Asthma in Adults

Description

Managing Asthma

Avoidance or control of the triggers that lead to asthma attacks is as much a priority as treatment of the disease. Of some concern are studies reporting no change in asthmatic symptoms after controlling cat or dust mite allergens. More research is needed to identify the reasons for this.

Indoor Protection

Controlling Pets. Patients who already have pets and are not allergic to them probably have a low risk for developing allergies. If pets trigger asthma, however, they should be kept outside. If this isn't possible, they should at least be confined to carpet-free areas outside the bedroom. Cats harbor significant allergens, which can even be carried on clothing; dogs usually present fewer problems. Washing animals once a week can reduce allergens. Dry shampoos, such as Allerpet, are now available for both cats and dogs that remove allergens from skin and fur and are easier to administer than wet shampoos.

Controlling for Dust. A 2002 study reported that simply using a spray furniture polish is very effective for reducing both dust and allergens. Air cleaners, filters for air conditioners, and vacuum cleaners with HEPA filters can help remove particles and small allergens found indoors. Neither vacuuming nor the use of anti-mite carpet shampoo, however, is effective in removing mites in house dust. In fact, vacuuming stirs up both mites and cat allergens. Carpets and rugs should be avoided, if possible.

A HEPA (High Efficiency Particle Arresting) filter can remove the majority of harmful particles, including mold spores, dust, dust mites, pet dander and other irritating allergens from the air. Along with other methods to reduce allergens, such as frequent dusting, the use of a HEPA filtration system can be a helpful aid in controlling the amount of allergens circulating in the air. HEPA filters can be found in most air purifiers, which are usually small and portable.

Bedding and Curtains. Using semipermeable coverings to fully encase mattresses and pillows is the most proven effective step in reducing dust mite levels. (Vinyl mattress covers limit airflow and may also exacerbate, or even cause, asthma in children. Synthetic pillows may pose a significantly higher risk for severe asthma attacks in children than feather or no pillows.) Curtains should be replaced with shades or blinds and bedding washed using the highest temperature setting.

Reducing Humidity in the House. Although warm, moist air from vaporizers can greatly ease and moderate asthma attacks, living in a damp house is counter productive. Dust mites thrive in humidity and damp houses increase the risk for mold. On-going humidifiers, then, can be counterproductive. If they are used, humidity levels should not exceed 40% and they should be cleaned daily with a vinegar solution.

Gas Stoves, Kerosene, and Cooking. People with asthma who cook should choose electric ovens rather than gas, which release nitrogen dioxide, a substance that can aggravate asthma symptoms. (Children do not appear to be affected by gas cooking.)Kerosene (used in space heaters and lamps) may also produce allergic reactions. And, just smoky cooking can worsen asthma.

Exterminating Pests (Cockroaches and Mice). Cockroaches should be eliminated by professional exterminators. (One study reported that ridding a home of cockroaches and cleaning the house using standard housecleaning techniques failed to eliminate the cockroach allergens themselves.) Mice should be eliminated, and attempts should be made to remove all dust, which might contain mouse urine and dander.

Avoiding Smoking and Cigarette Smoke. Cigarette smoke can accelerate the decline in lung function related to asthma. Even exposure to secondhand smoke can double the risk of asthma-related emergency room visits. In one study, it was the most frequently cited trigger of asthma symptoms. Everyone should quit smoking and encourage others around them to quit. [For help in quitting, see Well-Connected, Report # 41, Smoking.]

Click the icon to see an image of common asthma triggers.

Outdoor Protection

Avoiding Outdoor Allergens. The following are some recommendations for avoiding allergens outside:

• Camping and hiking trips should not be scheduled during times of high pollen count (in the Northern states, May and June for grass pollen and mid-August to October for ragweed).
• Patients should avoid strenuous activity when ozone levels are highest, which usually occur in early afternoon, particularly on hot hazy summer days. Levels are lowest in early morning and at dusk.
• Asthma attacks are often higher during thunderstorms. It is not clear why. Some evidence points to a build-up of ozone that accompanies such storms. One study suggested that changing airflow patterns bring a sudden downdraft of air containing concentrations of pollens, small particles and allergens.
• Patients who are allergic to mold should avoid barns, hay, raking leaves, and mowing grass. Exposure to automobile fumes may worsen asthma. Fungi in car air conditioners can also be a problem.

Click the icon to see an image of fungus.

