NASAL RESISTANCE AND NASAL HISTAMINE CHALLENGE IN ALLERGIC SUBJECTS STUDIED BY POSTERIOR RHINOMETRY

Abstract

Posterior rhinometry allows quantitative measurement of nasal airway resistance and nasal power. We used this research tool in two separate studies. Initially 10 atopic and 6 nonatopic adults had nasal resistance and nasal power measured at 2 hour intervals for 6 hours on two separate days. A computer digital program was used to collect and analyze the data. Statistical analysis showed considerable intra subject and inter subject variability as well as significantly higher mean measurements of nasal resistance in the allergic population. Nonatopic subjects showed very constant lower values for nasal resistance. We then evaluated whether intranasal insufflation of histamine would cause eustachian tube dysfunction (ETD) in atopic adults. These subjects had normal baseline nasal power measurements by posterior rhinometry and normal eustachian tube function by swallow test. All had quantifyable changes in nasal power after a single dose of 0.55 mgm histamine delivered into each nares for 6 seconds. Four of the five atopic subjects had eustachian tube obstruction documented by 9-step tympancmetry within 5 to 20 minutes after peak nasal power was recorded. In both studies, posterior rhinometry was a useful tool to objectively quantify measurement of nasal resistance so that we could document the higher and more variable measurements found in atopic patients and correlate nasal resistance changes caused by histamine with ETD in these patients.