Early testing and grade of the reaction are affecting factors of skin test positivity in β-Lactam allergies.

β-Lactams are the most widely used antibiotic family in the world. Nevertheless, they also stand out as the primary culprits for inducing drug hypersensitivity reactions (HSR). Between May 2018 and March 2023, patients with suspected HSRs to β-lactams, who underwent skin tests (ST), were retrospectively screened.