Asthma comes from a Greek word that means “to breathe hard”.
This is the most common chronic lung disease. 

Asthma occurs when the main air passages of your lungs, the bronchial tubes, become inflamed & narrow. 

A trigger will make the muscles of the bronchial walls tighten and as it constricts, it makes the airways narrower.

At the same time cells in the lungs produce extra mucus which may be thick, gelatinous and sticky, making them difficult to cough up and sometimes completely blocking the airways. 

The above causes people to cough, wheeze, experience tightness of chest and feeling short of breath, the characteristics symptoms of asthma.

These are the sub topics on this page:

• Warning signs of Asthma Attack

• What happens in an Asthma Attack

• Causes and Triggers

• How Asthma is classified

• Treatment

• Allergen immunotherapy

• Support your immune system

Most asthma attacks are preceded by warning signs. Recognizing these warning signs and treating the symptoms early can help prevent attacks or keep them from becoming worse.

Warning signs and symptoms of asthma in adults may include:

Increased shortness of breath or wheezing 
Disturbed sleep caused by shortness of breath, coughing or wheezing 
Chest tightness or pain 
Increased need to use bronchodilators — medications that open up airways by relaxing the surrounding muscles 
A fall in peak flow rates as measured by a peak flow meter, (a simple and inexpensive device that allows you to monitor your own lung function )

Children often have an audible whistling or wheezing sound when exhaling and frequent coughing spasms.

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What happens in an asthma attack

 

Asthma has been redefined by the National Heart, Lung and Blood Institute (NHLBI) as “a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role, in particular, mast cells, eosinophils, T-lymphocytes, neutrophils, and epithelial cells.”

Inflammation is now known to be a key element in the development / underlying problem cause of asthma.

When an allergen enters your airway, your immune response triggers the production of antibodies, Ig E, which attach themselves to mast cells in the bronchi, nose or skin. Allergic reaction happens on the second encounter. 

So when the same allergen enters your system, the eosinophils, (through a series of chemical reactions), form leukotrienes in their membranes. These toxic, pro-inflammatory substances, including histamines released causes the blood vessels to dilate, capillaries to leak resulting in swelling. The nerve endings will be tickled ( hence the itch) and mucus will plug the windpipe causing the patient to choke.

Histamines cause the airways to contract. Leukotrienes constricts the airways more than histamine, thus its effects lasts longer. They also stimulate mucus production and make the tiny blood vessels more permeable, hence allergens can enter easily. But more important they cause the eosinophils to migrate to new areas, where the inflammatory process starts again, thus worsening the asthmatic symptoms.

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Causes and triggers

 

Asthma is probably due to a combination of environmental and genetic factors. You're more likely to develop asthma if it runs in your family and if you're sensitive to environmental allergens or irritants. Early, frequent infections and chronic exposure to secondhand smoke or certain allergens may increase your chances of developing asthma.

Exposure to various allergens and irritants may trigger your asthma symptoms. The following are common things that trigger asthma symptoms:

• Allergens, such as pollen, animal dander or mold 

• Cockroaches and dust mites 

• Air pollutants and irritants including smoke

• Strong odors or scented products or chemicals 

• Respiratory infections, including the common cold 

• Physical exertion, including excessive exercise 

• Strong emotions and stress 

• Cold air 

• Certain medications, including beta blockers, aspirin and other nonsteroidal anti-inflammatory drugs 

• Sulfites, preservatives added to some perishable foods such as tartrazine, (the orange coloring), MSG, peanuts, shellfish

• Gastroesophageal reflux disease (GERD), a condition in which stomach acids back up into your esophagus. GERD may trigger an asthma attack or make an attack worse. 

• Sinusitis 

• Climate changes in temperature and humidity

Asthma is strongly linked to allergy. Allergies can make asthma worse. However not all people with asthma have allergies, and not all people with allergies have asthma.

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The results of your physical exam and diagnostic tests will help your doctor classify how severe your asthma is.  This provide a guide as to how it should be treated. The four main classifications of asthma are:

• Mild intermittent. This is the mildest form of asthma. Generally, people with mild intermittent asthma have mild symptoms up to two days a week and up to two nights a month. 
  

