Mastitis

Mastitis is inflammation of the lactating breast — most often unilateral, most common in the first 6-12 weeks postpartum but possible at any point during lactation — that exists on a continuum rather than as a single fixed diagnosis. Current evidence-based practice, led by the Academy of Breastfeeding Medicine's 2022 revision of its core mastitis protocol, reframes the condition as a spectrum: ductal narrowing (the everyday "blocked duct" or "plug") can progress to inflammatory mastitis, which — if unresolved — can progress further to bacterial mastitis and, less commonly, to a phlegmon or a drainable abscess.^[1] A related but distinct entity, the galactocele (an obstructed, cystic collection of stagnant milk), and early postpartum breast engorgement are also covered in this chapter.^[1]

The lactating breast contains innumerable small, interlacing ducts rather than one duct feeding one lobule — which is why a "clogged duct" cannot be massaged or expressed out as a single plug (see Recognize the Condition). (Rajendra prabhune, CC BY-SA 4.0, Wikimedia Commons)

The single most consequential update in modern mastitis management is this: the traditional advice to "keep the breast empty" — pumping after every feed, aggressively massaging a "clog," or feeding on a fixed frequent schedule specifically to drain the affected breast — is now understood to worsen ductal narrowing and inflammation, not resolve it.^[1] Milk volume is governed by a feedback inhibitor of lactation: the more milk is removed, the more is made, so "emptying" an already inflamed, edematous breast simply drives more blood flow and swelling into already-narrowed ducts.^[1] The modern approach instead favours physiologic, on-demand feeding; gentle, non-deep technique; ice rather than heat; and a genuinely selective, evidence-based approach to antibiotics that reserves them for bacterial mastitis specifically, not for the entire spectrum.^[1] Equally important for pharmacist counselling: bacterial mastitis is not a reason to stop breastfeeding or discard milk — it is safe for the infant to continue feeding from the affected breast throughout treatment, and interrupting feeding tends to worsen engorgement and outcomes rather than protect the infant.^[1][2]

Pathophysiology: hyperlactation and dysbiosis, not "milk stasis"

Mastitis-spectrum conditions arise from a combination of host, microbial, and medical factors that narrow the lactiferous ducts and disrupt the normally protective diversity of the human milk microbiome (mammary dysbiosis).^[1] Hyperlactation — milk production that exceeds what the infant actually removes, whether from genuinely high supply or from iatrogenic over-removal (pumping "to keep the breast empty," feeding or pumping on a fixed schedule instead of on demand) — is the single most important host risk factor: it drives alveolar distension, interstitial edema, and ductal narrowing.^[1] Layered onto this, when the normally heterogeneous population of commensal bacteria lining the ducts (coagulase-negative staphylococci and viridans streptococci) is disrupted by antibiotic exposure, probiotic use, or Cesarean birth, an opportunistic pathogen — usually a single dominant strain of Staphylococcus or Streptococcus — can proliferate and form a biofilm inside an already-narrowed duct, driving the transition from inflammatory to bacterial mastitis.^[1] Milk stasis has long been taught as the underlying cause of mastitis, but current evidence does not support this as a proven mechanism — it remains a plausible, unproven hypothesis, and the interventions it used to justify (aggressive pumping, deep massage to "break up" a clog) are now recognized as actively harmful rather than therapeutic (see Non-Pharmacologic Treatment).^[1]

The mastitis spectrum

Early postpartum engorgement — a related but distinct entity

Physiologic breast engorgement from the onset of copious milk production (lactogenesis II) shares some clinical features with the mastitis spectrum but is not itself an inflammatory or infectious process.^[1] It presents as bilateral breast pain, firmness, and swelling, usually between postpartum days 3 and 5 (later, up to day 9-10, in multiparous mothers, and further delayed after Cesarean birth, which itself delays lactogenesis II).^[1] Appropriately managed engorgement should not progress to a mastitis-spectrum condition — see Special Populations for its specific management.

A myth worth actively correcting: "candida mastitis"

Despite persistent popular belief, no scientific evidence supports a diagnosis of "candida" or "thrush" mastitis — deep, shooting breast pain has long been attributed to a yeast infection of the ducts, but this has never been demonstrated, and sterilizing pump parts or infant toys to "eradicate" yeast is not recommended and does not help.^[1] A patient with burning, needle-like breast pain and a history of treated bacterial mastitis more often has subacute mastitis (above) than a fungal infection — treat the actual diagnosis rather than defaulting to an antifungal (see Common Errors to Avoid).

