Prevalence of allergic rhinitis with lower airways inflammation: A new endotype with high risk of asthma development?

Aim: Asthma and allergic rhinitis share common pathophysiological mechanisms. However, while asthma phenotypes and endotypes are defined basing on both clinical and immunological features, rhinitis classification is still based on severity and frequency of symptoms. Recently, fractional exhaled nitric oxide (FeNO) has been suggested as a possible biomarker of rhinitis to asthma development.