The mastitis spectrum

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The mastitis spectrum


The mastitis spectrum

The management of mastitis has changed in recent years, moving away from an assumption of infection and advice to increase frequency of breastfeeding or milk expression, and towards an understanding of the role of inflammation, milk duct narrowing, milk stasis and hyperlactation. There is now recognition that the umbrella term ‘mastitis’ can include inflammatory or bacterial mastitis, galactocele and breast abscess.

This article focuses mainly on mastitis in lactating women. In 2022, the Academy of Breastfeeding Medicine (ABM) released updated guidance on the management of the mastitis spectrum, which we summarise here alongside other references where identified (Academy of Breastfeeding Medicine protocol 36, Breastfeeding Medicine 2022;17:360). Non-lactational mastitis is rare and is more likely to have an infectious aspect; we address this separately.

This article was reviewed in April 2025. Red Whale would like to thank GP colleagues Dr Naomi Dow (International Board-certified lactation consultant (IBCLC)) and Dr Emma Cockerell (ABM peer supporter) for lending us their expertise in this area.

Headlines

Mastitis is an inflammatory condition of the breast tissue.

  • Fever and pain with localised redness and swelling can occur in the absence of infection due to ductal inflammation and stromal oedema.
  • Bacterial mastitis can arise if inflammation is not adequately managed.

Treatment of lactational mastitis should be aimed at:

  • Managing pain and inflammation using cool packs, NSAIDs and paracetamol.
  • Treating breast oedema using lymphatic drainage sweeping techniques.
  • Identifying and managing predisposing factors such as hyperlactation (oversupply) and suboptimal infant positioning and attachment to the breast.

Antibiotics should only be used if the following are present (WHO 2000, Mastitis causes and management):

  • Symptoms which do not improve after 24–48h of effective self-care measures.
  • Severe symptoms suggestive of systemic infection.

There is mixed evidence on the role of nipple trauma and breast milk culture in bacterial mastitis. Bacteria and fungi identified on the nipple are regularly identified in healthy milk. More recent evidence suggests that mastitis is not caused by retrograde spread of pathogenic bacteria from nipple trauma (ABM protocol 36, Breastfeeding Medicine 2022;17:360).

Breast abscesses and severe mastitis with systemic symptoms, rapidly progressing infection or immunocompromise should be referred URGENTLY for hospital admission (BMJ 2016;353:i2646).

When should I worry about cancer?

The NICE guidance (NICE 2015 (updated 2023), NG12) makes referral for suspected breast cancer very simple.

Suspected breast cancer pathway referral
Refer using suspected cancer pathway:
  • People aged ≥30y with unexplained breast lump with or without pain.

  • People aged ≥50y with unilateral nipple discharge, retraction or other changes of concern (e.g. Paget’s).

  • Consider a suspected cancer pathway referral for:
  • People aged ≥30y with an unexplained lump in the axilla.

  • People with skin changes suggestive of breast cancer.
  • If you are concerned that your patient might be presenting with a new inflammatory breast cancer, we have included details on how to distinguish this from mastitis in the subheading below.

    What we cover in this article

    • Definitions, pathophysiology and prevalence.
    • Presentation.
    • Investigation.
    • Management.
    • Complications and when to refer.
    • Microskills: lymphatic drainage.
    • Pitfalls: how to spot a new inflammatory breast cancer masquerading as mastitis; management of mastitis in HIV-positive women.
    • Prognosis.
    • Non-lactational mastitis.

    You may find our associated articles Breastfeeding: benefits and problems and Benign breast disease helpful for a wider view of other common breast symptoms, including vasospasm, nipple discharge and benign breast masses.

    Definitions, pathophysiology and prevalence

    The definitions below have been adapted from the ABM protocol.

