[Neonatal mastitis: 12 years of experience]

Mastitis is an inflammation of the breast that may be accompanied by an infectious process. The most frequently isolated bacteria is Staphylococcus aureus. The vast majority of cases are unilateral and have good prognosis. The aim of this study was to characterize neonatal infectious mastitis diagnosed and treated in a tertiary hospital.

Retrospective analysis of all clinical records of infants < 2 months of age diagnosed with neonatal mastitis between January 2000 and June 2011. Clinical, laboratory and microbiological data, as well as treatment and outcome, were analyzed.

Twenty-one children met inclusion criteria, fourteen were female. The median age at diagnosis was 21 days. Mastitis was unilateral in 19 cases. The most frequent signs were swelling and erythema. Fever was documented in three children. The bacteria identified in the breast exudate was methicillin susceptible Staphylococcus aureus in six cases and methicillin-resistant Staphylococcus aureus in three cases. The most frequently used antibiotic was flucloxacillin, with a median duration of ten days. There were 11 cases of breast abscess, ten drained surgically and one with spontaneous drainage. In two cases with isolation of methicillin-resistant Staphylococcus aureus there was a good outcome with surgical drainage, despite treatment with a ß-lactam. There were no other complications.

As described in literature, in this series neonatal mastitis was more frequent in girls and unilateral. The development of breast abscess occurred in half of the cases. The only bacteria isolated was Staphylococcus aureus (9 cases), methicillin resistant in three cases, two of which with good outcome with surgical drainage, despite treatment with a ß-lactam.