Appropriate Antigen Concentrations and Timing of a Nasal Provocation Test

PURPOSE: We aimed to determine appropriate antigen concentrations and the right time to evaluate intranasal changes when performing a nasal provocation test (NPT). Also, we sought to analyze the diagnostic usefulness of individual nasal symptom and peak nasal inspiratory flow (PNIF). MATERIALS AND METHODS: We divided 46 patients into allergic rhinitis (AR) group (n=19) and a non-allergic rhinitis (NAR) group (n=27). We performed intranasal challenge with 100 AU/mL of Dermatophagoides pteronyssinus (DP) and measured changes in nasal symptoms [scored using the visual analogue scale (VAS)] and PNIF%. If the patient showed significant changes, VAS and PNIF were assessed again after another 15 minutes. In patients without significant changes, we administered 1000 AU/mL and measured changes in nasal symptoms and PNIF% after 15 and 30 minutes. RESULTS: Fifteen minutes after the 100 AU/mL challenge, the AR group showed more significant VAS changes in all nasal symptoms, total nasal symptom score (TNSS), and PNIF% change than the NAR group. Among the AR group, patients who did not respond to 100 AU/mL exhibited less significant differences relative to the NAR group, even after 1000 AU/mL challenge. Receiver operating characteristic curve analysis for VAS changes 15 minutes after 100 AU/mL challenge revealed that all nasal symptoms had area under the curve (AUC) values of ≥0.84 (p<0.001). TNSS change had an AUC value of 0.929 (p<0.001), while PNIF% change had an AUC value of 0.834. CONCLUSION: We could determine the optimal concentration (100 AU/mL), timing (15 minutes after challenge), and parameters (changes in TNSS and PNIF%) when performing NPT.