Many different factors can cause rashes, ranging from harmless to serious. Sometimes, the cause of a rash is clear, such as exposure to poison ivy or similar. Often, a rash appears without an obvious cause but clears up on its own within a few days.
Breast rashes, in particular, require special attention. In some cases, a rash on the breast can be a sign of breast cancer. For this reason, any rash on the breast should be examined by a doctor.
Breast cancer and rashes
Most of the time, rashes are not cancer. However, because they can be a sign of cancer, rashes and skin changes should be examined by a doctor. Detecting breast cancer as early as possible increases the chances of successful treatment and a cure.
Inflammatory breast cancer
IBC is a rare and aggressive cancer. The symptoms include breast swelling and redness.
Inflammatory breast cancer (IBC) is a rare form of breast cancer that can grow and spread quickly. Its symptoms often appear like a rash or skin irritation and may include:
- breast swelling
- thickening of the skin on the breast
- small ridges or indents that look like orange peel
- redness of the skin
- pain, tenderness, or itching
- feeling of warmth or heaviness in one breast
- nipple changes, such as inversion, flattening, or dimpling
IBC accounts for 1 to 5 percent of all breast cancers in the United States, according to the National Cancer Institute.
With IBC, the cancer cells interfere with lymph vessels in the skin. This results in the changes in the skin's appearance and texture. Often, a lump cannot be felt in the breast at all, and the cancer may not show up on a mammogram.
IBC usually has no noticeable symptoms until skin changes are seen or felt. Once these changes occur, IBC is at an advanced stage. Treatment is needed quickly to keep it from spreading further.
Common forms of treatment include:
- chemotherapy to shrink the cancer
- surgery to remove the cancer
- radiation therapy
- hormone therapy, for IBC that has spread in the body or for IBC containing hormone receptors
Paget's disease of the breast
Paget's disease of the breast is a type of cancer that affects the skin on the nipple and usually the skin around the nipple, known as the areola.
Paget's disease is usually treated with chemotherapy or by removing part or all of the breast.
A diagnosis of Paget's often means that there is a tumor inside the breast. Most often, a type of invasive breast cancer is found in people who have Paget's disease.
Symptoms of Paget's disease include:
- a nipple or areola that itches or tingles
- skin changes on or around the nipple, such as redness, crusting, flaking, or thickening
- a nipple that becomes flat
- yellow or bloody discharge from the nipple
Treatment for Paget's disease depends upon where any other tumors in the breast are located. Possible treatments include:
- removal of the breast, which may include removal of lymph nodes
- conservative breast surgery that removes the nipple and areola only
- chemotherapy or hormonal treatments
Conservative breast surgery is often paired with radiation of the breast to treat any other tumors.
Like IBC, Paget's disease is rare. It accounts for 1 to 4 percent of all breast cancer cases, according to the National Cancer Institute.
Breast cancer treatment and rashes
Women who are undergoing treatment for breast cancer may get breast rashes as a result of their treatments. Some breast cancer medications, chemotherapy, hormone therapy, and radiation can all cause breast rashes.
Women who are taking any medications or undergoing breast cancer treatment should ask their healthcare team about possible side effects, including breast rashes.
Other types of rashes
The skin on the breast is prone to many common and relatively harmless rashes. Some common, noncancerous rashes that appear on the breasts and other areas of the body include:
- Fungal infections: Fungi on the skin can cause a red, sore, or itchy rash. Candida is a common fungal infection that can appear under the breasts and in other skin folds.
- Allergic reactions: Dermatitis, hives, and skin swelling are often caused by an allergen or irritant touching the skin. If the skin on the breast has been exposed to new fragrances or substances that can cause an allergy, it is possible to develop these rashes.
- Skin conditions such as eczema, seborrheic dermatitis, or psoriasis: Redness, itching, scaling, and rough texture are common symptoms of these conditions, which can be widespread and often don't affect the breasts alone.
- Illnesses such as shingles: A shingles rash is usually very painful and may cause a single stripe of blisters on the body. Shingles can develop on or near the breast area.
These rashes often do not affect the breasts alone, but they can in some cases.
Breast conditions that cause rashes
Some conditions and skin rashes only affect the breast area. People will not find these rashes on other areas of the body. They are not cancer, but they may require medical attention:
This is an infection caused by bacteria that get inside the breast, usually through the nipple. Abscesses often affect breast-feeding women, who may get cracked or irritated nipples.
Breast abscesses can also affect women who are not breast-feeding if their breast skin is cracked or injured, or they have undergone a nipple piercing.
Breast-feeding women may experience mastitis, a painful buildup of milk in the milk ducts.
Mastitis is an infection in the milk ducts of the breast. It often begins with a blocked milk duct in a breast-feeding woman. The stagnant milk in the blocked duct builds up and allows bacteria to grow.
Mastitis can cause a painful, hard, swollen lump that may be red or hot. It can also cause a fever, chill, and a general feeling of being unwell.
Mammary duct ectasia
Most common in women over age 50, mammary duct ectasia occurs when a milk duct's walls thicken and get wider, which can lead to a buildup of fluid.
Mammary duct ectasia may cause a thick, green or black discharge from the nipple, as well as redness, pain, or nipple changes. It may go away on its own or have to be treated with antibiotics.
When to see a doctor
Breast rashes or changes do not usually mean a person has breast cancer.
However, IBC is aggressive and dangerous and Paget's disease may involve an invasive type of breast cancer. Consequently, any new rash or skin change on the breast should be examined by a doctor.