A breast infection/mastitis is an infection located in the tissue of the breast and/or milk duct. Breast infections are usually caused by a common bacteria found on normal skin (Staphylococcus aureus). The bacteria enter through a break or crack in the skin, usually the nipple. The infection then takes place in the parenchymal (fatty) tissue and causes swelling of the parenchymal tissue outside the milk ducts. This swelling compresses on the milk ducts, and the result is pain and swelling of the infected breast. Breast infections most commonly occur in women who are breastfeeding. Breast infections that are not related to breastfeeding must be evaluated by a breast surgeon, to differentiate from a rare form of breast cancer.

Some common symptoms of breast infections include:

  • breast pain
  • breast lump
  • breast enlargement on one side only
  • swelling, tenderness, redness, and heat in breast tissue
  • nipple discharge (may contain pus)
  • nipple sensation changes
  • itching
  • tender and/or enlarged lymph nodes in armpit on the same side
  • fever

Once an infection is suspected, evaluation by a healthcare professional is recommended. They will perform a physical exam, and likely will obtain imaging for further evaluation, with a mammogram or breast ultrasound.

Treatment usually includes applying moist heat to the infected breast tissue for 15 to 20 minutes four times a day, as well as antibiotics. If you are breastfeeding, you are encouraged to continue to breastfeed or to pump to alleviate engorgement while receiving treatment. At times an associated abscess may be present. A breast abscess is a painful collection of pus that forms in the breast. Abscesses require more extensive treatment, including incision and drainage. This can be performed by your healthcare provider or a breast surgeon, usually under ultrasound guidance. These are regularly performed by our breast surgeons at the Hunterdon Breast Surgery Center.