Taking a Rational Approach to a Reported Antibiotic Allergy.

Up to 10% of hospitalized patients have an antibiotic allergy label in their medical file, most frequently concerning penicillins. However, the vast majority of reported allergies to antibiotics does not represent a "true" allergy but are due to drug intolerance, idiosyncratic reactions or symptoms of the concurrent infectious disease. Since antibiotic allergy labels result in deviation from first-choice antimicrobial therapy, tackling the issue of incorrect antibiotic allergy labelling, already at young age, is a core element of antibiotic stewardship. In this article, we describe the structured approach to the patient with a presumed antibiotic allergy with emphasis on key elements of allergy-specific history taking and the limited risk of cross-allergic reactions between beta-lactam subclasses.