    • Ductal narrowing (may also be referred to as ’blocked’ duct): microscopic ductal inflammation related to alveolar distension. Presents as a tender focal area of induration or congested breast tissue. It may be mildly erythematous, but does not have associated systemic symptoms. Be mindful of patient’s skin colour and differing dermatological appearances, i.e. patients with darker skin colours may have more subtle skin changes and may not be red.
    • Mastitis: inflammation of the breast which typically presents in a segmental distribution affecting ducts, alveoli and surrounding connective tissue.
      • Lactational mastitis is common, affecting approximately one in four women (Incidence of and Risk Factors for Lactational Mastitis: A Systematic Review, Wilson et al, Journal of Human Lactation, 2020).
      • Usually occurs in breastfeeding women (lactational mastitis), but can occur in non-lactating women (non-lactational mastitis).
    • Inflammatory mastitis: when ductal narrowing is persistent, milk is not removed efficiently from that part of the breast. The accumulated milk leads to local inflammation, causing increasing pain, oedema and erythema, with the development of systemic symptoms such as fever, chills and tachycardia.
    • Bacterial mastitis: secondary development of infection within the inflamed breast tissue. Symptoms can be difficult to distinguish from inflammatory mastitis.
    • Galactocele: a cyst-like collection of milk which occurs due to duct narrowing. Moderately firm. Size may fluctuate with breastfeeding. Not usually painful, hot or erythematous, but can become so if infected.
    • Phlegmon: a firm, fluid collection within the breast that arises due to excessive deep tissue massage to try and resolve ductal narrowing and inflammatory mastitis. Symptoms can be difficult to distinguish from inflammatory mastitis.
    • Breast abscess: a localised collection of pus within the breast, with progressive induration and erythema, causing a painful mass which may be fluctuant. There may or not may be systemic symptoms such as fever and tachycardia.
    • Granulomatous mastitis: a rare inflammatory reaction in the breast which can occur following bacterial mastitis, but is also seen in non-lactating women. Thought to be autoimmune in origin.

    Pathophysiology of lactational mastitis

    Presentation

    We should suspect mastitis in women presenting with a painful breast, usually with a wedge-shaped, red, firm area, and with a fever or general malaise. It is not possible on symptoms or signs alone to distinguish inflammatory from bacterial mastitis (ABM protocol 36, Breastfeeding Medicine 2022;17:360).

    Features which might indicate that infection is more likely include:

    • Localised erythema (or equivalent skin changes), pain and/or oedema of the breast.
    • Persistent systemic symptoms.
    • History of previous bacterial mastitis.

    Consider breast abscess in women with a history of recent mastitis or past breast abscess who develop a painful lump in the breast with redness and heat of the overlying skin. The mass may be fluctuant.

    Investigation

    Investigation with breast milk culture is not usually needed in simple lactational mastitis.

    It may be recommended in recurrent mastitis, and is included in ABM guidance for this scenario. However, breast milk is not a sterile fluid, and culture will therefore usually be positive. Considerable expertise is required to accurately interpret and manage milk culture results.

    In recurrent mastitis, imaging may be advised in secondary care to rule out underlying mass or granulomatous mastitis changes (see complications below).

    Management

    Management of the mastitis spectrum should start with prevention: teaching good breastfeeding technique and providing adequate support in the early postnatal phase (NICE 2025, NG247). Much of this will sit with our colleagues in infant feeding teams and community support services, including peer support. GPs are unlikely to have the time or skills to provide support with latching; however, we have a responsibility to signpost appropriately.

    The ABM protocol on mastitis offers some specific advice we can give:

    • Reassure women that early mastitis symptoms are usually not infective and will resolve with some simple interventions such as wearing a well-fitted bra and using ice packs for comfort.
    • Educate women on what is ‘normal’ in the early days of breastfeeding, including signs of engorgement, and advise that normal glandular tissue may feel ‘lumpy’ at times.
    • Feed the infant on demand, but do not attempt to empty the breasts at every feed or increase feeds from the affected breast.
      • Overfeeding from the affected breast may trigger a cycle of hyperlactation and worsen local inflammation.
      • Women can hand express small amounts of milk to relieve discomfort if needed.
      • Minimise using breast pumps, and only express the volume of milk the infant needs.
    • Feeding position: patients can attempt different feeding positions if this helps them feel more comfortable, but this will not address oedema or inflammation.
    • Sunflower or soy lecithin 5–10g daily by mouth may be taken to reduce inflammation in ducts and emulsify milk. Consider breast-specific probiotics (Limosilactobacillus salivarius and Ligilactobacillus fermentum), although the ABM acknowledges that evidence of effectiveness is mixed.
    • Avoid: deep tissue massage of the affected breast, saline soaks (including Epsom salts), applying cabbage leaves (there is no evidence that they work better than ice packs, and they might carry Listeria!) and ‘dangle-feeding’ (feeding an infant on the floor with the mother hovering above).

