[Relationship between inflammation of upper and lower respiratory airways]

Dysfunction of the upper and lower airways frequently coexists, and they appear to share key elements of pathogenesis. Data from epidemiologic studies indicate that nasal symptoms are experienced by as many as 78% of patients with asthma and that asthma is experienced by as many as 38% of patients with allergic rhinitis. Among patients with nasal polyps 27-51% have asthma. Polyps of nasal mucosa usually exacerbates symptoms of concomitant asthma. Studies also have identified a temporal relation between the onset of rhinitis and asthma, with rhinitis frequently preceding the development of asthma. Patients with allergic rhinitis and no clinical evidence of asthma commonly exhibit nonspecific bronchial hyperresponsivenes. The mechanisms upper and lower airway dysfunction are under investigation. They include nasal-bronchial reflex, mouth breathing caused by nasal obstruction, and pulmonary aspiration of nasal contents. Nasal allergen challenge results in increases in lower airway reactivity within 30 minutes, suggesting a neural reflex. Improvements in asthma associated with increased nasal breathing may be the result of superior humidification, warming of inspired air, and decreased inhalation of airborne allergens. Postnasal drainage of inflammatory cells during sleep also may affect lower airway responsiveness. The effective management of allergic rhinitis relieves symptoms of asthma. A link between allergic rhinitis and asthma is evident from epidemiologic, pathophysiologic, and clinical studies. The development of differential diagnosis of rhinitis has multiplied their present classifications. This article presents classifications of rhinitis connected with lower airways dysfunction.