Acquisition of Resistant Enterobacteria During Oral Drug Challenge for Betalactams in Children

Direct drug provocation testing, without prior skin or in vitro testing, is the reference standard for confirming the diagnosis of drug hypersensitivity reactions in children reporting mild and delayed-onset reactions. However, optimal protocol(s) have not been standardized. Although a 2-days' provocation testing protocol is effective, increasing its duration (up to 14 days) may improve its diagnosis performance without increasing the risk of severe reactions. However, a prolonged provocation testing could increase the risk of emergence of bacterial resistances in the digestive flora. Longer duration could be associated with the emergence of extended-spectrum betalactamase producing enterobacteria. However, this point has never been confirmed. The study will include children (0-18 years); referring for histories of mild and delayed-onset reactions to betalactams. drug provocation testing will be performed with the suspected BLs in our department, as in clinical practice. Two groups of patients will be compared: a group performing short provocation testing (arbitrary defined as lasting 1 to 4 days) and a group with prolonged drug provocation testing (arbitrary defined as lasting 5-8 days). A rectal swab will be collected for each patient before the provocation testing, a second one at the end of the provocation testing. Each sample will be analyzed to detect the presence extended-spectrum betalactamase -producing enterobacteria.