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The U.S. National Asthma Education and Prevention Program (NAEPP) guidelines for the diagnosis and management of asthma recommend:
Symptoms of asthma include:
The word asthma originates from an ancient Greek word meaning panting. Essentially, asthma is an inflammatory lung condition that makes it difficult to breathe properly.
When people inhale, the air travels through the following structures:
Asthma is a chronic condition in which these airways undergo changes when stimulated by allergens or other environmental triggers. Such changes appear to be two specific responses:
These actions in the airway cause coughing, wheezing, and shortness of breath (dyspnea), the classic symptoms of asthma.
In the hyperreactive response, smooth muscles in the airways of the lungs constrict and narrow excessively in response to inhaled allergens or other irritants. Airways in everyone's lungs respond by constricting when exposed to allergens or irritants, but there are major differences in the hyperreactive response that occurs in people with asthma:
The hyperreactive stage is followed by the inflammatory response, which generally contributes to asthma in the following way:
Inflammation appears to be present in the lungs of all patients with asthma, even those with mild cases, and plays a key role in all forms of the disease.
Doctors don’t fully understand the causes of asthma. They believe the disorder is most likely caused by a combination of genetic (inherited) factors and environmental triggers (such as allergens and infections). Asthma tends to run in families, so children whose parents have asthma are more likely to develop it themselves.
Nearly half of adults with asthma have an allergy-related condition, which, in most cases developed first in childhood. (In patients who first develop asthma during adulthood, the allergic response usually does not play a strong causal role.)
In people with allergies, the immune system overreacts to exposure to allergens. Allergic asthma is triggered by inhaling certain substances (allergens) such as:
An asthma attack can also be induced or aggravated by direct irritants to the lungs. Important irritants involved in asthma include cigarette smoke, indoor chemicals, and air pollution.
Respiratory viral and bacterial infections play a role in some cases of adult-onset asthma. In both children and adults with existing allergic asthma, an upper respiratory tract infection often worsens an attack.
About 22 million Americans have asthma.
Before puberty, asthma occurs more often in males, but after adolescence, it is more common in females. In adults, women are more likely to report severe symptoms than men.
Hormonal fluctuations or changes in hormone levels may play a role in the severity of asthma in women. Between 30 - 40% of women with asthma experience fluctuations in severity that are associated with their menstrual cycle. Some women first develop asthma during or shortly after pregnancy, while others first develop it around the time of menopause (perimenopause).
African-Americans have higher rates of asthma than Caucasians or other ethnic groups. They are also more likely to die of the disease. Ethnicity and genetics, however, are less likely to play a role in these differences than socioeconomic differences, such as having less access to optimal health care, and greater likelihood of living in an urban area (another asthma risk factor).
Studies report a strong association between obesity and asthma. Evidence also suggests that people who are overweight (body mass index greater than 25) have more difficulty getting their asthma under control. Weight loss in anyone who is obese and has asthma or shortness of breath helps reduce airway obstruction and improve lung function.
GERD. At least half of patients with asthma have gastroesophageal reflux disease (GERD), the cause of heartburn. It is not entirely clear which condition causes the other or whether they are both due to common factors. Treating GERD does not appear to improve asthma control.
Aspirin-Induced Asthma. Aspirin-induced asthma (AIA) is a condition in which asthma gets worse after taking aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs). AIA often develops after a viral infection. It is a particularly severe asthmatic condition, associated with many asthma-related hospitalizations. In about 5% of cases, aspirin is responsible for a syndrome that involves multiple attacks of asthma, sinusitis, and nasal congestion. Such patients also often have polyps (small benign growths) in the nasal passages. Patients with aspirin-induced asthma (AIA) should avoid aspirin and other NSAIDs, including ibuprofen (Advil and other brands, generic) and naproxen (Aleve, generic).
Asthma is usually chronic, although it occasionally goes into long periods of remission. Long-term outlook generally depends on severity:
Lung function declines faster than average in people with asthma, particularly in those who smoke and in those with excessive mucus production (an indicator of poor treatment control).
