Abstract:Objective To evaluate the value of exhaled nitric oxide in the severity evaluation of asthmatic children with remitting rhinitis. Methods A total of 214 asthmatic children were randomly allocated to a untreated control and a conventional treatment group. Patients in each of the two subclasses were classified as asthma with concurrent rhinitis and asthma without concurrent rhinitis. Values of the 20% fall in forced expiratory volume in 1 second (PC20FEV1) and fractional exhaled nitric oxide (FeNO) were measured. Results The PC20FEV1 level was significantly higher in untreated asthma patients without rhinitis than in those with concurrent rhinitis (P<0.05), while FeNO was not significantly different between these two groups (P>0.05). There were no significant differences in both FeNO and PC20FEV1 between treated asthma patients with and without concurrent rhinitis (P>0.05). PC20FEV1 was significantly increased (P<0.05) but FeNO was significantly decreased (P<0.05) in asthma patients with concurrent rhinitis after conventional treatment. In asthmatic children without concurrent rhinitis, treatment significantly decreased the level of FeNO (P<0.05) but had not effect on PC20FEV1 (P>0.05). Conclusions Exhaled nitric oxide measurement may be useful in the severity evaluation of asthmatic children with remitting rhinitis.