According to Gurjit K. Khurana Hershey’s chapter “Asthma”, in the 2011 edition of Rudolph’s Pediatrics, cases of asthma are increasing:3
“Asthma is estimated by the World Health Organization to affect 150 million people worldwide, and its global pharmacotherapeutic costs exceed $5 billion per year. In children, where asthma remains the leading cause of emergency care and hospitalization, rates continue to rise. From 1980 to 1996, asthma prevalence among children 0 to 17 years of age more than doubled, from 3.6% in 1980 to 7.5% at the peak of the trend in 1995. […] prevalence remains at high levels, and in 2005, 12.7% of children had been diagnosed with asthma at some point in their lifetime […].
Children of American Indian or Alaska Native descent have current asthma prevalence rates 25% higher, and black children are 60% higher, than those in white children. […] Puerto Rican children have the highest prevalence of all groups, 140% higher than non-Hispanic white children.”
What is asthma?
Asthma is a chronic respiratory disease characterized by a constricting inflammation of the airways leading to labored breathing.
Allergies contribute to asthma because the continued injury from allergy-induced inflammation changes the structure of lung tissue.
The Hygiene Hypothesis along with increasing allergy rates, are seen as an explanation for the rise in asthma. Yet, it may not be the whole story. It is not just a more hygienic environment, but also how a child’s immune system develops in an excessively clean environment.
According to Hershey, change in “critical early life exposures has resulted” in change in our immune system’s ability to adapt, and “this has translated to the observed trends in prevalence rates for allergic disorders, including asthma”.4
Risks for asthma include allergies, second hand smoke, air pollution (from exhaust fumes-and chemicals from metals, farming, cosmetic, or manufacturing), infections, reflux, obesity, and a family history of asthma.
Allergies and Asthma
The rate of allergies and asthma in children are on the rise. No one cause has been identified as the causative factor, but given the slow pace of genetic change, the rise of chronic illnesses likely reflects an increase in the burden of environmental exposures.
What is an allergy? How do they develop? And what are the long-term effects?