Penicillin allergy de-labeling: Adaptation of risk stratification tool for patients and families To the Editor,Penicillin allergy is a common drug allergy diagnosis reported in 10% of the population . However, over 90% of patients are found to be non-allergic upon allergist assessment . This discrepancy is often due to misclassification of symptoms in patients who receive penicillin-based antibiotics . Erroneous penicillin allergy labeling is a public health problem associated with use of alternative antibiotics that are generally less effective, more toxic, or more costly .We previously developed and validated a decision support tool to assess penicillin allergy risk. It has been adapted into a mobile version that can be administered by various healthcare professionals. The goal of this study is to adapt the existing mobile tool into a patient-friendly version and validate it against the gold standard (allergist) assessment. If effective, this will empower lay individuals to conduct their own assessments and gain knowledge about levels of allergy risk. With this knowledge, patients can better advocate for themselves, potentially increasing efficiency of healthcare visits and reducing wait times for subspecialist assessments.Between April and September 2023, 127 pediatric patients ages 6 months to 17 years and pregnant adults referred to the BC Children’s and Women’s Hospital for assessment of penicillin allergy were invited to use the patient tool to complete a self-assessment, resulting in the assignment of a risk category: (1) allergic; (2) high risk, possible allergy; (3) low risk, unlikely to be allergic; and (4) not allergic. Informed consent was obtained. 84 patients completed the self-assessment prior to their appointments and at their appointments the allergist conducted an assessment using the validated tool. Construct validity (ability of the patient tool to measure penicillin allergy risk) was captured by comparing the patient-oriented tool and the allergist assessment using intra-class correlation (ICC), where ICC = 0 (no agreement) to 1 (excellent agreement).The primary outcome was the reliability of the patient tool to measure penicillin allergy risk compared with the gold standard allergist assessment. The secondary outcomes were to monitor potential safety risks and determine patient satisfaction with the tool.The patient tool and allergist assessment demonstrated agreement in 57/84 (67.9%, Figure 1) assessments. Of these, 45/57 (78.9%) patients were stratified as low risk or not allergic by both the patient and the allergist. 33 of these 45 patients have undergone an oral penicillin challenge; 33/33 (100%) passed, de-labeling the allergy.
