Objective: To investigate the natural course from rhinitis to asthma in the patients with autumnal pollinosis.
Methods: 1096 patients with autumnal pollinosis, 488 males and 632 females, aged 38 +/- 14 (5 - 77), 511 with pure allergic rhinitis and 585 with allergic rhinitis complicated with asthma, underwent skin test of inhalant allergens, serum IgE specific to autumnal pollens, and questionnaire survey.
Results: The age range of rhinitis induced by autumnal pollens was 2 - 75. The peak onset age of rhinitis was 15 - 44, and the peak onset age of asthma was 25 - 54. 33% of the rhinitis patients complicated with asthma (194/585) had their first attack of rhinitis and the first attack of asthma in the same year, 66% of them (386/585) had the first attack of asthma later than the first attack of rhinitis, and only 0.8% of them (5/585) had their first attack of asthma earlier than that of rhinitis. 37% of the patients with autumnal pollen allergic rhinitis (410/1096) developed asthma within 5 years, 47% (511/1096), within 9 years, 5% (58/1096) within 10 approximately 19 years, and 1.5% (16/1096) within 20 - 40 years.
Conclusion: Almost half of the patients with autumnal pollen allergic rhinitis develop to seasonal allergic asthma within 9 years.