From the Guidelines
A breast abscess is primarily caused by a bacterial infection, most commonly Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus (MRSA), that develops in the breast tissue. This typically occurs when bacteria enter through a cracked or damaged nipple, particularly during breastfeeding (lactational abscess) 1. Non-lactational abscesses can develop from infected hair follicles, sebaceous glands, or previous breast surgeries. Risk factors include poor breastfeeding technique, milk stasis (when milk remains in the breast), untreated mastitis (breast inflammation), smoking, diabetes, obesity, and compromised immune function. The infection begins as mastitis and, if left untreated, can progress to form a pocket of pus (abscess).
Causes and Risk Factors
- Bacterial infection, most commonly Staphylococcus aureus, including MRSA 1
- Cracked or damaged nipple, particularly during breastfeeding
- Infected hair follicles, sebaceous glands, or previous breast surgeries
- Poor breastfeeding technique
- Milk stasis
- Untreated mastitis
- Smoking
- Diabetes
- Obesity
- Compromised immune function
Treatment
Treatment usually involves antibiotics such as clindamycin, TMP-SMX, doxycycline, or minocycline, along with drainage of the abscess either through needle aspiration or surgical incision 1. Pain management with acetaminophen or ibuprofen is also important. Breastfeeding women should continue nursing or expressing milk from the affected breast to prevent milk stasis, which can worsen the condition. Warm compresses applied to the affected area can help improve blood circulation and promote healing.
Antibiotic Therapy
- Clindamycin: 300-450 mg PO TID for adults, 10-13 mg/kg/dose PO every 6-8 h for pediatric patients 1
- TMP-SMX: 1-2 DS tab PO BID for adults, trimethoprim 4-6 mg/kg/dose, sulfamethoxazole 20-30 mg/kg/dose PO every 12 h for pediatric patients 1
- Doxycycline: 100 mg PO BID for adults, <45kg: 2 mg/kg/dose PO every 12 h for pediatric patients 1
- Minocycline: 200 mg 3 1, then 100 mg PO BID for adults, 4 mg/kg PO 3 1, then 2 mg/kg/dose PO every 12 h for pediatric patients 1
From the Research
Causes of Breast Abscess
- Breast abscesses are often caused by bacterial infections, with Staphylococcus aureus being the most common pathogen 2, 3, 4, 5, 6
- Methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) are both common causes of breast abscesses, with MRSA being more resistant to antibiotics 2, 3, 4, 5
- Other bacteria, such as coagulase-negative Staphylococcus, diphtheroids, Pseudomonas aeruginosa, and Proteus mirabilis, can also cause breast abscesses 3, 6
- Anaerobic bacteria are more commonly found in breast abscesses of non-lactating patients, particularly those who smoke or do not have diabetes 6
Risk Factors
- Breastfeeding is a significant risk factor for developing breast abscesses, particularly those caused by Staphylococcus aureus 2, 4, 5, 6
- Diabetes and smoking may also increase the risk of developing breast abscesses, although the relationship between these factors and the etiology of breast abscesses is not fully understood 6