Breast Abscess



  • Breast abscess: localized accumulation of infected fluid within the breast parenchyma
  • Mastitis: breast inflammation with or without infection. This can be associated with lactation (puerperal) or nonlactational.
  • Associated with lactation or fistulous tracts secondary to squamous epithelial neoplasm or duct occlusion
  • System(s) affected: skin/exocrine, immune
  • Synonym(s): mammary abscess; peripheral breast abscess; subareolar abscess; puerperal abscess

Pregnancy Considerations
Most commonly associated with postpartum lactation


  • Most common benign breast problem during pregnancy and puerperal period (1)
  • Predominantly reproductive age and perimenopausal (between ages 18 and 50)
    • Puerperal abscess: lactational
    • Subareolar abscess: reproductive age through postmenopause (2)
      • 90% of nonlactational breast abscesses are subareolar (1).
      • Nipple piercing associated in increased risk of subareolar abscess (3)
      • Smoking linked to recurrences (3)
  • Predominant sex: female
  • Higher incidence in African American, diabetic, smoking, or obese women (3)


  • Ranges estimate up to 11% of breastfeeding women; the Academy of Breastfeeding Medicine cites 3% (2),(4).
  • Puerperal abscess has highest incidence within 12 weeks postpartum (3) and while weaning from breastfeeding (4).

Transient condition; recurrences are most strongly associated with smoking, surgical treatment, and increased age (3).

Etiology and Pathophysiology

  • Puerperal abscesses:
    • Likely that bacteria (often from infants oral flora) gain entry through cracks/fissures in the nipple (1)
    • Insufficient treatment of mastitis
    • Unattended postpartum engorgement and other situations leading to breast milk stasis (4)
    • Lactose-rich milk and plugged lactiferous duct causing stasis, leading to microbial growth and subsequent abscess formation
  • Subareolar abscess:
    • Associated with squamous metaplasia of the lactiferous duct epithelium, keratin plugs, ductal ectasia, fistula formation (2)
    • Higher incidence in patients with nipple piercings (3)
  • Microbiology
    • Staphylococcus aureus is most common cause for lactational abscesses (3),(4).
    • Methicillin-resistant S. aureus (MRSA) is a significant cause (4).
    • Less common causes (3)
      • Streptococcus pyogenes, Escherichia coli, Bacteroides, Corynebacterium, Pseudomonas, Proteus
      • Anaerobes and mixed flora are more common in subareolar abscesses.
      • In patients with breast implants, coagulase negative S. aureus is more common.
      • In nonlactational abscesses, lack of growth is a common result.

No current evidence to support a genetic predisposition to breast abscess formation (lifestyle/environment have been implicated more often)

Risk Factors

  • Maternal age >30 (5)
  • Primiparous (5)
  • Pregnancy ≥41 weeks’ gestation (5)
  • Puerperal mastitis
    • Up to 11% progression to abscess (3)
    • Most often due to inadequate antibiotic and anti-inflammatory treatment of mastitis (4)
    • Risk factors (stasis) (4):
      • Infrequent or missed feeds
      • Poor latch, weak or uncoordinated suckling
      • Damage or irritation of the nipple
      • Nipple inversion or retraction
      • Inefficient removal of milk (by baby or pump)
      • Oversupply of milk
      • Illness in mother or baby
      • Rapid weaning
      • Plugged duct
      • Pressure on the breast (i.e., tight bra, car seatbelt)
      • Maternal stress and fatigue
  • General risk factors (3)
    • Smoking; diabetes; obesity
    • African American
    • Nipple piercing
  • Medically related risk factors
    • Steroids
    • Breast implants
    • Lumpectomy with radiation
    • Inadequate antibiotics to treat mastitis
    • Topical antifungal medication used for mastitis

General Prevention

  • Frequent breast emptying with on-demand feeding and/or pumping to prevent mastitis
  • Early treatment of mastitis with milk expression, antibiotics, and compresses
  • Smoking cessation to minimize occurrence/recurrence

Commonly Associated Conditions

Lactation, mastitis, weaning

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