• Hyperlactation (oversupply) — from genuinely high milk production or from iatrogenic over-removal (frequent pumping "to keep the breast empty," feeding or pumping on a fixed schedule instead of on demand) — the single most important modifiable host risk factor across the entire spectrum.^[1]
• A previous episode of mastitis, particularly if the underlying driver (hyperlactation, pump/massage habits) was not addressed at the time.^[2]
• Prolonged engorgement or poor milk drainage from an ineffective infant latch, tongue-tie, or an infant unable to transfer milk effectively.^[2]
• Nipple trauma or cracking — commonly taught as a cause of ascending infection, but current evidence characterizes this association as confounded rather than clearly causal; bacteria and fungi are regularly identified on the nipple-areolar complex of lactating people with no nipple damage and no mastitis at all.^[1]
• Cesarean birth — associated with delayed lactogenesis II and, independently, with disruption of the normal milk microbiome (dysbiosis).^[1]
• Recent maternal antibiotic or probiotic use, which can alter the normal, protective diversity of the milk microbiome.^[1]
• Exclusive pumping, regular breast pump use, nipple shield use, or an improperly fitted pump flange — each associated with a higher risk of dysbiosis and/or ductal trauma.^[1]
• Excessive deep breast massage, including from an electric toothbrush or a commercial vibrating massage device used specifically to "work out a clog" — causes microvascular injury and worsens, rather than resolves, ductal narrowing.^[1]
• Maternal stress, sleep deprivation, and a history of anxiety or depression — associated with both a higher rate of mastitis symptoms and reduced response to reassurance alone; screening for a perinatal mood or anxiety disorder is part of a complete assessment (see Assessment & Diagnosis).^[1]
• Abrupt weaning or a sudden, significant reduction in feeding/pumping frequency.

History and examination

Mastitis-spectrum diagnosis is clinical, based on history and examination — position on the spectrum (see Recognize the Condition) is determined primarily by the presence and duration of systemic symptoms and by whether a discrete fluid collection can be felt or seen on imaging, not by a laboratory test.^[1] Ask specifically about the onset and duration of local findings (induration, erythema, pain) versus systemic findings (fever, chills, myalgia, malaise); duration of symptoms; feeding/pumping frequency and any recent change in routine; a history of previous mastitis and how it was managed; and screen for the modifiable risk factors above (pump flange fit and frequency, massage habits, recent weaning or schedule change).^[2] Examine for the differential: a hard, red, tender, swollen area is consistent with mastitis, a clogged duct, or engorgement, while a fluctuant mass raises concern for abscess, and progressive skin change or peau d'orange raises concern for inflammatory breast cancer — actively consider this differential at every visit, not just the first.^[2][1]

Laboratory testing has limited value

C-reactive protein and white blood cell count are markers of inflammation, not infection specifically, and are of limited utility in diagnosing bacterial mastitis — a normal or mildly elevated result does not reliably distinguish inflammatory from bacterial mastitis and should not be relied on to make or exclude the diagnosis.^[1]

When to obtain a sterile milk culture

Milk culture is not needed for a first, straightforward episode responding to first-line therapy, but should be considered specifically when: there is no symptomatic improvement 48 hours after starting first-line antibiotics (to identify a resistant or less common pathogen, including MRSA); the mother is expressing milk for an immunocompromised infant in a neonatal intensive care unit; she is a health care worker in a setting with a high prevalence of MRSA; or she has recurrent infections, where culture-directed therapy replaces further empiric guessing.^[1] A proper technique matters for a genuinely useful result: clean the nipple and areola (a topical antiseptic solution or soap-and-water washing, then air-dry), express 5-10 mL of milk into a sterile container using sterile gloves without letting the nipple contact the container, and send it labelled as a "body fluid culture" rather than a "wound culture."^[1]

Imaging: distinguishing phlegmon, abscess, and galactocele

Ultrasound is the imaging modality of choice whenever a discrete fluid collection is suspected. It differentiates a phlegmon (heterogeneous, ill-defined fluid collection with surrounding hyperemia and edema) from a true abscess (a well-defined collection, often with a visible wall) and from a galactocele (a simple or loculated cystic collection, without the surrounding hyperemia and edema of an infectious process).^[1] Ultrasound also confirms simple ductal narrowing or inflammatory mastitis, in which imaging typically shows hyperemia and edema without any discrete fluid collection at all.^[1]

