Mastitis and breast abscesses

Mastitis is inflammation of the breast, usually associated with an abundant supply of milk. If milk is not drained effectively from a part of the breast, it can become pressurised and leak into surrounding tissue, triggering an inflammatory response. It is a continuum from engorgement through to breast abscesses.

Sometimes mastitis is preceded by a blocked duct – a small tender lump. The Breastfeeding Network has self-help information for mother’s, which will resolve the majority of cases without additional treatment. 

Occasionally mastitis can become infective due to skin breaks in the nipples or a noninfective mastitis that does not clear effectively. Mastitis presents with breast pain (often unilateral, affecting a defined area, worse prior to feeding which may intensify during feeding due to let down), malaise, fever and flu-like symptoms. Signs include a firm breast swelling +/- erythema, pyrexia and occasionally nipple fissures.

Mastitis that does not clear can become an abscess, although abscesses can also occur without preceding symptoms of mastitis. A fluid filled sac may also be a galactocele (harmless sac filled with milk).

DO NOT stop breastfeeding

Rest

• Feed baby as usual but do not add additional breastfeeds or pumping sessions.
• The mother should try to rest as much as possible (eat well, hydrate)

Reduce Inflammation

• Consider over the counter ibuprofen to reduce some inflammation in the breast
• Use ice (wrapped in a cloth) or cold packs on the breast for 10 minute intervals (max every 30 minutes). Do not use heat packs.

Medications

• Ibuprofen and paracetamol are both safe to take while breastfeeding if no contraindications for the mother
• Consider antibiotics if there is an infected nipple fissure, worsening/no improvement in symptoms after 24 hours of measures to promote effective milk removal, there is microbiological evidence of infection.

Investigations:

• Consider a culture of the breast milk to identify the pathogen in severe or recurrent cases or where there is a deep “burning” pain. NICE CKS provides more information on this.
• Uncommonly an infection that does not clear may be a sign of inflammatory breast cancer and needs further investigation.

When to admit

Rarely mastitis can result in sepsis – emergency admission to the breast team (via general surgeons) should be arranged in this case. Mothers should be supported to have their babies with them in hospital.

An abscess presents as a well-defined firm, extremely tender swelling +/- redness or hyperpigmentation. They are typically managed by US guided drainage or incision and drainage (under GA) and need same day referral.