Chronic rhinitis is a common chronic nasal mucosal inflammatory disease. Its clinical symptoms and severity are diverse, mainly including allergic rhinitis, local allergic rhinitis, non-allergic rhinitis with hypereosinophilia syndrome and idiopathic rhinitis. All kinds of rhinitis have clinical symptoms such as nasal congestion, runny nose, sneezing, and nasal itching, but the causes are different. At present, the diagnosis of idiopathic rhinitis (IR) is based on detailed medical history and negative allergen test results, which is a diagnosis of exclusion. According to the position paper of the European Academy of Allergy and Clinical Immunology (EAACI), nasal hyperresponsiveness is an abnormal reaction of the nasal mucosa to stimuli that most people can tolerate. One of the distinguishing features of non-allergic rhinitis. cold dry air (CDA) nasal provocation test has been proved to be a good, safe and tolerable test for nasal hyperresponsiveness, with superior sensitivity and specificity. At present, there is still a lack of clear diagnostic criteria for IR. Therefore, optimizing CDA nasal provocation test, determining the diagnostic efficacy of CDA nasal provocation test with different parameters for IR, and initially constructing an IR diagnostic model can provide more comprehensive guidance for clinical diagnosis and treatment, which has important clinical significance.

The visual analogue scale (VAS) of nasal symptoms, rhinoconjunctivitis quality of life questionnaire (RQLQ), total nasal symptom score (TNSS), total nasal volume (TNV), minimum cross-sectional area (MCA), peak inspiratory flow (PNIF), and total nasal resistance (TNR) at 75Pa were recorded before and after nasal ventilation function test and CDA nasal provocation test.

Inclusion Criteria:

• IR patients: 1. Aged 18-65 years; 2. The presence of symptoms of rhinitis for more than 2 years, often triggered by non-specific stimuli, serum and nasal secretion allergen specific IgE test negative, nasal endoscopy examination ruled out severe anatomical disease and sinusitis with or without polyps, nasal secretion smear no eosinophils, allergic rhinitis, local allergic rhinitis, eosinophilia non-allergic rhinitis were excluded; 3. IR patients who visited the Department of Otorhinolaryngology, the First Affiliated Hospital of Nanjing Medical University and were willing to undergo CDA nasal provocation test; 4.Ptients who are willing to provide specimens for free to promote the study of the diagnostic efficacy of CDA nasal provocation test for IR.
• Healthy volunteers: 1. Aged 18-65 years; 2. Did not have any nasal symptoms and tested negative for allergens.

Exclusion Criteria:

• 1. Patients received glucocorticoids, immunomodulatory drugs, antihistamines, and other treatments that may affect the study results within the past 1 month. 2. Patients with unstable diseases (including severe asthma) and active immune system diseases; 3. Smoking; 4. Pregnant or lactating women; History of nasal surgery within 5.3 months; 6. Patients with any nasal conditions that may interfere with the efficacy or safety evaluation of CDA nasal provocation test; 7. Patients with low compliance and refusing to accept specimen and questionnaire collection.

All the individual participant data only available to reasearchers participated in this study