Discussion
In this cohort of pediatric patients hospitalized for ABSSSI, prescription of antibiotics with broad Gram-negative activity or treatment for longer than 10 days occurred in two-thirds of cases. Admission through an emergency department and primary management by a medical (vs. surgical) service were associated with broad Gram-negative therapy or treatment for longer than 10 days.
Since the emergence of CA-MRSA, few studies have evaluated antibiotic utilization in pediatric patients hospitalized with ABSSSI. In one such study of children admitted to US hospitals for S. aureus skin infections between 1999 and 2008, Herigon et al demonstrated that use of clindamycin increased 3-fold whereas use of β-lactams markedly declined. However, this study was limited to S. aureus infections and only reported the use of oxacillin/nafcillin, cefazolin and antibiotics with activity against MRSA. In Canada, where the incidence of CA-MRSA was low, Kam et al demonstrated frequent use of first-generation cephalosporins and other anti-staphylococcal penicillins, with less frequent use of clindamycin. Neither of these studies reported the duration of therapy. Our study therefore adds to the prior literature through the inclusion of various types of ABSSSI, providing more detailed data regarding antibiotic selection and duration of therapy and identifying factors that influence prescribing patterns.
Similar to the findings by Herigon et al, clindamycin was the most commonly prescribed antibiotic in our study, with less frequent use of vancomycin. However, we also observed frequent use of agents with broad Gram-negative activity such as higher generation cephalosporins (18% of cases) and β-lactam/β-lactamase inhibitor combinations (15% of cases). In cases where antibiotics with broad Gram-negative activity were prescribed, they accounted for nearly one-third of all antibiotic days demonstrating that exposure to these agents was not trivial. This is particularly notable in that Gram-negative organisms were identified in only 5 cases. The fact that of these 5 cases, 4 involved polymicrobial growth, 3 involved cultures of wounds and antibiotics with Gram-negative activity were administered in only 1 suggests that these Gram-negative organisms may not have been clinically relevant. Regardless, our findings do not support the routine use of antibiotics with broad Gram-negative activity and suggest the need to better educate pediatric providers regarding the microbiology of ABSSSI and to develop interventions to promote the appropriate spectrum of therapy.
Several pediatric studies have suggested that adjunctive antibiotic therapy may not be necessary after abscess drainage in outpatients. To the best of our knowledge, there have been no clinical trials evaluating the appropriate duration of antibiotic therapy in children hospitalized with cutaneous abscess or other types of ABSSSI. We found that treatment durations were relatively prolonged (median 11 days) in all 3 types of ABSSSI, perhaps reflecting the lack of data to promote shorter durations of therapy. In adults, the available evidence suggests that courses of <7 days are as effective as longer courses. Although it is not known whether these findings can be extrapolated to children, shorter courses may be adequate because children with ABSSSI have relatively few comorbid conditions and a low rate of clinical failure. Shortening the duration of therapy therefore represents an attractive option to reduce unnecessary antibiotic exposure in children. Our findings underscore the need to include children in future randomized trials to delineate the shortest effective duration of therapy for ABSSSI.
We found it noteworthy that not a single pediatric case involved infectious diseases consultation, a sharp contrast to adult cases where infectious diseases consultation is common. This suggests that the vast majority of pediatric cases were uncomplicated and responded rapidly to treatment, supporting the assertion that antibiotic use might be safely reduced in this population. A comanagement model between primary and infectious diseases services may represent 1 method to optimize antibiotic use and outcomes for ABSSSI, as has been shown with other infectious diseases. Antimicrobial stewardship interventions are another approach to improve antibiotic use and have been shown to impact prescribing practices in adults hospitalized with ABSSSI. The results of our logistic regression models suggest that children admitted through emergency departments, those with head or neck involvement and those treated by nonsurgical services may be at increased risk for exposure to antibiotics with Gram-negative activity or prolonged treatment courses and may warrant particular attention as stewardship interventions are developed. Furthermore, because most of the antibiotic therapy is completed after hospital discharge, review of prescriptions written at discharge may improve antibiotic selection and reduce treatment durations.
In addition to the limitations previously outlined, this study has at least 4 other limitations. First, this is a secondary analysis from a larger cohort study that was not specifically designed to evaluate antibiotic utilization in pediatric cases. Despite this, the findings suggest there may be opportunity to reduce antibiotic use in children hospitalized with ABSSSI. Second, the sample size was relatively small which limited the statistical power of the logistic regression models. Furthermore, because of the retrospective nature of the study, the results of the regression models cannot be assumed to represent causation. Third, many cases were reported from a freestanding children's hospital, potentially limiting the generalizability of the findings. Finally, as discussed above, no studies have been performed to delineate the appropriate duration of therapy in children hospitalized with ABSSSI. Our endpoint concerning duration of therapy was therefore based on data from adult studies.
In summary, pediatric patients hospitalized with ABSSSI are frequently exposed to antibiotics with a broad spectrum of Gram-negative activity or prolonged treatment durations. Antibiotic use in such cases could potentially be reduced through prescription of shorter durations of antibiotics with Gram-positive activity, although the greatest opportunity appears to lie in reducing treatment durations. These findings highlight the need for studies to determine the shortest effective duration of therapy in pediatric patients hospitalized with ABSSSI.