[Comparative analysis of exhaled nitric oxide in children and teenagers with allergic and non-allergic rhinitis].

BACKGROUND

There is subclinical bronchial inflammation in patients with allergic rhinitis (AR). There is less evidence of inflammation of the lower airway in non-allergic rhinitis (NAR).

OBJECTIVE

To investigate the inflammation of the lower airway by exhaled nitric oxide (FeNO) in patients with AR and NAR without asthma and its link to lung function, the severity of rhinitis, and biomarkers of atopy.

METHODS

A cross-sectional study of patients aged 6 to 18 years, with AR or NAR without asthma. Spirometry, serum IgE, blood eosinophil count and FeNO were carried out. Rhinitis was classified according to the ARIA guide.

RESULTS

Forty patients were included; 28 with AR and 12 with NAR. Patients with AR showed higher FeNO levels (medium 36.5 ppb; range 5-114) than those with NAR (medium 7 ppb; range 5-24) (p = 0.0011). Elevated FeNO was linked to spirometric abnormalities [OR= 7.14 (95 % CI 1.04-49.04), p = 0.049)]. In AR, there was correlation between FeNO and blood eosinophils (r = 0.41, p = 0-33).

CONCLUSIONS

Both children and teenagers with AR showed higher FeNO than patients with NAR, which was correlated with blood eosinophilia and altered lung function.