[Reevaluation of penicillin allergy labeling, appropriate use of β-lactam antibiotics, and multidrug resistance].

Approximately 10% of the population reports being allergic to penicillin, although usually less than 1% really are. In addition, people with proven allergies over the years may no longer be allergic. Unconfirmed penicillin allergy and use of alternative antimicrobials result in more treatment failures; more severe adverse effects. Higher cost; longer hospitalizations; increase in the emergence of multi-resistant germs associated with health care. The risk of cross-allergy between β-lactam groups is usually <2%, depending on the similarity of the side chains, so prescribing antibiotics from another β-lactam group is safe as long as we take into account the structural similarity. Incorporating the reassessment of allergies and improving the prescription of antibiotics in this group of patients reduces the generation and spread of multi-resistant germs, and the associated costs. There are simple methods and specific scores that simplify allergy reassessment. The objective of this review is to expose how, through these methods, the delabeling of patients erroneously labeled as allergic and the safe prescription of β-lactam antibiotics can be achieved.