Incidence of bloodstream infections and predictive value of qualitative and quantitative skin cultures of patients with overlap syndrome or toxic epidermal necrolysis: a retrospective observational cohort study of 98 cases

Abstract Background Epidermal necrolysis (EN) involving ≥10% body surface area (BSA) is often complicated by bacterial infections. Objective To describe the epidemiology of bloodstream infections (BSIs) in EN involving a BSA≥10% and the diagnostic performances of skin cultures for predicting the pathogen(s) isolated from BSIs. Methods This retrospective single-center observational study was conducted between 2009 and 2017. All patients referred at the acute phase for EN involving a BSA≥10% were included. All clinical and bacteriological relevant data were collected (blood and skin cultures results, number, severity and time of BSI). Sensitivity, specificity, and predictive values of skin cultures and impact of the bacterial inoculum were investigated. Results Out of 98 patients, 46 (46.9%) had ≥1 BSI episode during the hospital stay [ Staphylococcus aureus (n=17, 36.9%) and Pseudomonas aeruginosa (n=17, 36.9%)]. Skin cultures were concordant with blood cultures in 32 cases (71.1%). The positive and negative predictive values were 57.7% and 89.4% for S. aureus and 50.0% and 80.9% for P. aeruginosa , respectively. BSI increased with cutaneous inoculum of S. aureus . Limitations Retrospective monocentric design and few total number of BSI. Conclusion Skin cultures for S. aureus and P. aeruginosa may help in predicting the pathogens involved in bloodstream infections.