Infections, allergies, and shingles may also cause a breast rash. A healthcare professional should examine any unexplained rashes on the breast to properly diagnose and treat the cause.

Learn about breast cancer rashes, including causes, risk factors, when to see your healthcare provider, and more.

What Does a Breast Cancer Rash Look Like?

Rashes are not a common symptom of cancer. A breast cancer rash is a sign of inflammatory breast cancer or Paget’s disease of the breast, both of which are rare conditions and difficult to diagnose due to the absence of a lump. 

Inflammatory Breast Cancer (IBC)

IBC is a rare, aggressive cancer typically affecting women with dense breast tissue. Symptoms may include:

A rash appearing swollen and redPink, reddish-purple, or bruised skin Ridges on the skin (like the skin of an orange)A rapid increase in breast size and/or breast rashBreasts feeling heavy, burning, or tender

Paget’s Disease

A disease of the nipple, this rare condition is associated with breast cancer. Symptoms may be mistaken for dermatitis or eczema and include:

Red, flaky, crusty, thickened, or scaly skin around the nipple and areola  Flattened nipple Yellowish or bloody discharge  Soreness, inflammation, itchiness, or burning

Other Causes of a Breast Rash

Various other conditions can cause a breast rash unrelated to breast cancer.

Infection

Infections can be caused by intertrigo, an inflammatory rash occurring along skin folds like the breast. Moisture, friction, and lack of ventilation can cause inflammation. Friction can cause the skin to break down and become susceptible to fungal or bacterial infections. Symptoms may include:

Red, scaly skinItchiness, stinging, or burning sensations 

Mastitis

Mastitis, or inflammation of the breast, is often due to an infection. It commonly affects breastfeeding women when a milk duct becomes blocked. It can also affect women who aren’t breastfeeding as well as men. Symptoms include:

PainSwellingWarmthRedness

Allergies

An allergic reaction is typically in response to pollen, food, or medicine but may also occur in response to other triggers. Exposure to an allergen can cause hives that may affect the chest and breasts. Symptoms include raised, red bumps or welts and itchy skin.

Shingles

Shingles, also known as herpes zoster, is a condition caused by the chickenpox virus. The virus remains inactive in the body and can reactivate later in life. Shingles cause a rash that may affect the chest and breast area. Symptoms of shingles include:

Painful, itchy, or tingling skinRash with blistersPainFever or chillsHeadacheUpset stomach

Additional Cancer Symptoms

Breast cancer symptoms vary by the individual; some people are asymptomatic and present few or no symptoms initially. Symptoms of breast cancer may include:

New lump in the breast or armpit Thickening or swelling in or near the breast or armpit Changes in breast size or shape Irritation, dimpling, or puckering of the skin Nipple discharge other than breast milk, including blood Scaly, flaky, red, or swollen skin in the nipple or breast area Pain in the nipple area or anywhere on the breastA pulling in of the nipple

These symptoms can also be signs of other conditions, so speaking to your healthcare provider is the best way to determine their causes. 

Risk Factors

Many factors may contribute to the risk of developing cancer, including genetics, lifestyle, and environmental factors. Risk factors may include:

Genetic predisposition (family history of breast or ovarian cancer)  Genetic mutations (changes), including changes in BRCA1 and BRCA2 genes Age History of breast cancer or non-cancerous breast disease   Dense breast tissue (breasts that have more connective tissue than fatty tissue)  Reproductive history that includes increased exposure to estrogen, such as the early onset of menstruation, first pregnancy after 30, not breastfeeding, not having a full-term pregnancy, or later menopause  History of radiation therapy to the chest or breast  Not being physically active Having excess weight or obesity after menopause Using hormone therapy to treat menopause symptoms  Drinking alcohol

When to See Your Healthcare Provider

A person experiencing changes or abnormal symptoms affecting the breast should see their healthcare provider. A healthcare provider may run tests to diagnose or rule out breast cancer, including a physical and breast exam.

Awareness of how your breasts look and feel can help you catch any symptoms or changes. If you notice any changes during a breast self-exam, notify your healthcare provider.

Summary

A breast rash can indicate inflammatory breast cancer (IBC), a rare, aggressive cancer that often goes undetected. Paget’s breast disease is another rare cancer-related condition that can cause a rash. Other conditions unrelated to breast cancer may cause a breast rash, including infection, allergic reaction, or shingles.

Imaging tests like a mammogram, ultrasound, or magnetic resonance imaging (MRI) Biopsy of breast tissue  Blood tests 

If you have a breast rash, speak with your healthcare provider so they can run diagnostic tests to determine the cause and treat the underlying condition. 

A Word From Verywell

The sudden onset of a breast rash can be alarming. A rash may not necessarily indicate breast cancer, but it’s crucial to see a healthcare provider who can determine the cause. Self-examination and noticing breast changes can play a critical role in the timely detection of breast cancer.