Emergency department treatment failures for skin infections in the era of community-acquired methicillin-resistant staphylococcus aureus

Background: Despite rapidly increasing incidence of skin and soft tissue infections (SSTIs) presenting to emergency departments (EDs), outcome data for these infections are limited. Methods: This is a retrospective cohort study of children with culture-positive SSTI, managed as outpatients from a large pediatric ED in the year 2006. The primary outcome was treatment failure, defined as presence of 1 or more of the following: (1) change in antibiotic owing to poor clinical response, (2) subsequent incision and drainage, or (3) hospitalization. Demographics, isolated pathogens, and therapeutics were also assessed. To accurately capture the outcome of interest, only children who are observed in the hospital-based primary care network were included. Results: Among 148 eligible subjects, there were 158 SSTIs including 131 abscesses, 19 folliculitis, and 8 cellulitis. Mean age was 9.1 ± 6.2 years, 41.2% were male, and 94.6% were African American. Methicillin-resistant Staphylococcus aureus (MRSA) was isolated in 66%, methicillin-sensitive S. aureus (MSSA) in 21%, and others in 13%. Outcome data were available for 144 subjects (97.2%). Emergency department treatment failure rate was 7.6% (95% confidence interval, 3.3%-12.0%); 10 of 11 failures were abscesses. Only S. aureus produced treatment failure and occurred in 13.3% of MSSA and 6.4% MRSA infections (odds ratio, 1.9; 95% CI, 0.5-7.1). An antibiotic to which the organism was sensitive was prescribed for 9 (81.8%) of 11 treatment failures and did not differ between MRSA and MSSA; appropriate antibiotics were used in 91.5% of treatment successes. Conclusions: The rate of ED treatment failure for SSTI is low and is more likely to occur with S. aureus infection, irrespective of methicillin resistance or appropriate antibiotic therapy.