Impact of Inhaled Corticosteroids on the Natural History of Asthma in Children

摘要

Wheezing is a common symptom in pre-school children and its temporal patterns has been studied in epidemiological studies according to its natural history. Tucson Children's Respiratory Study followed unselected children from birth to 6 years of age. Symptoms characterized from this study were transient wheezing (onset before 3 years and resolve by 6 years), late-onset wheezing (symptoms commence after 3 years and persist after 6 years) and persistent wheezing (onset before 3 years and persist after 6 years). This was largely confirmed later by Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort, who used different approach in defining wheezing phenotypes during the first 7 years of life. The analysis suggested other phenotypes as intermediate-onset wheeze (commence at 18 months of age) and prolonged early wheeze (onset at first year with remission at 69 months of age). During school age, longitudinal studies of asthmatics followed to adulthood demonstrated that there is an association between the severity of asthma symptoms during childhood and persistence of asthma to adult life. A cohort study that followed up wheezing children from school age to adolescent suggested that wheezing does not change significantly in late onset and persistent wheezes with an increase in risk of being atopic. Moreover, young adults with active asthma 27% had newly diagnosed asthma during adolescence period.