Reducing Exposure to Air Pollution. A number of studies have linked air pollution to asthma. An important 2000 study found a strong association between higher mortality rates from heart and lung diseases and high levels of specific pollutants (ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide). Some experts point out that asthma rates in North America have increased over recent years while the prevalence of many common air pollutants have declined. So pollution is unlikely to be a primary cause of asthma. Nevertheless, evidence strongly suggests that air pollution can worsen existing asthma and patients should take precautions if they are exposed to polluted air.

Occupational Asthma and Reducing Risk

A number of studies have estimated that between 2% and 26% of adult-asthma cases are related to work history. Some experts encourage physicians to suspect occupational factors in all cases of adult-onset asthma. Although workers who have allergies, who smoke, or both are at higher risk than others, any worker exposed to occupational triggers may be at risk for asthma.

Work-related asthma is one of two types:

• Work-aggravated asthma, in which existing asthma symptoms are triggered by irritants at the workplace.
• Occupational asthma, which is new-onset asthma strongly associated with conditions at work.

Occupational asthma is further categorized as the following:

• Nonlatent (symptoms occur right after exposure to an irritant, usually high concentrations of gas, fumes, dust, or chemicals).
• Latent (symptoms develop after prolonged exposure to substances in the workplace).

Occupational Triggers. Over 250 agents have been identified as potential occupational triggers of asthma and the list is growing. A few of the chemicals and substances that are particularly problematic include:

• Isocyanates used in the manufacture of polyurethane, paints, steel, and electronics.
• Trimellitic anhydrides (TMA) used in many plastics and epoxies.
• Western red cedar, oak, redwood, and mahogany.
• Metal salts (platinum, nickel, and chrome) and metal working fluids.
• Vegetable dusts (soybeans, grains, flour, cotton, and gums).
• Biologic agents (Bacillus subtilis, pancreatic enzymes).
• Xylanase used in the baking industry.
• Pharmaceutical agents (penicillin, phenylglycine acid chloride).
• Glutaraldehyde used to sterilize medical equipment.
• Red dye made from the cochineal insect.
• Diacetyl, the main chemical in artificial butter flavoring used in popcorn.

Workers in these industries and others, including farmers, hairdressers, and those who work in the garment industries are at risk for asthma.

Preventing Occupational Asthma. In people whose asthma is caused by workplace conditions, improved ventilation or face masks may help.

Sometimes, however, even low levels of chemical agents can trigger an asthma attack. In such cases, leaving the job is the only way to prevent the condition from getting worse. Because such a step can be emotionally and financially threatening, workers should be sure that occupational substances are the cause of the asthma by having a complete check-up by a lung specialist.

If the diagnosis of occupational asthma is certain, patients should obtain advice on available compensation plans for disability. The effects of workplace asthma can be permanent. However, in one study, 70% of people with asthma experienced significant improvement in symptoms after leaving the job.

Medications for Treating Seasonal Allergies

Patients with chronic allergic rhinitis may require daily medications. Patients with severe seasonal allergies may be advised to start medications a few weeks before the pollen season, and to continue it until the season is over. Effective medications include the following:

• Anti-inflammatory Agents. Nasal corticosteroids are now considered to be the most effective measure for preventing allergy attacks. Comparison studies are reporting that nasal steroid sprays are more effective than the second generation antihistamines loratidine (Claritin) and cetirizine (Zyrtec). One study also indicated that nasal steroid treatment was more effective than allergy shots. Leukotriene-antagonists and nasal cromolyn may be beneficial in specific cases of allergies.
• Antihistamines. A 2002 study reported that infants with allergies who were given the antihistamine cetirizine (Zyrtec) were much less likely to develop asthma later on. This encouraging research warrants more work.
• Allergy Shots. Allergy shots (immunotherapy) are proving to reduce asthma symptoms and the use of asthma medications in patients with known allergies. It is not yet known if this approach is more effective or safer than other therapies. This treatment poses some risk for severe allergic reactions.

[For detailed information see Well-Connected Report #77 Allergic Rhinitis (Hay Fever and Rose Fever) and Chronic Nasal Congestion.]

Treating and Preventing Medical Conditions that Trigger Asthma

Preventing and Treating Respiratory Infections. A 2002 study of adult asthmatics indicated respiratory infections, including the common cold, can act with allergies to worsen asthma. People with asthma should try to minimize their risk for respiratory tract infections. Washing hands is a very simple but effective preventive measure.

There has been some question concerning influenza vaccinations because of some reports that vaccines may worsen asthma. Recent and major studies have been reporting, however, that the vaccination is safe for adults and children. It is also very important for patients to reduce their risk for respiratory diseases. Still, 90% of asthma patients remain unvaccinated.

