Assessing the Diagnostic Properties of a Graded Oral Provocation Challenge for the Diagnosis of Immediate and Nonimmediate Reactions to Amoxicillin in Children.

Importance: The diagnostic properties of a graded provocation challenge (PC) among children presenting with a rash in the course of amoxicillin treatment are currently unknown.

Objective: To assess the accuracy and the negative predictive value of the PC in a cohort of children referred with suspected allergy to amoxicillin.

Design, Setting, And Participants: A cohort study was conducted between March 1, 2012, and April 1, 2015, at the allergy clinic of the Montreal Children's Hospital, Montreal, Quebec, Canada.