Screening for a perinatal mood or anxiety disorder

Because women with a history of anxiety or depression have higher rates of mastitis symptoms, and because the postpartum period is itself the highest lifetime-risk window for a new mood or anxiety disorder, screen for perinatal mood and anxiety disorders (PMADs) as a routine part of assessment — with particular attention to a patient who seems defeated or withdrawn by breastfeeding difficulty, who cannot tolerate stopping pumping despite reassurance, or whose reported pain is out of proportion to examination findings.^[1]

• Correctly place the presentation on the mastitis spectrum (ductal narrowing, inflammatory mastitis, bacterial mastitis, phlegmon, abscess, or galactocele) so treatment intensity actually matches the diagnosis, rather than defaulting to antibiotics for everyone.
• Relieve pain and inflammation with the interventions that genuinely help (ice, scheduled NSAID/acetaminophen, gentle lymphatic-drainage technique) while actively avoiding the ones that do not (deep massage, aggressive pumping, cabbage leaves).
• Reserve antibiotics for confirmed or strongly suspected bacterial mastitis, using an agent, dose, and duration matched to the likely organism and any penicillin/cephalosporin allergy.
• Support the patient in continuing to breastfeed or express milk throughout treatment, at a frequency and volume that mirrors physiologic infant demand rather than a fixed "empty the breast" schedule.
• Identify and, where possible, address the underlying driver — hyperlactation, pump technique, massage habits, latch/tongue-tie — so the episode does not simply recur.
• Recognize progression to phlegmon or abscess promptly, and secure source control (aspiration or drainage) rather than escalating oral antibiotics indefinitely.
• Screen for and support a perinatal mood or anxiety disorder, and provide genuine reassurance and psychosocial support as an active part of treatment, not an afterthought.
• Avoid the specific, still-common practices this chapter's evidence base has moved away from: unnecessary antibiotics for non-bacterial stages, deep massage, pump-to-empty advice, cabbage leaves/castor oil/saline soaks, unroofed nipple blebs, and empiric antifungal treatment for "candida mastitis."

• Feed or express on demand, not to a schedule, and never with the explicit goal of "emptying" the breast — milk volume responds to a feedback mechanism where more removal drives more production; overfeeding the affected breast or "pumping to empty" perpetuates a cycle of hyperlactation and worsens the tissue edema and inflammation actually driving symptoms.^[1] If the affected breast is too edematous and inflamed for the infant to latch or for hand expression to work, it is reasonable to feed from the unaffected breast only during the acute phase and return to the affected side once edema and inflammation subside, expressing small comfort volumes by hand in the meantime rather than a full pump session.^[1]
• Minimize breast pump usage. A pump stimulates milk production without the physiologic, bacterial-exchange benefit of infant feeding, and can itself cause trauma if flange size, suction strength, or session duration is wrong — limit expression to when mother and infant are separated or pumping is otherwise medically necessary, at a frequency and volume mirroring what the infant would actually take, not a fixed "keep it empty" routine.^[1]
• Avoid deep massage of the lactating breast. Deep massage — including from an electric toothbrush or a commercial vibrating massage device — increases inflammation, tissue edema, and microvascular injury, and is a primary risk factor for phlegmon and abscess formation; a systematic review concluded that although breast massage may reduce pain, it should not be recommended as standard care because an atraumatic technique requires extensive training to master.^[1] A gentle lymphatic drainage technique is different and reasonable: very light touch/traction of the skin ("like petting a cat"), starting with small circles at the junction of the internal jugular and subclavian vein and in the axilla, then light-touch strokes from the nipple toward the clavicle/axilla — this reduces swelling by assisting lymph movement rather than by force.^[1] "Hands-on pumping" (gentle compressions during pump use) provides an effect similar to hand expression and is safe if excessive manual force is avoided.^[1]
• Ice, not heat, for symptomatic relief — ice can be applied every hour or more often if desired, and reduces the vasodilation, edema, and ductal narrowing that heat can actually worsen; a randomized trial found warm showers and antipyretics did not improve mastitis outcomes.^[1] Heat may still provide comfort for some patients and is not absolutely contraindicated, but ice is the better-evidenced default.^[1]
• Do not use cabbage leaves, castor oil, saline soaks, or a silicone breast pump insert filled with Epsom salt. Studies have not demonstrated cabbage leaves to be more effective than ice — any benefit is likely from cold, not a specific property of cabbage — and cabbage carries a real risk of Listeria contamination.^[1] Castor oil does not treat a deep-organ-space inflammatory process and can itself cause tissue damage, particularly combined with massage; Epsom-salt-filled silicone inserts contribute to localized hyperemia and edema; and general wound-care evidence does not support saline soaking for pain or nipple trauma.^[1]
• Avoid nipple shields — available evidence does not support their use for this purpose; neither safety nor effectiveness has been demonstrated, and they represent nonphysiological breastfeeding that can result in inadequate milk extraction (the infant passively drinking from the shield's reservoir rather than transferring milk from the breast).^[1]
• Wear an appropriately fitting, supportive (not tight or constricting) bra — lactating breasts are highly vascular and benefit from support to avoid dependent lymphedema and progressive back/neck pain, but a garment that compresses the tissue can itself contribute to ductal narrowing.^[1]
• If a nipple bleb is present, do not unroof it. A bleb represents ductal inflammatory cells and debris propagating to the surface and lodging there; deroofing it causes trauma and further luminal narrowing rather than resolving anything. Oral lecithin and a topical steroid applied to the surface of the nipple (see Pharmacologic Treatment Options) are the recommended approach instead.^[1]
• Avoid routine sterilization of breast pump parts and other household items, and avoid deliberately scrubbing the nipple between feeds. Mastitis is not a contagious condition and does not result from unhygienic practice — pump parts should be cleaned appropriately (basic washing) after each use, but routine sterilization is not necessary to prevent mastitis, and vigorous nipple cleaning can macerate the skin and cause pain without any protective benefit.^[1]
• Reassure, and actively educate on normal lactation physiology. Lactating breasts normally feel lumpy and full, and a low-estrogen postpartum hormonal state predisposes to sweating and hot flashes that can mimic fever — patients should be reassured that infection does not develop over a period of hours, and that morning pain/redness after a long stretch of sleep typically reflects alveolar distension and lymphatic congestion rather than a new infection.^[1] Help mothers identify concrete ways to decrease stress and increase rest, and connect them with resources they may need to avoid unwanted early weaning.^[1]
• Screen for and support a perinatal mood or anxiety disorder as an active part of management, not a side conversation (see Assessment & Diagnosis).^[1]