Asthma patients should ask their physicians about the flu vaccine and also whether they should receive the vaccination against pneumococcal pneumonia.

Zanamivir, a new drug used for treating influenza, is now considered safe for asthma patients 12 years of age or older. And, in one study, asthma patients treated with zanamivir experienced fewer flu symptoms and their lung function improved. [See Well-Connected Report #94, Colds, Flus, Sore Throats, and Acute Bronchitis.]

Treatments for GERD. Treating gastroesophageal reflux disease (GERD) with drugs that reduce acid may reduce symptoms of both conditions in some patients who also have asthma. Not all such patients report improved asthma symptoms with GERD treatments, and they do not appear to have much effect, in any case, on actual lung function. But studies suggest this approach works in only certain patients, with one study suggesting that such asthmatic individuals tended to be overweight and to have severe GERD in the lower part of the esophagus. [See Well-Connected Report #85, Heartburn and Gastroesophageal Reflux Disease.]

Managing Hormonal-Related Asthma. Women who suspect that menstrual-related changes may influence asthma severity should keep a diary recording their menstrual dates and times of asthma attacks. In some cases, adjusting medications in anticipation of menstruation may help prevent attacks. Some small studies have suggested that hormonal agents called gonadotropin-releasing hormone (GnRH) analogues may help women with severe premenstrual asthma. Such drugs reduce or suppress estrogen levels, however, and can have severe side effects. More research is needed to determine if the disadvantages outweigh the benefits.

Dietary Factors

Weight Loss. People who are both asthmatic and overweight may reduce asthma symptoms simply with weight loss.

Fruits, Vegetables, and Whole Grains. Healthy foods are important for lung function. Specific foods that may be important for healthy lungs are those that contain antioxidants (best obtained from fresh, deep green and yellow-orange fruits and vegetables), selenium (fish, red meat, grains, eggs, chicken, liver, garlic), plant chemicals called flavonoids (apples, onions), and magnesium (green leafy vegetables, nuts, whole grains, milk, and meats).

Fish Oil. Omega-3 fatty acids, found in cold water oily fish and in supplements (preferably DHA-EPA, which are the important compounds in fish oil) have anti-inflammatory effects. Some evidence suggests they may be helpful for people with asthma, although it is weak.

Caffeine. Caffeine has properties that are similar to theophylline, an agent used to treat asthma. A major analysis of studies reported that caffeine improved lung function for up to four hours after consumption. (People who are going to have their lung function tested should avoid drinking coffee, tea, or other caffeinated beverages for at least four hours beforehand.)

Alcohol. In adults, some research suggests that alcohol intake may influence allergy severity. One Spanish study found that as little as one drink a day is enough to worsen dust mite allergies.

Role of Food Allergies. Although 67% of asthmatics believe their symptoms are aggravated by food allergies, studies indicate that this belief may be true in only 5% of cases. The primary suspects are monosodium glutamate, or MSG (found in some canned soups, cheese, and certain vegetables), and sulfites (preservatives in wine and foods that include processed frozen potatoes and tuna). Contrary to what many believe, dairy products do not appear to exacerbate asthma symptoms in people who are not already allergic to them.

Exercise

Asthma is no reason to avoid exercise. Historically, about 10% of US athletes who participated in the Olympics have been asthmatic. Some studies are indicating that long-term exercise may even help control asthma and reduce hospitalization. Patients should consult their physicians before embarking on any exercise program, however. Uncontrolled asthma can be dangerous and, in rare cases, fatal for athletes, even some with mild asthma. Use of the inhaler is extremely important.

People who enjoy running should probably choose an indoor track to avoid pollutants. Swimming is excellent for people with asthma. Yoga practice, which uses both stretching, breathing, and meditation techniques may have particular benefits. One study reported that two-thirds of patients who practiced yoga regularly were able to reduce or stop taking their asthma medications.

Exercise-induced asthma is a limited condition that has specific recommendations.

Reducing Stress and Mood Disorders

People with asthma have no higher rate of anxiety or depression than the general population. However, such emotions interact with the effects of asthma and its treatments in important ways:

• Negative emotions can discourage compliance with medication and the ability to cope.
• Poor control of asthma symptoms, in turn, increases the risk for negative emotions.
• Stress and depression have been associated with more severe symptoms and even an increased risk of fatal asthma attacks.

Some evidence suggests that stress reduction techniques, a positive attitude and relaxation techniques may be very helpful in the long-term management of asthma. [See the Well-Connected Report #31 Stress.]