# The Clinical Impact of Antibiotic Allergy Labels on One‐Year Outcomes of Solid Organ Transplant Recipients

## TL;DR

This study shows that incorrect antibiotic allergy labels may lead to worse outcomes for organ transplant patients, including longer hospital stays and more infections.

## Contribution

The study is the first to analyze the impact of antibiotic allergy labels on post-transplant outcomes in a large cohort.

## Key findings

- Patients with a penicillin allergy label were more likely to test positive for Clostridioides difficile.
- Allergy-labeled patients used more alternative antibiotics and had longer hospital stays.
- Antibiotic allergy labels may be a modifiable risk factor for poor transplant outcomes.

## Abstract

Antibiotic allergy labels (AALs) are common and often incorrect. They have many potential impacts, including the use of broader‐spectrum antibiotics and suboptimal treatment of infections. The impact of inaccurate allergy labels on post‐transplant outcomes in the solid organ transplant population is not well described. We performed a retrospective review of 2,373 consecutive solid organ transplants occurring between 2011 and 2021, to analyze the impact of AALs, specifically penicillin, on outcomes in the first year after transplantation. Three hundred and twenty‐two patients (13.6%) had a penicillin allergy label, while 572 patients (24%) had at least one antibiotic allergy label. Patients with a penicillin allergy label were more likely to have a positive Clostridioides difficile test (p = 0.021). Patients with allergy labels also had significantly more utilization of alternative antimicrobial agents (p < 0.001) and longer inpatient hospital durations (p = 0.013). This study suggests that AALs may be a risk factor for inferior outcomes after solid organ transplantation and could represent a modifiable target for pre‐transplant optimization.