing bigger. Your doctor may recommend corticosteroid creams and allergy medicines such as antihistamines to ease your symptoms. 

Pregnancy-induced eczema

Changes in how your immune system works and the hormonal changes that happen during pregnancy to protect your unborn child can trigger eczema symptoms or worsen them. This pregnancy-induced eczema can cause you to have intense itching. You may have other symptoms such as rashes that ooze fluid or bleed, dry skin patches, bumps, itching, and thickened or hardened skin.

Your doctor will be careful about prescribing medicines for you for the safety of your developing baby but may recommend moisturizers, corticosteroid creams, and antihistamines to manage your symptoms and control the disease.

Circulating hormones

A hormone called estrogen may also be to blame if you have a rash on your breasts when you’re pregnant. The placenta, the organ that connects your baby to your uterus and delivers nutrients and oxygen, releases this hormone around 5 days after conception and then again around 9 weeks into the pregnancy. Estrogen helps maintain pregnancy, but it can also cause rashes and itching in some pregnant people.

Talk to your doctor about any rashes you notice or any other skin symptoms. They will recommend the right treatment for you.

See your doctor if any of your symptoms get worse. They’ll do an exam to figure out what’s causing your rash so they can recommend the best treatment. Some simple rashes go away quickly with a cream you can apply to your skin.

Your doctor may want you to get a mammogram. This can give them a better idea of what’s going on inside your breast.

If your symptoms don’t clear up soon, your doctor may also want to do a biopsy. They’ll remove a small piece of your breast tissue and look closely at it under a microscope.

If you have a breast infection, you’ll need antibiotics. Make sure you finish all your medicine, even if you start feeling better right away.

Unless your doctor suggests otherwise, you won’t need to stop nursing if you have mastitis. Try to fully empty your breasts so you’re less likely to get an abscess -- a pocket of pus that may need draining. Drink plenty of fluids and get lots of rest to help your body fight off a breast infection.

Signs that you should call your doctor right away include:

  • Fever
  • Intense pain
  • Red streaks coming from your breast
  • Yellow or green pus
  • Open sores

Because so many different things can cause breast rashes, they’re not always preventable. But you can take steps to avoid some types.

To prevent mastitis:

  • Let your baby empty one breast fully before moving to the next.
  • Make sure your baby latches on well.
  • Alternate your breastfeeding position each time.
  • Consider seeing a lactation consultant.

To avoid intertrigo and yeast infections:

  • Wash the area under your breasts with a gentle cleanser two times a day, then gently pat dry with a clean towel.
  • Choose a well-fitting bra made of cotton or another natural material.
  • Maintain a healthy weight.

To prevent heat rash:

  • Wear loose, breathable clothing, especially when it’s hot.
  • Apply antiperspirant underneath your breasts.
  • Stay hydrated and don’t let yourself get overheated.

Having rashes on your breasts can make you feel uncomfortable and concerned, but they aren’t usually caused by a serious problem. An infection or a common skin condition is often the culprit. In rare cases, they may be caused by breast cancer. Your doctor may treat it based on what’s causing it. See a doctor if your symptoms seem serious or are long-lasting.

What do breast cancer rashes look like?

Breast cancer rashes look like insect bites or bruises. They may be pink, purple, red, or discolored and cover a large part of the entire breast. The rashes could also cause itching and pain.

What does a stress rash look like on the breast?

Stress rashes on the breast appear as raised, red, or skin-colored, and itchy bumps called hives. They can also appear on other areas of your chest.

Can a bra cause a rash on the breast?

Your bra could cause a rash if you’re allergic to the material it's made of.

Is it normal to have a rash on your breast?

You can get skin rashes anywhere on your body, including your breasts. Because it’s an area where skin can rub together and get sweaty, the skin under your breasts is prone to intertrigo, yeast infections, and heat rash.

When should I be worried about a rash on my breast?

Breast rashes are rarely serious. But see your doctor if you have a rash along with:

  • Pain or fever
  • A rash that blisters or oozes
  • Swelling in the lymph nodes of your neckor underarms
  • A lump in your breast
  • A nipple that’s flat or appears inside-out
  • Skin that resembles the peel of an orange

How can I prevent rashes on my breast?

You can prevent minor breast rashes by:

  • Keeping the skin around your breasts dry and clean
  • Wearing breathable tops and bras
  • Keeping your weight at a healthy level