First-Line Treatment for Mastitis
The first-line treatment for mastitis is a beta-lactamase-resistant penicillin such as dicloxacillin or flucloxacillin at a dose of 500 mg four times daily for 7-10 days, along with continued breastfeeding and supportive measures. 1
Diagnosis and Assessment
Mastitis is characterized by:
- Focal breast tenderness
- Overlying skin erythema or hyperpigmentation
- Systemic symptoms (fever, malaise)
- Typically occurs in the first 3 months postpartum with an incidence of approximately 10% 2
The diagnosis is primarily clinical and does not require laboratory tests or imaging in most cases. However, consider:
- Milk cultures for guiding antibiotic therapy in severe or recurrent cases
- Ultrasonography to identify abscesses in immunocompromised patients or those with worsening/recurrent symptoms 2
Treatment Algorithm
Step 1: Conservative Management (1-2 days)
- Continue breastfeeding from the affected breast
- Use nonsteroidal anti-inflammatory drugs for pain and inflammation
- Apply ice to the affected area
- Minimize pumping (contrary to previous recommendations)
Step 2: If No Improvement After 1-2 Days, Add Antibiotics
- First choice: Dicloxacillin or flucloxacillin 500 mg QID for 7-10 days 1, 3
- Alternative: Cephalexin 500 mg QID for 7-10 days 3
- For penicillin-allergic patients: Clindamycin or erythromycin
Step 3: For Severe Cases or Treatment Failure
- Consider hospital admission with IV antibiotics if:
- Signs of sepsis develop
- Symptoms worsen despite oral antibiotics
- Abscess formation is suspected
- Surgical drainage or needle aspiration for confirmed abscess 3
Evidence for Antibiotic Selection
The WHO Pocket Book of Hospital Care for Children specifically recommends cloxacillin/flucloxacillin at 50 mg/kg QID for mastitis 1. This recommendation is based on the fact that Staphylococcus aureus is the most common causative organism in mastitis.
A Cochrane review found insufficient evidence to definitively confirm or refute antibiotic effectiveness for lactational mastitis, highlighting the need for more high-quality studies 4. However, clinical practice guidelines and expert consensus continue to recommend antibiotics when conservative measures fail.
Dicloxacillin has been shown to have minimal transfer into breast milk with a relative infant dose of only 0.03%, making it safe for use in breastfeeding mothers 5.
Important Considerations
- Continue breastfeeding during treatment - this is crucial for recovery and does not pose a risk to the infant 3
- Avoid practices that may worsen mastitis:
- Excessive pumping to empty the breast
- Heat application
- Aggressive breast massage
- These practices can cause overstimulation and tissue trauma 2
Prevention
- Ensure proper lactation technique with good infant latch
- Encourage physiologic breastfeeding rather than pumping when possible
- Frequent, complete emptying of the breast through effective breastfeeding
- Address sore nipples promptly as they can precipitate mastitis 3
Emerging Concerns
As methicillin-resistant S. aureus (MRSA) becomes more common, it may become a more frequent cause of mastitis, potentially requiring different antibiotic choices in the future 3. Consider MRSA coverage for recurrent or non-responsive cases.