Pneumococcal Mastitis with Septicemia in a Pregnant Woman with Systemic Lupus Erythematosus

Purulent mastitis due to Streptococcus pneumoniae is extremely rare and is thought to be transmitted to the mother from the respiratory tract of the child during breastfeeding. We report herein a case of a 37-year-old, pregnant, Japanese patient in her third trimester with systemic lupus erythematosus (SLE) who presented with bacteremic pneumococcal mastitis despite the absence of lactation. Previous studies suggested that a marked susceptibility to S. pneumoniae among patients with SLE may play an important role in the development of severe infections due to this organism. Clinicians should be aware of this susceptibility and the importance of pneumococcal vaccination for patients with SLE.