Learn more about the causes of these conditions, as well as nine evidence-based tips on how to manage them.
“I’ve been trying to massage out this clogged duct for the past week, every time I put her on the breast or when I’m in the shower or getting changed. But the blockage hasn’t gone away and worse, a couple of other lumps appeared. I had a high fever overnight and today I feel absolutely awful.”
Mastitis means “inflammation of the breast”, but the term lacks consensus when applied to lactation.
It is conventionally understood to refer to an inflammation of the lactating breast, characterised by a localised lump with erythema and pain. Systemic symptoms, including fever, myalgia and rigor, may or may not be associated.
Mastitis affects about one in four breastfeeding women in the first six months postpartum, with 70% of cases occurring in the first eight weeks post-birth.1, 2 The incidence of mastitis varies widely across locations, a situation that a recent systematic review suggests may be because mastitis is mostly preventable.2
Healthy lactating breasts are often lumpy, but these lumps decrease or disappear after breastfeeds.
A blocked duct has been described as a palpable and persistent lump that develops gradually, sometimes associated with localised tenderness or pain, in the absence of erythema or systematic symptoms. A blocked duct is best understood as a form of inflammation that is less severe than mastitis on a spectrum of benign inflammatory presentations in otherwise healthy lactating breasts, and which may worsen into a mastitis.
What causes blocked ducts and mastitis?
Excessively high milk pressures within the ducts and glands severely stretch or break apart tight junctions between lactocytes and duct epithelial cells, triggering inflammatory cascades. Very high backpressures are caused by:
- Inadequate milk removal, relative to the woman’s rate of milk production, or
- Mechanical compression of the milk ducts.
As a result, there are two key steps for both prevention and treatment of blocked ducts and mastitis:
Step 1. Frequent and flexible extraction of milk
A milk ejection is accompanied by contractions of the alveoli and dilations of the ducts.3, 4 Milk ejections and milk removal occur in response to:
- Stimulation and negative pressures generated by
- Baby suckling (which is the most efficient way to extract milk)
- Breast pump
- Positive pressure generated by gentle hand expression.
Very frequent opportunities for milk removal result in frequent milk ejections (most of which aren’t felt by women).
Step 2. Elimination of mechanical forces that cause excessively high milk gland and ductal backpressures
These mechanical forces are:
- “Breast tissue drag” (that is, stretching mechanical forces from a vacuum competing with the weight of the breast pulling in a different direction) during suckling or pumping, which both compresses ducts and causes nipple pain and damage;5-7
- Deep mechanical pressure on the breast (lump massage or vibration) that causes
- Ductal compression
- Microvascular trauma, which causes microhaemorrhage and increased interstitial fluid, which worsens tissue swelling, which worsens duct compression and milk backpressure;
- Other focussed external pressure applications to the breast (e.g., breast shells, tight garment, massage towards the armpit).
When should antibiotics be prescribed for mastitis?
Current clinical protocols recommend antibiotics once mastitis (however it is defined) has been present for 12-24 hours, or immediately if the mastitis occurs in the presence of nipple pain.8, 9 But a 2013 Cochrane review found insufficient evidence to support antibiotics in the treatment of mastitis.10
In general, Australian doctors prescribe more than twice the amount of antibiotics relative to our European counterparts.11 It is not surprising, then, that 77%-89% 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
But Scandinavian women diagnosed with mastitis or breast inflammation are much less likely to be prescribed antibiotics: 38% in a Finnish study and 15% in a Swedish study.15, 16
In the latter 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 that included a fit and hold intervention, recommendation to increase frequency of breastfeeds, and daily phone follow-up so that women were more confident tolerating 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. Regardless of country or rate of antibiotic prescription, abscess is found to develop in about 3% of women diagnosed with mastitis.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 recent human milk microbiome research also shows that the assumption that Staphylococcus causes mastitis and must be eliminated with an antibiotic is much too simplistic.21-23
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.24
Fever is the body’s immune response to an inflammatory process and is not necessarily due to bacterial overgrowth or infection.25 Aggressive fever suppression with antipyretics may even worsen inflammation.26, 27 High levels of leukocytes and c-reactive protein in patients with mastitis indicate inflammation, not a bacterial load, and are not usually helpful investigations.28 The 2007 Kvist et al study found that 52% of women presented with a fever, between one and seven days after the onset of symptoms. But there was no association between fever at presentation and the need for antibiotics.16
Unfortunately, the presence of even small quantities of antibiotics in human milk alter microbial diversity and possibly the resilience of the maternal milk and gut microbiomes, and the baby’s gut microbiome. Polymerase chain reaction (PCR) analysis shows that antibiotic administration reduces Lactobacilli and Bifidobacterium counts in human milk.29
Over the past decade or more, the high rates of antibiotic use in women with mastitis has been challenged, noting the World Health Organisation’s urgent call for antibiotic stewardship in the context of the “slow motion catastrophe” of global antimicrobial resistance.14, 24, 30 Antibiotics remain a treatment of last resort, when the signs and symptoms of breast inflammation accompanied by fevers persist without resolution over a period of days, or once the women’s symptoms are particularly severe.
