Puerperal Mastitis

Puerperal (lactational) mastitis is inflammation of the breast in lactating women, with or without infection, affecting about 2 to 10% (up to 20%) of breastfeeding women, most commonly in the first 6 weeks postpartum and usually unilateral.

The primary mechanism is milk stasis (poor attachment, infrequent or missed feeds, abrupt weaning, tight clothing, oversupply, blocked ducts) with an inflammatory response, followed by bacterial infection through nipple fissures. The commonest organisms: Staphylococcus aureus (including MRSA), coagulase negative staphylococci, streptococci, and Corynebacterium; breast abscess occurs in 3 to 11% of mastitis.

Risk factors: nipple trauma, previous mastitis, diabetes, maternal fatigue and stress, poor latch, use of nipple shields, and breast pump use.

• Localised breast pain, erythema, warmth, firm wedge shaped swelling, often in the upper outer quadrant
• Systemic: fever of 38.5 degrees C or above, chills, myalgia, malaise ("flu like illness")
• Nipple fissures or cracks, with possible discharge
• Abscess: fluctuant, painful mass with persistent fever despite antibiotics, overlying skin thinning
• Complications: recurrent mastitis, chronic abscess, mammary fistula, sepsis, cessation of breastfeeding

• Clinical diagnosis; examination of both breasts and axillae, nipples for fissures, and baby's latch
• Milk culture (midstream expressed milk after cleaning the nipple) for severe, recurrent, hospital acquired, or non-responding cases, or MRSA suspicion
• Ultrasound for suspected abscess (hypoechoic collection with irregular borders) or poor response to treatment at 48 to 72 hours
• Blood tests (full blood count, C-reactive protein) when systemically unwell; blood cultures if septic
• Biopsy and mammography for persistent mass or lack of response (exclude inflammatory breast cancer or other lesions; the presence of skin changes persisting beyond 2 weeks requires evaluation)

• Continue breastfeeding or expressing milk from the affected breast. It is safe for the infant, and effective milk removal speeds recovery.
• Feed frequently, starting on the unaffected side if painful. Correct latch and positioning, and use gentle lymphatic drainage massage (avoid deep massage).
• Analgesia and anti-inflammatory therapy: ibuprofen 400 mg three times daily (reduces inflammation and pain; compatible with breastfeeding) and paracetamol 1 g every 6 hours. Use cold packs between feeds, and warmth before feeds if helpful.
• Give antibiotics when symptoms persist after 12 to 24 hours of effective milk removal, in the presence of nipple fissures, or if severe or systemic illness.
• Standard regimen: flucloxacillin 500 mg four times daily for 10 to 14 days (or cefalexin 500 mg four times daily; or dicloxacillin 500 mg four times daily).
• Penicillin allergy: clindamycin 300 to 450 mg every 6 hours or erythromycin 500 mg four times daily.
• MRSA suspected: trimethoprim-sulfamethoxazole 160/800 mg twice daily, clindamycin, or doxycycline (short course, with consideration of infant), or IV vancomycin for severe cases.
• Abscess: ultrasound guided needle aspiration, repeated every 1 to 3 days with saline irrigation as needed. It is first line for abscess under 3 cm.
• Incision and drainage is used for large, multiloculated or thin skinned abscesses. Breastfeeding continues on the affected side if the incision is away from the areola. Antibiotics are given for 7 to 14 days.
• Recurrent mastitis: investigate causes (latch, infant tongue tie, oversupply, nipple colonisation).
• Consider prophylactic antibiotics (cefalexin 500 mg daily) or probiotic Lactobacillus fermentum or salivarius for prevention, and referral to lactation consultant.
• Consider Candida infection (burning nipple pain with shooting pain): treat with miconazole gel and fluconazole 200 mg loading dose then 100 mg daily for 14 days.
• Rule out inflammatory carcinoma in non-resolving cases, with imaging and biopsy.