Linking upper and lower airways

Background: Upper and lower airways are similar in many ways, including com mon triggers, pathogenic mechanisms, and response: to treatment. Explanatio ns for the posed linkage between upper and lower airways include nasal-bron chial reflux, postnasal drainage of inflammatory material into the lower ai rways, and dry air impinging on the nasal mucoas. Conclusion: Treatment modalities such as antihistamines and corticosteroid aerosols by the nasal route improve both the upper and lower airways.