Breast abscess

Page last reviewed: 13/07/2011

A breast abscess is a painful collection of pus that forms in the breast. Most abscesses form just under the skin and are the result of a bacterial infection.

Symptoms of a breast abscess

A breast abscess is a painful, swollen lump in the breast. It may also:

  • be red
  • feel hot
  • cause the skin over it to swell
  • cause a high temperature (fever) 

How common are breast abscesses?

Breast abscesses occur most commonly between 18 and 50 years of age, but they are very uncommon in women who are not producing milk.

When a woman is breastfeeding, an infection may occur as a result of bacteria entering the breast tissue, or because of a blocked milk duct. Milk ducts are the tiny tubes that carry the milk. This can cause a condition called mastitis (inflammation of the breast). If it is not treated, a breast infection can lead to the development of an abscess.

Mastitis affects around 1 woman in 10 who are breastfeeding. One study found that, of the women with mastitis who were treated with antibiotic medicines, around 3 in 100 developed a breast abscess.

Outlook

A breast abscess can be treated by draining the collection of pus, either by using a needle and a syringe or by making an incision (cut) in the abscess to let the pus escape (see Breast abscess - treatment).

A breast abscess may cause some long-term complications. After a breast abscess, about 1 woman in 10 may not be able to breastfeed again. If an abscess is very large and requires more extensive surgery, for example, to remove part of the breast, it could result in the breast being disfigured.

Antibiotics
Antibiotics are medicines that can be used to treat infections caused by mircro-organisms, usually bacteria or fungi.
Inflammation
Inflammation is the body's response to infection, irritation or injury. It causes redness, swelling, pain and sometimes a feeling of heat in the affected area.

Page last reviewed: 13/07/2011

Most breast abscesses are linked to mastitis (inflammation of the breast). Mastitis usually affects women who are breastfeeding, although it can sometimes also occur in women who are not breastfeeding.

Women who smoke cigarettes have an increased risk of developing mastitis and breast abscesses outside of pregnancy and breastfeeding. This condition is known as periductal mastitis.

See the Health A-Z topics about Mastitis (breastfeeding) and Mastitis (non-breastfeeding) for more information.

How breast abscesses form

Most abscesses are caused by a bacterial infection. The bacteria may enter the breast and milk duct through a small crack or break in the skin of the nipple. Such cracks may appear during breastfeeding. However, sometimes the infection is caused by an overgrowth of bacteria that normally exist quite harmlessly within the milk ducts. An overgrowth of bacteria might result from a collection of stagnant milk in a blocked milk duct.

When bacteria enter your body, your immune system (the body's natural defence system) tries to fight them off by sending white blood cells to the affected area. As the white blood cells attack the bacteria this can create a pool of infection that creates an abscess.

The hollow fills with pus to form an abscess. The pus contains a mixture of dead tissue, white blood cells and bacteria. The abscess may get larger and more painful as the infection continues and more pus is produced.

Immune system
The immune system is the body's defence system, which helps protect it from disease, bacteria and viruses.
Inflammation
Inflammation is the body's response to infection, irritation or injury. It causes redness, swelling, pain and sometimes a feeling of heat in the affected area.
White blood cells
White blood cells are the part of the body that fights infection and disease.

Page last reviewed: 13/07/2011

A breast abscess is usually a complication of mastitis (inflammation of the breast). If you have been to see your GP due to mastitis, you may already have been given antibiotics, which are medicines that treat bacterial infections. If your symptoms do not improve, you should return to your GP.

If after taking antibiotics your breast is still hard, red and painful, your GP may refer you to a specialist breast unit to confirm the diagnosis of a breast abscess. Confirmation of the diagnosis is usually done using an ultrasound scan.

If your surgeon confirms that you have a breast abscess, it can usually be successfully treated by draining it.

Small breast abscesses

A small abscess can be drained using a needle.

Ultrasound is sometimes used to guide the needle into place.  

Large breast abscesses

For larger breast abscesses, a small incision (cut) is made in the abscess to let the pus drain out.

Before the procedure, an injection of local anaesthetic will usually be given to numb your breast tissue. General anaesthetic (painkilling medication that makes you unconscious) is not usually needed for this treatment unless the abscess is deep.

Further tests

You should always visit your GP if you notice any changes to your breasts, such as lumps or a discharge (leaking fluid) from your nipples. These could be a sign of breast cancer, although in 9 out of 10 cases breast lumps are benign (non-cancerous). See the Health A-Z topic about Breast lumps for more information.

If your GP is unsure about the diagnosis of a breast abscess,you may need further investigation at a symptomatic breast unit.

Antibiotics
Antibiotics are medicines that can be used to treat infections caused by micro-organisms, usually bacteria or fungi.
Inflammation
Inflammation is the body's response to infection, irritation or injury. It causes redness, swelling, pain and sometimes a feeling of heat in the affected area.

Breastfeeding

If you have a breast abscess and you are breastfeeding your baby, you should try to continue to breastfeed.

Your GP may recommend that you use a breast pump to express milk from the affected breast. A breast pump is a device that can be used to encourage milk to flow from your breasts. You can safely continue to breastfeed your baby from the other breast as normal.

For more information about breastfeeding, see the Health A-Z topic about Mastitis - treatment or Breastfeeding, or the Birth to five section about how to breastfeed.

Content provided by NHS Choices www.nhs.uk and adapted for Ireland by the Health A-Z.

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