Describes inflammation of the breast tissue, both acute or chronic

Aetiology

Can be classed by lactation status:

• Lactational mastitis (more common) is seen in up to a third of breastfeeding women; it usually presents during the first 3 months of breastfeeding or during weaning
  • Causative organisms: staph aureus, strep pyrogenes
  • Risk factors include poor breastfeeding technique, nipple damage, maternal stress, and previous history of mastitis
• Non-lactational mastitis (less common) can also occur, especially in women with other conditions such as duct ectasia, as a peri-ductal mastitis
  • Tobacco smoking is an important risk factor, causing damage to the sub-areolar duct walls and predisposing to bacterial infection
  • Causative organisms: mixed organisms, anaerobes

Pathophysiology

Pathophysiology of lactational (puerperal) mastitis)

• Milk stasis leads to an inflammatory response and potential secondary infection
  • Milk stasis may occur due to inadequate milk removal, either from poor breastfeeding techniques or infrequent feeding
  • Cracked or sore nipples can provide a point of entry for bacteria, primarily Staphylococcus aureus, leading to infective mastitis

Clinical features

• Localised symptoms: painful, tender, red, and hot breast.
• Systemic symptoms: Fever, rigors, myalgia, fatigue, nausea, and headache
• The condition is usually unilateral and, if lactational, tends to present within the first week postpartum
• In some cases, mastitis may develop into a breast abscess, manifesting as a fluctuant, tender mass with overlying erythema

Investigations

• Clinical diagnosis
• If an abscess is suspected → early referral to secondary care and ultrasound

Management

• Non-lactational mastitis should be treated with antibiotics - first line flucloxacillin 500 mg orally every 6 hours 10-14 days first line, second line augmentin 625 mg every 8 hours for 7 days
• The first line management of lactational mastitis is to continue breastfeeding/milk drainage
• The BNF advises treating lactational mastitis with antibiotics (flucloxacillin/augmentin) 'if systemically unwell, if nipple fissure present, if symptoms do not improve after 12-24 hours of effective milk removal of if culture indicates infection’