Childhood asthma is common and its prevalence is increasing in most co
untries of the world. Large-scale studies indicate that approximately
one-third of children with asthma have had five or more episodes of wh
eezing in the previous 12 months. Such frequency of symptoms leads to
a significant number of days lost from school, interference with physi
cal exercise, and underfunctioning at school because of interrupted sl
eep. In cases of more severe asthma, the more frequent school absences
may affect the individual's education and, possibly, choice of career
. In addition to the extensive individual burden of asthma, the burden
on the family is substantial. Additional housework may be required to
reduce the child's exposure to potential environmental triggers. Time
''off work'' may be required to take care of a sick child. In cases o
f severe asthma, children regularly wake at night, and 50% of parents
indicate limitation of their social life. Sibling studies show that so
metimes siblings who do not have asthma are neglected and that parents
may have insufficient time to devote to them. Mortality in pediatric
asthma is low, but there has been little reduction in recent years. Wh
en viewed as potential life-years lost, the burden is considerable in
social and economic terms. In the United States, the mean annual cost
per patient has been estimated at in excess of US$1,000. In Australia,
the cost ranges from A$85 to A$884 per patient, depending on asthma s
everity. In the United Kingdom the estimated annual costs of childhood
asthma to the Health Service are between pound 100 million and pound
150 million. To reduce the burden to patients, their families, and hea
lth care services, improved understanding of the basic pathophysiology
of asthma is necessary. Environmental issues need to be addressed as
does delivery of care using appropriate devices and effective therapeu
tic medications. (C) 1997 Wiley-Liss, Inc.