Continue to breastfeed and/or express
Prior to feeding or expressing apply warmth (heat pack) to the affected area to improve milk flow
Following massage/ breastfeeding / expressing, apply a cool pack for a few minutes to reduce discomfort
analgesia eg Paracetamol or Ibuprofen
Maintain a good fluid intake (up to 8 glasses of water per day)
rest as much as possible (but don't get a DVT!)
usually will need antibiotics (eg. iv or o flucloxacillin - safe for infant but may cause some diarrhoea)
consider admission if very unwell
consider diagnostic ultrasound if suspicion of breast abscess which may need surgical drainage