Comparison of airway responsiveness to exercise and histamine inhalation in asthmatics

In order to investigate the differences between EIA positive and negative subjects, pulmonary function data at rest, atopic tendency and bronchial sensitivity and reactivity were compared. Pulmonary function data revealed no significant difference between two groups except closing volume which was higher in EIA positive patients (p less than 0.01) and also Rrs which was higher in EIA positive patients only in female (p less than 0.05). Incidence of positive skin tests and higher levels of IgE were more frequent in EIA positive, however, IgE was not significantly different. Relationship between % fall of FEV1 after exercise and bronchial sensitivity was examined, however, no correlation was found in two parameters. Bronchial reactivity was not different in two groups. This suggests that EIA positive patients cannot be distinguished from EIA negative by pulmonary function data at rest or by atopic tendency, and also that different mechanisms play a role to produce airway constriction following exercise and inhalation challenge.