    Refer all women with signs of sepsis, rapidly progressing infection or immunocompromise URGENTLY for hospital admission (BMJ 2016;353:i2646).

    In addition to the advice above, we can:

    • Advise rest, which can help with oedema, inflammation and pain (WHO recommendation).
    • Advise NSAIDs and paracetamol for pain relief.
    • Treat nipple blebs with lecithin orally and topical mild–moderate potency corticosteroids, wiped off the nipple before the next feed. De-roofing blebs can increase risk of infection.
    • Treat breast oedema by teaching patients how to perform lymphatic drainage sweeping (see microskills for how to do this).
    Antibiotic management of lactational mastitis
    When to use antibiotics?
  • If symptoms do not improve after 24–48h of effective milk removal.

  • If there are severe symptoms suggestive of systemic infection.
  • Which antibiotics to use? The BNF (accessed February 2025) recommends:
  • Flucloxacillin 10–14 days.

  • If penicillin allergic: erythromycin 10–14 days.

  • At Red Whale, we were a little surprised at the recommendation for a 14-day course of antibiotics – a learning point for us! Our expert IBCLC colleagues gave advice that a shorter course is thought to increase the risk of recurrence. The ABM protocol does state that a shorter course can be considered if there is rapid resolution of cellulitis.

  • The ABM protocol suggests that second-line options could include clindamycin 300mg four times daily for 10–14 days or co-trimoxazole for 10–14 days.

  • We recommend taking advice from your friendly local microbiologist at this stage.

    Complications and when to refer

    Complication Management
    Breast abscess Refer all cases of suspected breast abscess for same-day surgical review, imaging and drainage.
  • Around 3–11% of women with acute mastitis will develop a breast abscess.

  • Women should continue to feed from the affected breast.

  • Antibiotics will usually be required in addition to drainage, and will be continued for 10–14 days.

  • Inflammation may take several weeks to resolve. Women are likely to be offered interval examination/imaging to ensure full resolution.

  • After a breast abscess, a small number of women (<2%) will develop a milk fistula: abnormal connection between the skin surface and the breast duct in the breast, resulting in spontaneous drainage of milk from this site.
  • Recurrent mastitis There is no clear consensus definition of recurrent mastitis. Patients may have re-curring mastitis symptoms such as fever, breast redness, breast swelling and/or breast pain every 2–4 weeks or less often.
  • Risk factors include inadequately treated prior mastitis or failure to address underlying mastitis causes.

  • Prophylactic antibiotics have not been shown to prevent recurrent mastitis.

  • Recurrent mastitis at the same site should prompt us to check for underlying breast disease.

  • Consider milk culture in recurrent mastitis, although care is needed in the interpretation of the results of this.

  • Signpost to skilled breastfeeding support such as an infant feeding team or International Board-Certified Lactation Consultant (IBCLC).
  • Galactocele
  • Diagnosis must be confirmed by ultrasound. GPs should therefore refer patients with suspected galactocele in the absence of infection urgently to the breast clinic, as with any breast lump.

  • Infected galactoceles should be treated as a breast abscess, with same-day discussion with secondary care.
  • Aspiration almost always ends in recurrence, with increased risk of infection, but a surgical drain may be cited for symptomatic relief.

  • Infected galactoceles will require antibiotics as well as drainage.
  • Phlegmon
  • These fluid collections may require more prolonged courses of antibiotic, and need close follow-up to monitor for progression to breast abscess.

  • Refer to the breast clinic for confirmation of diagnosis and appropriate management.
  • Subclinical/subacute mastitis Chronic duct inflammation leads to the development of a biofilm, which narrows the duct still further and causes local pain and inflammation.
  • The most common bacterial causes are coagulase negative Staphylococci or virdirans Streptococci, part of the usual breast microbiome, which means that systemic mastitis symptoms are uncommon.

