What is Asthma?

Asthma is a non-communicable chronic inflammatory disease of the airways. It is usually a long-term lung condition.  According to information on Asthma Australia website, people with asthma have sensitive airways in their lungs which react to triggers, causing a ‘flare-up’. In a flare-up, the muscles around the airway squeeze tight, the airways swell and become narrow and there is more mucus. These things make it harder to breathe.An asthma flare-up can come on slowly (over hours, days or even weeks) or very quickly (over minutes). A sudden or severe asthma flare-up is sometimes called an asthma attack.

Asthma affects people of all ages. It could be diagnosed at either younger or older age. Asthma cannot be cured, but for most people it can be well controlled by following a daily management plan.

AsthmaSymptoms

A person’s asthma symptoms can vary over time - sometimes they will have no symptoms, especially when their asthma is well-controlled. Symptoms often vary from person to person, but they are most commonly:

• Breathlessness
• Shortness of breath  
• Wheezing  
• Tight feeling in the chest
• Continuing cough

Symptoms often occur at night, early in the morning or during/just after activity. They are caused by the narrowing of the airways.

People with asthma are often referred to as "twitchy," meaning they seem to overreact to stimuli such as aero-allergens and cold, dry air. Over time, the airways, or bronchial tubes, become inflamed and sensitive. This increased inflammation, if not treated, will often lead to an asthma attack, which involves changes in the bronchial tubes and airways, in the following ways:

• The muscles around the bronchial tubes tighten, causing the airways to narrow. This is known as bronchospasm or bronchoconstriction.

• Mucus is produced within the bronchial tubes further restricting air flow.

Asthma symptoms can:

• Be mild, moderate or severe.
• Vary from person to person.
• Flare up from time to time and then not appear for long periods.
• Vary from one episode to the next.

Asthma is one of the most prevalent chronic conditions affecting people. Asthma can first be diagnosed at any age, but often starts in childhood. If your asthma is well controlled, you should only have occasional asthma symptoms.

Causes and Triggers of Asthma

Global prevalence of asthma has been increasing over yearsand it is estimated that, on average, it is rising by 50% every decade. According to World health Organisation, more than 300 million people currently suffer from asthma. Researchers have yet to pinpoint the cause for the increase in asthma. However, a family history of asthma and/allergy (eczema, allergic rhinitis) have been identified as one of the strongest risk factors for developing asthma.

In addition to the above risk factor, exposure in infancy, to high levels of antigen such as house dust mites as well as exposure to tobacco smoke orchemicalirritants in the workplace have been identified as major causes of asthma.

Some of the potential asthma allergic triggers are:

• Moulds/Moisture,
• Animal dander,
• Pollen,
• Cockroaches,
• Dust mites

In addition to allergic triggers, the following non -allergic triggers are risk factors:

• Certain drugs (ASA, beta blockers)
• Chemicals, fumes and odours
• Respiratory viral infections
• Weather (cold air, thunderstorms),
• Strenuous physical exercise can exacerbate asthma.
• Tobacco smoke
• Air pollution: Smog

Urbanization, on the other hand, has been identified to be correlated with an increase in asthma. The nature of the risk is unclear because studies have not taken into account indoor allergens, although these have been identified as significant risk factors.

Researchers continue to try to find out more about what causes asthma and how we might prevent it.

Asthma Diagnosis and Treatments

Medical experts in the area of asthma have developed evidence-based, clinical practice guidelines that are used to diagnosis and establish treatment plans for patients with asthma and other allergic diseases. To diagnose asthma, a thorough history is taken and a physical examination is performed. A spirometer is used to objectively measure the amount of air inhaled and exhaled and to determine the level of airway obstruction. Allergy skin testing is conducted to determine which specific substances trigger the airway inflammation that can lead to asthma attacks. During skin testing, a tiny amount of allergen is scratched or lightly pricked into the skin. If a person is allergic to a specific allergen, a large ‘wheal’ or bump will appear on the skin. If allergies are knownto be an asthma trigger, immunotherapy then may be considered as a treatment option.Because asthma is a chroniccondition, it usually requires continuous medical care.

Medication therapies are designed to minimize the airway inflammation component of asthma as well as to treat airway narrowing. Patients with moderate to severe asthma have to take long-term medication daily (for example, anti-inflammatory drugs) to control the underlying inflammation and prevent symptoms and attacks. If symptoms occur, short-term medications (inhaled short-acting beta2-agonists) are used to relieve them.

Asthma medications are in form of anti-inflammatory and non-anti-inflammatory drugs. Anti-inflammatory drugs are taken daily to control asthma and prevent asthma attacks. Inhaled corticosteroids are the most popular and most likely to be effective anti-inflammatory medications for most people suffering from asthma. They reduce swelling and mucus production in the airways, making them less likely to react to triggers. Inhaled corticosteroids include beclomethasone (QVAR), budesonide (Pulmicort), fluticasone (Flovent), flunisolide (Aerobid, Aerospan), and ciclesonide (Alvesco) all of which are usually taken twice-a-day, and mometasone (Asmanex) and fluticasone furoate (Arnuity Ellipta), which may control asthma in some patients when taken just once-a-day.

Two other popular types of anti-inflammatory medications include the leukotriene modifier pills monteleukast (Singulair), which can be taken just once a day, zafirlukast (Accolate) taken twice a day, and zileutin (Zyflo) taken four times a day. The third type of anti-inflammatory drug is the inhaled cromones: cromolyn (Intal) and nedocromil (Tilade).

The biologic mepolizumab (Nucala) is a once a month injection that targets blood cells which trigger asthma attacks. It keeps interleukin 5 (IL-5) from binding with those cells and in doing so lowers the number of severe asthma incidents. It can also help a patient reduce the amount of their other asthma medications, but it is only recommended for patients 12and older.

An anti-IgE drug, omalizumab (Xolair), is an injection usually taken once every two to four weeks and works by inhibitingthe allergic inflammation that often causes constriction of the airways. Because of its high cost, Xolair is usually reservedfor patients with difficult-to-control allergic asthma.

Medication is not the only way to control asthma.Environmental control measures are alsoimportant to avoid or eliminate factors that induce or trigger asthma flare-ups.Allergy test results can help individuals become aware of and avoid their personal asthma triggers.

Although asthma symptoms may be mild for most people, failure to use appropriate drugs orcomply with treatment, coupled with an under-recognition of theseverity of the problem, canlead to unnecessary deaths, most of whichdo not occur in the hospital.

Asthma –Related Death Risk Factors

The following are some of the risk factors for asthma-related death:

• Previous history of a near-fatal asthma event
• Recent poorly controlled asthma with increased shortness of breath, nocturnal awakenings, and rescue inhaler use
• Prior severe asthma exacerbation where you were intubated or admitted to an intensive care unit.
• Two or more asthma-related hospital admissions or three or more visits to the emergency room for asthma
• Using 2 or more canisters of your short-acting bronchodilator like albuterol in a month
• If you have trouble identifying when your asthma symptoms are worsening or you are having an asthma attack
• Being poor and from a location far from a medical facility
• Substance abuse
• Significant psychiatric disease
• Other significant medical problems like a heart attack and other lung diseases