What is the treatment for a mother with unilateral mastitis who is breastfeeding?

Treatment of Unilateral Mastitis in Breastfeeding Mothers

Continue breastfeeding from the affected breast while initiating conservative management first, and only add antibiotics if symptoms fail to improve within 24-48 hours. 1, 2, 3

Initial Conservative Management (First 24-48 Hours)

• Start with a 1-2 day trial of conservative measures before antibiotics, as most mastitis cases are inflammatory rather than truly infectious 3
• Use NSAIDs for pain control and anti-inflammatory effect 3
• Apply ice to the affected breast 3
• Continue direct breastfeeding from the affected breast—this is essential for resolution and does not harm the infant (unless the infant's mouth would contact purulent drainage) 1, 2, 4
• Minimize pumping, as overstimulation can worsen the condition 3
• Avoid aggressive breast massage, heat application, and excessive pumping, as these may exacerbate inflammation 3

Antibiotic Therapy (If No Improvement in 24-48 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, 4
• Both antibiotics are safe during breastfeeding with minimal transfer to breast milk 1

Alternative Antibiotics for Special Circumstances

• For penicillin allergy: Erythromycin or azithromycin are acceptable, but avoid macrolides during the first 13 days of infant life due to very low risk of infantile hypertrophic pyloric stenosis 1
• For suspected or confirmed MRSA (consider if high local prevalence, previous MRSA infection, or no response to first-line therapy): Clindamycin is an option, though use with caution as it may increase GI side effects in the infant 1
• Amoxicillin/clavulanic acid is a broad-spectrum alternative that is safe during breastfeeding 1

Monitoring and Follow-Up

• Reevaluate within 48-72 hours if symptoms worsen or fail to improve to rule out breast abscess, which occurs in approximately 10% of mastitis cases 1, 2, 4
• Consider obtaining milk cultures to guide antibiotic therapy, especially in refractory cases 3
• Perform ultrasonography if abscess is suspected, particularly in immunocompromised patients or those with recurrent symptoms 3

Management of Complications

• If breast abscess develops, surgical drainage or needle aspiration is required 4
• Breastfeeding can usually continue even with a treated abscess 4
• Early treatment of mastitis and continued breastfeeding help prevent abscess formation 4

Critical Pitfalls to Avoid

• Do not stop breastfeeding—this worsens the condition by preventing effective milk removal 1, 2, 3
• Avoid overstimulation through excessive pumping, heat, or aggressive massage, as these practices are no longer recommended and may worsen inflammation 3
• Do not delay antibiotic initiation beyond 48 hours if conservative measures fail, as this increases abscess risk 1, 4
• Consider MRSA coverage in areas with high prevalence or treatment failures 1