Death from asthma is a relatively uncommon event, and most asthma deaths are preventable. It is very rare for a person who is receiving proper treatment to die of asthma. However, even when it is not life threatening, asthma can be debilitating and frightening. Asthma that is not properly controlled can interfere with school and work, as well as with daily activities.
Asthma symptoms vary in severity from occasional mild bouts of breathlessness to daily wheezing that lasts even when a patient takes large doses of medication. After exposure to asthma triggers, symptoms rarely develop abruptly but progress over a period of hours or days. Occasionally, the airways have become seriously obstructed by the time the patient calls the doctor.
The classic symptoms of an asthma attack include:
The end of an attack is often marked by a cough that produces thick, stringy mucus. After an initial acute attack, inflammation lasts for days to weeks, often without symptoms. (The inflammation itself must still be treated, however, because it usually causes relapse.)
The following signs and symptoms may indicate a life-threatening situation:
Asthma often progresses very slowly, but it may sometimes develop to a fatal or near-fatal attack within a few minutes. It is very difficult to predict when an attack will become very serious.
Exercise-induced asthma (EIA) is a limited form of asthma in which exercise triggers coughing, wheezing, or shortness of breath. This condition generally occurs in children and young adults, most often during intense exercise in cold dry air. Symptoms are generally most intense about 10 minutes after exercising and then gradually resolve.
EIA is triggered only by exercise and is distinct from ordinary allergic asthma in that it does not produce a long period of airway hyperactivity, as allergic asthma does. (However, some people have both forms of asthma.) People who have only EIA do not need long-term maintenance therapy.
Asthma occurs primarily at night (nocturnal asthma) in as many as 75% of patients with asthma. Attacks often occur between 2 and 4 a.m. Nighttime attacks may indicate poor asthma control.
When asthma is suspected, the patient should describe for the doctor any pattern related to the symptoms, and possible precipitating factors, including:
A number of disorders may cause some or all of the symptoms of asthma:
If symptoms and a patient's history suggest asthma, the doctor will usually perform pulmonary function tests to confirm the diagnosis and determine the severity of the disease.
Using a spirometer, an instrument that measures the air taken into and exhaled from the lungs, the doctor will determine several values:
If the airways are obstructed, these measurements will fall. Depending on the results, the doctor will take the following steps:
The patient may receive skin or blood allergy tests, particularly if a specific allergen is suspected and available for testing. Allergy skin tests may help diagnose allergic asthma, although they are not recommended for people with year-round asthma.
While medications play an essential role in the management of asthma, appropriate management of asthma also involves:
The severity of asthma is classified into four groups: Intermittent, Mild Persistent, Moderate Persistent, and Severe Persistent. Six specific components of severity are used to classify patients. These components are:
Patients can greatly reduce the frequency and severity of asthma attacks by understanding the difference between coping with asthma attacks and controlling the disease over time.
Medications for asthma fall into two categories:
Patients can greatly reduce the frequency and severity of asthma attacks by understanding the difference between coping with asthma attacks and controlling the disease over time. Unfortunately, many patients do not understand the difference between medications that provide rapid short-term relief and those that are used for long-term symptom control. Many patients with moderate or severe asthma overuse their short-term bronchodilator medications and underuse their long-term corticosteroid medications. The overuse of bronchodilators can have serious consequences; not using steroids can lead to permanent lung damage.
These are the signs of well-controlled asthma:
A stepwise approach is recommended for treating asthma. Medications and dosages are increased when needed, and decreased when possible. Based on a patient’s age and asthma severity, there are specific recommendations regarding whether to use long-term control medications and which ones to use. Patient education, environmental control measures, and management of any other conditions are also needed. Doctors may always adjust these recommendations based on a specific patient.
In choosing therapy, doctors must also consider the risk an individual patient has for more severe exacerbations. Factors that may contribute to this include parental history of asthma, atopic dermatitis, and known sensitivity to different allergens or foods. Patients should be reevaluated within 2 - 6 weeks of starting therapy to assess response.
