Exhaled nitrogen monoxide (FeNO) is considered an indirect marker of inflammation of lower airways and is increased on patients with allergic asthma and hay fever.
Measuring of FeNO should be performed on patients that have symptoms that can indicate asthma and on patients diagnosed with asthma that are not responding to the treatment they are receiving or they are showing exacerbation. The measurement of exhaled NO in children is also just as important. Nowadays, the diagnosis of childhood asthma and allergic cough is easier and more sure. This way we can ensure that children will receive the correct treatment.