New national study links asthma to allergies

Sep 27, 2007

Researchers at the National Institutes of Health (NIH) have found that more than 50 percent of the current asthma cases in the country can be attributed to allergies, with approximately 30 percent of those cases attributed to cat allergy.

“It has long been debated whether people who develop asthma have a genetic propensity to develop allergies, or atopy,” said Darryl C. Zeldin, M.D., a senior investigator at the National Institute of Environmental Health Sciences (NIEHS). “This new research shows that 56.3 percent of asthma cases are attributed to atopy.” Atopy is a condition that results from gene-environment interactions and can be measured by a positive skin test to allergens (or allergy causing substances in the environment).

The study, available online today in the Journal of Allergy and Clinical Immunology, was conducted by researchers at the National Institute of Environmental Health Sciences (NIEHS) and the National Institute of Allergy and Infectious Diseases, both parts of the NIH. The data come from the Third National Health and Nutrition Examination Survey (NHANES III), a nationally representative sample of the population of the United States.

“Sensitization to cat appears to be a strong risk factor for asthma in this study,” said Zeldin. Zeldin and his co-authors, however, point out that some research shows that exposure to cats, particularly early in life, may be a protective factor. “We are not advocating parents get rid of pets, but if you suspect that you or your child might have cat allergies or get asthmatic-like symptoms, you should consult with a physician about the best course of action for your family,” added Zeldin.

The NIH researchers looked at skin test data for ten allergens. A positive skin test reaction to cat allergens accounted for 29.3 percent of the asthma cases, followed by the fungus Alternaria at 21.1 percent and white oak at 20.9 percent. “Each of 10 allergen-specific skin tests was strongly associated with asthma; however, after adjustment by a variety of subject characteristics and all the allergens, only skin tests to cat, Alternaria and white oak were independently and positively associated with asthma,” said Peter Gergen, M.D., M.P.H, of NIAID's Division of Allergy, Immunology and Transplantation, a co-author on the paper.

Other allergens tested include: Ragweed, dustmites, Russian thistle, Bermuda grass, peanuts, perennial rye and german cockroach. Approximately 10,500 individuals participated in the skin testing. During these tests, skin was exposed to allergy-causing substances (allergens) and a positive test was determined by the size of the reaction on the skin.

“This study tells us that allergy is a major factor in asthma,” Gergen said. “But this study also tells us is that there are many people who get asthma who don’t have allergies. We need to do more research to understand what is causing the asthma that is not related to allergies.”

“This study confirms that the environment plays a major role in the development of asthma,” said Zeldin. “Given the complexity of this disease it won’t be easy, but if we can prevent, block or reverse atopy, we could reduce a large proportion of asthma cases.”

Source: National Institute of Environmental Health Sciences

Explore further: Florida university opens TB lab in Haiti

add to favorites email to friend print save as pdf

Related Stories

Review: 3 weather phone apps help you on the go

Dec 05, 2012

(AP)—For me, climate change is a serious issue. No, I'm not referring to the debate over global warming. My concerns are much simpler. I'm constantly checking the weather for the hours and days ahead because ...

Fish kills trigger red tide alerts, first responders

Oct 05, 2011

Acting on a tip from a constituent, Cameron County Commissioner Sofia Benavides recently drove out to a section of the Gulf Coast within her jurisdiction, Boca Chica Beach, between the mouth of the Rio Grande ...

How plants absorb pollutants

Mar 29, 2011

The environmental concern is great when considering the role of toxic contaminants in the plant-soil relationship. Understanding plant's absorption and accumulation of these contaminants from the soil would be incredibly ...

Recommended for you

Florida university opens TB lab in Haiti

10 minutes ago

The University of Florida on Wednesday opened a state-of-the-art lab in Haiti to train researchers to better understand and fight tuberculosis.

Impact of whooping cough vaccination revealed

2 hours ago

The most comprehensive study to date of the family of bacteria that causes whooping cough points to more effective vaccine strategies and reveals surprising findings about the bacteria's origin and evolution. The new results ...

Saudi announces 11 new MERS infections

7 hours ago

Saudi Arabia on Wednesday announced 11 new cases of MERS, including a 13-year-old child, as its acting health minister vowed to keep the public better informed on the coronavirus.

User comments : 0

More news stories

High-calorie and low-nutrient foods in kids' TV

Fruits and vegetables are often displayed in the popular Swedish children's TV show Bolibompa, but there are also plenty of high-sugar foods. A new study from the University of Gothenburg explores how food is portrayed in ...

Male-biased tweeting

Today women take an active part in public life. Without a doubt, they also converse with other women. In fact, they even talk to each other about other things besides men. As banal as it sounds, this is far ...