Direct Amoxicillin Challenge Without Preliminary Skin Testing for Pediatric Patients With Penicillin Allergy Labels

Abstract

To study the safety of direct provocation testing (DPT) without a preceding penicillin skin test (PST) in individuals considered low risk for immunoglobulin E (IgE)-mediated or non-IgE–mediated hypersensitivity on the basis of clinical history.A total of 54 pediatric (age: 1–17 years) patients at an academic-affiliated pediatric outpatient allergy clinic.This was a retrospective observational study. Patients were selected to undergo DPT without PST if considered low risk on the basis of clinical history. DPT was offered to patients with a history of nonspecific rash or urticaria. Patients were excluded if they had a history of (1) severe symptoms of respiratory distress, (2) vomiting, (3) angioedema, (4) mucosal involvement, (5) skin desquamation or blister formation, (6) target lesions, (7) new onset fever, (8) joint, kidney, or liver problems, and (9) required emergent treatment during the index reaction. A single dose of oral amoxicillin (20 mg/kg up to 500 mg) was given, and patients were observed for 60 minutes. Physical examination and vital signs were performed at baseline and every 15 minutes. If no reaction was noted, the penicillin allergy label was removed from the chart.A total of 54 patients previously labeled as penicillin allergic but considered low risk received DPT. One patient was excluded from analysis because of a diagnosis of anaphylaxis during the index reaction. The median age at index reaction was 2 years; the median age at DPT was 7 years. Nonspecific rash was reported by 57.4%, hives was reported by 38.9%, and emesis was reported by 5.5% during the index reaction. A total of 9.3% reported reaction within 1 hour of exposure, 42.6% reported reaction onset >1 hour after exposure, and 48.1% were unable to recall timing of index reaction. All 53 patients passed the DPT and had penicillin allergy removed from their chart. No adverse reactions were reported during the DPT, and there were no reports of delayed reactions.In this cohort of pediatric patients with penicillin allergy labels who were determined to be at low risk for immediate IgE-mediated hypersensitivity reactions, DPT without PST was found to be safe and effective in testing for penicillin allergy.It has been well established that the majority of patients labeled as penicillin allergic (up to 10% of US population) are not truly allergic. There has been a push to delabel patients, but this can involve several steps, including prick skin testing, intradermal testing, and an oral challenge. The time, cost, and invasiveness of this process may make this less attractive to children and their parents. This study supports other similar studies that, in low-risk patients, a direct oral challenge with observation is adequate for delabeling low-risk patients.