ASTHMA


1.0 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.
Bronchial tubes that are chronically inflamed may become overly sensitive to allergens (specific triggers) or irritants (nonspecific triggers). The airways may become "twitchy" and remain in a state of heightened sensitivity. This is called "bronchial hyperreactivity" (BHR). It is likely that there is a spectrum of bronchial hyperreactivity in all individuals. However, it is clear that asthmatics and allergic individuals (without apparent asthma) have a greater degree of bronchial hyperreactivity than nonasthmatic and nonallergic people. In sensitive individuals, the bronchial tubes are more likely to swell and constrict when exposed to triggers such as allergens, tobacco smoke, or exercise. Amongst asthmatics, some may have mild BHR and no symptoms while others may have severe BHR and chronic symptoms.
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.

An estimated 300 million people worldwide suffer from asthma.
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.


2.0 Which triggers cause an asthma attack?

Asthma symptoms may be activated or aggravated by many agents. Not all asthmatics react to the same triggers. Additionally, the effect that each trigger has on the lungs varies from one individual to another. In general, the severity of your asthma depends on how many agents activate your symptoms and how sensitive your lungs are to them. Most of these triggers can also worsen nasal or eye symptoms.
Triggers fall into two categories:-

•allergens ("specific");
•nonallergens -- mostly irritants (nonspecific)

Once your bronchial tubes (nose and eyes) become inflamed from an allergic exposure, a re-exposure to the offending allergens will often activate symptoms. These "reactive" bronchial tubes might also respond to other triggers, such as exercise, infections, and other irritants.

The following is a simple checklist.
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
•additives, such as sulfites
•work-related agents, such as latex, epoxides, and formaldehyde

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
•night time
•GERD (gastroesophageal reflux disorder)
•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


3.0 Asthma symptoms and signs

The symptoms of asthma vary from person to person and in any individual from time to time. It is important to remember that many of these symptoms can be subtle and similar to those seen in other conditions. All of the symptoms mentioned below can be present in other respiratory, and sometimes, in heart conditions. This potential confusion makes identifying the settings in which the symptoms occur and diagnostic testing very important in recognizing this disorder.
Below 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


Asthma fact
Asthma is classified according to the frequency and severity of symptoms, or "attacks," and the results of pulmonary (lung) function tests.

•30% of affected patients have mild, intermittent (less than two episodes a week) symptoms of asthma with normal breathing tests
•30% have mild, persistent (two or mores episodes a week) symptoms of asthma with normal or abnormal breathing tests
•40% have moderate or severe, persistent (daily or continuous) symptoms of asthma with abnormal breathing tests


4.0 Asthma Treatment

The goal of treatment is to avoid the substances that trigger your symptoms and control airway inflammation. You and your doctor should work together as a team to develop and carry out a plan for eliminating asthma triggers and monitoring symptoms.
There are two basic kinds of medication for treating asthma:
- Control drugs to prevent attacks
- Quick-relief drugs for use during attacks
Control drugs for asthma control your symptoms if you don't have mild asthma. You must take them every day for them to work. Take them even when you feel okay.
The most common control drugs are:
Inhaled corticosteroids (such as Azmacort, Vanceril, AeroBid, Flovent) prevent symptoms by helping to keep your airways from swelling up.
Long-acting beta-agonist inhalers also help prevent asthma symptoms. Do not take long-acting beta-agonist inhaler drugs alone. These drugs are generally used together with an inhaled steroid drug. It may be easier to use an inhaler that contains both drugs.
Other control drugs that may be used are:
Leukotriene inhibitors (such as Singulair and Accolate)
Omalizumab (Xolair), which blocks a pathway that the immune system uses to trigger asthma symptoms
Cromolyn sodium (Intal) or nedocromil sodium (Tilade)
Aminophylline or theophylline (rarely used anymore)
Asthma quick-relief drugs work fast to control asthma symptoms:

You take them when you are coughing, wheezing, having trouble breathing, or having an asthma attack. They are also called "rescue" drugs.
They also can be used just before exercising to help prevent asthma symptoms that are caused by exercise.
Tell your doctor if you are using quick-relief medicines twice a week or more to control your asthma symptoms. Your asthma may not be under control, and your doctor may need to change your dose of daily control drugs.
Quick-relief drugs include:
Short-acting bronchodilators (inhalers), such as Proventil, Ventolin, and Xopenex
Your doctor might prescribe oral steroids (corticosteroids) when you have an asthma attack that is not going away. These are medicines that you take by mouth as pills, capsules, or liquid. Plan ahead. Make sure you do not run out of these medications.
A severe asthma attack requires a check-up by a doctor. You may also need a hospital stay, oxygen, and medications given through a vein (IV).
Asthma action plans are written documents for anyone with asthma. An asthma action plan should include:
- A plan for taking asthma medications when your condition is stable
- A list of asthma triggers and how to avoid them
- How to recognize when your asthma is getting worse and when to call your doctor or nurse
A peak flow meter is a simple device to measure how quickly you can move air out of your lungs.
It can help you see if an attack is coming, sometimes even before any symptoms appear. Peak flow measurements can help show when medication is needed, or other action needs to be taken.
Peak flow values of 50% - 80% of a specific person's best results are a sign of a moderate asthma attack, while values below 50% are a sign of a severe attack.