Diagnosis
Infection of the breast.
Epidemiologic Risks
Breastfeeding, alterations in duct drainage. Trauma.
Microbiology
S. aureus and streptococci in the peripartum time, sub-nipple infection are often mixed anaerobic.
Actinomycosis may be a cause as well (PubMed).
And there is the usual hodgepodge of unusual organisms.
Empiric Therapy
Peripartum: cephalexin OR dicloxacillin. If MRSA an issue and not breastfeeding, tmp/sulfa (I give 2-3 ds po tid) or doxycycline.
Lactational mastitis often gets better with no antibiotics.
Sub-nipple infections/abscess: amoxicillin/clavulanate OR clindamycin.
If there is an abscess, drain it.
A recent study demonstrated that lactobacilli were equal to antibiotics, they did not have a placebo group and they did not report whether susceptibility results made a difference in outcomes, so it is so flawed I remain skeptical (PubMed). CID loves to call studies "Major Articles" but I am not certain they use the same definition of 'major' that I do.
Last Update: 11/06/18.