Early postpartum engorgement

Manage as its own distinct entity rather than as early mastitis: minimize intravenous fluids during labour, since interstitial fluid accumulation from IV loading worsens later edema and engorgement; promote rooming-in to allow physiologic, on-demand breastfeeding rather than a scheduled or restricted routine; teach hand expression, including reverse-pressure softening of the areola before latch, to relieve pressure and support an infant who cannot yet transfer milk effectively; and use the same gentle lymphatic-drainage technique, ice, and scheduled analgesia as for the rest of the spectrum.^[1] Appropriately managed engorgement should not progress to ductal narrowing, inflammatory mastitis, or bacterial mastitis.^[1]

Recurrent mastitis

There is no consensus definition, but patients describing fever, redness, swelling, and/or pain recurring every 2-4 weeks (or less often) warrant a different approach than treating each episode as an isolated event.^[1] Obtain a milk culture to establish a genuine diagnosis of recurrent bacterial mastitis, rather than treating empirically again, and to identify an uncommon or resistant pathogen — coagulase-negative staphylococci are commonly present in milk as normal flora but have also been identified as an opportunistic pathogen in mastitis, and MRSA/resistant CoNS will not respond to the typical agents used for acute mastitis.^[1] Evaluate breastfeeding and pumping practices specifically for the risk factors above (excessive massage, unnecessary or excessive pumping, hyperlactation) and address them directly; consider a daily probiotic containing one of the two specific studied strains (Ligilactobacillus salivarius or Limosilactobacillus fermentum) for prevention, recognizing that efficacy is strain-specific and cannot be generalized to any probiotic product.^[1] Prophylactic antibiotics have not been shown effective for prevention and risk selecting resistant organisms, so are not recommended.^[1] Multiple recurrences at the same location warrant radiology evaluation to rule out an underlying mass or another abnormality such as granulomatous mastitis — and any concern for inflammatory breast cancer specifically warrants urgent referral to breast surgery and oncology (see Red Flags & Refer).^[1]

Subacute mastitis

Because individual mammary microbiomes differ in the threshold at which an opportunistic pathogen becomes symptomatic, and because milk culture may not grow a dominant organism even when subacute mastitis is clinically likely, treatment should be individualized based on history and clinical suspicion rather than a single algorithm.^[1] A macrolide such as azithromycin may have the best efficacy in this specific clinical scenario, plausibly related to its intracellular mechanism of action against biofilm-forming organisms, though the evidence base remains limited and more study is needed.^[1] Probiotics containing L. salivarius or L. fermentum are also a reasonable adjunct, with the same strain-specific caveat as above.^[1]

