Wheezing With Colds Raises Risk of Asthma

Wheezing With Colds Raises Risk of Asthma
Rhinovirus-Related Wheeze Big Risk Factor in Kids

WebMD Health NewsReviewed by Louise Chang, MD Oct. 1, 2008 -- Infants and toddlers who wheeze when they are sick with colds have a big risk of developing asthma later in childhood, a new study shows.

Wheezing with rhinovirus infection during the first three years of life was associated with a tenfold increase in asthma risk by age 6, researchers from the University of Wisconsin report.

Nearly 90% of the children in the study who wheezed with rhinovirus infection during their third year of life had a diagnosis of asthma three years later.

There are more than 100 identified rhinoviruses that are known to cause colds, but until now, these viruses have not been strongly associated with asthma risk, the study's principal investigator tells WebMD.

Instead, much attention has been focused on another common infectious agent, known as respiratory syncytial virus (RSV). Young children who are hospitalized with RSV infections have a high risk of developing asthma later in childhood.

"When we started this study we fully expected to find that RSV was the big culprit, but that is not what we found," says Robert F. Lemanske Jr., MD.

Colds, Wheezing, and Asthma
Wheezing occurs as a result of airway narrowing, and it is characterized by a whistling sound in the lungs during breathing.

As many as half of children will wheeze with respiratory illness at some point during their first three years of life, but many of them will not go on to develop asthma.

Early respiratory illness is a well-recognized risk factor for childhood asthma, but the impact of specific respiratory viruses on the airway disorder is not well understood.

In an effort to better understand the relationship between virus illness and childhood asthma, Lemanske and colleagues closely followed 259 children from birth through their sixth birthdays.

The children were considered at high risk for developing asthma because one or both parents had asthma or respiratory allergy.

By age 6, 28% of the children had been diagnosed with asthma.

Children who wheezed while sick with colds during the first year of life were three times more likely than children who did not wheeze while sick to develop the respiratory disease.

Wheezing with rhinovirus infection during the second year of life was associated with a sixfold increase in asthma risk, and wheezing with infection during the third year of life increased asthma risk about 30-fold.

By comparison, wheezing with RSV infection during the first three years of life was associated with a threefold increase in asthma risk, and RSV-associated wheezing during the third year increased asthma risk tenfold.

Wheezing with rhinovirus infection was identified as the most significant predictor of asthma in these high-risk children.

Wheezing With Colds Should Raise Suspicion
The next step, Lemanske says, is to examine specific rhinoviruses to see if some are more closely linked to asthma risk than others.

"Not everybody who gets a cold develops asthma," he says. "Are there certain strains that are more pathologic? We don't know."

He adds that the message to parents and pediatricians is that any wheezing associated with respiratory illness should raise suspicions about asthma.

"We would argue that kids who wheeze with rhinovirus need to be followed closely," Lemanske says.

American Thoracic Society past president John Heffner, MD, agrees.

"We have known that respiratory infections that lead to hospitalization are associated with increased asthma risk in children," he tells WebMD. "But now we know that the risk extends to common infections that don't often lead to hospitalization."

View Article Sources
SOURCES:

Jackson, D.J. American Journal of Respiratory and Critical Care Medicine, Oct. 1, 2008; vol 178: pp 667-672.

Robert F. Lemanske Jr., head of the division of pediatric allergy, immunology and rheumatology; professor of pediatrics and medicine, University of Wisconsin School of Medicine and Public Health, Madison.

John Heffner, MD, chair of medicine, Providence Portland Medical Center, Portland, Ore.; past president, American Thoracic Society.