Mastitis: management (including indication for antibiotics), side-effects, prevention

Management of mastitis: key principles

Here are the key principles of management of the breast inflammation commonly referred to as mastitis (even though mastitis technically applies to all breast inflammation because it means 'inflammation of the breast'). Mastitis in the commonly used sense is a localised acute inflammation of a lactating breast.

1. Frequent flexible milk removal (Principle #1). Milk removal and accompanying ejections may occur with

   • Vacuum from the baby suckling (which is the most efficient way to extract milk) or the breast pump, or

   • Positive pressure generated by gente hand expression.

   Information about frequent flexible feeds is available here.

2. Cease massage, including lump massage, vibration, Therapeutic Breast Massage of Lactation or Manual Lymphatic Drainage, which are light massages applied across the breast skin from the nipple towards the axillae (Principle #2). You can find out why Therapeutic Breast Massage or Manual Lymphatic Drainage don't help here.

3. Resolve any other external application of mechanical pressure (Principle #2), discussed in detail here.

   • Bra or garments applying pressure to breast tissue

   • Sleeping position at night applying pressure to breast tissue

   • Cease use of silverettes or breast shell which apply pressure to breast tissue

4. Resolve any nipple and breast tissue drag or positional instability (Principle #2), discussed in the gestalt method, commencing here

5. If the mastits develops during weaning, the mother applies Principle #3, here. When her breasts run full, her milk production is being downregulated due to the effects of backpressure in the alveoli. However, clinical presentations of breast inflammation need to be avoided. She needs to either

   • Weaning from the breast in a more gradual way, or

   • Hand express or pump milk from her breasts frequently and flexibly on the affected side, if the mother is not offering the breast to the infant, until the signs and symptoms have resolved.

6. Some women with generous breasts may feel relief from the mastitis when they very gently move their breasts with the palms of their own hands (Principle #5). They may like to do this in a warm or hot shower. You can read when this might be useful here.

7. As much rest as possible.

8. Analgesia (paracetamol or acetaminophen, or ibuprofen) as required rather than regularly prescribed.

   • The use of warm showers and antipyretic prescriptions did not improve outcomes in the Kvist et al 2007 breast inflammation study.36

   • By using analgesia in response to acute discomfort only, suppression of mammary immune response may be avoided.

   • Patients should be educated that overuse of antipyretics may negatively affect the body’s capacity to downregulate the inflammatory response.5, 111, 112

9. Reasure the woman that breast inflammation typically resolves without antibiotics. See the discussion about antibiotic use below.

   • Consider sending the woman home with antibiotic script depending on clinical judgement

10. Daily or regular follow-up is important, timing your follow up according to your clinical judgement or risk.

11. Investigation with ultrasound imaging is essential if signs and symptoms of localised breast inflammation are severe and not resolving, or the lump is enlarging rather than resolving, or the lump is fluctant, to exclude abscess or other pathology.70 The indications for ultrasound imaging are discussed here.

There is no indication for midstream milk culture and sensitivities in mastitis

There is no scientific rationale for

• Midstream milk culture and sensitivities from a breastfeeding mother’s milk in the context of breast inflammation, unless abscess is identified.

• Investigating c-reactive protein or the full blood count, as both white cells and c-reactive protein are markers of inflammation, not necessarily infection.36, 109, 110

When are antibiotics indicated in the treatment of mastitis?

Overuse of antibiotics for breast inflammation continues, in the context of the World Health Organisation’s urgent call for responsible antimicrobial stewardship, in the context of the 'slow motion catastrophe' of global antimicrobial resistance.30, 38, 42, 6 Antibiotic over-prescribing is described as a tragedy of the commons in which a shared resource is over-exploited by some, acting in their own interests, to the eventual detriment of all.121, 122

In general, Australian doctors prescribe more than twice the amount of antibiotics relative to our European counterparts.11 It is not surprising, then, that over 90% of Australian women and 86%-97% of United States women diagnosed with mastitis are prescribed antibiotics, with comparable rates in New Zealand and Canada.12-14

Scandinavian women diagnosed with mastitis or breast inflammation, however, are much less likely to be prescribed antibiotics, at 38% in a Finnish study and 15% in a Swedish study.15, 16 In the 2007 study by Kvist et al, 85% of 210 episodes of mastitis in 205 breastfeeding women recovered without recourse to antibiotic therapy, having received help which included a fit and hold intervention, recommendation to increase frequency of breastfeeds, and daily phone follow-up which helped women tolerate symptoms until they resolved.16

