Changing Incidence of Methicillin-Resistant Staphylococcus aureus Skin Abscesses in a Pediatric Emergency Department

Abstract

OBJECTIVES: The primary objective of this study was to determine the etiology of skin abscesses in a pediatric emergency department (ED) during a 4-year period and to determine whether the incidence of methicillin-resistant Staphylococcus aureus (MRSA) skin abscesses has increased. The secondary objective was to characterize MRSA infections by antibiotic susceptibility during the same period. METHODS: A retrospective chart review examining all cases of skin abscess requiring an incision and drainage seen in a free-standing children's hospital ED from January 1, 2003, to December 30, 2006, was performed. Demographic and clinical data were abstracted from the medical records. Culture results, including sensitivities to antibiotics, were obtained to identify how many of these patients had MRSA. RESULTS: The charts of 442 children were analyzed, and 274 (62%) had MRSA isolated during the entire study period. In 2003, 36.2% of all drained abscesses were caused by MRSA, and by 2006, this increased to 66.5% (P < 0.001). Methicillin-resistant S. aureus isolates were sensitive to trimethoprim-sulfamethoxazole in 99% of the cases, but the sensitivity of MRSA to clindamycin decreased from 96% in 2003 to 87% by 2006. All isolates remain sensitive to rifampin, vancomycin, and gentamicin. CONCLUSIONS: The incidence of MRSA skin abscesses has increased in the pediatric ED population and now accounts for greater than 50% of all abscesses. If antimicrobial therapy is indicated for the treatment of these abscesses, cultures should be obtained, and antibiotics should be chosen to provide MRSA coverage.