Severe Lactational Mastitis With Complicated Wound Infection Caused by Streptococcus pyogenes

Puerperal mastitis, a complication occurring during the breastfeeding period, is often caused by Staphylococcus aureus. Here we report on severe streptococcal mastitis in a lactating breast, with subsequent invasive disease and wound healing problems.

The 41-year-old woman (G2, P2) presented at 2 weeks postpartum to our hospital with painful swelling and reddening of the left breast, in addition to fever and malaise, and complained about a nipple fissure on the left breast. Previously, her 4-year-old son was treated for an acute otitis media and her husband experienced flu-like symptoms.

Due to the severity of the symptoms, Clindamycin antibiotic treatment was initiated intravenously. Streptococcus pyogenes was isolated in the milk. This strain is commonly known to cause infections of the upper respiratory tract, skin, and soft tissue, but rarely mastitis. Furthermore, the participant developed invasive disease with abscess formation and skin erosion with a milk fistula. Special dressing was applied to promote wound healing. The participant continued breastfeeding well into the child's 2nd year of life.

This rare form of complicated mastitis with invasive disease caused by Streptococcus pyogenes called for an interdisciplinary approach. We want to draw attention to other pathogens causing mastitis and to alert health care workers to promote hygiene in lactating women to prevent transmission.