A new study proposes that intensive care unit (ICU)-led antibiotic allergy assessment and testing programmes are feasible, effective and safe, even without specialised immunology and allergy services.
The findings support expanding ICU-led antibiotic allergy assessment and testing, which could reduce the unnecessary use of alternative antibiotics and improve patient outcomes.
Many patients who receive antibiotics in the ICU will have an incorrectly documented allergy to them, most commonly related to penicillin. Mislabelling issues can lead to using less effective or broader-spectrum antibiotics, which can cause drug-resistant bacteria, increased Clostridium difficile infections, and longer hospital stays.
To determine whether ICU staff could undertake allergy assessment and testing programmes independently, the researchers set out to verify allergy labels and check whether patients were allergic to antibiotics, particularly penicillin.
Between September 2022 and September 2023, the ICU ward at St James’s Hospital in Dublin, Ireland, admitted 78 patients with a documented antibiotic allergy label. The researchers divided the 62 patients eligible for the study into four risk groups: non-immune mediated reactions, low-, intermediate-, and high-risk allergies.
Non-immune mediated reactions were directly de-labelled. Low-risk allergies underwent direct drug provocation testing and intermediate-risk cases received skin testing followed by drug provocation and high-risk allergies were confirmed without testing.
The researchers found that many patients had outdated or incorrect allergy information, leading clinicians to avoid using their first-choice medication, such as penicillin, and instead use less effective and often more expensive alternatives.
Most patients (94%) with non-immune, low- or intermediate-risk allergies were de-labelled. A total of 13 patients (21%) were risk-assessed as having non-immune-mediated reactions and were directly de-labelled.
Some 38 patients (61%) were risk evaluated as having low- or intermediate-risk allergies, and antibiotic allergy testing was performed on 35 of these patients. High-risk allergies were confirmed in 11 patients (18%). The researchers reported no adverse events during testing.
Antibiotic allergy assessment and testing were successful in critically ill patients, and drug provocation testing without prior skin testing was safe in patients with low-risk allergies.
The study highlighted how ICU-led antibiotic allergy assessments and testing can optimise antibiotic selection and mitigate the risks of antimicrobial resistance.
The researchers suggested that such testing should be standard practice in ICU units worldwide and would be beneficial in wards with limited resources and no immunology specialists.
This adds to previous research published last year by the University of Birmingham that found de-labelling low-risk penicillin allergy patients outside specialist clinics to be ‘potentially achievable’.
Reference
Alamin, S et al. Antibiotic allergy de-labeling in the intensive care unit: The prospective ADE-ICU study. Journal of Critical Care 2025; Feb: DOI: 10.1016/j.jcrc.2024.154977.
