To provide effective treatment and management of mastitis and breast abscess during lactation.

All staff involved with the diagnosis and management of mastitis must be aware of this guideline to ensure effective treatment and management of mastitis and breast abscess during lactation. This includes doctors, lactation consultants, midwives, nurses, allied health staff and pharmacists.

Mastitis: inflammation of the breast which may or may not be associated with a bacterial infection.

Inflammatory mastitis: Inflammation of the breast tissue resulting from ductal narrowing. Presents as increasingly red, oedematous and painful area of the breast. May be associated with systemic signs and symptoms such as fever, chills and tachycardia even in the absence of infection.

Infective mastitis is a progression from inflammatory to bacterial mastitis. Infective mastitis presents as worsening cellulitis and pain that commences in a specific region of the breast and may spread to other quadrants of the breast. Systemic symptoms are normally present. If systemic symptoms are not present but the breast is not responding to conservative treatment, infective mastitis should be considered.

The most common pathogen is Staphylococcus aureus. Less commonly, the pathogen may be a beta-haemolytic Streptococcus (such as Group A or Group B streptococcus) or Escherichia coli. Community-acquired methicillin-resistant S. aureus (MRSA) is increasingly being identified as the causative pathogen, although rates of MRSA remain relatively low in most parts of Australia.

Breast Abscess: a collection of pus in the breast which can occur as a complication of mastitis. It may result from inadequately treated mastitis or abrupt weaning during mastitis.

NSAIDS; nonsteroidal anti-inflammatory drugs.

Incidence
The reported incidence of mastitis ranges from 10 to 20% in the first six months postpartum, with most episodes occurring in the first six weeks. However, mastitis can occur at any time during breastfeeding. Around 3-11% of women with acute mastitis will develop a breast abscess.

Multiple factors may contribute to the development of mastitis. Mastitis is now considered to encompass a spectrum of conditions resulting from ductal inflammation and narrowing and stromal oedema. (ABM 2022).

Risk factors for mastitis

• Incomplete breast drainage due to:

  • Poor positioning and attachment

  • Missed feeds or long intervals between feeds

  • Tongue-tie

  • Abnormal infant oral anatomy

  • Ineffective infant sucking

• Restrictive clothing/external pressure on the breast

• Trauma to breasts or nipples e.g., from aggressive breast massage

• Poorly managed engorgement, oversupply or hyperlactation

• Unresolved blocked ducts or white spot on the nipple (blocked nipple pore)

• Rapid or abrupt weaning

• Stress, fatigue, overall poor health and nutrition

• Previous history of mastitis

Risk factors for breast abscess

• Delayed or inadequately treated mastitis

• Abrupt weaning especially during an episode of acute mastitis

• Smoking

Prevention

• Responsive, physiological breastfeeding according to baby's needs.

• Optimise breastfeeding positioning and attachment. Seek advice from an experienced midwife or lactation consultant if there are any concerns with breastfeeding.

• Effective management of breast fullness and engorgement.

• Avoid excessive milk expression and overstimulation of milk supply.

• Avoid constrictive clothing.

• Prompt attention to any signs of milk stasis, ductal narrowing or blockages.

  • Apply warmth to the affected area of the breast if this provides comfort and assists milk flow. Avoid excessive heat which may increase inflammation.

  • Very lightly massage the affected area under the shower or during a feed. Avoid vigorous, deep massage and vibrating devices.

  • Breastfeed or express the breast until the area is softened and feels more comfortable but avoid overstimulation through excessive breast drainage.

  • Repeat this process until the symptoms resolve

  • Anti-inflammatory medication e.g. NSAIDS

  • Apply ice packs every 1 hour or more frequently if desired to reduce inflammation

  • Therapeutic ultrasound may be effective to manage persistent ductal inflammation, oedema and blocked ducts. Refer the woman to a physiotherapist trained in this procedure if indicated.

• Eat a well-balanced diet and ensure adequate rest.

Signs and Symptoms of Mastitis

Signs and symptoms may develop rapidly and may include:

• Reddened area on the breast that may be tender or painful, swollen and hot to touch. Redness may be localised or generalised.

• The skin over the affected area may look shiny and tight with red streaks.

• Flu like symptoms may be experienced fever, lethargy, body aches, headache, nausea and vomiting.