Key points regarding recommendations for adults include:
Most asthma drugs are taken with inhalers. In a hospital setting, or when a patient cannot use an inhaler, a nebulizer may be used. A nebulizer is a device that administers the drug in a fine spray that the patient breathes in. The two basic inhaler devices are the metered-dose inhaler (MDI) and dry powder inhalers (DPIs).
Metered-Dose Inhaler. The standard device for administering any asthma medication is the metered-dose inhaler (MDI). This device, particularly when used with a spacer, allows precise doses to be delivered directly to the lungs. (The spacer is a tube that is attached to the inhaler. It serves as a holding chamber for the medication that is sprayed by the inhaler.) MDI-delivered drugs must be used regularly as prescribed and the patient carefully trained in their use in order for them to be effective and safe. Some patients hold the MDI too close to their mouths, or even inside them. Others may exhale too forcefully before inhalation.
The spacer helps improve medication delivery by allowing the patient additional time to inhale. In addition, MDIs can continue to deliver propellant even after the drug has been used up. Patients should track their medicine and throw the device away when the last dose has been administered.
Dry Powder Inhalers. Dry powder inhalers (DPIs) deliver a powdered form of beta2-agonists or corticosteroids directly into the lungs. Some patients find that they are easier to manage than MDIs. Humidity or extreme temperatures can affect the performance of these inhalers, so they should not be stored in humid places (bathroom cabinets) or locations subject to high temperatures (glove compartments during summer months.
Dry-powder may cause tooth erosion, and children are advised to rinse their mouths out right after using a DPI and to brush twice a day with fluoride toothpaste.
People who self-manage their asthma with peak air flow measurements and adjust their medications as needed have fewer hospitalizations and unplanned doctors' visits, and, generally, have a better quality of life than those who rely only on the occasional doctor or emergency room visit to control symptoms. Doctors recommend that patients with even mild asthma monitor their own conditions.
In general, monitoring involves the following steps:
Guidelines from the National Asthma Education and Prevention Program (NAEPP) emphasize that most asthma medications are safe for pregnant women. The guidelines recommend that pregnant women with asthma have albuterol available at all times. Inhaled corticosteroids should be used for persistent asthma. Patients whose persistent asthma does not respond to standard dosages of inhaled corticosteroids may need a higher dosage or the addition of a long-acting beta-agonist to their drug regimen. For severe asthma, oral corticosteroids may be necessary. The NAEPP notes that while it is not clear if oral corticosteroids are safe for pregnant women, uncontrolled asthma poses an even greater risk for a woman and her fetus. Pregnant women with asthma face increased risks for complications including pre-eclampsia (a condition associated with high blood pressure) and preterm delivery.
Bronchial thermoplasty is an outpatient procedure that was FDA-approved in 2010 but is reserved for select adult patients whose severe and persistent asthma has not been helped by inhaled corticosteroids and long-acting beta agonist medications. The procedure uses radiofrequency energy to heat lung tissue and reduce the thickness of smooth muscle in the airways so that patients can breathe better. While bronchial thermoplasty may help reduce the number of severe asthma attacks over the long term, the procedure carries a number of risks including the possibility of asthma attacks during the course of treatment. More experience is needed to evaluate long-term risks and benefits of this invasive treatment. Preliminary reports suggest that the benefits are long lasting with minimal delayed adverse effects.
These medications quickly control acute asthma attacks.
Beta2-agonists do not reduce inflammation or airway responsiveness but serve as bronchodilators, relaxing and opening constricted airways during an acute asthma attack. They are used alone only for patients with mild and intermittent asthma. Patients with more severe cases should use them in combination with other drugs.
Specific short-acting beta2-agonists include:
Short-acting bronchodilators are usually administered through inhalation and are effective for 3 - 6 hours. They relieve the symptoms of acute attacks, but they do not control the underlying inflammation. If asthma continues to worsen with the use of these drugs, a doctor may prescribe corticosteroids or other drugs to treat underlying inflammation.
