Cold dry air provocation is a reliable diagnostic tool in nonallergic rhinitis

No diagnostic criteria have been available for nonallergic rhinitis (NAR) to this point in time. Nonspecific nasal hyperresponsiveness (NHR), which could be efficiently assessed by cold dry air (CDA) provocation, is an essential feature of NAR. Thus, this study's purpose was to assess the diagnostic value of CDA provocation in discriminating patients with NAR from healthy individuals.

CDA provocation was performed among 13 healthy volunteers and 15 NAR patients. Nasal symptom scores, total nasal volume (TNV), total nasal resistance (TNR) and minimal cross-sectional area (MCA) were checked before and after the provocation. Non-paramedic tests and receiver operating characteristic (ROC) curves were used in data evaluation.

Subjects in the NAR group showed significantly larger changes after CDA provocation in total nasal symptom score (TNSS) and nasal congestion score compared with healthy volunteers, while the change for rhinorrhea score was comparable. Similarly, significant differences in the change of MCA and TNV were witnessed between both groups. We built a predictive model for NAR, Y = minus 3.285 plus 2.520 times the difference of TNR (%) plus 1.027 times the difference of TNSS minus 6.542 times the difference of TNV (%), whose area under curve was 0.93. According to the Youden index, the criterion was set to be Y greater than -0.52, when its sensitivity and specificity were 93.3% and 84.6%, respectively.

With superior patient-friendliness, safety and efficacy, we successfully performed the first NAR predictive model in the Chinese population, based on a short protocol of CDA provocation, by means of both subjective scores and objective tests (acoustic rhinometry and rhinomanometry).