Exhaled nitric oxide in the diagnosis and management of asthmaTurner, SteveCurrent Opinion in Allergy and Clinical Immunology: February 2008 - Volume 8 - Issue 1 - p 70–76 doi: 10.1097/ACI.0b013e3282f3b4b0 Mechanisms of allergy and adult asthma: Edited by Stephen T. Holgate and J. Andrew Grant Buy Abstract Author InformationAuthors Article MetricsMetrics Purpose of review Gaseous nitric oxide is present in our exhaled breath and may be a biomarker for asthma. The purpose of the present paper is to review recent studies that have explored the potential of exhaled nitric oxide as a biomarker for asthma diagnosis and treatment. Recent findings The upper limit of exhaled nitric oxide has been described in several populations, using a standard methodology. Measurements of exhaled nitric oxide have good specificity but relatively poor sensitivity for diagnosing asthma. The inter- and intra-subject variability of exhaled nitric oxide values in asthmatics remains uncertain. Clinical trials have used exhaled nitric oxide to guide steroid treatment in asthmatics with varied success. The greatest success is in studies where inhaled corticosteroids are reduced and/or withdrawn in stable asthmatics. These pioneering clinical trials have given insight into how exhaled nitric oxide might be a useful index of control of eosinophilic airway inflammation. Summary Measurements of exhaled nitric oxide have the potential to be useful in the management of allergic asthma and the answers to a number of important questions are awaited. Department of Child Health, University of Aberdeen, Aberdeen, UK Correspondence to Dr Steve Turner, School of Medicine, Department of Child Health, Royal Aberdeen Children's Hospital, Foresterhill, Aberdeen AB25 2ZG, UK Tel: +44 1224 552471; fax: +44 1224 551919; e-mail: firstname.lastname@example.org Copyright © 2008 Wolters Kluwer Health, Inc. All rights reserved.