Red spots on the breast are usually symptoms of a rash or other skin condition. Less commonly, they can also be a visual sign of breast cancer.

Being able to recognize the early signs of breast cancer can allow for earlier diagnosis and treatment and improve a person's outlook.

In this article, we look at whether red spots or a rash on the breast can be a sign of breast cancer. We also cover other possible causes of red spots on the breast and when to see a doctor.

Are red spots a sign of breast cancer?

Although red spots or a red rash on the breast are usually symptoms of a noncancerous condition, they can sometimes be an early sign of breast cancer and a person should monitor them closely.

Red spots are a typical feature of inflammatory breast cancer or IBC, which is a rare, but aggressive form of breast cancer.

In the United States, IBC accounts for only around 2%−4% of breast cancer cases, yet it contributes to 7%−10% of deaths from breast cancer.

People with IBC typically do not have breast lumps, which are a common symptom in other types of breast cancer.

IBC affects the skin and the lymph vessels of the breast and symptoms can include:

• rapid changes in the skin around the affected breast
• redness and warmth of the skin on the breast
• breast swelling
• breast pain
• itchiness
• thickening of the breast skin
• enlargement or heaviness of the affected breast
• breast skin that feels and appears thick and pitted, similar to an orange peel

Red spots or a red rash on the breast can also be a sign of another rare type of breast cancer known as Paget's disease of the breast or Paget's disease of the nipple.

According to the National Cancer Institute, Paget's disease of the breast accounts for around 1%–4% of all cases of breast cancer. It is also more common in older people, with an average age of diagnosis of 57 years.

Paget's disease of the breast usually starts by affecting the skin of the nipple. It then spreads to the dark skin around the nipple, which is known as the areola. When the disease is at its advanced stages, it may also affect the skin surrounding the areola.

Typically, Paget´s disease affects only one nipple, and it can resemble other noncancerous skin conditions, such as eczema and dermatitis.

Common signs and symptoms that affect the nipple and areola include:

• scaly, red, thickened and crusted skin
• very dry skin
• color changes
• pain or itching

Other symptoms of Paget's disease may include:

• inversion or deformation of the nipple
• yellowish fluid or blood coming out of the nipple
• a noticeable mass in the breast

A noticeable mass occurs in around 50% of people with Paget's disease of the breast.

Other possible causes of red spots

There are many other possible causes of red spots or rashes on the breast, including the following:

Nipple dermatitis

Nipple dermatitis is an inflammation of the skin on the nipple and areola. This condition can occur in women who are breast-feeding. It usually causes pain.

Causes of nipple dermatitis include:

• skin irritation due to infant attachment
• atopic dermatitis and other allergic reactions
• bacterial, viral, and yeast infections

Breast abscess

A breast abscess is a buildup of pus in the breast that results from a bacterial infection. The bacteria get inside the breast through the nipple. Breast abscesses can be painful and most commonly affect women who are breast-feeding.

Doctors usually treat abscesses with antibiotics, drainage, or needle aspiration.

Mammary duct ectasia

Mammary duct ectasia is a noncancerous or benign condition that affects the milk ducts in the breast. The ducts become wider, and their walls become thicker, which can lead to a blockage and buildup of fluid.

Mammary duct ectasia typically occurs in women undergoing menopause, although it can also occur in younger women, men, and children.

It usually causes bloody nipple discharge and redness or tenderness of the nipple and areola. Sometimes, a mass may be present under the areola.

Mastitis

Mastitis is a painful inflammation of the breast and is more common in women who are breast-feeding. It results from milk becoming trapped in the breast and a bacterial infection in the area.

Mastitis typically causes redness, warmth, and tenderness of the affected breast. However, more serious symptoms can include fever, breast abscess, and a serious blood infection known as septicemia.

Other rashes

Other types of rash that can affect the breast include:

• Candidiasis is a fungal infection and typically occurs in the skin folds, including under the breasts.
• Atopic dermatitis, also known as eczema, is an inflammation of the skin that causes redness, itching, and may cause the skin to scale, crust over, or ooze fluid.
• Psoriasis is an inflammatory and chronic skin condition that causes reddish patches of skin covered with silvery scales.
• Hives, also known as urticaria, is an allergic reaction to certain foods, medications, or other substances. It causes red, raised, and itchy skin rashes.
• Shingles is a nerve infection that causes a painful red rash along a nerve that can occur anywhere on the body, including on or near the breast area.
• Scabies is an itchy skin condition that occurs when small mites burrow into the skin. Scabies is contagious and can spread quickly through close physical contact with infected people.
• Seborrheic dermatitis is a common inflammatory skin condition that mainly affects the scalp and causes red and scaly patches. These patches can also appear on the face and upper part of the body, including the breasts.
• Cellulitis is a potentially serious skin condition. It occurs when bacteria enter the skin through a break or crack and cause swelling, redness, warmth, and pain in the affected area. Cellulitis can occur anywhere on the body and spread to other parts.

When to see a doctor

Red spots or a rash on the breast is usually not a cause for concern but can sometimes be a sign of a more serious condition, including breast cancer.

People should see a doctor, as soon as possible, if the rash occurs alongside any of the following symptoms:

• changes in the breast skin
• new spots or rashes on the breast
• severe pain
• swelling, warmth, and redness of the breast
• fever
• wounds that do not heal
• fluid leaking from the rash
• red streaks coming from the rash

A person should also see a doctor for any rash that does not go away after a while or any rash that appears severe or causes other symptoms that raise concerns.