If you have a red spot on your breast that appears to be a pimple or bug bite, it could very well be either of those. The spot could also be due to an infection, allergic reaction, or other skin irritation.

Most types of breast cancer don’t cause red spots on the breast. There are a few types that can, but they’re rare.

Let’s take a look at these uncommon breast cancers and other conditions that can cause red spots on the breast, as well as signs that you should see your doctor.

It’s not common, but a red spot on the breast can sometimes be a sign of breast cancer.

Inflammatory breast cancer (IBC) is rare, making up about 2 to 4 percent of breast cancer cases.

A small red spot that looks very much like an insect bite or rash can be an early sign of IBC. This type of breast cancer is aggressive. It usually involves the lymph nodes by the time of diagnosis.

Another rare type of breast cancer is called Paget’s disease of the breast. It makes up about 1 to 4.3 percent of all breast cancers. In some cases, it can cause a red lesion on the nipple or areola, which can look like an insect bite or eczema.

When you think of signs of breast cancer, you probably think about the discovery of a lump. IBC is different than most types of breast cancer in that it usually doesn’t involve a tumor you can feel, at least in the early stages.

You might not have any symptoms at all until the lymph vessels become involved. Signs and symptoms of IBC include:

  • breast tenderness or pain
  • itching
  • redness
  • swelling
  • skin that feels warm to the touch
  • pitted or dimpled skin that resembles an orange peel
  • skin that looks like a rash, hives, or bruise
  • nipple flattening or inversion
  • swollen lymph glands on the neck or under the arms
  • one or more lumps in the breast

Paget’s disease begins with a lesion at the nipple or areola. It can advance to surrounding skin. Signs and symptoms of Paget’s disease can include:

  • thickening of lesions
  • redness
  • itching
  • tingling
  • pain
  • scaling, flaking, or crusting of skin around the nipple
  • nipple flattening or inversion
  • yellow or bloody nipple discharge

Bug bites can look like pimples or rashes. They appear suddenly and are typically itchy. Here’s how to recognize some bug bites you might find on your breast:

  • Flea bites look like small red bumps arranged in groups of three.
  • Mosquito bites are puffy white and red bumps.
  • Bedbug bites are clusters of three to five bites in a zigzag pattern.
  • Scabies look like tiny bumps or blisters that form thin, irregular burrow tracks. Itching tends to get worse at night.

Although pimples most often develop on the face, back, shoulders, and chest, they can also form on your breasts. Here are some ways to identify acne on your breasts:

  • Whiteheads look like bumps just under the surface of the skin.
  • Blackheads are darker bumps on the surface of the skin.
  • Papules are small pink bumps that may feel a bit tender.
  • Pustules look red at the bottom with pus on top.
  • Nodules are large solid bumps that form deep in the skin. They may be painful.
  • Cysts are deep bumps filled with pus. They may be painful.

A red spot on the breast due to cancer may appear as the following:

  • IBC. A rash with swelling, itching, dimpling, and changes to the nipple.
  • Paget’s disease. Thickening red spot typically on the nipple or areola. You may also have:
    • crusting
    • scaling
    • nipple discharge
    • other changes to the nipple

Here are some more potential causes for red spots on your breast.

Infection

Anyone can develop a breast infection, but the majority of infections tend to develop in women who are breastfeeding.

Mastitis is an infection of the milk ducts. It usually affects only one breast. Accompanying symptoms may include:

  • headache
  • fever
  • flu-like symptoms

Hives

Hives affect about 20 percent of people at some point. They can pop up anywhere, including the breasts.

These raised red bumps are the result of an allergic reaction. They tend to be itchy and turn white when you press on them. Hives can come and go quickly.

Atopic dermatitis

Also known as eczema, this condition causes redness, swelling, and scaling of the skin. Atopic dermatitis can flare up, go into remission, and flare up again.

You can treat pimples on the breasts with at-home remedies and over-the-counter (OTC) skin care products. If it’s a recurring issue, consider seeing a dermatologist for treatment.

If you don’t already have a dermatologist, our Healthline FindCare tool can help you connect to physicians in your area.

Many bug bites resolve on their own. Others, such as scabies, require treatment.

No matter what the cause, see your doctor if you notice signs of infection, or if the red spot or pimple-like bump persists.

Don’t ignore concerning symptoms if you:

  • have a personal or family history of breast cancer
  • are at increased risk for breast cancer
  • suspect you have breast cancer

Talk to your doctor right away. Early diagnosis and treatment makes cancer easier to treat and usually results in a better outcome.

Make an appointment to see your doctor if you’re at all concerned about a red spot on your breast.

Your doctor will probably begin with a physical examination of your breasts. In the case of pimples, bug bites, or allergic reactions, this may be enough to reach a diagnosis.

If your doctor suspects breast cancer, they may use the following tests to help make a diagnosis:

A biopsy, or tissue sample, is needed to confirm a diagnosis of breast cancer.

A red spot on your breast is more likely to be a pimple, bug bite, or rash than a sign of breast cancer. But if you have any cause for concern, have your doctor take a look at it.

See your doctor right away if:

  • You also have swollen lymph nodes on your neck or under your arm.
  • The skin on your breast looks thickened, pitted, or dimpled.
  • There’s swelling of the breast, or it’s warm to the touch.
  • You see discharge, inversion, flattening, or other changes to your nipple or areola.

These can be signs of inflammatory breast cancer or Paget’s disease of the breast, two rare types of breast cancer.