Objective To determine the characters and difference of the impact of persistent allergic rhinitis of different degrees on the lower airway. Methods All patients enrolled in this study were categorized into three groups, the mild group(165 subjects), the moderate/severe group(101 subjects), and the normal control group(136 healthy subjects). Induced sputum differential cytology tests, measurements of exhaled nitric oxide concentration and methacholine bronchial provocation tests were performed. The character and difference in the lower airway among the three groups were compared. Results ① The measurements of fractional exhaled nitric oxide concentration and the positive rate of fractional exhaled nitric oxide concentration of the moderate/severe group and the mild group both had significant statistical difference with the normal control group(39.07±24.29 vs 25.81±18.68 vs 9.01±10.01, P＜0.01; 66.19% vs 33.33% vs 8.82%, P＜0.01) ; ② Proportion and positive rate of eosinophils in induced sputum of the two rhinitis groups had no significantly statistical difference with each other(5.51±9.11% vs 4.02±7.10%; 40.59% vs 35.57%, P＞0.05), but they both had significantly statistical difference with the normal control group(5.51±9.11% vs 0.48±1.28%, 4.02±7.10% vs 0.48±1.28%; 40.59% vs 1.47%, 35.57% vs 1.47%, P＜0.01); ③ Positive rate of bronchial provocation test of the moderate/severe group had significantly statistical difference with the mild group and the normal control group(14.85% vs 4.24%,14.85% vs 1.23%, P＜0.01), but the mild group had no significantly statistical difference with the normal control group(4.24% vs 1.23%, P＞0.05). Conclusion ① The disparity of the lower airway inflammation consists in perennial allergic rhinitis of different degrees; ② Our research demonstrates that the moderate/severe perennial allergic rhinitis exhibits superior lower airway abnormality, indicating that such patients have high-risk of suffering from asthma, in view of this condition, they should be paid sufficient attention to by otorhinolaryngologists and respiratory physicians.