• Mild persistent. You have mild persistent asthma if you have asthma symptoms more than twice a week, but no more than once in a single day. 
  

• Moderate persistent. If you have asthma symptoms once a day and more than one night a week, you may have moderate persistent asthma. 
  

• Severe persistent. This is the most severe form of asthma, causing symptoms throughout the day on most days and frequently at night. 

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Although there is no cure for asthma, there are some very effective asthma treatments that can help to control your symptoms. An asthma management plan aims to:

• Reduce your asthma symptoms
• Limit the amount of medication you have to take
• Prevent emergency visits to hospital
• Improve your asthma-related quality of life

There are 2 kinds of medication:

1. Bronchodilator drugs or Relievers- drugs that relieve the symptoms of an attack should one occur. Relievers help to relax the muscles around the airways so that they open up and allow to breathe more easily.
   

2. Preventers-drugs which if taken regularly, may prevent an attack from occurring. Preventers reduce inflammation and make your lungs less sensitive to asthma triggers.

 

Bronchodilator drugs

There are several types of bronchodilators of which short-acting beta agonist drugs are the most common. 

These Short-acting bronchodilators are often called "rescue" or "quick-relief" medications as they stop the symptoms of an asthma attack in progress.

They are taken through an inhaler device and the drugs take effect almost immediately in relieving the wheezing, coughing and breathlessness. Inhaled therapy is preferable to tablets as the drug is delivered directly to the lungs where it works and thus does not affect other parts of the body.

A nebulizer is also used for severe attack. The same effect can also be gotten by using a metred dose inhaler and spacer.

Add-on therapy

These add-on are used usually in severe asthma or whose asthma is not controlled by the other methods on its own. As the name suggests, they should not be used as a sole therapy. 

They include long-acting beta agonists (LABAs), Anticholinergics, Oral theophylline and Leukotriene receptor antoagonist drugs (LTRAs). 

Note: 

1. Although generally not as effective as inhaled corticosteroids, leukotriene modifiers are an option if you have mild asthma and want to avoid corticosteroids.
   

2. Theophylline may be helpful for relieving your nighttime symptoms of asthma. But theophylline may cause side effects, such as nausea and vomiting, severe abdominal pain, diarrhea, acid reflux, confusion, fast or irregular heartbeat, and nervousness.

 

Preventive Drug

Current maintenance therapy for asthma is directed primarily at airway inflammation. The regular use of topical inhaled steroids on the air passages is a very effective means of managing the chronic symptoms of asthma. Inhaled steroids work by reducing the airway inflammation.

However, inhaled steroid therapy usually takes a few weeks before real benefit is noticed, and continued benefit requires regular long-term use. 

The steroids used to treat asthma are completely different from the anabolic steroids used by some body builders and athletes.

Asthma is a complex disease. It’s spasm as well as inflammation and therefore different drugs are prescribed to control different components of the disease. 

Antihistamines

These are prescribed to stop allergy symptoms like sneezing and itchy eyes. They block the action of the histamines released to stimulate the organs affected eg they reduce the capillary fragility which produces the redness in allergic reactions, or reduce excessive tears and salivation.

They have no effect on rate of histamine release, nor do they inactivate histamine. Histamine is the chemical released by the mast cells lining the skin and mucus membranes when they are irritated by an allergen.

Side effects include drowsiness, dry mouth, blurred vision, dizziness, nausea and loss of appetite. Newer drugs reduced this effect but some causes heart rhythm problems (arrhythmias). 

High doses of vitamin C and flavonoid quercitin has been shown to have a histamine lowering effect.

Corticosteroids

Treating mild asthma with corticosteroids may help reduce bronchial inflammation and control the progression of the disease. It helps to reduce the frequency of the attacks.

Side effects associated with inhaled corticosteroids can include hoarseness or loss of voice, oral yeast infections (thrush), and cough. Long-term use of inhaled corticosteroids may slightly increase the risk of skin thinning, bruising, osteoporosis, eye pressure and cataracts. In children, inhaled corticosteroids may slow growth.

Use a spacer when using a metered-dose-inhaler form of corticosteroid, and rinse your mouth with water after each use. This reduces the amount of drug that is swallowed and absorbed into your body and reduces side effects, such as mouth and throat irritation and oral yeast infections (thrush).

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