This study also showed that nipple damage did not increase the need for antibiotics, and that abscess developed in 3% of cases, regardless of antibiotic use. Abscess develops in about 3% of women diagnosed with mastitis, regardless of country or rate of antibiotic prescription.14, 17

A number of studies have shown decreased microbiome diversity and increased counts of Staphylococcus aureus in the milk of women with mastitis,2, 18-20 but human milk microbiome research has shown that the assumption that Staphylococcus causes mastitis and must be eliminated with an antibiotic is much too simplistic.21-23

Persistent signs and symptoms at the most severe end of the spectrum of breast inflammation may require antibiotics. You can find why the unhelpful diagnoses such infective mastitis, phlegmon, and subacute mastitis or mammary dysbiosis recommended in Clinical Protocol #36 do not help breastfeeding women, and contribute to concerning overuse of antibiotics here and here.

Antibiotics remain a treatment of last resort when signs and symptoms of breast inflammation persist without resolution or are particularly severe.

NDC clinical guidelines for antibiotic use in breast inflammation, commonly referred to as mastitis

Flucloxacillin or dicloxacillin 500 mg 4 times daily is recommended; cephalexin 500mg 4 times daily if allergic to penicillin; and clindamycin if the patient is known to have an anaphylactic reaction to penicillin, because of the risk of cross-reactivity between cephalexin and penicillin. If methicillin resistant Staphylococcus Aureus is suspected or proven, bactrim or clindamycin are prescribed. If breast inflammation does not improve with oral antibiotics, intravenous flucloxacillin, cephazolin or vancomycin may be necessary.70

• Think of a breast inflammation as a viral upper respiratory tract infection. It can feel miserable for a number of days, accompanied by fevers, mylagia, rigor and fatigue. As the days pass, the symptoms gradually improve and the fevers lessen. The patient might still feel unwell after five days, but is improving.

• Any new lump that has persisted for a week requires ultrasound, to exclude breast cancer, unless it is clinically clear that the lump is resolving and close to complete resolution. You can find out about using ultrasound to diagnose abscess here.

• If the lump has persisted a week but is clinically resolving, and you and the patient are happy not to ultrasound, close followup is required until complete resolution.

• Fevers with breast inflammation can be expected to persist for a number of days. By 72 hours, the fevers should be lessening and the inflammation showing signs of improvement.

• By day 5, persisting fevers and no signs of improvement require antibiotic use.

• If the lump is not improving and the patient has been taking antibiotics, even with normal ultrasound, referral to the hospital for intravenous antibiotics is indicated.

Evidence

• In 2007 Kvist et al’s randomised controlled trial of 210 episodes of breast inflammation in 205 lactating women concluded that daily follow-up and support while a woman awaited her body’s anti-inflammatory response was effective treatment for the great majority of lactating mothers with breast inflammation. This was regardless of how long symptomatic women waited before presenting at the midwifery clinic, which ranged from 1-7 days. All patients received usual care, which included unspecified fit and hold adjustments and advice to decrease inter-feed intervals.36, 100, 109 Kvist reflects that with daily follow-up, women were able to tolerate systemic symptoms while resolution occurred without recourse to antibiotics. Daily follow-up also allowed detection of the 15% of patients who required antibiotics.

• In their 2007 study, Kvist et al found that 85% of 210 episodes of breast inflammation in 205 breastfeeding women recovered without recourse to antibiotic therapy.36, 100 The presence of nipple damage did not increase the need for antibiotics. Women received care when they presented with any or a mix of the following: a tense breast not relieved by breastfeeding, and/or lumps in the breast tissue, breast redness, fever, or pain. The treating midwives used the term breast inflammation with patients, rather than mastitis. The time that elapsed before presenting at the clinic didn’t affect outcomes. All women were provided with ‘essential care’, which included both advice to decrease feeding intervals and fit and hold support (though the techniques used for this fit and hold support are not described).36 Women who took longer to recover had significantly higher scores for increased breast tension not relieved by breastfeeding and for erythema. But there was no difference in experience of pain between those who required antibiotics and those who didn’t. The authors concluded that clinical signs and symptoms of breast inflammation do not help clinicians make a decision about antibiotic use.36, 97, 100, 109

