Adding a second skin prick test reading and modifying the cut-off for beta-lactam-specific IgE enhances the sensitivity in the routine diagnostic workup for immediate beta-lactam hypersensitivity.

To overcome the low sensitivity of allergological tests, optimized reading times of the SPT of BL, a lower cut-off for in vitro detection of BL-specific IgE, and intradermal testing of Penicillin, Ampicillin, and BL-determinants contribute to overall sensitivity under real life conditions to diagnose immediate BL-hypersensitivity.