Penicillin Allergy Risk Characterization based on a measuring algorithm in a High Complexity Clinic in Medellín 2023-2024

Abstract

Background: Worldwide, 10-20% of the population report penicillin allergies, yet over 90% tolerate treatment, suggesting misdiagnosis due to the loss of IgE-mediated labels, requiring exploration of algorithms to predict low-risk allergies when diagnostic tests are unavailable. Objective: Characterize a population in a high-complexity Clinic in Medellín according to the risk of penicillin allergy indicated by the algorithm. Method: A single-center cross-sectional observational design was conducted in Clínica Medellín Sede Occidente. For four months, a survey based on PEN-FAST criteria, was developed. This algorithm predicts the risk of a positive penicillin allergy test. Therefore, patients were categorized based on it. Results: 48 patients were enrolled in the study. 31 patients were female (64.6%) and the median age was 70 years (IQR 12.5). Applying PEN-FAST score, patients were categorized as “Very Low Risk” with Score 0 (n=29, 60.4%). “Low risk” with Score 1 (n=12, 25%) and Score 2 (n=4, 8.3%). “Moderate Risk” with Score 3 (n=2, 4.2%) and “High Risk” with Score 5 (n=1, 2.1%). Conclusion: 93.7% of the patients, categorized as presenting “Very Low Risk” and “Low Risk” allergies, could eventually undergo oral challenges to be safely delabelled.