Having a father with asthma may put children with the disease at risk for more severe symptoms.

A new study shows that children with asthma whose fathers also suffer from the respiratory disease are more likely to develop serious airway constriction than other children with asthma.

Serious airway constriction occurs when the breathing tubes within the lungs become overly sensitive and constrict in response to irritants, such as dust, or other stressors, making it more difficult to breathe. Constriction caused by this airway hyper-responsiveness is a hallmark of asthma and closely related to disease severity.

"It is also an important determinant of long-term outcome, not only with respect to asthma symptoms, but also to airway growth and maturation, as well as lung function decline," says researcher Benjamin Raby, MD, MPH, of Brigham and Women's Hospital in Boston, in a news release.

Researchers say previous studies have shown that a parental history of asthma can influence childhood asthma, but this is the first to suggest that the father's contribution may be more significant in affecting airway hyper-responsiveness in children with established asthma.

In the study, researchers followed more than 1,000 children aged 5 to 12 with mild to moderate asthma for nearly five years. The results appear in the September issue of the American Journal of Respiratory and Critical Care Medicine.

At the start of the study, researchers measured airway responsiveness and found the children whose fathers also had asthma were more likely to have airway hyper-responsiveness than children whose fathers didn't have asthma.

Brain Activity May Play Role in Asthma

How Serious Is Your Asthma? Rate Symptoms

When Parents Have Asthma

The relationship between a paternal history of asthma and increased risk of airway hyper-responsiveness remained significant throughout the course of the study even after taking other risk factors, like exposure to cigarette smoke, socioeconomic status, and other demographic factors into account.

A maternal history of asthma was not linked to airway hyper-responsiveness. Children with two parents with asthma had greater degrees of lung sensitivity on lung-function testing than children whose parents did not have asthma.

Researchers say that may seem contradictory, and previous studies have suggested a link between maternal and childhood asthma. But they say those studies involved younger children, and these results are part of a growing body of evidence that shows the paternal influence of asthma increases with age.

According to the American Academy of Allergy Asthma and Immunology, one factor alone cannot predict who will develop asthma. But there are a few factors that have been linked to the development of the condition in children, including:

—Wheezing in babies and children with colds

—Children with allergies tend to have a higher risk for developing childhood asthma.

—A family history of asthma and/or allergy

—Childhood exposure to smoke and allergens

The American Academy of Allergy, Asthma and Immunology also suggests that if your child has asthma, talk to your doctor about making your home a better living environment for your child by reducing allergens. Ask them about an instrument called a peak flow meter that can measure your child's breathing and lung function.

The organization also stresses that when allergies and asthma do strike, early treatment is essential.

Frequently Asked Questions about Asthma

Get Tips for Allergy-Proofing Your Home

By Jennifer Warner, reviewed by Brunilda Nazario, MD

SOURCES: Raby, B. American Journal of Respiratory and Critical Care Medicine, September 2005; vol 172: pp 552-558. News release, American Thoracic Society. American Academy of Allergy, Asthma and Immunology.