[Diagnostic evaluation of β-lactam antibiotic allergy].

Many patients report a β-lactam allergy or hypersensitivity without actually having this allergy. Targeted questioning, in combination with an accurate description of the nature of the symptoms, leads to rejection of a large number of these presumed allergies. In a suspected allergic reaction one has to distinguish between the potentially life-threatening, acute type I mediated allergy and delayed type IV skin reaction. The diagnostic evaluation of a suspected allergy is described in this article. Three cases are presented of a presumed allergic reaction to β-lactam antibiotics. Patient A was a 62-year-old woman with anaphylaxis triggered by amoxicillin/clavulanate who, after analysis, was advised to avoid all β-lactam antibiotics. Patient B was a 58-year-old man with anaphylaxis triggered by amoxicillin/clavulanate as a result of a selective allergy to amoxicillin. Patient C was a 50-year-old man who had had a possible reaction to a penicillin in his childhood. Analysis in an allergology department can be useful for further treatment.