Appropriate Antigen Concentrations and Timing of a Nasal Provocation Test

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).

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.

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.

We could determine the optimal concentration (100 AU/mL), timing (15 minutes after challenge), and parameters (changes in TNSS and PNIF%) when performing NPT.