The diagnosis of non-life-threatening immediate penicillin allergy should not rest upon low sIgE results between 0.10 kUA/L and 0.35 kUA/L in isolation

Abstract

Uncertainties remain about the optimal decision threshold for sIgE results in patients with a penicillin allergy. Historically, the cut-off for sIgE results has been set at 0.35 kUA/L, but recently it has been suggested that lowering the threshold to 0.10 kUA/L could improve diagnosis. This study aims to assess the clinical relevance of low sIgE values between 0.10 and 0.35 kUA/L for penicillins in patients who experienced immediate reactions to amoxicillin (AmX), amoxicillin-clavulanic acid (AmC), or a non-specified penicillin and demonstrating negative skin testing.