Treatment of Mastitis in Breastfeeding Patients
For breastfeeding patients with mastitis, initiate a 1-2 day trial of conservative management with NSAIDs, ice application, and continued breastfeeding before starting narrow-spectrum antibiotics targeting Staphylococcus aureus if symptoms fail to improve within 12-24 hours. 1
Initial Conservative Management (First 12-24 Hours)
- Start with non-antibiotic measures for 1-2 days, as most mastitis cases are inflammatory rather than infectious, with 14-20% resolving spontaneously 1
- Continue breastfeeding or milk expression regularly, as this is essential for treatment and discontinuation can worsen the condition 2
- Use NSAIDs for pain management 1
- Apply ice to the affected breast 1
- Avoid excessive pumping, aggressive breast massage, and heat application, as these can worsen inflammation through overstimulation 3
Antibiotic Therapy (If No Improvement After 12-24 Hours)
First-Line Antibiotics
- Dicloxacillin 500 mg orally four times daily is the preferred agent for methicillin-susceptible S. aureus, which causes the majority of infectious mastitis 1
- Cephalexin 500 mg orally four times daily is an equally effective alternative, particularly useful for penicillin-allergic patients 1
- Both antibiotics are safe during breastfeeding with minimal transfer to breast milk (dicloxacillin RID = 0.03%, well below the 10% threshold of concern) 1, 4
MRSA Coverage Considerations
- Consider MRSA-active antibiotics (such as trimethoprim-sulfamethoxazole or clindamycin) for patients with: 1
- High local MRSA prevalence
- Previous MRSA infection
- Failure to respond to beta-lactam antibiotics within 48-72 hours
Indications for Hospitalization
- Admit patients with systemic symptoms suggesting sepsis risk, including fever and chills indicating systemic involvement 2, 1
- Provide intravenous antibiotics for worsening symptoms or sepsis concern 3
- Ensure access to breast pump if prolonged separation from infant occurs 2
Imaging and Further Evaluation
- Ultrasound is indicated for: 5
- Immunocompromised patients
- Worsening or recurrent symptoms
- Suspected abscess (occurs in approximately 10% of mastitis cases)
- Do not routinely obtain imaging for uncomplicated mastitis 3
Management of Complications
- Breast abscesses require drainage (surgical or needle aspiration), but breastfeeding can continue on the affected side as long as the infant's mouth does not contact purulent drainage 2
- Early treatment of mastitis and continued breastfeeding prevent abscess formation 6
Red Flags Requiring Urgent Evaluation
- Symptoms persisting beyond 1 week of appropriate antibiotics may indicate inflammatory breast cancer and warrant urgent evaluation 1
- Erythema occupying at least one-third of breast surface or peau d'orange appearance requires urgent ultrasound and possible biopsy within 48 hours 1
- History of mastitis not responding to at least 1 week of antibiotics should raise suspicion for malignancy 5
Critical Pitfalls to Avoid
- Never discontinue breastfeeding during mastitis treatment, as this worsens the condition 2
- Avoid overfeeding, excessive pumping, and aggressive breast massage, as these increase risk through overstimulation of milk production and tissue trauma 3
- Do not delay antibiotic therapy beyond 24 hours if conservative measures fail, as this may lead to abscess formation 2
- Take dicloxacillin with at least 4 fluid ounces of water and not in the supine position or before bed to minimize risk of esophageal irritation 7