Side Effects of Beta2-Agonists. Side effects of all beta2-agonists include:
Beta2-agonists have serious interactions with certain other drugs, such as beta-blockers, and patients should tell their doctors about any other medications they are taking. People with diabetes, heart disease, high blood pressure, hyperthyroidism, an enlarged prostate, or a history of seizures should use these drugs with caution.
Loss of Effectiveness and Overdose. Short-acting beta2-agonists become less effective when taken regularly over time, which increases the risk for overuse. Overdose can be serious and in rare cases even life threatening, particularly in patients with heart disease.
Two inhaled drugs, ipratropium bromide (Atrovent) and tiotropium (Spiriva) act as bronchodilators over time. Neither is highly beneficial for acute asthma attacks. Moreover, the drugs are not approved specifically for asthma. They may, however, have some benefits:
Common oral corticosteroids include prednisone, prednisolone, methylprednisolone, and hydrocortisone. They very effectively reduce inflammation. They are generally used for asthma flareups that do not respond to inhaler medications. In some severe cases, they may be used as maintenance therapy. Usually, the dosage starts out higher and is then gradually reduced over a 5 - 7 day period.
Adverse effects of prolonged use of oral steroids include cataracts, glaucoma, osteoporosis, diabetes, fluid retention, susceptibility to infections, weight gain, hypertension, capillary fragility, acne, excess hair growth, wasting of the muscles, menstrual irregularities, irritability, insomnia, and psychosis. Osteoporosis (bone thinning) is a common and particularly severe long-term side effect of prolonged steroid use.
No one should stop taking any steroids without consulting a doctor first. If the doctor orders steroids withdrawn, regular follow-up monitoring is necessary. Patients should talk to their doctors about ways to prevent adrenal insufficiency during withdrawal, particularly during stressful times when the risk increases.
These medications are taken on a regular basis to prevent asthma attacks and control chronic symptoms.
Corticosteroids, also called glucocorticoids or steroids, are powerful anti-inflammatory drugs. Steroids are not bronchodilators (they do not relax the airways) and have little short-term effect on symptoms. Instead, they work over time to reduce inflammation and prevent permanent injury in the lungs. They can also help prevent asthma attacks from occurring. The use of inhaled corticosteroids in patients with moderate-to-severe asthma reduces the risk of rehospitalization and death from asthma.
Taking a corticosteroid drug through an inhaler makes it possible to provide effective local anti-inflammatory activity in the lungs with very few side effects elsewhere in the body. (By contrast, steroids taken by mouth have considerable side effects throughout the body.) Inhaled corticosteroids are recommended as the primary therapy for any patient needing long-term control medications for persistent asthma.
The most recent generation of inhaled steroids include fluticasone (Flovent), budesonide (Pulmicort), triamcinolone (Azmacort and others), flunisolide (AeroBid), mometasone furoate (Asmanex), and ciclesonide (Alvesco). These steroids are sometimes combined with a long-acting beta2-agonist in a single inhaler, such as budesonide-formoterol (Symbicort), fluticasone-salmeterol (Advair), and mometasone-formoterol (Dulera). Optimal timing of the dose is important and may vary depending on the medication.
Inhaled steroids are generally considered safe and effective and only rarely cause any of the more serious side effects associated with prolonged use of oral steroids. The following are side effects of inhaled steroids:
Long-acting beta2-agonists (LABAs) are used for preventing an asthma attack (not for treating attack symptoms). These drugs should never be used alone in the treatment of asthma in adults or children. They can be dangerous when used alone, because they can mask asthma symptoms, and they can increase the risk of asthma death unless paired with an inhaled steroid. LABAs should only be used in combination with an asthma controller medication, such as an inhaled corticosteroid. LABAs should be used for the shortest time possible, and should only be used by patients whose asthma is not adequately controlled by asthma controller medications.
