The burden of pediatric
asthma remains high with one-third of patients being under- or overtreated because of the unique challenges in the assessment and management of childhood
asthma. Until recently, there has been no point of care tool for assessing the underlying airway
inflammation (i.e., inflammometry) in
asthma. Recently, fractional exhaled
nitric oxide (FeNO) has emerged as an important
biomarker for the assessment and management of
asthma. Recent evidence indicates that FeNO identifies T-helper cell type 2 (Th2)–mediated airway
inflammation with a high positive and negative predictive value for identifying
corticosteroid responsive airway
inflammation. This article examines the evidence for FeNO as a predictor of Th2-mediated inhaled
corticosteroid (ICS) responsive airway
inflammation and reviews recent studies evaluating the role of FeNO, whether helpful or not, in the assessment and management of pediatric
asthma. FeNO is a reliable adjunct to traditional tests in the assessment of suspected
asthma. Importantly, it is useful for identifying and for excluding ICS-responsive airway
inflammation. Although individual study results have varied, collectively,
asthma managed using FeNO is associated with lower exacerbation rates compared with clinical algorithms alone. Finally, FeNO may be useful in identifying patients at risk for future impairment or loss of
asthma control during reduction/cessation of ICS treatment. FeNO testing has an important role in the assessment of pediatric patients with suspected
asthma and in the management of pediatric patients with established
asthma. Additional studies will continue to define the exact role of FeNO testing in pediatric
asthma.