Specific Nasal Provocation Test with Dermatophagoides Pteronyssinus, Monitored by Acoustic Rhinometry, in Children with Rhinitis

Abstract

Background Currently, the diagnosis of allergic rhinitis (AR) is arrived at predominantly by a clinical history and by systemic sensitization tests, but specific nasal provocation tests (NPT) may establish a better direct correlation between etiologic surveyed allergens and nasal symptoms. Objectives To standardize the specific NPT with one of the most important house-dust mites, Dermatophagoides pteronyssinus, monitored by acoustic rhinometry, in children and adolescents, and propose a simplified specific NPT to improve its clinical applicability as a diagnostic tool. Methods Sixteen controls (group 1) and 17 patients with an AR diagnosis sensitized to D. pteronyssinus (group 2) underwent a specific NPT with D. pteronyssinus. The acoustic rhinometry was performed after instillation of 0.15 mL of increasing concentrations of D. pteronyssinus (5000 BU/mL). The test was finalized after (1) instillation of the final concentration of D. pteronyssinus, or (2) after a 20% or more reduction in the volume of the first 5 cm of the nasal cavity (V5), or (3) a score of >3 in the symptoms questionnaire (a score from 0 to 7). A simplified specific NPT with two concentrations was proposed and implemented in a group of 10 patients with AR (group 3). Results At the end of the specific NPT, the median (range) variation in V5 was -5.7% (-9 to 4%) in the control group and -22.8% (-24 to -20%) in group 2. None of the patients in the control group and 88% of group 2 (15/17) showed positive specific NPT results. The simplified specific NPT triggered a positive response in 80% of patients in group 3, with median (range) V5 variation of -30.4% (-36 to -20%). Conclusion This protocol has been proven safe and useful to differentiate between children and adolescents with AR and controls. Concentrations of 1:1000 and 1:100 D. pteronyssinus were the best for use in simplified specific NPT, which made it simpler and faster, and expanded its clinical applicability.