Asthma is inflammation and narrowing of the bronchial tubes. Air travels in and out of the lungs through these tubes.
Inflamed Bronchus in the Lungs
The cause of asthma is not known. It does seem to run in some families. Current research suggests a combination of environment, genetics and biology may lead to asthma. Possible triggers of an asthma attack in a person with asthma include:
- Cold weather
- Viral illness
- ]]>Gastroesophageal reflux disease]]> (GERD)
- Sulfites used in dried fruits and wine
- Medications, such as ]]>aspirin]]> , ]]>ibuprofen]]> , and beta-blockers
Exposure to irritants or allergens, including:
- Cigarette smoke, smoke from a wood-burning stove
- Pet dander
- Mold and mildew
- Smog or air pollution
- Perfumed products
These factors increase your chance of developing asthma. Tell your doctor if you have any of these risk factors:
- Living in a large urban area
- Regularly breathing in cigarette smoke]]> (including second-hand smoke)
- Regularly breathing in industrial or agricultural chemicals
- A parent who has asthma
- History of multiple respiratory infections during childhood
- Low birth weight
- Being overweight
- ]]>Gastroesophageal reflux disease]]> (GERD)
- Tightness in the chest
- Trouble breathing
- Shortness of breath
- Chest pain
- Self-limited exercise, difficulty keeping up with peers
The doctor will ask about your symptoms and medical history and perform a physical exam:
Tests may include:
- Peak flow examination—blowing quickly and forcefully into a special instrument that measures your output of air
- Pulmonary function tests]]> (PFTs)—breathing into a machine that records information about the function of your lungs
- Bronchoprovocation tests—lung function tests performed after exposure to methacholine, histamine, or cold or dry air to stimulate asthma; can help to confirm asthma in unclear cases
- Exhaled nitric oxide (a marker of airway inflammation)—to suggest the diagnosis and manage medications
- ]]>Allergy tests]]> —usually skin or sometimes blood tests to find out if allergies may be contributing to the symptoms
The treatment approach to asthma is four-fold:
- Regular assessment and monitoring
- Control of contributing factors (eg, gastroesophageal reflux and sinusitis]]> ), avoidance of allergens or irritants
- Patient education ]]>*³]]>
Often, you'll need to take more than one type of medication.
Medications Used to Control Asthma
These medications are used to control the condition and avoid asthma attacks, not to treat an acute attack:
- Inhaled corticosteroid—used daily to reduce inflammation in your airways
Long-acting beta agonists—(eg, inhaled
) used daily to prevent asthma attacks; should not be taken without an inhaled corticosteroid
- May increase the risk of asthma-related death, intubation (putting a tube in the windpipe to breath), and hospitalization—If you have any concerns, talk to your doctor. ]]>*²]]>
- ]]>Cromolyn sodium]]> or nedocromil sodium inhaler—used daily to prevent asthma flare-ups or to prevent exercise-induced symptoms
- ]]>Zafirlukast]]> , ]]>zileuton]]> , and ]]>montelukast]]> —taken daily to help prevent asthma attacks
- ]]>Omalizumab]]> (Xolair)—a monoclonal antibody against immunoglobulin E (IgE), given as an injection under the skin, used along with other medications
- ]]>Theophylline]]> —taken daily to help prevent asthma attacks, not as commonly used because of interactions with other drugs
Medications Used to Treat an Asthma Attack
These medications are used to treat an asthma attack:
- Quick-acting beta agonists—(eg, inhaled ]]>albuterol]]> , ]]>xopenex]]> ) relax your airways so that they become wider again, may also be used to avoid exercise-induced asthma attacks
- Anticholinergic agents—inhaled medications, such as ]]>ipratropium]]> , that function as a bronchodilator, typically only used in an emergency setting
Corticosteroids—pills, injections, or intravenous (IV) medications given to treat acute flare-up of symptoms
- Pills may be taken for a longer period of time if you have severe asthma that isn't responding to other treatments.
- ]]>Epinephrine]]> —a shot given to stop an asthma attack
There are no guidelines for preventing asthma because the cause is unknown. However, you can help prevent asthma attacks by avoiding things that trigger the attacks. Some general guidelines include:
- Keep windows closed.
- Consider getting HEPA filters for your heating/cooling system and your vacuum cleaner.
- Keep the humidity down in your house.
- Avoid strenuous outdoor exercise during days with high air pollution, a high pollen count, or a high ozone level.
- Get a yearly flu shot]]> .
- Treat allergies and sinusitis.
- Don't smoke.
- Avoid breathing in chemicals or second-hand smoke.
- Don't regularly use a wood-burning stove . Researchers reported that heating systems that are more efficient and non-polluting can help to reduce asthma symptoms in children. ]]>*¹]]>
- If allergies trigger your asthma attacks, ask your doctor about allergy shots.
Talk to your doctor about:
- An appropriate level of exercise for you
- Ways track your asthma—This will help you to identify and treat flare-ups right away.
American Academy of Allergy, Asthma, and Immunology
American Lung Association
Asthma and Allergy Foundation of America
Allergy Asthma Information Association
The Canadian Lung Association
Bone R, et al. Pulmonary and Critical Care Medicine . St. Louis, MO: Mosby-Year Book, Inc; 1998.
Cecil RL, Goldman L, Bennett JC. Cecil Textbook of Medicine. 21st ed. Philadelphia, PA: WB Saunders Company; 2000.
Conn HF, Rakel RE. Conn's Current Therapy 2001 . 53rd ed. Philadelphia, PA: WB Saunders Company; 2001.
High ozone levels harmful to respiratory system, especially for asthmatics. American Academy of Allergy, Asthma & Immunology website. Available at http://www.aaaai.org/media/resources/academy_statements/position_statements/mold.pdf . Accessed June 23, 2008.
Kleigman RM, Jensen HB, Behrman RE, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, PA: Saunders Elsevier; 2007.
*¹10/29/2008 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed/what.php : Howden-Chapman P, Pierse N, Nicholls S, et al. Effects of improved home heating on asthma in community dwelling children: randomised controlled trial. BMJ. 2008 Sep 23.
*²1/6/2009 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed/what.php : Levenson M. Long-acting beta-agonists and adverse asthma events meta-analysis. Joint Meeting of the Pulmonary-Allergy Drugs Advisory Committee, Drug Safety and Risk Management Advisory Committee and Pediatric Advisory Committee. December 10-11, 2008.
*³2/17/2009 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed/what.php : Bailey EJ, Cates CJ, Kruske S, Morris A, Chang A, Brown N. Culture-specific programs for children and adults from minority groups who have asthma. Cochrane Database Syst Rev. 2009;(1):CD006580.
Last reviewed February 2009 by ]]>Julie D.K. McNairn, MD]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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