Breastfeeding and Mastitis: 2026 Synthesis: What mechanisms, what treatments?

A new recommendation has just been published on the management of breast inflammation during breastfeeding. While the Clinical Protocol #36 of the Academy of Breastfeeding Medicine (ABM, 2022) laid the foundations for a spectrum-based approach, the new 2026 surgical guidelines and the theoretical model of Dr. Pamela Douglas (2022) redefine the pathophysiological mechanisms and reference interventions.

We present a synthesis for each of these three perspectives: the ABM clinical model, Douglas's mechanobiological model, and the 2026 technical recommendations, highlighting the differences between these approaches.

1. ABM Protocol #36 (2022): The Pathophysiological Spectrum

The ABM protocol introduces the concept of the "spectrum of lactating breast inflammations," a spectrum of conditions distinguishing several entities: in the context of dysbiosis or hyperlactation, a narrowing of the lactiferous ducts would occur, leading to a galactocoele or inflammatory mastitis, which could evolve into a phlegmon or bacterial mastitis and then an abscess.

NB: This protocol was strongly criticized by breastfeeding experts, as I explained in this article for the IPA website.

Mammary dysbiosis is described as a disturbance of the breast microbiome resulting from genetic factors, antibiotic use, probiotics, regular breast pump use, and cesarean birth.

This protocol has a very hyperlactation-oriented vision to explain the onset of mastitis, explaining that reducing drainage can temporarily increase edema and pain but prevents recurrences by involving the negative feedback loop (Feedback Inhibitor of Lactation: FIL).

The following table groups the themes addressed, pathophysiological explanations, measures to avoid, and proposed measures.

Themes	Explanation	Measures to Avoid	Proposed Measures: *General measures for all conditions + Specific measures*
Post-natal engorgement	Occurring between day 3 and 5, during milk coming in, with pain and bilateral interstitial edema.	Minimize fluid use during delivery, promote rooming-in, educate on manual expression, perform areolar counter-pressure.	Perform lymphatic drainage, apply cold (no cabbage leaves).
"Blocked ducts"	Following alveolar distension and/or mammary dysbiosis, creating inflammation and narrowing of ducts, creating a locally indurated area in an otherwise soft breast, with slight erythema, but no associated systemic symptoms.	Authors warn that frequent nursing to relieve will inhibit negative feedback (FIL), induce increased production and ultimately exacerbate inflammation. They advise against vigorous massage of the indurated area which can damage tissues.
Nipple bleb	Inflammatory cells from ducts migrating to the nipple surface.	Do not pierce it alone at home.	Lecithin orally. Corticoid cream on the nipple, wipe before nursing.
Inflammatory mastitis	If the blocked duct persists, progression of inflammation: erythema, edema, indurated and painful area in the breast, systemic signs (fever, body aches).	Avoid antibiotics that negatively impact the microbiome and increase infectious risk and pathogen resistance risk. No interest in prophylactic use of antibiotics.
Infectious mastitis	Progression of inflammatory mastitis to infectious mastitis following bacterial proliferation: Staphylococcus (e.g., S. aureus, S. epidermidis, S. lugdunensis, and S. hominis) and Streptococcus (e.g., S. mitis, S. salivarius, S. pyogenes, and S. agalactiae). Cellulite (induration and aggravated erythema) spreading from the initial region to several quadrants.	Antibiotics or probiotics Limosilactobacillus fermentum (fLactobacillus fermentum) or Ligilactobacillus (Lactobacillus salivarius).	Do not interrupt breastfeeding. Medical evaluation if systemic symptoms last more than 24h.
Phlegmon	Collection of heterogeneous and complex fluid following inflammation, favored by deep massages of inflammatory mastitis which aggravate edema and microvascular lesions. Confirmed by echography.	Antibiotics.
Abscess	Progression of infectious mastitis or phlegmon to a collection of infected fluid, in 3-11% of cases. Fever symptoms resolve then may reappear, or worsen.	Drainage, with preference for surgical drainage as aspirations are too numerous and discouraging.
Galactocoele and infected galactocoele	It develops when the blocked duct prevents milk flow: milk collection in a cyst. Can range from 1-10 cm. Firm mass whose size varies during the day depending on nursing, little painful, no erythema, no systemic signs, diagnosis by ultrasound.	Drainage if symptomatic.
Recurrent mastitis	Recurrence every 2-4 weeks or less, in a context of hyperlactation, dysbiosis, inadequate mastitis treatment.	Milk culture.	Probiotics. Radiological evaluation to rule out other pathology.
Subacute mastitis	Subacute mastitis occurs when the lumen of the ducts narrows under the effect of bacterial biofilms in a context of chronic mammary dysbiosis, leading to an increase in certain pathogenic bacteria, but with milder symptoms than infectious mastitis. In case of cesarean, exclusive milk pumping, use of nipple shields. Stab-like pain in the breast, burning, recurrent indurated areas, milk blebs on the nipple, hyperlactation.	Antibiotics, probiotics.