What is evidence-based management of breastfeeding women with blocked ducts or mastitis?
- Advise women never to apply pressure, vibration or massage to a lactation-related breast lump. This includes avoiding Therapeutic Breast Massage and Manual Lymphatic Drainage treatments, which have not been shown to be effective.31
- Encourage very frequent flexible milk removal from the affected breast, either by baby’s suckling or by gentle hand expression or pumping. This could occur 12 or more times on the affected breast over a 24-hour period (though counting is not necessary), remembering that the baby should never be pressured to feed. Women will have the most milk ejections if they feed or express for shorter periods but much more frequently.32 Advice to “drain” the breast by having long feeds followed by hand expression or pumping may increase supply beyond the infant’s needs and predispose to further mastitis.19
- Ensure that any breast tissue drag during breastfeeding is identified and managed. Eliminating breast tissue drag during suckling is particularly important if the woman also has nipple pain or damage.
- Advise as much rest as possible. Prudent use of ibuprofen may help with sleep at night.
- If the woman is considering weaning, strongly advise against it right now, as weaning risks worsened breast inflammation.
- Determine if the woman is pumping to create a supply that is in excess to the baby’s milk needs, as this places her at increased risk of mastitis.19 If so, she needs to continue to focus on frequent and flexible milk removal from the affected breast until recovered. Afterwards, recommend that she gradually cease pumping so that her supply downregulates to match the baby’s need.
- A woman with a more generous breast could, without causing further pain, apply a flat palm gently to her breast and very gently mobilise the whole of the affected breast in various directions a few times a day. She might also stretch her arms out in various directions to mobilise the breast. Moving the breast with her palms may stimulate letdowns and help with milk removal, which is likely to be the most important benefit. Both strategies move the breast tissue and support venous and lymphatic drainage. (A woman doesn’t require referral to a physiotherapist or massage therapist for this.)
- Follow-up daily by phone after the initial consultation if the woman is feverish or her symptoms are severe, or provide regular follow-up until resolution.16
- If antibiotics are required, prescribe flucloxacillin or dicloxacillin 500mg four times daily; cephalexin 500 mg four times daily if allergic to penicillin; and clindamycin if the patient is known to have an anaphylactic reaction to penicillin.8 Severe breast inflammation that doesn’t quickly respond to oral antibiotics requires hospitalisation for intravenous treatment.8
Other commonly used interventions for blocked ducts and mastitis, such as positioning the infant so that the chin or nose points to the area of inflammation, advice to “drain” the breast, oral lecithin, probiotics or therapeutic ultrasound, are not supported by evidence.22, 33-39
A more detailed version of this article is available here.
References
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- Wilson E, Woodd SL, Benova L. Incidence of and risk factors for lactational mastitis: a systematic review. Journal of Human Lactation. 2020;36(4):673-686.
- Ramsay DT, Kent JC, Owens RA, Hartmann PE. Ultrasound imaging of milk ejection in the breast of lactating women. Pediatics. 2004;113:361-367.
- Geddes DT. The use of ultrasound to identify milk ejection in women – tips and pitfalls. International Breastfeeding Journal. 2009;4(5):doi:10.1186/1746-4385-1184-1185.
- Douglas PS, Geddes DB. Practice-based interpretation of ultrasound studies leads the way to less pharmaceutical and surgical intervention for breastfeeding babies and more effective clinical support. Midwifery. 2018;58:145–155.
- Douglas PS, Keogh R. Gestalt breastfeeding: helping mothers and infants optimise positional stability and intra-oral breast tissue volume for effective, pain-free milk transfer. Journal of Human Lactation. 2017;33(3):509–518.
- Douglas PS, Perella SL, Geddes DT. Ultrasound analysis shows that a gestalt intervention changes tongue movement during breastfeeding: a case series 2021;Under review.
- Amir LH, The Academy of Breastfeeding Medicine Protocol Committee. ABM Clinical Protocol #4: Mastitis, Revised March 2014. Breastfeeding Medicine. 2014;9(5):239-243.
- Amir LH, Trupin S, Kvist LJ. Diagnosis and treatment of mastitis in breastfeeding women. Journal of Human Lactation. 2014;30(1):10-13.
- Jahanfar S, Ng CJ, Teng CL. Antibiotics for mastitis in breastfeeding women. Cochrane Database of Systematic Reviews. 2013;1:Doi:10.1002/14651858.CD14005458.pub14651853.
- Hill-Cawthorne G, Negin J, Capon T, Gilbert GL, Nind L, Nunn M, et al. Advancing Planetary Health in Australia: focus on emerging infections and antimicrobial resistance. BMJ Global Health. 2019;4:e001283.
- Foxman B, D’Arcy H, Gillespie B, Bobo JK, Schwartz K. Lactation mastitis: occurrence and medical management among 946 breastfeeding women in the United States. American Journal of Epidemiology. 2002;155:103-114.
