Is a Rash Under Your Breast A Sign of Cancer?

Breast cancer is the leading type of cancer among Malaysian women, with an incidence rate of 34 new cases for every 100,000 women. Checking even the most common-looking rash under the breast could help with early detection. Although it’s not the only symptom, it could be a sign of breast cancer.

We look at other possible causes of a rash under the breast, and some remedies to help you find relief. 

Causes of a Rash Under Breast 

Finding a rash under the breast is worthy of further investigation, just to be on the safe side. Here are 5 possible causes of the pesky rash. 

1. Breast cancer

Paget’s disease of the breast is cancer that presents with a red, scaly and inflamed rash in the breast area, usually on the nipple and areola. Other symptoms include bloody or yellow nipple discharge and a flat or inverted nipple. It is quite rare, accounting for only 1% of breast cancer cases.

Inflammatory carcinoma is another type of rare breast cancer that can sometimes appear like a common rash. Along with redness and warmth, the skin also has a thickened, ridged, and pitted appearance like the skin of an orange (called peau d’orange), mimicking an infection. However, doctors now know that this is due to cancer cells blocking the lymph vessels in the breast. Swollen lymph nodes may also be present under the arm, near the collarbone, or in both areas. 

2. Heat rash or intertrigo 

The breasts create an area of folded skin that can trap heat and moisture. Rubbing from clothing that doesn’t breathe well can make it worse. The trapped heat causes the skin to become bumpy and irritated, forming a heat rash.

In some cases, the irritated skin makes it easier for bacteria or fungi present on the skin to overgrow. This can cause a more severe secondary immune response and therefore a more severe rash, called intertrigo. 

3. Skin diseases or infections that can also appear on the breast 

Often, a rash in the breast area is a result of a condition that affects several parts of the body. If you have seborrhoea, eczema, or psoriasis, for example, you may find patches of irritated and scaly skin under the breast. Viral infections like shingles, measles, or chickenpox also cause rashes on the body that may include the breast area.

Some breastfeeding women may have dermatitis or eczema on the breasts, especially the nipples. This could be due to irritation from their baby’s latch. The sensitive skin on breastfeeding breasts is also susceptible to irritation from clothing and poor ventilation. 

4. Allergy 

A full-on allergic reaction may present as a rash under the breast. Some people may get hives during a systemic allergic reaction, which could look like a rash. The reaction could be triggered by medication or irritants in products you put on your skin. When camping or hiking in a heavily wooded area, watch out for leaves and plants you may be allergic to. 

5. Insect bites 

In relation to camping and humid climates, insect bites are another possible culprit for what may appear as a rash under the breast. A mosquito or ant bite usually appears as one or two red spots. But a rash may result if your skin is especially sensitive to these bites.

Scabies is a particularly contagious parasitic mite infestation that requires a clear diagnosis and intensive treatment. So, if that itchy rash is a little more intense than the usual insect bite, go get checked!  

6. Damp-Heat 

“In meridian theory, a diagnostic philosophy within Traditional Chinese Medicine (TCM), the breast is associated with the Liver and stomach meridians. The main causative agent is Damp-Heat,” explains TCM physician Lim Sock Ling.

“The three syndromes include Damp-Heat in the Liver meridian, Spleen Deficiency with an accumulation of Dampness, and Blood Deficiency leading to Wind and Dryness,” she further explains. 

Non-Cancer-Related Breast Rash: Remedies and Prevention 

If it’s not cancer, there is usually a solution for the irritating rash. The treatment for the rash will depend on the exact cause. 

Self-care at home for simple rashes 

It’s good to practice proper hygiene and wear comfortable clothing. Wash under your breasts morning and night with a gentle soap. Follow by drying the area sufficiently. It’s also good practice to wear clean, well-fitting bras, and breathable clothing. Over-the-counter topical ointments can help ease any irritation. 

Proper diagnosis and treatment for viral or microbial infections 

If a rash under the breast is part of a systemic infection, treat the infection itself. Don’t try to wait it out at home by yourself. Proper diagnosis leads to proper treatment to get you on your way to healing. 

Traditional Chinese Medicine herbal remedies

Consider herbal formulations when dealing with an acute or chronic rash under the breast. These are the decoctions recommended by Physician Lim to treat symptoms: 

• For Damp-Heat in the Liver meridian – Clear Heat and Dampness with Long Dan Xie Gan soup (龙胆泻肝汤), Bi Xie Shen Shi soup (萆薢渗湿汤) and Er Miao powder (二妙散) 
• For Spleen Deficiency with an Accumulation of Dampness – Strengthen Spleen and remove Dampness, coupled with some herbs to clear Heat with Wei Ling soup (胃苓汤) 
• For Blood Deficiency leading to Wind and Dryness – Nourish blood, remove Wind, and clear Heat and Dampness with Yang Xue Ding Feng soup (养血定风汤) 

Another TCM remedy to consider is edible bird’s nest. Some studies have found that bird’s nest contains the Epidermal Growth Factor (EGF), which is responsible for reproducing keratinocytes and fibroblasts. Keratinocytes improve the skin barrier, while fibroblasts play a huge role in wound healing and influencing skin elasticity.

Don’t forget to consult a qualified TCM physician prior to taking any of the herbal decoctions mentioned.

If you find a rash under your breast, it doesn’t necessarily mean it’s breast cancer, but it’s a good idea to get it checked. Early diagnosis of a serious illness is better than catching it at a later stage.