[The relationship between reactivity and asthmatic attacks before and after acetylcholine inhalation test].

Sixty two asthmatic children participated in this study to clarify the relationship between the number of the days of asthmatic attack and the respiratory threshold of acetylcholine (RT-Ach) and % fall of FEV1.0 at the RT-Ach. In the age group 5 to 11, there was a statistically significant correlation between the RT-Ach and % fall of FEV1.0 at RT-Ach. However there was no such relationship in the age group 12 to 15. In the age group 5 to 11, there was a statistically significant correlation between the % fall of FEV1.0 and the number of the days of asthmatic attack during 10 days and one month before the inhalation test. However there was no such relationship in the age group 12 to 15. There was a statistically significant correlation between the % fall and the number of the days of asthmatic attack over 12 months following the inhalation test in the age group 12 to 15. There was no such relationship in the age group 5 to 11.