Breast infection

Definition

A breast infection is an infection in the tissue of the breast.

Alternative Names

Mastitis; Infection - breast tissue; Breast abscess

Causes, incidence, and risk factors

Breast infections are usually caused by a common bacteria (Staphylococcus aureus) found on normal skin. The bacteria enter through a break or crack in the skin, usually on the nipple.

The infection takes place in the fatty tissue of the breast and causes swelling. This swelling pushes on the milk ducts. The result is pain and lumps in the infected breast.

Breast infections usually occur in women who are breast-feeding. Breast infections that are not related to breast-feeding might be a rare form of breast cancer.

Symptoms

• Breast enlargement on one side only
• Breast lump
• Breast pain
• Fever and flu-like symptoms including nausea and vomiting
• Itching
• Nipple discharge (may contain pus)
• Nipple sensation changes
• Swelling, tenderness, redness, and warmth in breast tissue
• Tender or enlarged lymph nodes in armpit on the same side

Signs and tests

Breast-feeding women are usually not tested. However, an exam is often helpful to confirm the diagnosis and rule out complications such as an abscess.

Sometimes for infections that keep returning, milk from the nipple will be cultured. In women who are not breast-feeding, testing may include mammography or breast biopsy.

Treatment

Self-care may include applying moist heat to the infected breast tissue for 15 to 20 minutes four times a day.

Antibiotic medications are usually very effective in treating a breast infection. You are encouraged to continue to breast-feed or to pump to relieve breast engorgement from milk production while receiving treatment.

Expectations (prognosis)

The condition usually clears quickly with antibiotic therapy.

Complications

In severe infections, an abscess may develop. Abscesses need to be drained, either as an office procedure or with surgery. Women with abscesses may be told to temporarily stop breast-feeding.

Calling your health care provider

Call your health care provider if:

• Any portion of the breast tissue becomes reddened, tender, swollen, or hot
• You are breast-feeding and develop a high fever
• The lymph nodes in the armpit become tender or swollen

Prevention

The following may help reduce the risk of breast infections:

• Careful nipple care to prevent irritation and cracking
• Feeding often and pumping milk to prevent engorgement of the breast
• Proper breast-feeding technique with good latching by the baby
• Weaning slowly, over several weeks, rather than abruptly stopping breastfeeding

References

Newton ER. Breast-feeding. In: Gabbe SG, Niebyl JF, Simpson JL, eds. Obstetrics: Normal and Problem Pregnancies. 5th ed. Philadelphia, PA: Churchill Livingston Elsevier; 2007:chap 22.

Grobmyer SR, Massoll N, Copeland EM III. Clinical management of mastitis and breast abscess and idiopathic granulomatous mastitis. In: Bland KI, Copeland EM III, eds. The Breast: Comprehensive Management of Benign and Malignant Disorders. 4th ed. Philadelphia, Pa: Saunders Elsevier;2009:chap 6.