Deposition of ragweed pollen and extract on nasal mucosa of patients with allergic rhinitis: effect on nasal airflow resistance and nasal mucus velocity.

This study was undertaken to ascertain whether nasal mucus velocity (NMV) could be altered by short-term exposure to antigen. Asymptomatic patients with a history of allergic rhinitis who had a positive cutaneous reaction to ragweed extract were investigated. The plan was to achieve approximately a fourfold elevation of nasal airflow resistance (NAR) with antigen challenge and then obtain serial measurements of NAR and NMV. NMV was not significantly altered when the antigen was introduced by nasal inhalation of (1) ragweed pollen grains, (2) nebulized ragweed extract for 10 breaths, and (3) nebulized ragweed extract for 30 min on each of 3 successive days. When ragweed extract was introduced by direct instillation of the solution into the nose, NMV fell below baseline values at either 0.5 or 1.5 hr, or at both times after administration. Persistence of impairment of mucociliary transport at a time when nasal airway constrictor response had dissipated suggested that a chemical mediator might have been responsible for the alteration of clearance. The failure to demonstrate depression of mucus transport with the inhalation studies might have been due to insensitivity of the radiopaque Teflon disk method or to a qualitatively different allergic reaction to direct instillation of antigen solution.