Table of Contents
Journal of Allergy
Volume 2012, Article ID 916926, 6 pages
Review Article

Environmental Effects on Fractional Exhaled Nitric Oxide in Allergic Children

1Health and Environment Unit, Regional Agency for Environment Protection/ARPA, Sicilia, Corso Calatafimi 217, 90129 Palermo, Italy
2Institute of Biomedicine and Molecular Immunology, “Alberto Monroy,” National Research Council of Italy, Via Ugo La Malfa 153, 90146 Palermo, Italy
3Department of Sciences for Woman and Child's Health, School of Pediatrics, University of Palermo, Via del Vespro 129, 90100 Palermo, Italy
4Institute of Clinical Physiology, National Research Council (CNR) of Italy, Via Trieste 41, 56126 Pisa, Italy

Received 1 May 2011; Revised 31 July 2011; Accepted 29 August 2011

Academic Editor: Mary Beth Hogan

Copyright © 2012 Stefania La Grutta et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Fractional exhaled nitric oxide (FeNO) is a non-invasive marker of airway inflammation in asthma and respiratory allergy. Environmental factors, especially indoor and outdoor air quality, may play an important role in triggering acute exacerbations of respiratory symptoms. The authors have reviewed the literature reporting effects of outdoor and indoor pollutants on FeNO in children. Although the findings are not consistent, urban and industrial pollution—mainly particles (PM2.5 and PM10), nitrogen dioxide (NO2), and sulfur dioxide (SO2)—as well as formaldehyde and electric baseboard heating have been shown to increase FeNO, whilst ozone (O3) tends to decrease it. Among children exposed to Environmental Tobacco Smoke (ETS) with a genetic polymorphisms in nitric oxide synthase genes (NOS), a higher nicotine exposure was associated with lower FeNO levels. Finally, although more studies are needed in order to better investigate the effect of gene and environment interactions which may affect the interpretation of FeNO values in the management of children with asthma, clinicians are recommended to consider environmental exposures when taking medical histories for asthma and respiratory allergy. Further research is also needed to assess the effects of remedial interventions aimed at reducing/abating environmental exposures in asthmatic/allergic patients.