<qa>  What was the total number of positive DPT to beta-lactams?investigators used 20 year experience in drug hypersensitivity to analyse retrospectively 171 patients accounting for 182 positive DPT to beta-lactams. Using survival analysis, they identified optimal doses to include in a data-driven protocol. This data-driven protocol will be applied to new prospective patients, to test its safety and benefits gain in time, hospital and patient benefits. 