Mastitis (Lactational)

Introduction

• Description: Mastitis is an infection of one or more ductal complexes of the breast, generally associated with breastfeeding and potentially causing significant morbidity if not recognized and aggressively treated.

• Prevalence: 2%–10% of women who are breastfeeding after delivery. Hospitalization for mastitis occurs in 9/10,000 deliveries.

• Predominant Age: Reproductive age; 2–12 weeks after delivery.

• Genetics: No genetic pattern.

Etiology and Pathogenesis

• Causes: Infection comes from organisms carried in the nose and mouth of a nursing infant, most commonly Staphylococcus aureus (especially methicillin-resistant S. aureus [MRSA]) and Streptococcus species. Common agents include β-hemolytic streptococci, Haemophilus influenzae, Haemophilus parainfluenzae, Escherichia coli, and Klebsiella pneumoniae.

• Risk Factors: Diabetes, steroid use, heavy cigarette smoking, milk stagnation (infrequent feedings, weaning), history of mastitis, nipple excoriation or cracking, and retracted (inverted) nipples.

Signs and Symptoms

• Firm, sore, red, and tender portion of the breast, most commonly in the upper outer quadrant

• High fever >38.3°C (>100.9°F), tachycardia, headaches, anorexia, and malaise

• Axillary nodes tender or enlarged

• In patients who are not breastfeeding a palpable, recurrent mass, accompanied by a multicolored discharge from the nipple or adjacent to a Montgomery follicle

Diagnostic Approach