Why Do I Have a Rash on My Breast?

Medically Reviewed by Poonam Sachdev on July 23, 2023
6 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 like 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

Infected breast tissue, also called mastitis, is most common in women 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 get 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

There are several common skin conditions that 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 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 women 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 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 women 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.

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.

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. 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.

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.

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 breast-feeding position each time.
  • Consider seeing a lactation consultant.

To avoid intertrigo and yeast infections:

  • Wash the area under your breasts with 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

Is it normal to have a rash on your breast?

You can get rashes on skin 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 neck or 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

Most breast rashes are nothing to worry about. But sometimes, a rash on your breast can be a sign of infection or of breast cancer. See a doctor if your symptoms seem serious or last a long time.