First signs of asthma often appear early in patient's life
■ Studies suggest several risk factors, question the use of a technology for monitoring, and reinforce the heterogeneity of the condition.
By Victoria Stagg Elliott — Posted Oct. 27, 2008
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When Todd Mahr, MD, an allergist in La Crosse, Wis., treats a wheezing child with eczema and repeated upper respiratory infections, parents often ask about the future. Will their offspring continue to have allergies? What about asthma? Will the child grow out it?
A set of studies in the Sept. 20 Lancet has made answering these questions a little easier. The publication coincided with the European Respiratory Society meeting held in early October in Berlin.
"They help us with that crystal ball," said Dr. Mahr, director of pediatric allergy and immunology at Gundersen Lutheran Medical Center.
One paper by researchers at the University of Arizona found those who had their first asthma symptoms at age 6 were more likely to have the condition chronically at age 22. Persistent wheezing, allergies, low airway function, bronchial hyper-responsiveness and asthmatic parents also increased risk. Women were twice as likely as men to be diagnosed with asthma between the ages of 16 and 22. Men who were asthmatic as children were more likely to go into remission.
Another study, this one from the National Institute of Health and Medical Research in Paris, found having rhinitis as a child predicted the development of asthma as an adult.
Experts praised these papers for fine-tuning the identification of those most likely to develop asthma and most in need of utilizing prevention strategies. The American Medical Association encourages physicians to educate parents of children with asthma on assessment and reduction of known risk factors for the disease. When appropriate, patients and families should be referred to asthma education programs.
"That kid you have to worry about getting asthma is the snotty kid with eczema or atopic dermatitis and a family history of asthma," said Richard Gower, MD, president-elect of the American College of Allergy, Asthma & Immunology. "The boys tend to outgrow it, and the girls start to have it in puberty."
Acetaminophen a risk?
Experts were particularly intrigued by a study by scientists from the Medical Research Institute of New Zealand implicating acetaminophen in the development of asthma. People who took the drug in the first year of life were 46% more likely to have asthma symptoms at age 6 and 7. Children currently taking it also had an increased risk that was dependent on the amount ingested.
Asthma specialists said the finding was provocative, although they expressed caution about casting blame. This study showed an association, but did not prove cause and effect.
"There might be something about children who require more frequent use of this medicine. [This study] certainly doesn't prove causality, and it would be inappropriate for ... clinicians to grasp onto this and no longer prescribe acetaminophen for children," said Mary Beth Fasano, MD, MSPH, associate clinical professor of medicine and pediatrics at the University of Iowa. She also is a member of the executive committee of the American Academy of Pediatrics' Section on Allergy and Immunology, though she was speaking personally.
A complex disease state
But doctors also say the biggest take-home message from these papers is how different asthma patients can be from each other, and an accompanying editorial urged discarding the concept that it is one single disease.
"Asthma is a complex heterogeneous disease state or set of conditions that present with variable symptoms. Sometimes it's easy to diagnose. Sometimes it's not. And it can have a variable course. We have to personalize treatment," said Dr. Gower, who is also an allergist and immunologist in Spokane, Wash.
But treatment is complicated, and a monitoring technology that many hoped would make it easier appears to be falling short. Specifically, another paper found that measuring exhaled nitric oxide did not improve outcomes when added to a care regimen based on guidelines from the National Heart, Lung and Blood Institute's National Asthma Education and Prevention Program.
"It added little to a carefully applied guideline approach," said Stanley Szefler, MD, the study's lead author and head of pediatric clinical pharmacology at National Jewish Health in Denver.
Physicians who have used this approach said it still has its uses, including diagnosis, assessing medication adherence, or tapering some drugs. But disappointment in its failure as a monitoring tool was high.
"It does have value, but it's not the hemoglobin A1c of asthma that people had hoped it would be," said Bradley Chipps, MD, a pulmonologist, allergist and immunologist in Sacramento, Calif.
Asthma specialists also say this study reinforces the message that the NHLBI guidelines work, but many of these physicians also acknowledge that they present challenges. Some of the medications recommended are expensive, and the guidelines are complicated and lengthy. "They're almost 500 pages long," Dr. Mahr said. "We need to simplify [them] into useable bits of information."
According to numbers from the National Health and Nutrition Examination Survey released by the Centers for Disease Control and Prevention in September, 7.3% of the U.S. population has asthma.