Salmeterol-fluticasone (Advair), formoterol-budesonide (Symbicort), and formoterol-mometasone (Dulera) are long-acting beta2 agonists products combined with a steroid in a single inhaler that are used for treatment of moderate-to-severe asthma. The LABA-only versions of these drugs are salmeterol (Serevent Diskus) and formoterol (Foradil Aerolizer).
Doctors are still trying to determine when long-acting beta2-agonists should be added to an asthma treatment plan. If your symptoms do not improve or if symptoms worsen with this type of drug, your doctor will recommend discontinuing it. Do not, however, stop taking this drug or other asthma medications without first talking with your doctor.
Leukotriene antagonists (also called anti-leukotrienes or leukotriene modifiers) are pills that block leukotrienes. Leukotrienes are powerful immune system factors that, in excess, produce a battery of damaging chemicals that can cause inflammation and spasms in the airways of people with asthma. As with other anti-inflammatory drugs, leukotrienes are used for prevention, NOT for treating acute asthma attacks.
Leukotriene antagonists include montelukast (Singulair), zafirlukast (Accolate, generic) and zileuton (Zyflo). These drugs are considered an alternative for long-term control of asthma. Other potential uses include preventing exercise-induced asthma.
Side Effects and Complications. Upset stomach, headache, and sore throat are the most common side effects of leukotriene antagonists. Because these drugs can raise liver enzyme levels, patients may need periodic liver tests..
Mental health disturbances and behavioral changes have been associated with these medications. These mood problems include agitation, aggression, anxiousness, dream abnormalities, hallucinations, depression, insomnia, irritability, restlessness, tremor, and suicidal thinking. Patients who take a leukotriene antagonist drug should be monitored for signs of behavioral and mood changes. Doctors should consider discontinuing the drug if patients exhibit any of these symptoms.
Omalizumab (Xolair) is FDA-approved for patients age 12 and older who have moderate-to-severe persistent asthma related to allergies. Omalizumab is a biologic drug that targets and blocks the antibody immunoglobulin E (IgE), a chemical trigger of the inflammatory events associated with an allergic asthma attack.
Omalizumab is given by injection every 2 - 4 weeks. It is used only to treat patients who have moderate-to-severe persistent asthma related to allergies whose symptoms are not controlled by inhaled corticosteroids.
Side Effects and Complications. About 1 in 1,000 patients who take omalizumab develop anaphylaxis (a life-threatening allergic reaction). Patients can develop anaphylaxis after any dose of omalizumab, even if they had no reaction to a first dose. Anaphylaxis may occur up to 24 hours after the dose is given.
Omalizumab should always be injected in a doctor's office, and health care providers should observe patients for at least 2 hours after an injection. Patients should also carry emergency self-treatment for anaphylaxis (such as an Epi-Pen) and know how to use it. With an Epi-Pen, or similar auto-injector device, patients can quickly give themselves a life-saving dose of epinephrine.
Anaphylaxis symptoms include:
The FDA is currently reviewing whether omalizumab may be associated with increased risk for heart and vascular problems (ischemic heart disease, arrhythmias, cardiomyopathy, heart failure, pulmonary hypertension, and blood clots).
Theophylline relaxes the muscles around the bronchioles and also stimulates breathing. Since the introduction of inhaled corticosteroids and long-acting beta2-agonists, theophylline is not used as often for asthma treatment. It may still be used in some circumstances, such as for treating nocturnal asthma. Theophylline is available in tablet, liquid, and injectable forms. Theophylline should not be used by people with peptic ulcers, and should be used with caution by anyone with heart disease, liver disease, high blood pressure, or seizure disorders.
Patients with asthma should get an annual flu vaccine, and they should receive the vaccination against pneumococcal pneumonia at least once.
Patients with asthma and chronic allergic rhinitis may need to take medications daily. Patients with severe seasonal allergies may need to start medications a few weeks before the pollen season, and to continue medicine until the season is over.
Immunotherapy ("allergy shots") may help reduce asthma symptoms, and the use of asthma medications, in patients with known allergies. They may also help prevent the development of asthma in children with allergies. Immunotherapy poses some risk for severe allergic reactions, however, especially for children with poorly controlled asthma.
