Mastitis

Snapshot

• A 33-year-old G2P2 woman presents with fever, chills, and acute onset pain of her left breast. She recently had her second child and has been breastfeeding exclusively for about 1 month. She reports having had this type of pain before with her first child. The pain resolved with antibiotics. On physical exam, her left breast is noted to be engorged and tender to palpation. There is localized erythema, induration, and warmth. She is given antibiotics and told to continue breastfeeding.

Introduction

• Clinical definition
  • inflammation of the breast often associated with milk stasis during lactation
• Epidemiology
  • incidence
    • 3-20% of lactating women
  • demographics
    • occurs in lactating women
    • often occurs within first 12 weeks post-partum
  • risk factors
    • lactation
    • injury to nipple
    • poor attachment of infant to breast
    • history of prior mastitis
• Pathophysiology
  • pathophysiology
    • milk stasis also creates favorable conditions for growth of bacteria
      • infection often starts from nipple fissures
      • often due to Staphylococcus aureus  
• Prognosis
  • prognostic variable
    • favorable
      • appropriate antibiotic treatment
  • survival with treatment
• very good

Presentation

• Symptoms
  • primary symptoms
    • tender, hot, and swollen breast
      • usually unilateral
    • flu-like myalgia
    • chills
    • fever
• Physical exam
  • inspection
    • localized redness on the breast
      • often wedge-shaped
    • warmth and induration on the breast
    • cracked nipples or visible fissure
    • swollen lump may indicate breast abscess
• may have purulent nipple discharge

Imaging

• Ultrasound
  • indication
    • If breast abscess is suspected
  • finding
• fluid pocket seen inside breast

Studies

• Labs
  • may see elevated white blood cell count
• Diagnostic criteria
• mastitis is typically diagnosed clinically based on physical exam

Differential

• Engorgement
  • pain relief and resolution of symptoms with emptying of milk
• Fibroadenoma
• no signs of infection

Treatment

• Conservative
  • continue breastfeeding 
    • safe for infants
      • not advisable in women with human immunodeficiency virus (HIV)
  • empty breasts of milk every 6 hours
    • indication
      • for mild symptoms lasting less than 1 day
• Medical
  • dicloxacillin or cephalexin
    • indications
      • symptoms persist after 1 day of effective, regular milk removal
      • visible nipple fissure
      • breast abscess
  • clindamycin or trimethoprim-sulfamethoxazole
    • indication
      • if MRSA is suspected    
• Operative
  • surgical drainage       
    • indication
      • breast abscess is diagnosed
    • techniques
      • first-line
        • needle aspiration with or without ultrasound guidance
      • otherwise
• incision and drainage for large abscesses

Complications

• Breast abscess
  • 3-12%of women with mastitis develop breast abscess
  • treatment
    • surgical drainage