Nov 16, 2004
Asthma's wheezy feeling
By Shelley Widhalm
THE WASHINGTON TIMES
Call it a family affair — Grace and Tom McCabe and their 12-year-old son Danny have allergies and Mr. McCabe and Danny have asthma.
"My asthma hasn't been so bad," says Mr. McCabe of Alexandria, who, like his son, is allergic to cats, dogs, mold, dust, grass and pollen, but, unlike him, is not taking allergy shots. "Long term, I want to do it, especially if we ever want to have any pets."
Danny has been taking allergy shots for more than three years to remove one of his asthma triggers and become less reliant on his inhaler.
"His breathing is much easier. When he takes a breathing test, you can tell his lung capacity is much greater now," says his mother.
Danny recalls his first asthma attack four years ago.
"I just couldn't breathe. My lungs could barely take up any air at all," he says. "It feels like you're going to explode."
More than 70 percent of the 20.3 million Americans reporting having asthma also have allergies, according to statistics from the American Academy of Allergy, Asthma & Immunology (AAAAI), a Milwaukee professional medical organization that promotes education and research.
"Asthma oftentimes is triggered by allergies," says Dr. Martha White, an AAAAI member and an allergist and immunologist for the Institute for Asthma & Allergy, a private practice and research center in Wheaton.
Asthma is present in one out of 20 people and allergies in one out of four to five people, Dr. White says. Those with allergies have a one-in-four chance of developing asthma, both of which are genetic, she says.
A team of American and Australian researchers found a gene linked with asthma, a step in understanding the genetic causes of the disease, after conducting a four-year-study reported last month in the New England Journal of Medicine.
The researchers discovered that a gene in the prostanoid pathway — the inflammatory biochemical pathway considered to be important in asthma — might be associated with the inflammation seen in the disorder, says Dr. Scott Weiss, pulmonary specialist and professor of medicine at Harvard Medical School.
Understanding the gene, along with other genes, will lead to a cure for the disease and help doctors predict the course it will take in individual patients and the best medications and treatments to use for them, Dr. Weiss says.
"Prediction isn't a cure, but prediction can be very helpful to patients," he says.
Asthma can be brought on by allergies, respiratory infections and exposure to irritants, such as air pollution. The disease is more prevalent in Western, urbanized countries, possibly, at least in the United States, from a decrease in air quality, spending more time indoors where dust and other allergens are located, and a tendency to be "too antiseptic," says Cynthia Liss, a registered nurse with a master's of science in nursing and a clinical instructor for the College of Nursing and Health Science at George Mason University.
"Asthma is becoming more and more well understood as an allergic disease, though there are cases of non-allergy asthma," says Mo Mayrides, director of public policy for the Asthma & Allergy Foundation of America (AAFA), a nonprofit patient organization based in Washington, dedicated to education, advocacy and research.
In the case of allergies, the body produces immunoglobin E (IgE), an antibody, against a specific allergen so that the next time the allergen is encountered, the allergen binds to the IgE molecule and with enough binding, triggers an allergic reaction, Dr. White says. Allergy shots can help, she says, by changing the body's immune system, so that the body stops producing IgE.
Asthma is a chronic lung disease in which the airways, the tubes that carry air in and out of the lungs, are blocked during an attack. Symptoms of wheezing, shortness of breath, coughing and chest tightness can result.
The muscles around the airways tighten, causing the airway openings to narrow. The inside walls of the airways become inflamed or swollen and can be sensitive to allergens — animal dander, dust mites, pollen and mold — and irritants — cigarette smoke, cold air, strong odors, stress and strong emotions, according to the National Heart, Lung and Blood Institute (NHLBI) of the National Institutes of Health, in Washington. The inflammation, along with extra production of mucus, causes the airway openings to narrow further.
"It's a very complex disease. However, it's one that responds in a very gratifying way to the proper treatment," says Dr. Harold Nelson, member of the NHLBI asthma expert panel and professor of medicine at the National Jewish Medical Research Center, a hospital and research facility located in Denver.
Two classes of medication are used to treat and control asthma, a disease that cannot be cured, according to NHLBI.
Controller or preventive medications, such as inhaled corticosteroids and leukotriene modifiers that are taken daily, keep the airways open by acting on the inflammation response. Rescue medications, or short-acting bronchodilators, are used as needed to help relax the muscles around the airways.
"The medications block one or another part of the inflammation process," says Dr. Norman H. Edelman, consultant for scientific affairs to the American Lung Association (ALA), based in New York. "Research is focusing on the development of new medications, for the most part focusing on various parts of the body's anti-inflammatory process."
The latest asthma medication, Xolair, a brand of anti-IgE that is injected bimonthly when other medications fail to work
, neutralizes or blocks the IgE by combining with it to make it ineffective. The FDA approved the medication in 2003 for moderate to severe asthmatics with a high level of IgE.
"The best treatments are the inhaled steroids
. They have been shown to decrease symptoms of asthma [and] to improve lung function or lung capacity," says Dr. Depak Soni, chief of pulmonary medicine at Inova Fair Oaks Hospital.
Dr. Soni emphasizes the importance of taking prescribed medications
, remarking that some patients will stop taking them when they start feeling better. The symptoms, at that point, likely will return, he says.
"Early treatment is probably key. The longer you wait to treat symptoms, the more difficult it becomes," Ms. Liss says. "Asthma can become progressively worse."Thomas recommends asthmatics take short-term medications before exercising since exercise also can be a trigger, along with keeping hydrated to prevent mucus buildup and spending additional time warming up and cooling down.
"I respect the disease process," says Ms. Thomas, a lifelong asthmatic.