Conclusions: Clinicians should consider this recommendation to measure FENO in patients with asthma in whom treatment is being considered based on current best available evidence.

The most important advantage of modelling NO dynamics is the gain of CANO that may be useful in assessing inflammation in small airways or lung parenchyma both in airway diseases and interstitial lung diseases.

This review discusses the clinical application of FENO measurement in asthma care, from diagnosis to treatment se- lection, and describes its place in current international expert guidelines.

Type 2 inflammation in asthma is generally suppressed by glucocorticoids, as evidenced by a rapid decrease in Feno (mediated by airway in- terleukin-13) when treatment with inhaled gluco- corticoids is initiated and an immediate decrease in blood eosinophil counts (mediated by sys- temic interleukin-5) with the use of oral gluco- corticoids.

Nasal NO is a sensitive and specific test for PCD in cooperative patients (generally over five years old) with a high clinical suspicion for this disease. To a lesser extent it may also be a useful adjunct in a potential diagnosis of CF.

Measurement of markers of type 2 inflammation, such as fractional exhaled nitric oxide (FeNO) or sputum eosin- ophil count, may be useful in the early stage of work-ups of patients with chronic cough.

CA2122 has some advantages in success rate, the mean attempts and time required for successful measurement of FeNO.