General measures for all conditions in the spectrum:

Reassurance measures: one can continue to breastfeed.
Education: on the fact that during breastfeeding one feels an aspect with nodules when the breast is full and this is normal.
Rest.
Frequency and modalities of nursing/pumping: Do not increase the frequency of nursing on the affected breast to not perpetuate a cycle of hyperlactation and aggravate edema and inflammation. Express a little manually to remain comfortable while waiting for lactation to equilibrate to the child's needs => here we see the very "cultural" "hyperlactation" approach, in a country where breast pumping takes the place of breastfeeding. Hyperlactation is, however, not the case for the majority of breastfeeding women!
Do not insist on trying to empty the breast if the breast is too edematous.
Minimize pump use which does not allow exchange of bacteria between mother and child and thus impacts the mammary microbiome and predisposes to dysbiosis; can also cause lesions if teats are inappropriate, or suction too strong. Keep a rhythm similar to breastfeeding in case of pumping.
Avoid sterilizing equipment.
Avoid nipple shields.
Avoid deep massages (and vibrating or massaging objects) which increase the risk of micro-lesions, inflammation, and edema.
Avoid Epsom salt baths, castor oil.
Apply cold, lymphatic drainage.
Anti-inflammatory type NSAIDs to reduce edema and inflammation and paracetamol for analgesia.
Treatment of hyperlactation.
Use of therapeutic ultrasound to reduce inflammation and edema.

Conclusion on this protocol: Very focused on hyperlactation, it mixes a theory on dysbiosis, narrowing of lactiferous ducts and has been challenged by other experts, notably regarding the use of probiotics, therapeutic ultrasound, or soy lecithin.

2. Dr. Pamela Douglas's Mechanobiological Model (2022)

Dr. Douglas's work proposes a radical paradigm shift: benign breast inflammation (BLBI) is primarily a mechanical response to excessive pressure, not a primary infection.

The FIL, serum protein responsible for negative feedback proposed as a hypothesis by Wilde in 1987, has never been scientifically proven: a specific protein has never been found and several mechanisms would come into play in this feedback: hormonal (growth factors, serotonin, etc.) and cellular signals.

Pamela Douglas, in a first article, proposes a mechanobiological model to understand benign breast inflammation during breastfeeding, challenging the dominant infectious paradigm. The author suggests that the main causes are not bacterial but mechanical, resulting from excessive intra-alveolar and intraductal pressures that break tight junctions between cells. These ruptures trigger inflammatory cascades and a protective immune response, including an increase in leukocytes in milk, rather than a pathogenic infection. The microbiome and milk cells are described as complex adaptive systems participating in inflammation regulation and tissue repair. Common interventions like local massage or vibrations are denounced because they aggravate stromal pressure and microvascular trauma. The model emphasizes prevention of overpressure and stabilization of immune systems rather than unilateral elimination of microorganisms. Fever and increased immune cells are interpreted as physiological repair mechanisms and not as signs of sepsis requiring antibiotics.

The article contests the existence of milk plugs or pathogenic biofilms causing inflammation, considering them often as late consequences of stasis and inflammation. A care approach respectful of systemic complexity is recommended to avoid over-medicalization and premature interruption of breastfeeding. Current protocols based on the dysbiosis hypothesis are deemed inappropriate as they do not target the mechanical root cause of the problem. Resolution of inflammation passes through the reduction of mechanical stress factors and support of the natural resilience of the mammary immune system. This perspective invites revising clinical classifications and management strategies to favor less invasive interventions. The author concludes that understanding mechanobiology is essential to optimize the duration and quality of breastfeeding. Future research is needed to validate this model and evaluate the effectiveness of mechanical interventions in managing inflammation. Finally, the article highlights the urgency of prioritizing clinical research on breastfeeding support to counteract diagnostic and treatment errors.

