Childhood Asthma on the Rise

It's the number one reason children miss school, the number one reason children visit the emergency room, and the most frequent reason for visits to the pediatrician—and it's increasing in prevalence and severity. No, it's not a new virus or bacteria. It's asthma.

Between 1980 and 1994, the overall prevalence rate of asthma in the United States increased 75 percent, with the most substantial increase occurring in children from birth to age four. That age group alone saw a 160 percent increase in prevalence. For children aged five to 14 years, the increase was 74 percent.

Yet researchers and experts in the field say asthma continues to be underdiagnosed and undertreated. One reason is that there is no universally accepted definition of asthma. Plus there are varying degrees of asthma, explains Jodi Giammarco, executive director of the Childhood Asthma Foundation. An asthma attack may be something as innocuous as a little wheezing or cough. "It can develop at any age," Giammarco says. "A baby can have asthma."

Children are more susceptible to developing asthma because they have narrower airways. Our lungs do not fully develop until late adolescence, so pollutants or illness can impact their development. Children also breathe more rapidly, adds Daniel Swartz, executive director of the Children's Environmental Health Network. This means they inhale more pollutants per pound of body weight.

Asthma can be difficult to diagnose. It helps if a physician can observe an attack and when parents give a detailed description of what the child was doing prior to the attack as well as an account of the actual attack.

Until recently, the standard test for asthma was spirometry, requiring the patient to blow forcefully into a tube, and was difficult to perform in young children. Now a newer test, called impulse oscillometry, assesses a person's lung function through normal breathing, eliminating the need for little kids to follow complex instructions.

The increase in asthma has made the public and doctors more aware of the disease, which can account for more cases of asthma being diagnosed. But it can't completely explain the increase. "We're not really sure why it's happening," Giammarco says. "You can't just put it down to the environment."