Histamine and allergen induced changes in nasal airways resistance measured by anterior rhinomanometry: reproducibility of the technique and the effect of topically administered antihistaminic and anti‐ allergic drugs.

Abstract

1. Changes in nasal airways resistance (NAR) following the topical application of histamine and allergen solutions were measured by passive anterior rhinomanometry. 2. The repeatability of five consecutive measurements of resting NAR prior to provocation with histamine or allergen (expressed as the coefficient of variation) was 32.8% and following instillation of saline control solution 37.2%. 3. The repeatability of five consecutive measurements of NAR during the nasal obstruction produced by histamine and allergen was similar to that recorded prior to provocation; the coefficients of variation (median values) being 39.6% and 33.1% respectively. The degree of variability was not related to the dose of agonist or the degree of nasal obstruction. 4. The reproducibility of histamine or allergen induced changes in NAR on four separate weekly occasions showed no significant intra-subject differences. 5. The effects of sodium cromoglycate (SCG), clemastine and ketotifen administered to the nasal mucosa 30 min before provocation with histamine and allergen were compared in a random order, double-blind, placebo controlled study. 6. Clemastine and SCG, but not ketotifen, significantly inhibited the nasal response to increasing concentrations of histamine. None of the drugs administered in the concentrations used in this study significantly inhibited the nasal response to allergen.