• Fever (temperature >38C)

Signs and Symptoms of Breast Abscess

• In addition to the signs and symptoms of mastitis, there may be increased localised swelling, pain and tenderness at the site of the abscess.

• There may be a palpable fluid collection in the affected area.

• Women with an encapsulated abscess may present with no systemic symptoms but will present with a breast lump and usually describe a recent episode of mastitis. 

• The diagnosis and location should be confirmed by diagnostic ultrasound.

Investigations

Routine investigations are not necessary but should be initiated if:

• Mastitis is severe, recurrent or there is an unusual presentation

• No response to antibiotics within 2 days

• The woman has an allergy to the usual therapeutic antibiotics

• Hospital admission is required

In these situations, investigations should include:

• Breastmilk culture and sensitivity: hand express a midstream clean catch sample into a sterile container (i.e. a small quantity of the initially expressed milk is discarded to avoid contamination with skin flora)

• Full blood count (FBC)

• C-reactive protein (CRP)

Other investigations to consider:

• Blood cultures should be considered if temperature > 38.5C

• Diagnostic ultrasound if an abscess is suspected.

Treatment of Mastitis

TREATMENT SHOULD BEGIN IMMEDIATELY

Refer to Lactation Consultant for appropriate feeding assessment and advice

Refer to Appendix 2 for Assessment and management of lactating women presenting with breast pain and possible mastitis algorithm.

1. Conservative treatment

Continue to breastfeed on demand: mastitis is not an indication for, nor an appropriate time to wean

• If milk is not flowing freely, apply warmth to the affected area prior to feeding; this will assist with let-down reflex and therefore improve milk flow and breast drainage.

• Feed from the affected breast first and ensure effective drainage before offering the second side. However it is not necessary to completely 'empty' the breast each feed.

• Correct any positioning or attachment problems - ensure good attachment and adequate milk transfer occurs with each feed.

• Change feeding position so that baby's chin points towards affected area.

• Apply a covered ice pack after feeding or expressing to reduce pain and swelling. Ice may be applied every hour or more frequently if desired.

• Avoid long intervals between feeds.

• If the baby refuses to breastfeed, is unable to attach, or the breast is too painful to feed from, express the affected breast (as outlined below) and breastfeed from the unaffected side only. Baby can be fed extra expressed breastmilk from the affected side if needed. Resume breastfeeding from the affected side once pain and inflammation subsides.

• If nipples are damaged and too sore to breastfeed, the woman may prefer to rest them and express ( see below).

Expressing during an episode of mastitis

• Routine expressing after a breastfeed to 'empty' the affected breast is not necessary. Expressing should only be done for comfort or to collect expressed breastmilk when required.

• If the baby is not feeding from the affected breast, express with an electric breast pump at least 8 times in a 24 hour period. Use pump on a gentle setting, or hand express if too painful to use a pump.

• Provide light breast compressions during expressing if necessary to aid milk flow.

• After expressing, rub a few drops of breastmilk into the nipples and apply a purified lanolin cream sparingly to the nipple.

• Feed baby with expressed breast milk by cup, oral syringe/finger-feed or bottle - as advised, or as preferred by mother. Refer to the CPG0186 Breastmilk: Expressing, Storing and Feeding.

Use of massage during an episode of mastitis

• Avoid vigorous, deep massage and vibrating devices which may increase inflammation, oedema and tissue injury.

• Utilise light sweeping of the skin towards the clavicle and axilla in between feeds (e.g. lymphatic drainage massage) or light breast compressions during feeds instead of deep massage.

General advice to the woman

• Rest - seek practical domestic help if possible.

• Maintain adequate fluid intake and a well balanced diet.

• Avoid restrictive clothing and wear a supportive but not restrictive bra or crop top.

• The use of oral sunflower or soy lecithin (5-10g daily) been shown to reduce ductal inflammation and emulsify milk.

• There is mixed evidence for the use of probiotics to prevent or manage mastitis. Probiotic strains which may be beneficial include Limosilactobacillus fermentum (previously known as Lactobacillus fermentum) or Ligilactobacillus salivarius (previously known as Lactobacillus salivarius).

Avoid weaning

• Weaning during mastitis increases the likelihood of developing a breast abscess.

• Advise the woman that mastitis is not an indication for, nor an ideal time to wean.

