Proposed epidemiological case definition for serious skin infection in children.

AIM: Researching the rising incidence of serious skin infections in children is limited by the lack of a consistent and valid case definition. We aimed to develop and evaluate a good quality case definition, for use in future research and surveillance of these infections.
METHODS: We tested the validity of the existing case definition, and then of 11 proposed alternative definitions, by assessing their screening performance when applied to a population of paediatric skin infection cases identified by a chart review of 4 years of admissions to a New Zealand hospital.
RESULTS: Previous studies have largely used definitions based on the International Classification of Diseases skin infection subchapter. This definition is highly specific (100%) but poorly sensitive (61%); it fails to capture skin infections of atypical anatomical sites, those secondary to primary skin disease and trauma, and those recorded as additional diagnoses. Including these groups produced a new case definition with 98.9% sensitivity and 98.8% specificity.
CONCLUSION: Previous analyses of serious skin infection in children have underestimated the true burden of disease. Using this proposed broader case definition should allow future researchers to produce more valid and comparable estimates of the true burden of these important and increasing infections.