Infection of the breast

There are 2 common causes of infection:

• Lactational breast abscess
• Periductal mastitis

Lactational breast abscess:

• Is a complication of lactation and breast-feeding
• The organism involved is nearly always Staphylococcus aureus
• It is believed that the bacteria get into the breast tissue through cracks in the nipple during feeding
• The abscess may break through into neighbouring segments and thus become multilocular

Clinical features of a lactational breast abscess:

History:

The baby may be anything from a few days to some months old

The mother may have noticed an obvious crack in the nipple (although this is unusual)

Segmental pain in the affected breast rapidly becomes severe and sleep is often lost

Physical findings:

• A tender red segment in the breast is seen
• May be evidence of nipple damage (i.e. a crack in its surface)
• Fluctuation is not a feature unless the abscess is advanced and beginning to point towards the skin, which may ultimately show evidence of necrosis

Management of a lactational breast abscess:

• If detected and treated early, acute mastitis can resolve
• Anti-staphylococcal antibiotics are prescribed in full dose
• If the nipple is obviously damaged, feeding on this side is stopped and the milk expressed from the healthy segments
• Continued pain and loss of sleep suggest that there is an abscess which, in its early stages, can be aspirated with a wide-bore needle under LA
• Ultrasound is a useful means of determining whether there is any pus to drain

Periductal mastitis:

• This condition affects young women in their 30s and is associated with smoking
• Is characterised histologically by a low-grade inflammatory response around the ducts adjacent to the nipple
• The bacteria involved are nearly always anaerobes

Clinical features of periductal mastitis:

• Tenderness develops on one aspect of the areola
• There is rarely any systemic disturbance
• Recurrent bouts may occur before the patient seeks medical attention
• A tender swelling at the edge of the areolar is seen, which may progress to abscess formation with a periareolar sinus and discharge

Investigation and management of periductal mastitis:

• Because there may be a discrete mass with only a few, if any, characteristics of inflammation, FNAC and mammography may be necessary to exclude an underlying carcinoma
• Inflammatory swellings may respond to antibiotics
• Once an abscess has formed – drainage is required
• A complication of abscess is the formation of a mammary duct fistula:
• Discharges intermittently
• May be associated with recurrent abscess formation
• The duct segment must then be excised because, in the presence of a duct abnormality, attempts to eradicate sepsis with antibiotics are usually futile