Links between bronchial asthma and allergic rhinitis in the Oita Prefecture, Japan.

Recent studies have strengthened the concept that bronchial asthma and allergic rhinitis are manifestations of an inflammatory process within a continuous airway. This study was performed to compare clinical findings in asthma with or without rhinitis in Japan. Nasal symptoms were present in 99.6% of asthma patients. The prevalence of allergic rhinitis in patients with asthma was 52.4%. Bronchial asthma attacks in one third of patients with rhinitis were coincident with worsening of nasal symptoms. In adults (> 16 years of age), rhinitis frequently preceded asthma, whereas asthma preceded rhinitis in children (< 16 years of age). The frequency of rhinitis in asthma decreases with increasing age. This study demonstrated a clear link between upper and lower airway disorders in Japan.