• The 2007 Kvist et al study found that 52% of women presented with a fever, between 1-7 days after the onset of symptoms. But there was no association between fever at presentation and the need for antibiotics.32

• In a 2008 comparison of the milk of 192 women with mastitis or breast inflammation and 466 healthy breast milk donors, Kvist et al found no correlation between higher bacterial counts and symptoms. There were no differences in bacterial counts between those prescribed and not prescribed antibiotics or those with and without breast abscess.109

• A 2013 Cochrane review by Jahanfar et al found insufficient evidence to support antibiotics in the treatment of mastitis.103

• In Australia, a 2024 study found that 91% of GPs prescribe antibiotics when a lactating woman presents with breast inflammation. This is unsurprising, since overall antibiotic use in Australia is high relative to Europe and Canada. For example, Australian doctors prescribe more than twice the amount of antibiotics overall compared with their European counterparts.113 Scandinavians are much less likely to prescribe antibiotics for diagnoses of mastitis or breast inflammation: just 38% in a Finnish study114 and 15% in the Swedish Kvist et al trial.36, 115 In the USA 86%-97% of women diagnosed with mastitis are prescribed antibiotics, and rates are similar in New Zealand and Canada.100, 109, 116, 117

It's useful to know that

• The presence of even small quantities of antibiotics in human milk alters the diversity and perhaps the resilience of the human milk and other microbiomes, and infant gut microbiota.36, 115

• PCR analysis shows that antibiotic administration reduces levels of 'friendly bacteria' Lactobacilli and Bifidobacterium in human milk.118

• Cellulitis is a bacterial skin infection but mastitis is an inflammatory condition of the breast stroma, associated with secondary inflammatory changes in the skin. Cellulitis does not usually accompany mastitis.

If antibiotics are required, clinical protocols have been developed from the findings linking Staphylococcus aureus with mastitis.5 You can find out about the link between mastitis and S aureus here.

It is possible that inappropriate use of antibiotics

• Prolongs the episode of mastitis

• Creates a more virulent mastitis.

This is because antibiotics kill the less resistant bacteria within the microbiome, and support the flourishing of the more resisent bacteria (e.g. multi-drug resistant S Aureus), enhancing the resistant organism's dominance and tendency to perpetuate either prolonged infection or more virulent infection.

The rate of antibiotic use does not impact upon rates of mastitis recurrence, and the rate of abscess formation remains at approximately 3% of women diagnosed with mastitis, regardless of country or rate of antibiotic prescription for mastitis.109

Consequences of mastitis

The research links mastitis with

1. Subsequent low milk supply

2. Introduction of formula and premature weaning

3. Abscess formation (develops in 3% of women with mastitis, regardless of whether or not antibiotics are prescribed).

Prevention of mastitis

• A 2020 Cochrane review by Crepinsek et al analysed 10 RCTs investigating the prevention of mastitis and concluded:

"We cannot be sure what the most effective treatments are for preventing mastitis because the certainty of evidence is low due to risk of bias, low numbers of woman participating in the trials, and large differences between the treatments which make it difficult to make meaningful comparisons."37

• Crepinsek et al found a moderate certainty of evidence that acupoint massage helped prevent mastitis.37

From the perspective of the mechanobiological model, the preventive strategies which are likely to have substantial impact, requiring research investment, relate to the mechanical impact of elevated intra-alveolar and intra-ductal pressure, which trigger inflammatory cascades and breast inflammation. Applying this theoretical frame, prevention focusses on Principles 1-5, discussed above.

• Frequent flexible milk removal (Principle #1), and

• Elimination of mechanical forces which cause high intraluminal pressures (Principle #2)), are fundamental.

Avoid increasing milk production beyond the baby's needs (Principle #4) is important in the medium and long term, discussed here. However, when a woman has blocked ducts, frequent flexible offers of the breast are required to downregulate the emergent inflammation.

References

The references numbered in Mastitis: prevalence, presentation, pathophysiology and in Mastitis: management (including indication for antibiotics), side-effects, prevention are located in the research publication found here.

Amir LH, Crawford SB, Cullinane M, Gzreskowiak LE. General practitioners' management of mastitis in breastfeeding women: a mixed method study in Australia. BMC Primary Care. 2024;161:https://doi.org/10.1186/s12875-12024-02414-12874.