Mastitis & Breastfeeding Problems

The mastitis spectrum is the bulk of this page; general breastfeeding-support and supplementation guidance for GPs follows at the end under Breastfeeding: expressing, supplementing & low supply.

The core paradigm has changed since this note was written. Mastitis is now understood as a spectrum of inflammatory conditions (nipple blebs, galactoceles, phlegmons, inflammatory mastitis, bacterial mastitis, recurrent mastitis, abscess) driven by ductal narrowing and breast dysbiosis — not simply “milk stasis” treated by draining the breast harder. There is no evidence milk stasis causes mastitis, and the old advice to increase feeding/pumping on the affected side is now considered actively counterproductive.

What NOT to do (a change from old advice)

• Do not increase feeding or pumping on the affected breast. Milk production runs on a feedback-inhibition mechanism — extra removal drives hyperlactation, which worsens ductal narrowing and inflammation. Feed/pump only the normal physiological amount.
• Do not deep-massage the breast — causes microvascular injury and more oedema (can itself produce a phlegmon).
• Do not apply heat (worsens inflammation) — use cold packs instead.
• Do not routinely give antibiotics for a red, inflamed breast — most of this spectrum is inflammatory, not infective, and antibiotics disrupt the breast microbiome, increasing the risk of progression to bacterial mastitis.
• Avoid nipple shields, cleaning/soaking the nipple, and topical products (especially combined with massage) — all disrupt the breast microbiome or cause tissue damage.
• Do not “unroof” a nipple bleb — causes trauma and further luminal narrowing.

Recognising the spectrum

Presentation	Features
Nipple bleb	White/yellow pinhead spot at the nipple, pain on feeding; may self-resolve
Galactocele	Firm cystic mass, size fluctuates with feeds, minimal pain, no erythema/systemic symptoms unless infected; simple cyst on USS
Phlegmon	Firm, mass-like area without fluctuance, often follows excessive deep massage; confirm on USS
Inflammatory mastitis	Erythema, oedema, pain in a region ± systemic symptoms (fever, chills, tachycardia) — can occur without infection
Bacterial mastitis	Inflammatory mastitis mismanaged → cellulitis, may spread to other quadrants
Recurrent mastitis	Episodes every 2–4 weeks; risk factors: waxing/waning hyperlactation, dysbiosis, inadequately-treated prior episodes
Abscess	Progressive induration/erythema, palpable collection; confirm on USS

Differentials: breast engorgement (bilateral, day 3–5 postpartum), breast cancer.

Predisposing factors: hyperlactation, breast pump overuse (no infant-mouth bacterial exchange, risk of trauma from wrong flange size/excess suction), not feeding directly from the breast, poor latch/tongue-tie, nipple shield use, deep massage, stress/ exhaustion, prior mastitis, dysbiosis (antibiotic exposure, LUSCS birth, diet).

Management

First-line, all presentations: treat as tissue inflammation — rest, cold packs (≤10 min, hourly as needed), NSAIDs + paracetamol, optimise latch/positioning, feed physiologically (on cue, not over-pumped).

Antibiotics — only start if:

• Systemic symptoms (fever, chills, headache, flu-like) persist >24 hours, OR
• Breast symptoms are not responding to conservative measures.

Most infections are S. aureus. Dicloxacillin/flucloxacillin 500mg QID — for 5 days if resolving rapidly, otherwise 10 days. Cefalexin 500mg QID (non-severe penicillin allergy) or clindamycin 450mg TDS (severe allergy). Consider milk culture if no improvement 48h after starting antibiotics. Severe cellulitis → ED for IV antibiotics.

Adjuncts with some evidence: sunflower or soy lecithin 5–10g orally daily (may reduce ductal inflammation, emulsify milk); probiotics (Ligilactobacillus salivarius preferred, or Limosilactobacillus fermentum) for treatment/prevention, particularly with dysbiosis risk factors. For a persistent nipple bleb not settling with conservative measures: a topical corticosteroid (e.g. mometasone 0.1% once daily) applied after a feed and washed off before the next.

Breast Abscess

If 48h after starting antibiotics the area remains hard/red/painful/enlarging, suspect abscess — arrange ultrasound.

• Systemically unwell: urgent ED referral for aspiration/drainage.
• Not systemically unwell: start antibiotics + arrange ultrasound; if confirmed, urgent referral for aspiration/drainage (the older “large-bore needle under local anaesthesia” approach is superseded by formal image-guided referral pathways).

Suspected galactocele or phlegmon: refer to breast/general surgeon; galactoceles generally need specialist drain placement (aspiration alone risks incomplete drainage, recurrence, or introducing infection with repeated attempts).

Consider referral to a lactation consultant or Child and Family Health Nurse for feeding support at any point.

Breastfeeding: expressing, supplementing & low supply

Breastfeeding is recommended by the WHO and Australian guidelines. In practice ~96% of Australian parents initiate but only ~39% are exclusively breastfeeding at 3 months, so GPs frequently see feeding difficulties and questions about supplementation.

Contraindications to breastfeeding (few)

• Absolute: maternal HIV (in Australia, advised not to breastfeed), active tuberculosis, syphilitic or active herpes lesions on the breast/nipple, untreated brucellosis, ongoing breast-cancer treatment; certain infant metabolic conditions (e.g. galactosaemia).
• Contraindicated medications: chemotherapy, radioactive pharmaceuticals, oral retinoids, amiodarone, gold salts. Most drugs are compatible — check LactMed or ring a medicines-in-pregnancy/lactation service rather than advising cessation by default.
• Relative: hepatitis B positive before the infant’s first HBV immunisation; hepatitis C positive if nipples are bleeding/cracked; illicit drug use.

Reasons breastfeeding gets disrupted

• Lactation risk factors: flat/inverted nipples, previous breast surgery, low supply, attachment issues, nipple pain, prior unsuccessful breastfeeding.
• Physiological: insufficient glandular development, failure of galactogenesis, maternal obesity or diabetes, infant factors affecting feeding (e.g. tongue-tie, cleft, prematurity).
• Psychological/social: postnatal depression and anxiety lower oxytocin (needed for let-down) and independently predict early weaning — screen for and treat perinatal mood disorders (see Perinatal mental health).

Assessing low supply

Distinguish perceived from true low supply. Reassuring signs of adequate intake: appropriate weight gain, ≥6 wet nappies/day, regular stools, a settled/satisfied infant. True low supply → optimise frequency and attachment first; galactagogues (e.g. domperidone) are second-line and specialist-guided.

Expressing and supplementing

• Expressing (hand or pump) is used to establish/maintain supply when the infant can’t feed directly, to relieve fullness, or to store milk. Correct flange size and avoiding excessive suction matter (wrong sizing/over-pumping causes trauma and drives the hyperlactation that predisposes to the mastitis spectrum above).
• Supplementation — when needed, in order of preference: expressed breastmilk → screened donor milk → formula. Choose the supplemental device on cost, ease and parental preference, ideally one that supports (rather than replaces) breastfeeding.
• If the underlying difficulty can be corrected, supplements can then be tapered.

Refer early to a lactation consultant, Child and Family Health Nurse, or the Australian Breastfeeding Association for hands-on support.