Mastitis

Background

• Inflammation of the breast tissue - can be infectious or non-infectious in etiology.
  • Continuum of disease - Plugged ducts → engorgement → non-infectious inflammation → infectious inflammation → abscess
  • Infection occurs due to bacterial colonization secondary to areolar inflammation and glandular obstruction
• Often occurs during the first few weeks to months postpartum, usually staph species with breast milk as culture medium
• Post-menopausal usually due to E. coli, Group D strep, Staph, anaerobes
  • Usually sub-areolar area due to chronic duct inflammation
  • 40% recurrence rates even after I&D

Clinical Features

• Erythematous region on breast with well-localized area of tenderness
• Fever/chills
• Flu-like symptoms

Differential Diagnosis

3rd Trimester/Postpartum Emergencies

• Acute fatty liver of pregnancy
• Amniotic fluid embolus
• Chorioamnionitis
• Eclampsia
• HELLP syndrome
• Mastitis
• Peripartum cardiomyopathy
• Postpartum endometritis (postpartum PID)
• Postpartum headache
• Postpartum hemorrhage
• Preeclampsia
• Resuscitative hysterotomy
• Retained products of conception
• Septic abortion
• Uterine rupture

Diagostic Evaluation

• Ultrasound useful to identify abscess
• Routine labs not indicated unless:
  • Treatment failure
  • Recurrent episodes
  • Hospital-acquired
  • Severe cases with systemic illness

Management

• No need to routinely interrupt breastfeeding with puerperal mastitis.
• For mild symptoms <24 hours, supportive care may be sufficient
  • Effective milk removal (frequent breast feeding - use pumping to augment milk removal)
  • Analgesia (NSAIDs)

Treatment directed at S. aureus and Strep and E. coli

• Uncomplicated mastitis → 10 days of antibiotics (regardless of MRSA suspicion)
• Dicloxacillin 500mg PO q6hrs, considered first line if breastfeeding given safety for infant OR
• Cephalexin 500mg PO q6hrs OR
  • Add TMP/SMX 2DS tabs PO q12hrs if suspect MRSA
• Clindamycin 450mg PO q8hrs (also provides MRSA coverage) OR
• Amoxicillin/Clavulanate 875mg PO q12hrs OR
• Azithromycin 500mg PO x1 on day 1, then 250mg PO daily for days 2-5

Disposition

• Admit for OR drainage if abscess suspected/identified
• Otherwise discharge