Breast Abscess/Mastitis

Descriptive text is not available for this imageBASICS

DESCRIPTION

  • Mastitis: inflammation or infection of the breast tissue
  • Breast abscess: localized pus and inflammation of the breast tissue often associated with infectious mastitis
  • Neonatal mastitis: mastitis occurring in the first 2 months of life
  • Lactational mastitis: mastitis occurring in association with lactation

EPIDEMIOLOGY

  • Neonatal mastitis
    • Peak age: 4 weeks
    • Male:female ratio 1:1.2–5.
  • Lactational mastitis
    • Incidence is 0.4–11% in lactating mothers.
    • More prevalent in African Americans, smokers, and obese patients
  • Nonlactational mastitis: occurs mostly in girls aged >8 years near puberty/menarche

ETIOLOGY

  • Neonatal/lactational mastitis
    • Predominately Staphylococcus aureus
    • Uncommonly group A or B Streptococcus; Bacteroides, Klebsiella, Enterococcus species; gram-negative enteric bacteria
  • Nonlactational mastitis
    • Same as above
    • Occasionally, Mycobacteria, Corynebacterium (granulomatous mastitis), actinomycosis (piercings).

RISK FACTORS

  • Neonatal mastitis
    • Female sex
    • Breast massage
  • Lactational mastitis
    • Age >30 years
    • Gestation ≥41 weeks
    • First pregnancy
    • Tobacco use
    • Massage
    • Hyperlactation
    • Pumping
    • Nipple shields
    • Delayed or inadequate treatment of mastitis
  • Nonlactational mastitis
    • Immunocompromised
    • Obesity
    • Tobacco use
    • Nipple piercing
    • Eczema

GENERAL PREVENTION

  • Avoid massage/manipulation.
  • Prompt treatment of mastitis/cellulitis
  • For prevention of lactational mastitis, avoid over-pumping; treat painful engorgement with nonsteroidal anti-inflammatory drugs (NSAIDs) and ice.

PATHOPHYSIOLOGY

  • Neonatal mastitis
    • Physiologic breast enlargement due to placental and maternal hormones
    • Spread of bacterial pathogens to breast parenchyma through nipple or bloodstream
  • Lactational mastitis
    • Traditionally explained as bacterial proliferation from milk stasis
    • New theory that hyperlactation and/or imbalance of the breast flora leads to ductal inflammation and connective tissue swelling, causing infectious mastitis or abscess.
  • Breast massage may play a role in both neonatal and lactational mastitis.
  • Nonlactational mastitis
    • Nipple or skin infection/trauma or underlying structural abnormalities (mammary duct ectasia, epidermal cysts, hidradenitis suppurativa) cause breast tissue edema and destruction by bacteria and/or its toxin.

COMMONLY ASSOCIATED CONDITIONS

  • Lactational mastitis: phlegmon
  • Neonatal mastitis: Concomitant serious bacterial infections (e.g., bacteremia, meningitis, UTI) are rare.

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