2025 Southeastern Residency Conference

Title: Evaluation of Antibiotic Allergies in Patients Who Underwent a Desensitization to Determine if a Desensitization Would Still Be Clinically Indicated Today


Authors: Sydney C. Hunt, Joanna L. Stollings, Elizabeth J. Phillips, and Cosby A. Stone, Jr


Background: The creation of antibiotic allergy risk stratification tools has called into question whether many of the previously performed antibiotic desensitizations would still be clinically indicated today. The purpose of this study was to evaluate how many of the desensitizations performed due to penicillin, cephalosporin, and trimethoprim-sulfamethoxazole allergies could have been avoided if current risk stratification tools were utilized. 


Methods: A retrospective review was conducted to risk stratify the allergy labels of patients who underwent a penicillin, cephalosporin, or trimethoprim-sulfamethoxazole desensitization between January 1, 2016 to December 31, 2023 at a quaternary referral center. The primary outcome was the incidence of low-risk allergy labels based on validated risk stratification criteria. Secondary outcomes included desensitization success rate and possible cost avoidance had an oral challenge been performed instead of a desensitization for allergies meeting low-risk criteria. 


Results: A total of 25 desensitizations were included: 13 (52%) for a penicillin, 6 (24%) for a cephalosporin, and 6 (24%) for trimethoprim-sulfamethoxazole. The most common desensitization antibiotics were penicillin G (n = 7, 28%) and trimethoprim-sulfamethoxazole (n = 6, 24%), and the most common desensitization indication was bacteremia (n = 7, 28%). Overall, 7 (28%) allergies were categorized as being low-risk. Out of the 25 desensitizations, 23 (92%) were successfully completed. An estimated $73,711.68 in healthcare spending could have been avoided had an oral challenge been performed instead of a desensitization in the patients identified to have low-risk allergies.


Conclusions: Nearly on-third of the antibiotic desensitizations could have been avoided had current allergy risk stratification tools been utilized, leading to decreased healthcare costs and possible allergy de-labeling.