Treatment of Mastitis While Nursing
Continue breastfeeding on the affected breast and start antibiotics targeting Staphylococcus aureus if symptoms do not improve within 12-24 hours of conservative management. 1, 2
Initial Conservative Management (First 12-24 Hours)
- Begin with frequent breast emptying through direct breastfeeding rather than pumping, as this is the cornerstone of treatment and allows 14-20% of cases to resolve without antibiotics. 2, 3
- Use NSAIDs for pain control and apply ice to reduce inflammation. 4, 3
- Avoid excessive pumping, heat application, and aggressive breast massage, as these practices overstimulate milk production and worsen tissue inflammation. 3
- Work with a lactation consultant to optimize infant latch and positioning, as poor technique precipitates mastitis. 5
When to Start Antibiotics
- Initiate antibiotics if symptoms fail to improve within 12-24 hours of conservative measures, as delaying treatment increases the risk of abscess formation (occurs in approximately 10% of mastitis cases). 2, 5
- Start antibiotics immediately if the patient presents with fever, chills, or systemic symptoms suggesting bacterial infection. 1
First-Line Antibiotic Selection
Dicloxacillin 500 mg orally four times daily is the preferred agent for methicillin-susceptible Staphylococcus aureus, which causes the majority of infectious mastitis cases. 2
Alternative first-line options include:
- Cephalexin 500 mg orally four times daily (equally effective and safe during breastfeeding). 2
- Amoxicillin/clavulanic acid for broader spectrum coverage. 2
For penicillin-allergic patients:
- Erythromycin or azithromycin are acceptable alternatives, though macrolides carry a very low risk of infantile hypertrophic pyloric stenosis if used during the first 13 days of the infant's life. 2
- Clindamycin for suspected or confirmed MRSA, but use cautiously as it may increase GI side effects in the infant. 2
MRSA Coverage Considerations
- Consider MRSA coverage if local MRSA prevalence is high, the patient has previous MRSA infection, or there is no response to first-line therapy within 48-72 hours. 2
- Clindamycin is the preferred oral agent for MRSA coverage during breastfeeding. 2
Critical Management Principles
Never discontinue breastfeeding during mastitis treatment, as this worsens the condition by preventing adequate breast emptying. 1, 2
- Breastfeeding can continue on the affected side even if an abscess has formed, provided the infant's mouth does not contact purulent drainage from the breast. 1
- All recommended antibiotics (dicloxacillin, cephalexin, clindamycin) are compatible with breastfeeding, with minimal transfer to breast milk. 2
- Continued breastfeeding during antibiotic treatment does not pose a risk to the infant and actively helps resolve the mastitis. 2
When to Reassess and Escalate Care
Perform urgent ultrasound if:
- Symptoms worsen or fail to improve within 48-72 hours of starting antibiotics. 2
- Recurrent symptoms develop. 4
- The patient is immunocompromised. 3
Consider hospitalization if:
- Fever and chills persist, suggesting systemic involvement or concern for sepsis. 1
- An abscess is identified requiring surgical drainage or needle aspiration. 1, 5
- The patient cannot tolerate oral antibiotics. 3
Common Pitfalls to Avoid
- Do not advise expressing and discarding breast milk, as this is illogical given that women after cesarean section are encouraged to breastfeed immediately despite similar drug exposure, and interrupting breastfeeding risks breast engorgement, blocked ducts, and worsening mastitis. 6
- Do not delay antibiotic therapy in patients with clear systemic symptoms, as this increases abscess risk. 2
- Do not recommend probiotics, as there is insufficient evidence supporting their use for treatment or prevention. 3