Synopsis
Recognise the inflammatory and bacterial spectrum of lactational mastitis, restore comfortable physiological milk removal, prescribe antibiotics when indicated, and identify abscess or systemic deterioration early.
- Lactational mastitis is a spectrum from milk stasis and sterile inflammation to bacterial infection, usually with focal breast pain, erythema and systemic influenza-like symptoms.
- Ask about abrupt feed changes, oversupply, pressure, ineffective attachment, nipple trauma and prior antibiotics; examine for a wedge-shaped inflamed area and a discrete collection.
- Continue comfortable breastfeeding and avoid abrupt weaning; express only enough to maintain physiological drainage when direct feeding is not possible, because aggressive over-emptying can worsen oversupply and oedema.
Key red flags
A persistent fluctuant mass, ongoing fever or absent improvement after appropriate treatment warrants urgent ultrasound for abscess and reconsideration of the diagnosis.
Investigation priorities
Identify ineffective attachment, painful compression and modifiable milk-transfer problems.
Management branches
A breastfeeding parent has 12 hours of focal tenderness and mild fever after several missed feeds, without a mass or systemic instability.
- Assess observations, hydration, breast and nipple, then watch attachment or arrange same-day lactation expertise to identify ineffective transfer or painful compression.
- Encourage continued comfortable feeding according to infant cues and hand expression only for comfort if needed; avoid deep massage and repeated pumping intended to empty the breast completely.
Key medicines
FlucloxacillinFor a stable adult with bacterial lactational mastitis and no relevant contraindication, NHS Dumfries & Galloway specifies flucloxacillin 500 mg orally four times daily for 10–14 days. Take the selected Flamingo 500 mg capsules at least one hour before or two hours after food, with a full 250 mL glass of water; remain upright immediately afterwards.Do not use with hypersensitivity to this product or beta-lactam antibiotics, or previous flucloxacillin-associated jaundice/hepatic dysfunction. Clarify serious delayed reactions as well as immediate allergy. At CrCl below 10 mL/min, obtain a prescriber decision on dose reduction or a longer interval before using the standard schedule; dialysis does not require a supplementary dose. Use caution with existing liver dysfunction. Review methotrexate toxicity, warfarin/INR when starting or stopping, probenecid and reduced voriconazole exposure. With concurrent paracetamol, severe renal impairment, sepsis or malnutrition increases high anion gap metabolic acidosis risk, especially at maximal paracetamol doses: review the combination and arrange risk-based monitoring. SPS compatibility applies to healthy term infants; monitor diarrhoea, thrush, rash and poor feeding.