[THE COURSE OF ASTHMA SYMPTOMS IN JAPANESE CHILDREN; THE FIRST REPORT FROM A MULTICENTER PROSPECTIVE COHORT STUDY].

BACKGROUND: The use of asthma control guidelines and anti-inflammatory drugs have significantly decreased the number of severe asthma cases including death from asthma. However, there are few prospective cohort studies among pediatric asthma patients in Japan describing the course of asthma symptoms with the treatment taken into consideration.

METHOD: We recruited a total of 851 children diagnosed with asthma through 90 hospitals and clinics in 2004 to 2006. Questionnaires were posted annually to collect data on their asthma symptoms, treatment and environmental exposures. We analyzed the disease course in the first 5 years among the children who were registered at age 4 or younger.

RESULTS: The disease course of a total of 641 children, aged 2.8+/-1.1 (mean+/-SD) at registration were analyzed. The proportion of children who had intermittent symptoms increased from 37.6% at registration to 86.5% at 5 years, and the proportion of children with intermittent severity increased from 7.0% to 38.9%, showing a significant decrease in the overall severity. The proportion of children using β2 stimulants decreased from 87.8% at registration to 53.5% at 5 years, while the use of inhaled cortico-steroids were 41.6% at registration and 38.1% at 5 years.

CONCLUSION: Most of the children with pre-school onset asthma had their symptoms controlled, and had decreased severity over 5 years.