http://www.revistaalergia.mx 272 Rev Alerg Mex. 2019;66(3):272-281 é e r g ia M Revista Al xi c o Colegio Mexicano de Inmunología Clínica y Alergia, A. C . Artículo original Comparative analysis of exhaled nitric oxide in children and teenagers with allergic and non-allergic rhinitis Ricardo Saranz, 1 Alejandro Lozano, 1 Natalia Andrea Lozano, 1 Graciela Alegre, 1 Laura Verónica Sasia, 1 Eugenia Cóncari, 1 Paula Robredo, 1 Marina Ponzio, 2 Álvaro Cruz 3 1 Universidad Católica de Córdoba, Clínica Universitaria Reina Fabiola, Servicio de Alergia e Inmunología, Córdoba, Argentina 2 Universidad Nacional de Córdoba, Facultad de Ciencias Médicas, Cátedra de Fisiología Humana, Córdoba, Argentina 3 Universidad Federal de Bahía, Bahía, Brasil Este artículo debe citarse como: Saranz R, Lozano A, Lozano NA, Alegre G, Sasia LV, Cóncari E, Robredo P, Ponzio M, Cruz Á. Análisis comparativo de la fracción exhalada de óxido nítrico en niños y en adolescentes con rinitis alérgica y no alérgica. Rev Alerg Mex. 2019;66(3):272-281. Abstract Background: There is subclinical bronchial infammation in patients with allergic rhinitis (AR). There is less evidence of infammation of the lower airway in non-allergic rhinitis (NAR). Objective: To investigate the infammation 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 classifed 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. Keywords: Rhinitis; Infammation; Spirometry; Exhaled nitric oxide Análisis comparativo de la fracción exhalada de óxido nítrico en niños y en adolescentes con rinitis alérgica y no alérgica ORCID Ricardo Saranz, 0000-0002-9716-1825; Alejandro Lozano, 0000-0002-1475-0676; Natalia Andrea Lozano, 0000-0002-1235-2105; Graciela Alegre, 0000-0001-8391-186X; Laura Verónica Sasia, 0000-0002-2478-2532; Eugenia Cóncari, 0000-0002-8759-0431; Paula Robredo, 0000-0002-3073-3200; Marina Ponzio, 0000-0002-3549-2063; Álvaro Cruz, 0000-0002-7403-3871 Correspondencia: Ricardo Saranz. rsaranz@arnet.com.ar Recibido: 2018-12-27 Aceptado: 2019-05-16 DOI: 10.29262/ram.v66i3.583