Hyperlactation as an underlying, recurring driver

Persistent high milk production that continues despite eliminating iatrogenic causes of excess removal (pump-to-empty habits, scheduled rather than on-demand feeding) may need dedicated pharmacologic management of hyperlactation itself, which is outside the scope of this chapter — refer to the Academy of Breastfeeding Medicine's dedicated hyperlactation protocol, or to a lactation-medicine specialist, for that specific management.^[1] Do not add or continue a galactagogue (domperidone, metoclopramide) in a patient whose recurrent mastitis is actually being driven by oversupply — this directly worsens the underlying problem (see Common Errors to Avoid).

Penicillin/cephalosporin allergy

Confirm whether a reported allergy is a true immune-mediated reaction or an intolerance before defaulting to clindamycin or sulfamethoxazole/trimethoprim — both carry a different adverse-effect profile and, for sulfamethoxazole/trimethoprim, real infant-specific cautions in early lactation (see Choose Initial Treatment).

Renal and hepatic impairment

Adjust cloxacillin, cephalexin, and sulfamethoxazole/trimethoprim doses for significant renal impairment per standard renal dosing references; clindamycin does not require renal dose adjustment but should be used cautiously in significant hepatic impairment. Acetaminophen should be used cautiously, or avoided, in significant hepatic impairment.

Exclusive pumping

The same principles apply — express milk at a frequency and volume that mirrors what the infant would actually take rather than a fixed maximizing schedule, confirm correct flange sizing to avoid nipple trauma, and apply the same "minimize pump usage during the acute phase, prefer gentle hand expression" approach described in Non-Pharmacologic Treatment.^[1]

Neonatal monitoring during maternal antibiotic treatment

Monitor the infant for vomiting, diarrhea, or a new rash during a maternal antibiotic course, and have the family seek assessment if these occur; a Canadian midwifery mastitis protocol also suggests considering an infant probiotic during maternal antibiotic treatment, referencing the Canadian Paediatric Society's position statement on probiotics in the pediatric population — this is a reasonable, individualized consideration rather than a strong or universal recommendation.^[2][4]

For ductal narrowing or inflammatory mastitis managed conservatively, arrange a follow-up check (by phone or in person) within 24-48 hours to confirm symptoms are trending toward resolution rather than progressing — most cases resolve fully with conservative measures alone.^[1]

• For bacterial mastitis started on antibiotics, reassess at 48 hours; expect clear symptomatic improvement. No improvement by then triggers a sterile milk culture and reassessment for phlegmon/abscess (see Choose Initial Treatment and Treatment Failure/Next Step).^[1]
• For a phlegmon, arrange interval clinical examination and repeat imaging until fully resolved — tissue inflammation and phlegmonous change can take several weeks to resolve, and a residual small, mass-like area during that time does not necessarily mean treatment has failed.^[1]
• After abscess aspiration or drain placement, follow up to confirm the collection has not reaccumulated and, if a drain was placed, to remove it once drainage has stopped (commonly within a few days).^[1]
• Monitor the breastfeeding infant for vomiting, diarrhea, or rash during any maternal antibiotic course.^[2]
• For recurrent mastitis, confirm resolution of the acute bacterial episode with follow-up examination, and revisit whether the modifiable risk factors identified (pump habits, massage, hyperlactation) have actually been addressed, not just discussed.^[1]
• Document the stage treated, what was tried, and the response, so a later episode is not simply re-escalated through the same steps without learning from what did or did not work.

