Mastitis

What is mastitis?

Mastitis is an inflammation of the breast, usually caused by an infection.

Mastitis most commonly occurs in breastfeeding women. It typically occurs within the first few weeks of breast feeding. Sometimes it occurs if you suddenly stop breastfeeding and the breasts become engorged with milk. Mastitis sometimes occurs in women who are not breastfeeding. Bacteria get into the milk ducts of the breast to cause the infection. This is often through a crack or sore in the nipple, (or from a nipple piercing), but some women without sore nipples develop mastitis.

What are the symptoms of mastitis?

Mastitis causes an area of hardness, pain, redness and swelling in the breast. It often starts in a section of breast near to the nipple. You may also develop a fever (high temperature) and feel unwell.

Mastitis or blocked milk duct?

A blocked milk duct sometimes occurs in breastfeeding women. A blocked milk duct can cause a painful swollen area in a breast. The overlying skin is sometimes red and inflamed, but not so intense as with infective mastitis. When you feed the baby, the pain may increase due to the pressure of milk building up behind the blocked duct. A blocked milk duct will usually clear within 1-2 days and symptoms will then go. However, in some cases a blocked milk duct becomes infected and develops into a mastitis. So, some cases of mastitis develop as a complication of a blocked milk duct, but some cases occur without a preceding blockage.

A blocked milk duct may clear more quickly by feeding the baby more often from the affected breast and gently massaging the breast whilst feeding.

What is the treatment for mastitis?

Infective mastitis is usually treated with a course of an antibiotic. However, a mild case may go without any treatment. If you notice a tender swollen area in a breast when you are breastfeeding, it may be a blocked milk duct or a developing mastitis. It may be reasonable to 'see how it goes' over a day or so. However, if symptoms become worse then see a doctor who may prescribe an antibiotic. The infection will usually clear within a few days once you start the antibiotic.

Are there any possible complications?

Occassionally, an abscess may form inside an infected section of breast. An abscess is a collection of pus. This causes a firm, red, tender lump. The pus in a breast abscess needs draining with a needle and syringe.

Some other points about mastitis

• If you are breastfeeding, continue to feed from the affected breast. This helps the milk to continue flowing and stops the breast from becoming engorged and making things worse. After each feed, try to express any remaining milk from the affected breast. Feeding from an infected breast does not harm the baby. (If the baby swallows bacteria from an infected breast, the bacteria will be killed by the acid in the baby's stomach.)
• The doctor will choose an antibiotic that is safe to give to breastfeeding women and will not harm the baby.
• You can take painkillers such as paracetamol or ibuprofen to ease pain and reduce fever.
• A breastfeeding baby may refuse to feed from the affected breast as the taste of the milk may change a little. If this occurs, feed from the other breast. However, express the milk from the affected breast to keep the milk supply going.

© EMIS and PIP 2006   Updated: June 2006