Manifestations of Inhalant Allergies Beyond the Nose.

The upper and lower airways are linked epidemiologically and pathophysiologically. The upper and lower airways are considered a single, functional unit characterized by shared immunologic mechanisms, often referred to as the unified airway. Upper and lower airway inflammatory disease frequently coexist in the same patient. Allergic rhinitis and rhinosinusitis are associated with asthma. Treatment of both diseases impacts asthma outcomes. The otolaryngologist may be the first physician to suspect and diagnose asthma in patients with upper airway complaints. A thorough understanding of the relationship between allergic rhinitis, rhinosinusitis, and asthma will facilitate early identification of asthma and improve patient outcomes.