Nasal Provocation Test is Useful for Discriminating Allergic, Nonallergic, and Local Allergic Rhinitis

BACKGROUND: No standard study protocol or diagnostic criteria based on nasal provocation test (NPT) and acoustic rhinometry (AR) results are available for allergic rhinitis. OBJECTIVE: We aimed to evaluate the usefulness of NPT plus AR for the differential diagnosis of local allergic rhinitis (LAR), allergic, and nonallergic rhinitis. METHODS: The medical records and skin-prick test (SPT) and NPT results of 262 patients with symptoms of chronic rhinitis were reviewed. Patients were allocated to one of three groups, that is, group A [n = 110, negative SPT result for Dermatophagoides pteronyssinus (DP)], group B (n = 53, weakly positive result), or group C (n = 99, strongly positive result). RESULTS: Twelve patients had a negative SPT result and provoked response in NPT [≥29% decrease of minimal cross-sectional area (MCA) after DP challenge] were diagnosed to have LAR. After DP challenge, group C showed significant aggravation of nasal symptoms and a greater decrease in acoustic parameters than groups A and B (p < 0.01). In patients with a more than or equal to 2 visual analog scale (VAS) increase in nasal obstruction (NO) after DP challenge, the criterion "a change of total nasal symptom score (TNSS) of more than or equal to 6.5" had 90.6% sensitivity and 77.4% specificity for the diagnosis of allergic rhinitis, whereas the diagnostic criterion "a total nasal volume (TNV) change at 30 minutes after DP challenge of more than or equal to 27.6%" had 73.4% sensitivity and 58.1% specificity. CONCLUSION: NPT with AR could be a useful tool for the differential diagnosis of allergic, nonallergic, and local allergic rhinitis.