A rapid literature review of the impact of penicillin allergy on antibiotic resistance

Background Antimicrobial resistance (AMR) is caused by the use and misuse of antibiotics. AMR is a global health concern, to which penicillin allergy (penA) labels appear to contribute. Patients who have penA labels are treated with non-penicillin antibiotics and receive more antibiotics when compared with patients without penA. Although penA is common, after formal allergy assessments, >90% of people with a penA label are found not to be allergic; therefore, broad-spectrum antibiotics are being misused and overused unnecessarily in these patients. Antimicrobial stewardship policies now advocate assessment to identify and remove incorrect penA labels; however, there is limited evidence on whether rectifying incorrect penA labels results in less AMR. This review aimed to assess the association between AMR and antibiotic allergy labels.

Methods A comprehensive literature search using EMBASE and MEDLINE databases was conducted. Studies were included if they compared the presence of infection or colonization with an antimicrobial-resistant organism in participants with and without antibiotic allergy.

Results Thirty-three studies were included, and all the studies were observational in design and included a variety of patient groups. Eighteen studies compared AMR outcomes in participants with and without penA, and the rest investigated the impact of beta-lactam allergy or any antibiotic allergy on AMR outcomes. MRSA was the most investigated pathogen, and 11 of 13 studies showed that penA was associated with MRSA. PenA labels were also associated with vancomycin-resistant enterococci (three of five studies). There was limited evidence on the impact of penA on extended-spectrum beta-lactamase-producing Enterobacterales and resistant Streptococcus pneumoniae.

Conclusion The presence of penA labels is associated with antibiotic resistance in key pathogens in a wide variety of patient groups.