Why is asthma becoming more of a problem?

From antiquity to the 1920s, the frequency of asthma and especially death from asthma was considered to be rare. In fact, asthma was not considered a significant cause of death during the early years of the 20th century. The Frenchman Armand Trousseau declared in his Clinique Medicale that "asthma n'est pas fatale" ("asthma is not fatal"). In the United States, Oliver Wendell Holmes had described asthma as a "slight ailment that promotes longevity." Clearly this perception of asthma has changed for many reasons. It has been only in the past 10 years that death from asthma has received increased attention when evidence was obtained that the rate was increasing. Few reports of asthma death had appeared until the late 1950s. Mortality today is disproportionately high for asthmatic patients aged 5 through 34 years. Asthma mortality rates have increased worldwide. Substantial increases in the rates of death from asthma in patients aged 5 through 34 years between the mid-1970s and the mid-1980s had been reported. Although asthma is still a relatively infrequent cause of death, it is nonetheless important to emphasize that the rates of death from asthma have risen in England and Wales, Australia, Canada, the Netherlands, Sweden, France, West Germany, Israel, the United States, and Denmark. This review attempts to put this data in perspective and to highlight some features, including pollution and treatment, that may contribute to this alarming problem.