Evaluation of acoustic rhinometry in a nasal provocation test with allergen

Background: The objective was to validate acoustic rhinometry (AR) in a nas al challenge with allergen. Methods: Nasal response to allergen provocation was based on clinical and s ymptom scores, cross-sectional changes of the nasal mucosa as measured by A R with the Rhinoklack(R) system, and peak nasal inspiratory flow (PNIF), in atopic and nonatopic volunteers. Results: After allergen challenge, mean variation in minimal cross-sectiona l area (Delta MCA), as measured by AR, or in peak nasal inspiratory flow (D elta PNIF) in nonatopic volunteers, was -0.4 +/- 14.3% and 5.2 +/- 15.7%, r espectively, compared to baseline. This allowed the determination of a reac tion threshold of -29% for Delta MCA and of -26% for Delta PNIF. All but on e of the 30 atopic patients reached the AR reaction threshold, whereas all patients reached the PNIF reaction threshold. AR and PNIF closely correlate d with clinical and symptom scores for nasal congestion, since there was no significant difference at reaction threshold between both methods. Conclusions: In an allergen provocation test, AR appears to be as specific and sensitive as peak nasal inspiratory flow, with the advantage of being i ndependent of the patient's active cooperation. Discrepancies between both methods emphasize the role of nasal cavity anatomy in measuring nasal conge stion by AR.