A 2-week-old infant presents with acute swelling in chest
A 2-week-old female presented with the sudden-onset of swelling and pain about the left breast. The history of the chief complaint revealed that the baby had been in good health until the day before admission when she was noted to be fussy. The left breast was noted to be larger than the right and had some erythema overlying it. By the next morning, the swelling was worse, and the baby had a fever of 101.5°F. She was taken to her primary provider who referred her for admission.
Her medical history included a normal pregnancy, labor and delivery with good prenatal care. Her first 2 weeks were that of a normal newborn. She had her first hepatitis B immunization in the nursery. Her family history is unremarkable, with no sick contacts, no travel, no trauma and no animal or insect exposure.
Images: Brien JH
Examination on admission revealed a normal-appearing 2-week-old female who was alert and active. The only positive finding was a swollen, painful and erythematous left breast as shown in Figures 1 and 2. Lab tests included a complete blood count with a WBC count of 23,000, with 87% granulocytes and a blood culture is pending.
What’s Your Diagnosis?
D.Group B streptococcus
The vast majority of neonatal mastitis is caused by S. aureus (C). This has been reviewed in numerous papers and online sites, all showing the same basic results. Uncommonly, the cause may be E. coli or other gram-negative bacilli, group A or group B strep, Enterococcus, sometimes mixed organisms; and Itzhak Brook, MD, MSc, would remind us that anaerobic organisms are often in the mix when properly cultured, even though their role remains in question. From a practical standpoint, since you cannot be sure as to the cause without culture results, empiric therapy should cover for staph, strep and gram-negative enterics.
Because a substantial number of S. aureus isolates are methicillin-resistant, it is prudent to use an effective MRSA antibiotic, such as vancomycin or linezolid (Zyvox, Pharmacia & Upjohn), along with an aminoglycoside or a third-generation cephalosporin. Obviously, if there is an abscess present, incision and drainage is indicated (Figures 3 and 4). If no abscess has formed, the infection may clear with antimicrobial therapy alone. If you practice in an area that has a low rate of clindamycin resistance to MRSA, in an older child who you can be relatively sure he or she is not septic, clindamycin may be a good empiric choice for the gram-positive coverage.
However, in any neonate or an older child who is septic, or with rapidly spreading cellulitis (Figures 5 and 6), I would still recommend vancomycin for empiric MRSA coverage. Continuation of therapy should be based on the culture and sensitivities, if possible.
For an abscess in a case that may involve the breast bud, where the port of entry is the nipple (Figures 7 and 8), it is advisable to have an experienced pediatric surgeon perform the incision and drainage, as damage to the breast bud can result in asymmetric development.
For a brief review of the full spectrum of mastitis, from birth through adolescence, I would recommend reading the paper written by Howard S. Faden, MD (Pediatr Infect Dis J. 2005;24;1113).
James H. Brien, DO, is a member of the Infectious Diseases in Children Editorial Board as well as Vice Chair for Education at The Children’s Hospital at Scott and White and is the Associate Professor of Pediatrics at Texas A&M University, College of Medicine, Temple, Texas. email: firstname.lastname@example.org. Disclosure: Dr. Brien reports no relevant financial disclosures.