Treating Adult Asthma
Adults are not immune to asthma. The disease affects approximately 10 million people over 21 years of age in the United States alone.
Adults with the disease generally fall into one of three groups: those who have had the disease since childhood; those who had the disease in childhood, became asymptomatic, then suddenly experienced a recurrence when they reached their 40s or 50s; and those who develop "occupational asthma."
"Patients who experience a recurrence of asthma in adult life are often the most difficult to manage," said Gary D. Harris, M.D., professor of medicine and pulmonologist at the Health Science Center. "The recurrence often seems to be related to a severe respiratory infection followed by re-exacerbation of the patient's asthma. This group of patients experiences acute airway obstruction that can be completely reversed when the disease first begins to recur. However, as the attacks continue to recur over months or years, the patients often experience chronic airway obstruction.
"Ultimately, they're never normal between episodes. They're just better, or less symptomatic some times than others," Dr. Harris added.
Sometimes, patients describe their asthma as "adult onset," recalling no symptoms of the disease during childhood. "With these patients we're concerned we might not be getting a really clear history of their childhood health," said Dr. Harris. "We often find that they did have respiratory disease in early life, if we can talk to parents or older siblings. There is also the possibility that the asthma went unrecognized.
"These patients tend to fall into that more severe category."
Adults develop occupational asthma when they're exposed to a new chemical or biological substance and develop a sensitivity to it. "Their sensitivity manifests itself as asthma immediately or when they're re-exposed to the substance or substances," Dr. Harris explained. The pulmonologist cited three occupation-related substances that can cause sensitivities and asthma attacks: a substance found in meat wrapping vinyl, another found in cottonseed and another in petroleum products. The sensitivity to meat wrapping vinyl is also called "meat wrappers disease."
"Usually, when adults develop these allergies, they have to leave that job environment," said Dr. Harris. "The general principal of asthma has always been avoidance. If you identify a trigger, the first line of treatment is avoidance."
Drug therapy for adult asthma is similar to that for children's asthma. "The focus is on controlling the inflammation, and several medications are available," said Dr. Harris. "The predominant medication is inhaled steroids--taken on a regular basis, whether the patient is symptomatic or not."
Another preventive therapy is cromolyn, which probably affects the inflammatory response, said Dr. Harris.
"Most recently, a new group of drugs called antileukotrienes have become available," Dr. Harris continued. "They are taken either once or twice a day and have been quite beneficial to a high percentage of patients with severe asthma. In many instances, the medication has allowed them to reduce the use of bronchodilators prescribed when the airways constrict acutely.
"None of this is curative, however," cautioned Dr. Harris. "The drugs were developed to prevent or reduce symptoms. We're not clear on what exact mechanisms cause patients to have asthma in the first place, nor on how to truly cure it."
In addition to new drug therapies, advances have been made in activity recommendations for asthma patients. "People are not dismissed from their work as they once might have been for recurrent episodes of asthma, unless the attacks are pinpointed to their specific job task," said Dr. Harris. "I think the public, asthmatics and people
"Another advance in treating asthma has been in controlling smoking and smoke exposure. Obviously, asthmatics shouldn't smoke, but many do. However, those who don't smoke are very much bothered by secondary smoke; when seated too near a smoking section asthmatics can, in fact, have difficulty. So, I'm a strong proponent of smoking control in public places to prevent the asthma patients from being exposed," said Dr. Harris.
One of the questions patients frequently ask Dr. Harris is if they should be tested for allergies. "The answer is probably 'yes,' especially if the patient has patterns that suggest exposure to the right environment causes the symptoms," he said. "A specific allergen or allergens can be identified and desensitization can be considered. However, the treatment modalities of desensitization appear to be less effective in adults than in children."
The bad news about asthma is the increase in the number of asthma sufferers. Dr. Harris reported a 29 percent increase in the incidence between 1980 and 1987, and he said the increase may be attributed to industrialization. "As our industrialization progresses, we are introducing more substances--more chemical substances, for instance-- and exposing people to them," he added.
Other possible contributors that Dr. Harris cited are air pollution, with cities experiencing higher concentrations of sulfur dioxide and other contaminants, and more chemicals or different formulations of them being introduced in the production of carpets and fabrics.