Mastitis

Definition

Mastitis is an infection of the ducts of the breast. It usually only occurs in women who are breastfeeding their babies.

Description

In the process of breastfeeding, the unaccustomed pull and tug by the infant suckling at the breast may result in the mother's nipples may becoming sore, cracked, or slightly abraded. This creates a tiny opening in the breast, through which bacteria can enter. The presence of milk, with high sugar content, gives the bacteria an excellent source of nutrition. Under these conditions, the bacteria are able to multiply, until they are plentiful enough to cause an infection within the breast.

Mastitis is most likely to occur in the fifth and sixth week of the postpartum period. Studies indicate an incidence of mastitis from 6–33% of all women who have a history of breastfeeding.

Causes and symptoms

The most common bacteria causing mastitis is Staphylococcus aureus, but sometimes Escherichia coli is responsible. In rare instances, Streptococcus can also induce an episode of mastitis. In 25–30% of people, Staphylococcus aureus is present on the skin, lining normal, uninfected nostrils. It is probably this bacteria, clinging to the baby's nostrils, that is available to create infection when an opportunity (i.e., a crack in the nipple) presents itself. A sluggish flow of milk and trauma to the nipples are the main contributing factors to the development of mastitis. Fatigue, stress, and returning to work may also predispose a nursing mother to developing the condition.

Diagnosis

The clinic, midwife, or office of the physician will most likely receive a call from the mother at home. The condition rarely occurs in the hospital. She will likely report general malaise, fatigue, headache, chills, an increased heart rate, and flu-like symptoms. Usually, only one breast is involved. An area of the affected breast becomes swollen, red, hard, and painful. A red streak may be evident. Often, the location of the infection is in the upper, outer quadrant, which is the location of most of the glandular tissue.

Lumps in the breasts may result from plugged milk ducts. Plugged ducts can contribute to mastitis. If the mother describes pain in both breasts, then the condition might be engorgement of the breasts, as opposed to mastitis, which almost always occurs unilaterally.

A definitive diagnosis of the offending pathogen involves obtaining a sample of breast milk from the infected breast. A culture is done to identify the pathogen. In practice, however, laboratory studies are done infrequently because antibiotic therapy is initiated before results are returned, and insurance companies may not cover the cost of the tests.[source]