Changes in bronchial responsiveness following nasal provocation with allergen

The relationship between upper airway inflammation and asthma is controversial. In the current study, we sought to investigate the relationship between allergic rhinitis and lower airway dysfunction by performing double-blind, randomized nasal challenges with allergen or placebo. Subjects were selected for a prior history of asthma exacerbations after the onset of seasonal allergic rhinitis symptoms. After the induction of a marked nasal-allergic reaction (with a technique of nasal provocation that limited allergen delivery to the nose), there were no changes in FEV1, specific conductance, or lung volumes either 30 minutes or 4 1/2 hours after nasal allergen challenge, nor any changes in peak flow rates followed hourly until the next day. However, nasal provocation with allergen resulted in a relative increase in bronchial responsiveness to methacholine compared with that to placebo (p = 0.011 at 30 minutes and p = 0.0009 at 4 1/2 hours after challenge). Our study suggests that, although a nasal-allergic response does not induce airflow limitation of the lower airways, it can alter bronchial responsiveness.