Relationship between nasal resistance and airway hyperreactivity following nasal provocation with Dermatophagoides...

To determine whether nasal allergic symptoms can cause bronchial hyperresponsiveness to methacholine, 30 subjects with allergic rhinitis (22 with allergic rhinitis and 8 with allergic asthmatic rhinitis) were studied. All subjects were skin test positive to Dermatophagoides pteronyssinus (DP) and underwent nasal allergic provocation with DP. After provocation, there was a severe nasal allergic reaction in the challenged nostril with a significant increase in nasal resistance both immediately and long (7 h) after DP exposure. There were no significant changes in the forced expiratory volume in 1 s and the forced expiratory flow rate between 25 and 75% of the forced vital capacity and in both allergic rhinitis and allergic asthmatic rhinitis patients. There was also no change in bronchial hyperresponsiveness to methacholine. The eosinophil counts, leukotriene B4, leukotriene C4 and platelet-activating factor levels in nasal discharges also showed no differences in both groups of patients. Our studies suggest that nasal provocation with limited allergen is a safe diagnostic technique. However, the relationship between nasal resistance and airway hyperreactivity is not obvious in this study. The similar concentrations of nasal inflammatory mediators in both allergic rhinitis and allergic asthmatic rhinitis indicate that bronchial hyperreactivity is not solely due to nasal drainage of inflammatory mediators.