Antibiotic allergy de-labeling in the intensive care unit: The prospective ADE-ICU study

Critically ill patients in the intensive care unit (ICU) are frequently prescribed antibiotics, with many reporting an antibiotic allergy label, predominantly to penicillin. Mislabeling contributes to suboptimal antibiotic use, increasing multidrug-resistant organisms and Clostridium difficile infections, and increased hospital length of stay. This prospective study implemented an antibiotic allergy assessment and testing program in the ICU, independently of clinical immunology/allergy services.

Trained ICU staff prospectively identified and risk assessed eligible patients as having a non-immune mediated drug reaction, or a low, intermediate or high risk antibiotic allergy. Non-immune mediated reactions were directly de-labeled. Low-risk allergies underwent direct drug provocation testing, while intermediate-risk allergies included skin testing followed by drug provocation testing. High-risk allergies were confirmed without testing.

Of 71 eligible patients, 62 underwent assessment. Antibiotic allergy de-labeling occurred in 48 of 51 patients (94 %) with a non-immune, low or intermediate risk allergy. High risk allergies were confirmed in 11 patients (18 %). The study resulted in increased penicillin use and decreased broad-spectrum antibiotic use. No adverse events occurred from testing.

This study shows the feasibility of ICU led antibiotic allergy assessment and testing, highlighting a potential model for implementation in settings lacking immunology/allergy services.