Treatment of allergies and sinusitis can help control asthma.
Respiratory infections, including the common cold, can interact with allergies to worsen asthma. People with asthma should try to minimize their risk for respiratory tract infections. Using alcohol-based hand rubs and washing hands are simple but effective preventive measures.
Patients with obvious symptoms of reflux (heartburn) may consider the following lifestyle changes:
Women who suspect that menstrual-related changes may influence asthma severity should keep a diary of their menstrual dates and times of asthma attacks. Sometimes, adjusting medications in anticipation of menstruation may help prevent attacks.
Children, adolescents, and adults with asthma are widely using alternative therapies. In one study, nearly half of asthma or allergy sufferers resorted to alternative treatments. To date, however, evidence does not support any value from most alternative therapies, including high-dose vitamins, urine injections, homeopathic remedies, and most herbal remedies.
Relaxation and Stress-Reduction Techniques. Some patients report benefits from many stress reduction techniques, such as acupuncture, hypnosis, breathing relaxation techniques, massage therapy, and meditation practices. There have been very few well-conducted studies supporting their use, however.
Breathing Exercises. Breathing exercises may help improve patients’ quality of life even if they do not have a major impact on medication reduction.
Probiotics. Probiotics are beneficial microbes that some believe may help protect against allergies and asthma. Probiotics can be obtained in active yogurt cultures and supplements, which are being studied for protection. However, evidence to date does not support efficacy in preventing or treating asthma.
Herbal Remedies. Few rigorous studies have evaluated herbal remedies for asthma. Manufacturers of herbal remedies and dietary supplements do not need FDA approval to sell their products. Just like a drug, herbs and supplements can affect the body's chemistry, and therefore have the potential to produce side effects that may be harmful. There have been a number of reported cases of serious and even lethal side effects from herbal products. Always check with your doctor before using any herbal remedies or dietary supplements.
Asthma action plans create a written document for patients to manage asthma during stable times and to more easily identify when asthma is worsening. Important components of a home program include:
Managing Asthma Exacerbations. Always refer to the written action plan from your doctors and nurses. Treatment approaches generally include:
Follow-up generally depends on the severity of asthma, how recently asthma was diagnosed, patient compliance, and whether recent changes in treatment were made.
It is important to avoid and control triggers that lead to asthma attacks.
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, take the following precautions:
Controlling for Dust. Spray furniture polish is very effective for reducing both dust and allergens. Air cleaners, filters for air conditioners, and vacuum cleaners with High Efficiency Particle Arresting (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. If possible, avoid carpets and rugs.
Bedding, Curtains, and Bedroom Environment.
Reducing Humidity in the House. Living in a damp house is counterproductive. Dust mites thrive in humidity and damp houses increase the risk for mold. Humidity levels should not exceed 30 - 50%:
Gas Stoves, Kerosene, and Cooking. Electric stoves and ovens are healthier than gas ones for people with asthma. Gas ovens release nitrogen dioxide, a substance that can aggravate asthma symptoms. Even smoky cooking can worsen asthma. Kerosene (used in space heaters and lamps) may also produce allergic reactions.
Exterminating Pests (Cockroaches and Mice).
Avoiding 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. Everyone should quit smoking and encourage others around them to quit.
Avoiding Outdoor Allergens.
Asthma is no reason to avoid exercise. Historically, about 10% of Olympic athletes have asthma. Some studies indicate that long-term exercise even helps control asthma and reduce hospitalization. Exercise can help control weight, which can help with asthma symptoms. Patients should consult their doctors before starting any exercise program, however.
People who enjoy running should probably choose an indoor track to avoid pollutants. Swimming is excellent for people with asthma. Yoga, which uses stretching, breathing, and meditation techniques, may have particular benefits.
Hints for Reducing Exercise Induced Asthma (EIA). EIA occurs only after exercise and is more likely to happen during regular paced activities in cold, dry air. The following are some suggestions for reducing its impact:
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