There is no research or biological rationale to support the belief that routine use of non-steroidal anti-inflammatories for mastitis 'treats the inflammation'
No medication is completely without risk of side-effects
No medication is completely without side-effects, even if extremely rare. It is our responsibility as good custodians of pharmaceuticals to prescribe only with good reason, accompanied by sharing accurate information with the patient. It is our responsibility, I'd argue, to avoid the comforting belief that treatment is always better than non-treatment!
We need to avoid clinical recommendations which mislead breastfeeding women, such as the advice that NSAIDs treat or help resolve mastitis by decreasing inflammation, which is simply untrue, built on collectively shared assumptions (that more treatment is better than less treatment) which lack an evidence base. Australian research demonstrates how as clinicians we typically overestimate the benefits of treatments!
In the clinic recently, I notice women presenting with, or even being hospitalised with, a severe mastitis - but never reporting a fever. They have, however, been taking ibuprofen (two 200 mg capsules) regularly from when they first felt the inflammation because they were (erroneously) advised that anti-inflammatory medication treats breast inflammation.
You can find out more about the role of fever and the mammary gland immune response in the human body's 'wound-healing' response to breast inflammation here.
Making the case for conservative ('when really needed') use of NSAIDs in the management of mastitis or breast inflammation (instead of routine administration)
Case study 1. Clinical guidelines concerning paediatric NSAID use have become increasingly conservative throughout my professional lifetime
For most of my professional life, clinical guidelines advised me, as a GP, to ask parents to regularly administer NSAIDS to infants with fever. We were told parents should do this because of a collective, consensus belief - in the absence of evidence or biological plausibility - that consistent four to six hourly doses of NSAIDs or paracetamol would prevent febrile seizures.
I have always been interested in the evidence base underlying clinical recommendations, and have always interpreted my clinical experience and research data through the lenses of evolutionary biology and complexity science. As a clinician, I took a different approach with my patients, and advised that they used NSAIDs or paracetamol to manage distress and also for infant and family rest at night, rather than as a routine administration.
I watched the guidelines become much more conservative about the use of NSAIDs and paracetamol in infants with viral illnesses as the years passed. Increasingly, clinical guidelines recognise that
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Clinical benefit is generally limited to symptom relief, not improved outcomes, and
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There is risk to any medication, as benign as it might seem. In infants, the risk profile for NSAIDs is now recognised as less forgiving, especially when the viral syndrome includes poor intake, vomiting/diarrhoea, or a vesicular rash.
Modern paediatric fever guidance now emphasises that antipyretics do not prevent febrile seizures and should not be used solely to normalise temperature; they are recommended when the child appears distressed. This framing has reduced “routine” NSAID use in self-limited viral infections.
As the UK's NICE guidelines make clear, paediatric fever management has shifted toward “treat distress, not the number”.
Case study 2. NSAIDs worsen the risk of bacterial overgrowth in the soft tissues of children with varicella
This is how I frame the appropriate use of NSAIDs (most commonly ibuprofen) in women with breast inflammation: it should not be recommended as routine, but as required in response to distress.
There are multiple occasional risks associated with NSAID use, which will be known to you as a clinician. I'd like to consider one specific example here, to see what you think. Clinical guidelines now recommend avoiding NSAIDs when infants or young children have a viral infection with chickenpox/varicella, because research has demonstrated an association with serious bacterial soft tissue or skin infections.
This finding (and change in clinical guidelines) makes an inquiring clinician wonder why there is an associated increased risk of bacterial soft tissue infection with NSAID use. Is it possible that in the case of viral skin infection, suppression of the body's immune response interferes with the regulatory function of the epidermis and dermis microbiome and predisposes to overgrowth of bacteria? This is speculative, but in the absence of evidence to guide us, I believe we need to be thinking critically in this way, for the sake of our patients.
If NSAIDS increase the risk of soft tissue bacterial infection in an infant with varicella, is it possible that routine administration of NSAIDs for women with inflammation of the breast stroma (or soft tissue) increases the risk of worsened trajectories due to the downregulating effects of routine NSAID use on mammary immunoregulation processes? Again, this is speculative, but as clinicans I propose we should always act conservatively, and think critically about medication use, in the absence of guiding evidence.
Case study 3. Antipyretics do not shorten illness duration of acute upper and lower respiratory tract infection, but increase risk of adverse events
A 2023 French systematic review by Nicolas et al demonstrates the limited evidence which underlies the use of antipyretics for fever in respiratory tract infections (RTIs). The authors note that
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It has been shown that severe infections with no fever are associated with increased mortality.
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Some studies conclude that fever may decrease the replication rates of most bacterial pathogens and some viral strains, and promotes immune response.
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Fever suppression was shown in one study to increase the expected number of influenza cases and deaths in the US.
The authors examine the evidence concerning antipyretics for fever in RTIs and conclude that there is a paucity of randomised clinical trials evaluating this issue, and it's not possible to draw the conclusion that antipyretics positively effect illness duration in respiratory tract infections. The authors conclude that the "symptomatic efficacy of antipyretics must be weighed against [the known risk of] their adverse events, particularly when fever [is] well tolerated."
Recommended resources
Mastitis management: secondary outcomes, indication for antibiotics, prevention
Selected references
Dubos F, Hue V, Grandbastien B, Catteau B, Martinot A. Bacterial skin infections in children hospitalized with varicella: a possible negative impact of non-steroidal anti-inflammatory drugs? Acta Derm Venereol. 2008;88(1):26–30. doi: 10.2340/00015555-0333.
Hoffman T, Del Mar C. Clinicians' expectations of the benefits and harms of treatments, screening, and tests - a systematic review. JAMA Internal Medicine. 2017;177(3):407-419.
Mazur-Ejankowska NK, Ejankowski M, Grzybowska ME et al. Toxic Epidermal Necrolysis and Steven-Johnson Syndrome During the Postpartum Period: A Literature Review with a Rare Case Presentation. J Clin Med. 2025 Dec 19;15(1):17. doi: 10.3390/jcm15010017. PMID: 41517265; PMCID: PMC12786465.
Nicolas M, Sun S, Zorzi F. Does the use of antipyretics prolong illness? A systematic review of the literature and meta-analysis on the effects of antipyretics in acute upper and lower respiratory tract infections. Infectious Diseases Now. 2023;53(104716):https://doi.org/10.1016/j.idnow.2023.104716.
Rodieux F, Piguet V, Desmeules J, Samer CF. Safety issues of pharmacological acute pain treatment in children. Clin Pharmacol Ther. 2019;105(5):1130–1138. doi: 10.1002/cpt.1358.
Ziesenitz VC, Welzel T, van Dyk M, Saur P, Gorenflo M, van den Anker JN. Efficacy and Safety of NSAIDs in Infants: A Comprehensive Review of the Literature of the Past 20 Years. Paediatr Drugs. 2022 Nov;24(6):603-655. doi: 10.1007/s40272-022-00514-1. Epub 2022 Sep 2. PMID: 36053397; PMCID: PMC9592650.