Long-Term Follow-Up After Penicillin Allergy Delabeling in Ambulatory Patients

Background: Unverified penicillin allergy label has negative health implications. To address this, several delabeling methods have been proposed. Objectives: To appraise the long-term outcomes of the penicillin allergy evaluation in ambulatory patients, focusing on subsequent use of penicillins in individuals found not allergic. A secondary objective was to examine the consistency between the evaluation's recommendations and the allergy label. Methods: A retrospective medical records review and phone survey were carried out in ambulatory patients who were evaluated for suspected penicillin allergy in our allergy unit. Patients with an uneventful oral challenge test (OCT) were interviewed regarding subsequent use of penicillins. Medical records were examined for antibiotic prescriptions and purchases. The records were also investigated for existing/erased penicillin allergy label and its consistency with the allergy evaluation. Results: Six hundred thirty-nine patients with an uneventful OCT were available for the survey. During a 56-month follow-up, 70% (447 patients) had used penicillins at least once. One hundred ninety-two patients (30%) did not use penicillins. The main reason for not using penicillins was lack of a clinical indication. Three hundred thirty-five patients (51.22%) carried a penicillin allergy label in their electronic medical file in spite of an uneventful OCT. Conclusions: Penicillin allergy annulling via OCT has proven to be effective. Most of the patients who previously avoided penicillins have reused penicillins safely.