Acoustic Rhinometry in Nasal Provocation Tests in Children and Adolescents

Objectives: To standardize acoustic rhinometry (AR) in nasal provocation tests (NPTs) with histamine in children and adolescents. Patients and Methods: We performed a cross-sectional validation to compare AR with anterior active rhinomanometry (AAR) during histamine NPT in 20 children and adolescents with persistent allergic rhinitis and 20 controls. Changes in total nasal resistance (AAR) were compared with changes in nasal volume in the first 5 cm (V5). Results: Compared with controls, patients with rhinitis had significantly higher mean total nasal resistance (0.34 Pa/cm(3)/s vs 0.21 Pa/cm(3)/s; P=.01) and lower mean V5 values (8.20 cm(3) vs 9.24 cm(3); P=.04) at baseline. The mean histamine concentration necessary to increase total nasal resistance by at least 100% was significantly lower in the rhinitis group than in the control group (0.72 mg/mL vs 2.4 mg/mL; P<.001). At the end of the NPT a mean increase of 126% in total nasal resistance and a mean decrease of 24.3% in V5 were observed in the rhinitis group. When compared with the AAR criteria, the highest sensitivity and specificity values were observed for a cutoff represented by a 19%-21% drop in V5. Conclusions: We found AR to be a feasible and sensitive tool for monitoring nasal response in children and adolescents undergoing histamine NPT. The best AR cutoff for ending the NPT was a 19%-21% drop in V5.