In a second article, Pam Douglas proposes a new classification and management of benign breast inflammations in lactation (BLBI) based on a mechanobiological model and complexity sciences. The author rejects the traditional pathogenic model (bacterial or fungal infection) and vague diagnoses like "blocked ducts," "phlegmon," or "dysbiosis," considering them ill-defined terms without solid etiologic proof. The fundamental cause identified is excessive increase in intraluminal pressure (intra-alveolar and intraductal), triggering an inflammatory cascade by rupture of cellular junctions. Prevention and management principles rely on eliminating harmful mechanical forces: avoiding massage of indurated areas, vibrations, and external pressures (tight bras) which aggravate microvascular trauma and edema. The key strategy is the elimination of conflicting force vectors during nursing and adoption of frequent and flexible breastfeeding to maintain physiological pressures. Preferred management includes daily follow-up, prudent use of analgesics, and only as a last resort and if symptoms persist, the use of antibiotics.

The article warns against over-medicalization and excessive antibiotic prescription, highlighting risks of bacterial resistance and microbiome disruption.

Finally, ultrasound investigation is crucial to rule out any malignant mass or pathology unrelated to lactation. The author formally advises against cold compresses, lecithin, probiotics, and lymphatic drainage, deemed ineffective or potentially harmful, and recommends daily follow-up to monitor natural evolution. Antibiotics are indicated only as a last resort for severe or persistent cases, highlighting the need for prudent antimicrobial management. Severe forms like abscess require surgical drainage, while asymptomatic galactocoeles can be monitored.

We present this approach in more detail during our training on the NDC Possums approach by Dr. Pam Douglas.

3. New Surgical Guidelines (Mitchell et al., JAMA Surgery 2026)

This publication represents the second volume of the guidelines from the American Society of Breast Surgeons, the Society of Breast Imaging, and the College of American Pathology on the management of benign breast diseases and addresses infectious and inflammatory breast conditions during breastfeeding: lactational mastitis (LM), granulomatous mastitis (GM), and periductal mastitis with squamous metaplasia of lactiferous ducts* (PDM-SMOLD). The authors first recommend supportive care (cold, anti-inflammatories) while strictly avoiding massages and too frequent pumping for non-infectious mastitis. For infectious mastitis, wait 24-48h without antibiotics except in case of frank cellulitis, then prescribe dicloxacillin or cephalexin. Hot compresses are contraindicated as they aggravate inflammation, and breastfeeding must be continued. In case of abscess, aspiration is often ineffective; incision with drainage is preferred, away from the nipple, with liquid culture. Surgical drainage can cause normal milk leakage, and the site must be protected to avoid fistula. Medications like cabergoline can reduce lactation if necessary. Themes of granulomatous or periductal mastitis are also addressed. These protocols aim to avoid complications while allowing continuation of breastfeeding.

Synthesis for Lactation Consultant Practice

The different sources around mastitis during breastfeeding therefore contradict each other on certain points, notably the frequency of nursing and pumping, the interest of probiotics, ultrasound, or soy lecithin. They agree on not massaging the indurated area to not aggravate the situation, and on using NSAIDs and analgesics.

Bibliography

Mitchell, K. B., et al. (2026). American Society of Breast Surgeons, Society of Breast Imaging, and College of American Pathology 2025 Guidelines for the Management of Infectious and Inflammatory Lesions of the Breast. JAMA Surgery.

Mitchell K.B et al . Academy Of Breastfeeding Protocol# 36: the mastitis spectrum, revised 2022. Med. Vol 17(5).2022 Disponible ici, consulté le 5/12/2022

Carmela Baeza et al. Re: ‘‘Academy of Breastfeeding Medicine Clinical Protocol#36: The Mastitis Spectrum, Revised 2022’’ by Mitchell et al. Med. Vol 17(11).2022 Disponible sur demande chez IPA. Et sa traduction sur le site de La Leche League

Elise Armoiry pour IPA: MASTITES : à propos du protocole de prise en charge de l’Academy Of Breastfeeding #36 de 2022. Dec 2022

Douglas P. Re-thinking benign inflammation of the lactating breast: Classification, prevention, and management. Women’s Health. 2022;18. doi:1177/17455057221091349. Disponible ici

Douglas P. Why the massage styles of ‘Therapeutic Breast Massage’ and ‘Manual Lymphatic Drainage’ are no more helpful than milk ejections for lactating women with breast inflammation and may even make things worse. Blog . Consulté le 5/12/2022 et disponible ici

Douglas. Rethinking benign inflammation of the lactating breast: clinical implications of the mechnobiological models of breast and nipple pain. 27^th ABM annual international meeting. 2022