(503) Project PEN-FAST: Unmasking Allergies for Antibiotic Optimization

Objective: Assess the clinical impact of the PEN-FAST scoring tool within the obstetric group at a single academic medical center.

Study Design: This was a single center, retrospective, observational analysis of pregnant patients with a documented penicillin or cephalosporin allergy admitted to the birthing center between January and June 2023 who also received an antibiotic and/or had a PEN-FAST assessment completed.

Results: Sixty-four patients were included in the final analysis. Within the analyzed cohort, 53 (83%) of patients had a PEN-FAST assessment completed, 17 (32%) of whom had their penicillin allergy successfully de-labeled. Among patients with a penicillin allergy that was not de-labeled, 11 (31%) had a score or assessment indicating that a cephalosporin could be safely utilized, nine (25%) had a score of three or greater, indicating a non-beta lactam antibiotic should be employed, and seven (19%) patients declined de-labeling despite a PEN-FAST assessment indicating a low-risk penicillin allergy, and the remaining nine (25%) were either referred for further workup or not de-labeled due to other reasons. Of the patients who had a PEN-FAST assessment completed, 38 (72%) received a penicillin or cephalosporin and 15 (28%) received alternate or no antibiotics. Comparatively, of the 11 patients who did not have a PEN-FAST assessment completed, two (18%) received a penicillin or cephalosporin and nine (82%) received an alternate antibiotic. Among all patients analyzed, there were no identified adverse reactions to penicillins or cephalosporins.



Conclusion: Within our cohort, 32% of patients had their penicillin allergy successfully de-labeled using the PEN-FAST assessment. Even without de-labeling due to factors such as patient preference, utilization of the PEN-FAST assessment resulted in a dramatic increase in the use of pencillins and cephalosporins as opposed to alternate antibiotics. Overall, the PEN-FAST assessment was an efficient and safe tool for stratifying risk of penicillin allergies within this cohort of patients and did impact antibiotic choice for the patients included.