Mastitis: A Common Breast Infection During Breastfeeding

Mastitis refers to a breast infection, usually of a bacterial nature. Mastitis is most common when breastfeeding: Breast infection is rarely seen outside of lactation. Left untreated, mastitis can develop into a painful abscess that requires surgical draining.

Breastfeeding and lactation are the most likely causes of mastitis. Breastfeeding places stress on the nipple and surrounding breast tissue, which often results in small skin cracks. Bacteria from the baby's mouth or the mother's skin may enter these abrasions and infect breast tissue. Mastitis affects the breast's parencyhmal, or fatty, tissue. Tissue inflammation presses on the breast's milk ducts, altering milk flow and causing pain.

Plugged milk ducts during lactation may also cause a breast infection. An erratic nursing schedule or missed feedings can cause breast engorgement, in which the breast fills with unused milk. This in turn can cause milk to stagnate and milk ducts to plug, creating a breeding area for mastitis-causing bacteria.

External pressure on the breasts during lactation also increases the chances of developing plugged milk ducts and breast mastitis. Tight clothing or ill-fitted bras can restrict milk flow and make breast infections more likely. Other objects or activities that can compress breasts and cause mastitis while breastfeeding include:

Towards the end of lactation, abruptly ceasing breastfeeding can cause a period of breast engorgement and increases the risk of mastitis. Using bottles and pacifiers during breastfeeding can alter how an infant suckles, making small cracks and abrasions in the breast more likely.

The main symptoms of mastitis are breast pain, swelling, redness, and fever. Generally, a breast infection affects only one breast. Breast enlargement, due to swelling and milk engorgement is also common during mastitis.

Mastitis may change nipple sensation, or result in nipple discharge with pus from the infection. Sensations of heat, itching, and tenderness may be felt in affected areas of the breast; these feelings result from an inflammatory immune reaction to the mastitis.

The most alarming symptom of mastitis is the presence of a breast lump. The lump is composed of swollen and inflamed breast tissue, which may develop into a breast abscess. As most women associate breast lumps with cancer, the initial reaction to a mastitis lump or breast abscess often includes anxiety and fear.

Smoking while breastfeeding increases the risk of breast mastitis. Smoking hinders the breasts' milk ejection reflex, raising the risk of breast engorgement and plugged milk ducts. Fatigue, anemia, and stress all increase a woman's chance of developing a breast infection during lactation.

Anatomical defects and surgical scars may also increase the risk of breast infection during lactation. Surgical scarring from a breast biopsy, cosmetic surgery, breast tumor removal, cyst removal, or breast abscess scars may all interfere with milk flow. Women with fibrocystic breast disease may have a slightly higher risk of breast mastitis than those with "normal" breasts.

Bacteria are usually the cause of mastitis during breastfeeding. The bacterial strains staphylococcus and streptococcus are the most common breast infection causes. The standard treatment for breast infection is antibiotic medication.

If mastitis symptoms do not improve within a day of starting antibiotics, it is possible the breast infection is a yeast infection, and not caused by bacteria. Yeast infections may pass to the breast from the mother's skin, or from a thrush infection in the baby's mouth.

An episode of mastitis during lactation may make a woman wonder if she should continue breastfeeding. The answer, usually, is yes. Continuing breastfeeding and expressing milk prevents breast engorgement and milk stagnation, both of which can worsen mastitis symptoms.

 

Mastitis during lactation presents little danger of infection to a suckling infant. The infection is not likely to pass to the baby through milk, and it may well be that the infant already had the infection, and passed it to the mother during breastfeeding.

A breast infection increases the amount of sodium in the affected breast's milk, and infants may prefer feeding at the other breast. Feeding the baby from the infected breast first helps maintain normal breastfeeding habits. If the infant refuses to take enough milk from the mastitis infected breast, excess milk should be expressed to prevent breast engorgement.

Self-care during a bout of mastitis can help alleviate symptoms and reduce the risk of a breast abscess or further breast infection. Applying a moist hot compress to the affected breast for fifteen to twenty minutes four times a day can help reduce mastitis pain. Some women gain relief from breast infection pain by expressing milk in a hot shower.

A severe case of breast infection may develop into a breast abscess. A breast abscess is an area of infected breast tissue filled with pus, dead cells, and fluid. A breast abscess can press upon milk ducts, causing lactation problems and pain.

A breast abscess can be treated by draining the abscess with a fine needle. If necessary, the abscess can be surgically removed through a breast incision. Women planning future pregnancies should be aware that surgical scarring increases the risk of mastitis during future lactation and breastfeeding.

It is possible for women to experience recurrent mastitis throughout lactation, a condition that disrupts breastfeeding and increases the risk of a breast abscess. In some cases, ceasing breastfeeding and ending lactation may be necessary to prevent further breast infection. Some doctors treat chronic breast infection during breastfeeding with prophylactic antibiotics. In other cases, breastfeeding women watch carefully for signs of plugged milk ducts and/or flu-like symptoms, and report such symptoms promptly.

Mastitis rarely develops outside of lactation. Women who do develop breast infection or abscess symptoms when not breastfeeding may require breast biopsies to rule out a rare type of breast cancer than mimics mastitis symptoms. Women who are breastfeeding usually do not undergo biopsy tests during mastitis or abscess diagnosis, but may require skin biopsies if antibiotic and antifungal treatments prove ineffective.

Resources

American Academy of Pediatrics. (nd). A woman's guide to breastfeeding. AAP Handbook.

American Cancer Society. (updated 2003). Benign breast conditions.

American Medical Association. (nd). The breast: Disorders.Medem Medical Library.

Beers, M.H., & Berkow, R. (ed). Breast disease. The Merck Manual of Diagnosis and Therapy, 17th Edition. Merck Research Laboratories, NJ, 1999.

Kumar, V., Abbas, A.K., Fausto, N. (ed). Robbins and Cotran Pathologic Basis of Disease, 7th edition. Elsevier Saunders, Philadelphia, 2005.

Tilson, B. (updated 2001). Mastitis: Plugged ducts and breast infections. La Leche League.

National Library of Medicine. (updated 2004). Breast infection.MedlinePlus Medical Encyclopedia.