Abstract Background Although drug provocation test (DPT) is the gold standard for diagnosing beta‐lactam hypersensitivity (BLHS), its optimal duration in mild non‐immediate cutaneous reactions remains uncertain. We compared the outcomes and negative predictive values (NPVs) of one‐day versus five‐day DPT protocols in children with suspected mild non‐immediate cutaneous BLHS. Methods We retrospectively reviewed patients (<18 years) evaluated between 2016 and 2023 for mild nonimmediate cutaneous BLHS. Our unit used a five‐day extended DPT protocol in earlier years and subsequently adopted a one‐day protocol as routine practice. Therefore, protocol assignment was period‐based. Demographics, index reaction features, culprit drugs, DPT results, and real‐life re‐exposure outcomes were recorded. Repeat DPT, when performed, was used to adjudicate true allergy and estimate final NPV. Results A total of 173 children (median age 7 years; IQR 4–10.5; 50.9% female) were included. DPT was performed a median of 11 months after the index reaction. One‐day and five‐day protocols were applied in 92 (53.2%) and 81 (46.8%) patients, respectively. Objective reactions during DPT occurred in 10/173 (5.8%) (positive DPT). Among 163 patients with negative DPT, 95 (58.3%) reported re‐exposure; 10/95 (10.5%) experienced recurrent symptoms (6 one‐day vs. 4 five‐day; p = .768). Five underwent re‐provocation, with one confirmed positive. Final NPVs were 93.1% for the one‐day protocol and 98% for the five‐day protocol ( p = .333). Conclusion In this period‐based retrospective cohort of selected low‐risk children with mild non‐immediate cutaneous beta‐lactam allergy, one‐day and five‐day DPT protocols yielded comparable NPVs. A single‐day protocol appears feasible for appropriately selected patients, although prospective studies are warranted.
Yaytokgil et al. (Fri,) studied this question.