Changes in the skin of the breast can occur due to almost any condition that affects the skin in other parts of the body.

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.

Are red spots a sign of breast cancer?

In the type of breast cancer known as inflammatory breast cancer, there is often redness, warmth, pain or tenderness, and a puckered or dimpled appearance to the breast. In the United States, IBC only accounts for around 2−4 percent of breast cancer cases, yet it contributes to 7−10 percent of deaths from breast cancer.

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 percent of all cases of breast cancer. It is also more common in older people, with an average age of diagnosis of 57 years.

Other common reasons for red breasts that are not cancerous and that affect the nipple and areola include:

1. Dermatitis (inflammation of the skin)
2. Eczema and sunburn can also cause skin changes in the breast.
3. Psoriasis, shingles, and hives
4. Nipple dermatitis is an inflammation of the skin on the nipple and areola. This condition can occur in women who are breastfeeding. It usually causes pain.
5. A breast abscess is pus in the breast that results from a bacterial infection. The bacteria gets inside the breast through the nipple. Breast abscesses can be painful and most commonly affect women who are breastfeeding.
6. Physical trauma
7. Allergies. Called a disease of the 21st century, allergies may appear as breast skin redness. They may occur due to the materials of your bra, foods or creams, soaps, shower gel etc.
8. Wrong size of bra.
9. Mastitis can make your breast look red too. Mastitis is a painful inflammation of the breast and is more common in women who are breastfeeding. It results from milk becoming trapped in the breast and a bacterial infection in the area. It typically causes redness, warmth, and tenderness of the affected breast.

In case you observe breast skin redness, make an appointment with your doctor ASAP to find out the reason and the appropriate treatment.

Sources:

Changes in Skin of the Breast: Symptoms & Signs, medicinenet.com