  • Patients are at higher risk if they have hyperlactation (oversupply); after recurrent mastitis; after a caesarean birth; or if exclusively breast pumping.

  • Symptoms include needle-like or burning breast pain, nipple blebs and recurrent areas of induration or congestion in the breast tissue.

  • Milk culture may not show a dominant organism.

  • Macrolide antibiotics may have better efficacy in this scenario.
  • Prognosis

    Most women will have complete recovery after mastitis or breast abscess.

    Microskills

    One piece of the advice to breastfeeding women who develop mastitis is to address breast oedema by using the ‘lymphatic drainage sweeping’ technique. But what is this and how should we advise our patients? Our IBCLC colleague advises:

    • Use very gentle touch – this is NOT massage. The idea is to just gently lift the skin to allow the flow of lymph along the lymphatic vessels.
    • Start by using fingers to perform 10 small circles at the junction of the internal jugular and subclavian veins.
    • Repeat this movement of 10 small circles in the axilla.
    • Using the flats of the fingers, continue with light sweeping motions from the nipple towards the clavicle.
    • Repeat as often as required.
    • Can be combined with ice packs as needed.

    Pitfalls: differentiating inflammatory breast cancer from mastitis

    A BMJ 10-minute consultation gives us some points to help differentiate inflammatory breast cancer from mastitis or breast abscess (BMJ 2016;353:i2646). 

    Differentiating inflammatory breast cancer from mastitis
    - Inflammatory breast cancer Mastitis
    Epidemiology/aetiology Rare (1–6% of breast cancers).
    Risk factors: age, family history, immunocompromise.
    Common.
    Risk factors: age, breastfeeding, smoking.
    History Breast globally enlarging at rapid rate.
    No fever.
    Breast does not usually enlarge.
    Fever.
    Examination Erythema of entire breast (pink–red).
    Generalised oedema or peau d'orange.
    Axillary lymphadenopathy may be present.
    Erythema affects a localised area within the breast.
    Oedema or peau d'orange usually affects a well-demarcated area of the breast.
    Axillary lymphadenopathy unlikely.

    Non-lactational mastitis

    Presentation

    Presentation is the same as for lactational mastitis: a discrete area of redness, heat and tenderness, with systemic symptoms of infection developing over hours to days. Symptoms can be central/subareolar or peripheral, and will usually be unilateral (BMJ 2016;353:i2646).

    Aetiology

    Smoking is the main predisposing factor.

    Other risk factors include: diabetes, rheumatoid arthritis, corticosteroid treatment, HIV infection or other immunocompromise, trauma to the breast (including through nipple piercing) and local skin disease such as eczema.

    Management

    In non-lactating women, mastitis is usually associated with infection.

    Antibiotics are advised for all:

    • Oral co-amoxiclav 500/125mg three times a day (clarithromycin or erythromycin with metronidazole in penicillin allergy) for 10–14 days.

    Follow-up and referral

    Advise follow-up if symptoms don’t resolve in 48h, and consider alternative causes if there has been inadequate response.

    Review all patients at 2 weeks to ensure full resolution of symptoms, and consider suspected cancer pathway referral if there are any concerning features of inflammatory breast cancer.

    The mastitis spectrum
  • Mastitis is an inflammatory condition of the breast, and is not always associated with infection.

  • Management of lactational mastitis should include pain relief, treatment of breast oedema and hyperlactation in the first instance.

  • Antibiotics should be reserved for severe systemic upset, or where conservative measures have not improved symptoms after 24–48h.

  • Breast abscess should be referred urgently for surgical drainage.

  • Non-lactational mastitis is usually infective, and requires antibiotics and close follow-up, with a low threshold for referral via suspected cancer pathways for concerning features.

  • Inflammatory breast cancer can mimic mastitis.
  • Useful resources:
    Websites (all resources are hyperlinked for ease of use in Red Whale Knowledge)
  • Physician Guide to Breastfeeding for Parents, Physicians, Lactation Consultants, Doulas
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