Background & Objectives: There are evidences that allergic rhinitis and asthma represent a continuity of disease. It is known that bronchial hyperreactivity is a most contributing factor for asthma, yet it remains controversial whether there is a direct cause-and-effect relationship between the upper and lower airway. This study was performed to evaluate a direct cause-and-effect relationship between the two diseases by using early allergic responses and to define the clinical factors for predicting bronchial hyperreactivity in allergic rhinitis patients.
Subjects & Methods: Seventy three patients with allergic rhinitis and 36 patients without allergic rhinitis were included in this study, where exclusion criteria were diagnosed asthma, chronic obstructive pulmonary diseases, nasal polyp and chronic paranasal sinusitis. Nasal provocation tests with allergen were applied to 29 allergic rhinitis patients. After 30 minutes, we investigated lower airway using symptom scores, bronchial provocation test with methacholine and pulmonary function test. Bronchial provocation test with methacholine was applied to 44 allergic rhinitis patients and 36 non-allergic rhinitis patient. We checked nasal symptom scores and the change of nasal volume by VAS and acoustic rhinometry, respectively. We also investigated the incidence and the predictive factors of bronchial hyperreactivity in allergic rhinitis patients.
Results: The early allergic response provocated at nasal cavity had little effect on bronchus. Bronchial stimuli with methacholine did not affect nasal cavity. The incidence of bronchial hyperreactivity is significantly higher in allergic rhinitis patients than in non-allergic rhinitis patients. Type of allergic rhinitis (especially persistent, moderate-severe group) and the disease-durations are valuable predictive factors of the bronchial hyperreactivity.
Conclusion: Although early allergic response has little effect on the nasobronchial relationship, there may be a significant correlation between allergic rhinitis and bronchial hyperreactivity. The correlation is more significant in the persistent, moderate-severe group of allergic rhinitis with long disease duration.
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