Clinical features of adult-relapse asthma in comparison with those of child-onset asthma and adult-onset asthma.

Clinical features of adult-relapse asthma (group B, n = 15) were compared with those of child-onset asthma (group A, n = 18) and adult-onset asthma (group C, n = 34) in terms of allergic component and bronchial hypersensitivity. The percentage of patients with high levels of serum IgE (> 300 U/ml) in groups A, B, and C was 83%, 73%, and 50%, respectively, and the percentage of patients with positive IgE RAST for house dust was 87.5%, 78.6%, and 46.7%, and that for mite was 93.3%, 92.9%, and 58.6% in groups A, B, and C, respectively. The histamine concentration of PC20 for the bronchial hypersensitivity test in groups A, B, and C was 196 micrograms/ml, 500 micrograms/ml, and 724 micrograms/ml, respectively. Thus, the adult-relapse asthma was closer to the child-onset asthma type in allergic state and closer to the adult-onset asthma type in bronchial hypersensitivity state. The classification employed here seemed to provide some merits in delineating the features of adulthood asthma.