Published online: November 23, 2017
Drug provocation test (DPT) is considered as the gold standard to diagnose drug allergy and is particularly important in the diagnosis of benign non-immediate betalactams (BL) allergy in children. However, DPT is not standardized, and there is a large variety of protocols currently used among various countries. Particularly, the duration (number of days) of the DPT to diagnose non-immediate reactions is still a matter of debate. In addition, the natural history of patients with a confirmed benign non-immediate allergy to BL remains unknown.
In a recently published article in The Journal of Allergy and Clinical Immunology: in Practice, Tonson la Tour and colleagues evaluated the natural history of BL allergy in children by performing a follow-up DPT 3 years after an initial positive DPT. Moreover, in case of negative initial DPT, a questionnaire was sent to patients to assess tolerance of a subsequent treatment with the incriminated BL, in order to determine the diagnostic value of a DPT using a 2-days protocol.
Among the 18 children with an initial positive DPT recruited from 2006 to 2011 at Geneva University Hospital, 16 patients (89%) had a negative follow-up DPT and 2 developed a benign rash. Among those 16 children, 11 tolerated a subsequent treatment with the incriminated antibiotic without any reaction, suggesting natural antibiotic tolerance acquisition. Among the 172 patients with an initial negative DPT using a 2-days protocol, 122 patients (71%) were treated again with the incriminated BL and only 4 (3.3%) reported an isolated generalized maculopapular exanthema. Based on these results, the negative predictive value of a 2-days DPT (96.7%) was excellent in our population.
The report of Tonson la Tour and colleagues shows that the vast majority of children with benign BL allergy become tolerant after several years and that a follow-up DPT is safe and useful to assess tolerance acquisition in this population. In addition, this study supports the use of a short DPT protocol (2 days), with a favorable benefit-risk balance. Using this protocol will lead to decreasing the number of children falsely labeled as “penicillin-allergic,” associated with decreased antibiotic resistance, and direct impact on patients’ health.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.