The lower airway pathology of rhinitis.

There is a close link between allergic rhinitis (AR) and lower airways disorders, and this concept has been clarified and confirmed in several studies. AR constitutes a main risk factor for new-onset asthma. Furthermore, numerous epidemiologic surveys indicate that AR is very frequently associated with asthma. Bronchial hyperreactivity, a component of asthma, has often been reported to be present in patients with AR. Bronchial hyperreactivity in AR might represent a prognostic factor for further progress to asthma. In this regard forced expiratory flow at 25% and 75% of pulmonary volume has been proposed as an early marker of bronchial involvement in patients with AR who perceive only nasal symptoms. A close structural and functional relationship between the upper and lower airways has been recently demonstrated. Finally, adequate treatment of AR might positively affect the course of asthma. Taking these facts into consideration, a new diagnostic approach should be considered in managing patients with AR: a possible bronchial involvement must be sought in each patient.