The following is the summary of “Penicillin Allergy Label Is Associated With Worse Clinical Outcomes in Bacterial Pneumonia” published in the December 2022 issue of Allergy and Clinical Immunology by Kaminsky, et al.

If you or a loved one has bacterial pneumonia, your doctor should start with a course of penicillins (PCN) or another carbapenem. Delaying antimicrobial treatment due to a PCN allergy label and using potentially ineffective alternative antibiotic regimens increases the risk of treatment failure and adverse drug reactions. Researchers set out to learn more about how being diagnosed with an allergy to PCNs affects patients’ chances of recovering from a bacterial pneumonia.

This retrospective cohort study employed TriNetX, a web-based platform for population cohort research to distinguish between individuals with and without a PCN allergy designation. Baseline characteristics and prevalence rates of chronic diseases were used to pair cohorts. Risks for hospitalization, ARF, intubation, intensive care unit admission, and death were compared during a 30-day period. The usage of antibiotics and the potential for their side effects were investigated. Each cohort included 68,748 patients after the matching process was complete.

It was found that patients with a PCN allergy label were more likely to be hospitalized (risk ratio [RR], 1.23; 95% CI, 1.22-1.24), experience acute respiratory failure (RR, 1.14; 95% CI, 1.12-1.15), require intubation (RR, 1.18; 95% CI, 1.13-1.22), require a higher level of care (RR, 1.11; 95% CI, 1.08-1.14), and die (RR, 1. When compared to patients without a PCN allergy label, those with a PCN allergy label used fewer PCNs and cephalosporins and more antibiotics from other classes. A PCN allergy label was also linked to a higher chance of experiencing negative medication responses. The diagnosis of PCN allergy is linked to poorer clinical outcomes in bacterial pneumonia, suggesting the need for preventative measures.