Asthma

What is asthma?

Asthma is a chronic inflammation of the bronchial tubes (airways) that causes swelling and narrowing (constriction) of the airways. The result is difficulty breathing. The bronchial narrowing is usually either totally or at least partially reversible with treatments.

Asthma affects people differently. Each individual is unique in their degree of reactivity to environmental triggers. This naturally influences the type and dose of medication prescribed, which may vary from one individual to another.

The scope of the problem

Asthma is now the most common chronic illness in children, affecting one in every 15. The number of new cases and the yearly rate of hospitalization for asthma have increased about 30% over the past 20 years. Even with advances in treatment, asthma deaths among young people have more that doubled.

How does asthma affect breathing?

Asthma causes a narrowing of the breathing airways, which interferes with the normal movement of air in and out of the lungs. Asthma involves only the bronchial tubes and does not affect the air sacs or the lung tissue. The narrowing that occurs in asthma is caused by three major factors: inflammation, bronchospasm, and hyperreactivity.

Inflammation

The first and most important factor causing narrowing of the bronchial tubes is inflammation. The bronchial tubes become red, irritated, and swollen. This inflammation increases the thickness of the wall of the bronchial tubes and thus results in a smaller passageway for air to flow through.

Bronchospasm

The muscles around the bronchial tubes tighten during an attack of asthma. This muscle constriction of the airways is called bronchospasm. Bronchospasm causes the airway to narrow further.

Common asthma triggers:

Allergens

• "seasonal" pollens
• year-round dust mites, molds, pets, and insect parts
• foods, such as fish, egg, peanuts, nuts, cow's milk, and soy

Allergy fact

About 80% of children and 50% of adults with asthma also have allergies.

Irritants

• respiratory infections, such as those caused by viral "colds," bronchitis, and sinusitis

• drugs, such as aspirin, other NSAIDs (nonsteroidal antiinflammatory drugs), and beta blockers (used to treat blood pressure and other heart conditions)
• tobacco smoke
• outdoor factors, such as smog, weather changes, and diesel fumes
• indoor factors, such as paint, detergents, deodorants, chemicals, and perfumes
• nighttime
• exercise, especially under cold dry conditions
• work-related factors, such as chemicals, dusts, gases, and metals
• emotional factors, such as laughing, crying, yelling, and distress
• hormonal factors, such as in premenstrual syndrome

Typical asthma symptoms and signs

The symptoms of asthma vary from person to person and in any individual from time to time. The following are the four major recognized asthma symptoms:

• Shortness of breath, especially with exertion or at night
• Wheezing is a whistling or hissing sound when breathing out
• Coughing may be chronic, is usually worse at night and early morning, and may occur after exercise or when exposed to cold, dry air
• Chest tightness may occur with or without the above symptoms

What medications are used in the treatment of asthma?

Most asthma medications work by relaxing bronchospasm (bronchodilators) or reducing inflammation (corticosteroids). In the treatment of asthma, inhaled medications are generally preferred over tablet or liquid medicines, which are swallowed (oral medications). Inhaled medications act directly on the airway surface and airway muscles where the asthma problems initiate. Absorption of inhaled medications into the rest of the body is minimal. Therefore, adverse side effects are fewer as compared to oral medications

To decrease the deposition of medications on the throat and increase the amount reaching the airways, spacers can be helpful. Spacers are tube-like chambers attached to the outlet of the MDI canister. Spacer devices can hold the released medications long enough for patients to inhale them slowly and deeply into the lungs. A spacing device placed between the mouth and the MDI can improve medication delivery and reduce the side effects on the mouth and throat. Rinsing out the mouth after use of a steroid inhaler also can decrease these side effects.

Combination inhaler therapy is now available for the treatment of asthma. These medications include Advair (fluticasone and salmeterol), Symbicort (budesonide and formoterol), and Dulera (mometasone and formoterol). Symbicort and Dulera use the standard MDI inhaler device with a dose counter. Advair has a unique powdered delivery system with a built-in counter.

Asthma At A Glance

• Asthma is a chronic inflammation of the bronchial tubes (airways) that causes swelling and narrowing (constriction) of the airways. The bronchial narrowing is usually either totally or at least partially reversible with treatments.
• Asthma is now the most common chronic illness in children, affecting one in every 15.
• Asthma involves only the bronchial tubes and usually does not affect the air sacs or the lung tissue. The narrowing that occurs in asthma is caused by three major factors: inflammation, bronchospasm, and hyperreactivity.
• Allergy can play a role in some, but not all, asthma patients.
• Many factors can precipitate asthma attacks and they are classified as either allergens or irritants.
• Symptoms of asthma include shortness of breath, wheezing, cough, and chest tightness.
• Asthma is usually diagnosed based on the presence of wheezing and confirmed with breathing tests.
• Chest X-rays are usually normal in asthma patients.
• Avoiding precipitating factors is important in the management of asthma.

Medications can be used to reverse or prevent bronchospasm in patients with asthma.