The influence of sex, allergic rhinitis, and test system on nasal sensitivity to airborne irritants: A pilot study

"Nasal irritant sensitivity" is an important construct in environmental hea lth science; functional measures, however, lack standardization. We perform ed duplicate measures of nasal irritant perceptual acuity on 16 subjects (e venly divided by sex and seasonal allergy status) using two different test compounds: carbon dioxide (CO2) (detection) and n-propanol (localization). The a priori hypotheses included a) allergic rhinitics will display lower p erceptual thresholds than nonrhinitics; 6) females will display lower perce ptual thresholds than males; and c) estimates of perceptual acuity using th e two test systems will be positively correlated. We obtained CO2 detection thresholds using an ascending concentration series, presenting 3-sec pulse s of CO2, paired with air in random order, by nasal cannula. We obtained lo calization thresholds by simultaneously presenting stimuli (ascending conce ntrations of Il-propanol vapor in air) and blanks (saturated water vapor in air) to opposite nostrils, with laterality randomized. In terms of test-re test reliability, individual replicate measures for CO2 detection threshold s correlated more closely than did the localization thresholds of volatile organic compounds (VOC) (r = 0.65 and r = 0.60, respectively). As an intere st comparison, log-transformed individual mean CO2 and VOC measures were po sitively correlated with an r of 0.63 (p < 0.01). In univariate analyses, s ex predicted both log-transformed COL and VOC thresholds (females being mor e "sensitive"; p < 0.05 and 0.001, respectively). Nasal allergies predicted sensory testing results only in the multivariate analysis, and then only f or VOC localization (p < 0.05). The question of population variation in nas al irritant sensitivity las well as the generalizability of results across test compounds) deserves further attention.