Due to the deleterious consequences of the false penicillin allergy label, all patients with a history compatible with an IgE-mediated reaction should be candidates for skin tests.(2)In the absence of a clinical history, skin tests should not be used as a screening method.(2)Patients with a family history of BL allergy, with no past history of reaction, do not need to be evaluated and can be given BL safely.(2). This evidence concerns the gene IGHE and allergic disease.