- Wamback KA. Lactation mastitis: a descriptive study of the experience. Journal of Human Lactation. 2003;19(1):24-34.
- Kvist L. Diagnostic methods for mastitis in cows are not appropriate for use in humans: commentary. International Breastfeeding Journal. 2016;11(2):doi 10.1186/s13006-13016-10061-13001.
- Jonsson S, Pukkinen MO. Mastitis today: incidence, prevention and treatment. Annals of Chiropractice Gynaecology. 1994;83:84-87.
- Kvist LJ, Halll-Lord ML, Larsson BW. A descriptive study of Swedish women with symptoms of breast inflammation during lactation and their perceptions of the quality of care given at a breastfeeding clinic. International Breastfeeding Journal. 2007;2(2):doi:10.1186/1746-4358-1182-1182.
- Amir LH, Forster DA, McLachlan H, Lumley J. Incidence of breast abscess in lactating women: report form an Australian cohort. 2004.
- Delgado S, Arroyo R, Martin R, Rodriguez JM. PCR-DGGE assessment of the bacterial diversity of breast milk in women with lactational infectious mastitis. BMC Infectious Diseases. 2008;8(Article 51):https://doi.org/10.1186/1471-2334-1188-1151.
- Cullinane M, Amir LH, Donath SM, Garland SM, Tabrizi SN, Payne MS, et al. Determinants of mastitis in women in the CASTLE study: a cohort study. BMC Family Practice. 2015;16:181.
- Rimoldi SG, Pileri P, Mazzocoo MI. The role of Staphylococcus aureus in mastitis: a multidisciplinary working group experience. Journal of Human Lactation. 2020;36(3):503-509.
- Fernandez L, Pannaraj PS, Rautava S, Rodriguez JM. The microbiota of the human mammary ecosystem. Frontiers in cellular and infection microbiology. 2020;10:Article 5866667.
- Oikonomou G, Addis MF, Chassard C. Milk microbiota: what are we exactly talking about? Frontiers in Microbiology. 2020;11(60):doi:10.3389/fmicb.2020.00060.
- Sakwinska O, Bosco N. Host microbe interactions in the lactating mammary gland. Frontiers in Microbiology. 2019;10:doi:10.3389/fmicb.2019.01863.
- Kvist L, Larsson Bw, Hall-Lord ML, Steen A, Schalen C. The role of bacteria in lactational mastitis and some considerations of the use of antibiotic treatment. International Breastfeeding Journal. 2008;3(6):doi:10.1186/1746-4358-1183-1186.
- Ingman WV, Glynn DJ, Hutchinson MR. Inflammatory mediators in mastitis and lactation insufficiency. Journal of Mammary Gland Biology and Neoplasia. 2014;19:161-167.
- Harper CV, Woodcock DJ, Lam C. Temperature regulates NF-kB dynamics and function through timing of A20 transcription. The Proceedings of the National Academy of Sciences. 2018;115(22):E5243-E5249.
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- Kvist LJ. Toward a clarfication of the concept of mastitis as used in empirical studies of breast inflammation during lactation. Journal of Human Lactation. 2010;26(1):doi:10.1177/0890334409349806.
- Soto A, Martin V, Jimenez E, Mader I, Rodriguez JM, Fernandez I. Lactobacilli and bifidobacteria in human breast milk: influence of antibiotic therapy and other host and clinical factors. Journal of Pediatric Gastroenterology and Nutrition. 2014;59:78-88.
- Lesho EP, Laguio-Vila M. The slow-motion catastrophe of antimicrobial resistance and practical interventions for all prescribers. Mayo Clinic Proceedings. 2019;94(6):1040-1047.
- Anderson L, Kynoch K, Kildea S, N L. Effectiveness of breast massage for the treatment of women with breastfeeding problems: a systematic review. JBI Database Systematic Reviews Implement Rep. 2019;17(8):1668-1694.
- Gardner H, Kent JC, Prime DK, Lai C-T, Hartmann PE, Geddes DT. Milk ejection patterns remain consistent during the first and second lactations. American Journal of Human Biology. 2017;29:e22960.
- Diepeveen LC, Fraser E, Croft AJ. Regional and facility differences in interventions for mastitis by Australian physiotherapists. Journal of Human Lactation. 2019;35(4):695-705.
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- Lavigne V, Glebezon BJ. Ultrasound as a treatment of mammary blocked duct among 25 postpartum lactating women: a restrospective case series. Journal of Chiropractic Medicine. 2012;11(3):170-178.
- Barker M, Adelson P, Peters MDJ, Steen M. Probiotics and human lactational mastitis: a scoping review. Women and Birth. 2020;d33:e483-e491.
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- Douglas PS. Re-thinking inflammation of the lactating breast Part A. Women’s Health. 2021:Under review.
- Douglas PS. Re-thinking benign inflammation of the lactating breast Part B. Women’s Health. 2021:Under review.