1. No improvement 48 hours after starting first-line antibiotics for bacterial mastitis: obtain a sterile milk culture to identify a resistant organism (including MRSA) or a less common pathogen before switching agents empirically, and re-examine specifically for an evolving phlegmon or abscess.^[1]
2. A firm, mass-like area develops or persists without fluctuance: obtain ultrasound to confirm or exclude phlegmon; if confirmed, plan an extended, individualized antibiotic course with interval examination and imaging until it fully resolves, since a phlegmon can still coalesce into a drainable abscess.^[1]
3. A well-defined, fluctuant fluid collection develops: proceed to ultrasound-guided or clinical aspiration with fluid culture and sensitivity for source control; consider drain placement as the initial, more definitive intervention rather than planning for repeated aspirations, particularly for a larger collection.^[1]
4. Symptoms recur at the same location after apparently successful treatment: treat as recurrent mastitis (see Special Populations) — obtain a milk culture, address modifiable risk factors, and obtain radiology evaluation to rule out an underlying mass after multiple recurrences at the same site.^[1]
5. Progressive erythema, skin retraction, or a peau d'orange appearance that does not fully resolve with adequate antibiotic treatment: treat as a possible inflammatory breast cancer mimic and refer urgently to breast surgery/oncology rather than continuing to escalate antibiotics.^[1]
6. The mother reports persistent needle-like or burning pain, nipple blebs, and a pattern of previously treated acute mastitis with milder recurring flares: reconsider subacute mastitis (see Special Populations) rather than repeating the same acute-bacterial-mastitis antibiotic course indefinitely.^[1]
7. The patient cannot tolerate stopping pumping, reports pain out of proportion to exam findings, or seems defeated/withdrawn about breastfeeding despite reassurance and appropriate treatment: screen (or re-screen) for a perinatal mood or anxiety disorder rather than attributing this solely to unresolved mastitis.^[1]

• Prescribing antibiotics for ductal narrowing or inflammatory mastitis without systemic symptoms or a strong bacterial-infection likelihood — most of this resolves with conservative care alone, and unnecessary antibiotic use disrupts the breast microbiome and raises resistance risk.^[1]
• Advising a mother to pump after every feed, feed on a strict schedule to "empty" the affected breast, or aggressively massage/knead a "clogged duct" to break it up — all of these worsen edema and ductal narrowing rather than resolving it, and deep massage is a specific, recognized risk factor for phlegmon and abscess formation.^[1]
• Recommending cabbage leaves, castor oil, saline soaks, or an Epsom-salt-filled silicone breast pump insert — none is better evidenced than ice, cabbage carries a real Listeria risk, and castor oil/aggressive topical products can cause tissue damage.^[1]
• Advising a mother to stop breastfeeding or discard milk because of bacterial mastitis — it is safe for the infant to continue feeding from the affected breast, and interrupting feeding worsens engorgement rather than protecting anyone.^[1][2]
• Unroofing a nipple bleb — this causes trauma and further luminal narrowing; treat with oral lecithin and a topical steroid on the nipple surface instead.^[1]
• Diagnosing and treating "candida" or "thrush" mastitis with an antifungal, or recommending sterilization of pump parts/infant toys to "eradicate yeast" — no scientific evidence supports this diagnosis; needle-like, burning breast pain in a patient with a mastitis history is more often subacute mastitis (see Special Populations).^[1]
• Recommending a nipple shield as a routine part of mastitis management — evidence does not support its safety or effectiveness for this purpose, and it can itself cause inadequate milk extraction.^[1]
• Ordering a CRP or white blood cell count to try to distinguish inflammatory from bacterial mastitis — both are non-specific markers of inflammation and are of limited diagnostic utility here.^[1]
• Continuing or adding a galactagogue (domperidone, metoclopramide) in a patient whose recurrent mastitis is being driven by genuine oversupply — this directly worsens the underlying hyperlactation problem.^[1]
• Treating every recurrence at the same site as "just mastitis again" without ever obtaining imaging — repeated same-location recurrence needs radiology evaluation to rule out an underlying mass, including the rare but aggressive inflammatory breast cancer.^[1]
• Missing a perinatal mood or anxiety disorder in a mother whose reported pain, or inability to stop pumping despite reassurance, is disproportionate to clinical findings.^[1]

How to use this table: doses are adult doses for a lactating patient and require patient-specific confirmation (renal/hepatic function, weight, true allergy history, and — where noted — infant age/gestational history). Drug pricing is intentionally omitted. Select any drug name to open its complete Pharmasist Drug Database page.

Bacterial Mastitis — First-Line, No Penicillin/Cephalosporin Allergy

Antibiotics are reserved for bacterial mastitis specifically — see Choose Initial Treatment for the full spectrum-staged approach and the evidence-quality caveat around antibiotic benefit.^[1]

Bacterial Mastitis — Penicillin/Cephalosporin Allergy, or Inadequate Response to First-Line Therapy

Confirm true allergy versus intolerance before selecting an agent from this group.^[1]

Analgesia and Anti-Inflammatory Support — Entire Spectrum

Pair scheduled analgesia with ice (see Non-Pharmacologic Treatment); both agents below are compatible with continued breastfeeding at these doses.^[1]

Ductal Narrowing, Nipple Blebs, Subacute Mastitis, and Recurrence Prevention

Evidence for this group is generally weaker than for the antibiotics above; frame accordingly when counselling.^[1]