Asthma is the irritation and swelling of airways combined with the tightening of muscles surrounding them. The resulting narrowing of the airways can result in:
- Chest tightness
- Shortness of breath
Asthma symptoms can flare up when exposed to certain “triggers”, which include infections, allergies, or strong fumes the asthma sufferer may come in contact with. The trigger causes the airways leading to the lungs to become even more inflamed and swollen, and the muscles surrounding them constrict further, making it difficult to breathe. Once you have such a reaction, the airways become more sensitive to other triggers.
Over five hundred thousand hospitalizations each year make asthma one of the most expensive diseases in the nation. Approximately 17 million people including 5 million children have asthma in the United States. The incidence of asthma has increased more than 50 percent in the last 15 years.
Asthma is categorized depending on the triggers that cause asthma reactions or “attacks”. One can suffer more than one type of asthma simultaneously. The categories or types of asthma include:
- Seasonal asthma – attacks may be triggered by tree, grass, or flower pollen or mold spores. Those whose asthma worsens in late summer or fall are likelier to be susceptible to ragweed. Some experience more frequent attacks in the spring when flowering plants abound.
- Non-allergic asthma –attacks may be triggered by, or the condition may worsen due to irritants such as wood or tobacco smoke, room deodorizers, fresh paint, perfumes, household cleaning products, chemicals, or air pollution. Respiratory infections such as colds, the flu, sinus infections, and even heartburn can trigger non-allergic asthma attacks.
- Exercise-induced asthma (EIA) – symptoms are triggered by physical activity and are typically experienced during or shortly after exercise. Exercise in cold, dry air or that which is accompanied by sudden changes in temperature should especially be avoided by those with EIA.
- Nocturnal asthma – symptoms seem to worsen at night when natural steroids and adrenaline the body produces, both of which protect against asthma, tend to be present at lower levels. Postnasal drip and sinus infections, which are caused by allergens such as pet dander and dust mites, and which also tend to be worse at night, are also potential contributors to potential reactions.
The most effective treatment for asthma is to identify the triggers and eliminate exposure to them. Treatment will depend on the type and severity of the illness an on the frequency of the symptoms. In some cases, desensitization to allergens may be an option. In others, additional medications may be required to control the disease.
Treatments for asthma are generally classified as preventers, relievers or emergency care. Bronchodilators may provide short-term relief in all patients and may be the only medication needed by those who experience only occasional attacks. For those who suffer more than two attacks per week, low-dose inhaled glucocorticoids, a mast-cell stabilizer, an oral leukotriene modifier, or theophylline may be recommended. For those who experience daily attacks, a higher dose of glucocorticoid may be prescribed along with a long-acting beta 2-adrenergic agonists (LABA), theophylline, or a leukotriene modifier. Oral glucocorticoids may be added to these treatments in case of severe attacks in severe asthmatics. The National Heart, Lung and Blood institute’s Guidelines for the Diagnosis and Management of Asthma (EPR-3) can be found online.
In November 2005, the U.S. Food and Drug Administration (FDA) issued a health advisory regarding the use of LABAs*. Certain studies had shown that these medications could lead to a worsening of asthma symptoms and even death. Currently available LABAs include bambuterol, formoterol, salmeterol, and sustained-release oral albuterol. Long-acting bronchodilators combined with inhaled steroids have become more widespread, the most common combination in the U.S. being Advair (salmeterol and fluticasone).
In May 2006, the FDA requested that the makers of the LABAs Advair Diskus, Serevent Diskus, and Foradil Aerolizer change their product labels to warn patients and healthcare professionals that these medications could increase the chance of severe asthma episodes which could sometimes result in death. The FDA also asked the manufacturers to make available a Medication Guide. The information on the proposed label changes explains that, although LABAs reduce the number of asthma episodes, they may increase the likelihood of a severe asthma episode when they do occur. The advisory also recommends that rather than being the first medicine used to treat asthma, LABAs should be prescribed only if other medications fail to control the asthma.
Asthmatics are more susceptible to pulmonary diseases in general when taking drugs or medications, sometimes for other conditions. These are discussed further in DRUG-INDUCED PULMONARY DISEASE. Drugs that have been known to cause other pulmonary diseases in asthmatics include:
Some drugs also list asthma as one of their potential side effects. Methotrexate (Trexall, Rheumatrex), for instance, a drug commonly used for treating rheumatoid arthritis and other connective tissue disorders, can cause asthma, among other pulmonary diseases, when used even in only anti-inflammatory doses.
Prognosis and Developements
Most studies show that early treatment with glucocorticoids averts, or at least lessens, a decline in lung function, and corticosteroids can help most of those with mild symptoms lead relatively normal lives. And recent medical advances are rather promising.
Research form the Harvard Medical School (HMS) appears to have linked the cause of asthma to a special type of natural “killer” cell. It also seems to indicate, however, that many asthmatics are not being treated with the right kinds of drugs.
Fortunately, even with current treatment methods and medications, the prognosis for asthmatics is generally good. Only 54 percent of children diagnosed with asthma are projected to continue carrying the diagnosis after a decade. About 0.06 percent of patients die from the disease each year.