• defined as inflammation of the breast with or without infection
  • Mastitis with infection may be lactational (puerperal) or non-lactational (e.g., duct ectasia).
  • Non-infectious mastitis includes idiopathic granulomatous inflammation and other inflammatory conditions (e.g., foreign body reaction).
• A breast abscess is a localised area of infection with a walled-off collection of pus. It may or may not be associated with mastitis.
• Staph aureus is the most frequent pathogen

• analgesia - paracetamol, ibuprofen
• effective milk extraction - continue breast feeding, breast pump
• Flucloxacillin (or dicloxacillin or cloxacillin) - 250-500mg qds (cephalexin or clindamycin if allergic)
• breast abscess needs surgical drainage

References include:
https://cks.nice.org.uk/mastitis-and-breast-abscess#!scenario
BMJ best practice Mastitis