What is the treatment for mastitis of the breast?

Treatment of Mastitis in Breastfeeding Women

For lactational mastitis, begin with a 1-2 day trial of conservative management (NSAIDs, ice, continued breastfeeding), and if symptoms do not improve within 24-48 hours, initiate antibiotic therapy with dicloxacillin 500 mg orally four times daily or cephalexin 500 mg orally four times daily as first-line agents. 1, 2

Initial Conservative Management (First 24-48 Hours)

• Start with non-antibiotic measures for 1-2 days before initiating antibiotics, as most mastitis cases are inflammatory rather than infectious 2
• Administer NSAIDs for pain and inflammation 2
• Apply ice to the affected breast 2
• Continue direct breastfeeding from the affected breast—this does not pose risk to the infant and helps resolve the condition 1, 3
• Minimize pumping, as overstimulation can worsen inflammation 2
• Avoid aggressive breast massage and heat application, which may exacerbate symptoms 2

When to Initiate Antibiotics

Begin antibiotics if symptoms do not improve after 24-48 hours of conservative management, or immediately if:

• Severe symptoms are present at onset 2
• Patient appears systemically ill or septic 2
• There is concern for abscess formation 3

First-Line Antibiotic Selection

For methicillin-susceptible Staphylococcus aureus (most common cause):

• Dicloxacillin 500 mg orally four times daily (preferred agent) 1
• Cephalexin 500 mg orally four times daily (equally effective alternative, particularly for penicillin-allergic patients) 1

Both antibiotics are safe during breastfeeding with minimal transfer to breast milk 1

Alternative Antibiotics for Special Circumstances

For penicillin-allergic patients:

• Erythromycin or azithromycin are acceptable alternatives 1
• Caution: Very low risk of infantile hypertrophic pyloric stenosis if macrolides used during first 13 days of infant life; generally safe after this period 1

For suspected or confirmed MRSA (consider if):

• High local MRSA prevalence 1
• Previous MRSA infection 1
• No response to first-line therapy after 48-72 hours 1
• Treatment: Clindamycin (use with caution as it may increase GI side effects in infant) 1

Broad-spectrum option:

• Amoxicillin/clavulanic acid is safe during breastfeeding based on limited human data 1

Monitoring and Follow-Up

• Reassess within 48-72 hours of starting antibiotics 1
• If symptoms worsen or fail to improve, reevaluate to rule out abscess formation (occurs in approximately 10% of mastitis cases) 3, 2
• Obtain ultrasound in immunocompromised patients, those with worsening/recurrent symptoms, or when abscess is suspected 2
• Consider milk cultures to guide antibiotic therapy, especially if initial treatment fails 2

Critical Red Flags Requiring Further Evaluation

Suspect inflammatory breast cancer (not simple mastitis) if:

• Symptoms persist despite ≥1 week of appropriate antibiotics 4
• Rapid onset with erythema occupying ≥1/3 of breast 4
• Peau d'orange appearance 4
• Symptoms duration <6 months with progressive course 4
• Action: Perform core needle biopsy or skin punch biopsy to exclude malignancy 4

Management of Breast Abscess

• Breast abscess requires surgical drainage or needle aspiration 3
• Breastfeeding can usually continue from the affected breast even with a treated abscess 3
• Early treatment of mastitis and continued breastfeeding help prevent abscess formation 3

Key Clinical Pitfalls to Avoid

• Do not discontinue breastfeeding—continued nursing from the affected breast is therapeutic and safe for the infant 1, 3
• Avoid excessive pumping and aggressive breast massage—these worsen inflammation through overstimulation 2
• Do not delay antibiotics in severe cases—waiting too long increases abscess risk 3
• Do not use probiotics—insufficient evidence supports their use for treatment or prevention 2