• Provide reassurance that breastfeeding can safely continue during the use of anti-inflammatory and antibiotic medications.

• If the woman still wishes to wean it is better to do so once mastitis has resolved.

• If woman still wishes to wean when mastitis is present advise her to express until the mastitis is resolved and then gradually decrease the number of expressions/day over a period of a week or two, then cease.

• If the woman chooses to wean despite the above advice, then antibiotic cover will be necessary until all symptoms have resolved.

2. Pharmacological treatment

Women should be reassured that the medicines listed in this guideline are compatible with breastfeeding.

Analgesia and anti-inflammatory medications

• Paracetamol is considered safe to be used during breastfeeding. It is the usual medicine of choice for short-term analgesia and anti-pyretic. Maximum paracetamol dose is 4g per 24 hours.

• Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen are effective in reducing symptoms relating to inflammation. It can be safely used while breastfeeding as only small amounts of ibuprofen are excreted into breastmilk.

Antibiotic therapy

• PLEASE REFER TO APPENDIX 1 FOR THE RECOMMENDED ANTIBIOTIC REGIMEN

• If symptoms of mastitis are mild and have been present for less than 12- 24 hours, conservative treatment as outlined above may be sufficient.

• If symptoms are not improving within 12-24 hours or if the symptoms are moderate or severe, antibiotics should be started in conjunction with anti-inflammatory medication and continued conservative treatment.

• Oral antibiotics are recommended and should continue for at least 5 days but may be required for up to 10-14 days.

• Improvement should be seen within 2 to 3 days of antibiotic treatment. If there is no symptomatic improvement after 48 hours, milk should be collected for culture and sensitivity.

• If there are signs of systemic sepsis or the woman is acutely unwell, or if the woman is unable to tolerate oral antibiotics, she should be admitted to hospital and Intravenous (IV) antibiotics commenced.

• IV antibiotics should continue for at least 48 hours or until substantial clinical improvement is seen.

• Any baby whose mother is on antibiotic therapy should be monitored for systemic effects such as changes to the gastro-intestinal flora (with symptoms such as diarrhoea, vomiting and thrush) or skin rashes.

Other treatment considerations

• If the mother is admitted to hospital, her baby should remain with her to facilitate frequent breastfeeding. Refer to the BHS CPP0427 'Admission of an Infant/Child for Nutritional Maintenance or as a Visitor"

• Ongoing support and care by medical and nursing or midwifery staff and a lactation consultant is required to ensure that the episode of mastitis is resolving.

• Failure to improve after two to three days may indicate a breast abscess.

• Inflammatory breast cancer can resemble mastitis; this condition should be considered when the presentation is atypical or when response to treatment is not as expected.

• Vertical transmission of HIV from mother to child is more likely in the presence of mastitis. In the unlikely situation that a mother with HIV is breastfeeding:

  • Avoid breastfeeding on affected side until mastitis resolves.

  • Express from affected breast and discard.

Treatment of Breast Abscess

1. Medical treatment

• A breast abscess requires urgent referral to a breast surgeon for medical treatment.

• Ultrasound guided needle aspiration is the preferred treatment, but occasionally surgical drainage may be required. Recurrent aspirations are often required until the abscess resolves.

• Breastmilk and aspirate should be collected for culture and sensitivity.

• Analgesic, anti-inflammatory and antibiotic therapy is required as per Treatment of Mastitis - Pharmacological treatment.

2. Management following aspiration or surgical drainage

• Breastfeeding should continue as outlined under Treatment of Mastitis - conservative treatment.

• Unless the site of surgical incision is on the areola, or there is purulent discharge from the nipple, immediate post-operative breastfeeding will aid healing by avoiding engorgement.

• A hydrocolloid dressing will aid healing, absorb discharge and because it is thin, interfere less with achieving good attachment. Care is necessary to ensure any dressing does not impinge on the nipple.

• Positioning of the baby may need to be modified to avoid pressure on the aspiration/ incision site or interference with drain tube if in-situ.

• If the baby is unable to feed directly from the affected breast, the breast should be expressed (as above) until the mother is able to resume breastfeeding from that breast.

• Reassure the woman that breastmilk leaking from the incision site may occur and will not prevent healing.

• Ongoing support and care by medical staff and a lactation consultant is required.