New Zealand, along with countries like Australia and Great Britain, has one of the highest rates of asthma in the world. It disproportionately affects Maori and Pacific Island people, and those from lower socio-economic groups. Exposure to certain dusts or chemicals may predispose people in some lines of work to asthma.
Signs and symptoms
Asthma attacks are characterised by difficulty breathing – especially exhaling. The severity of asthma symptoms varies between individuals. Some experience only mild symptoms while others have very severe symptoms. Attacks can happen suddenly and can occur after periods of being relatively symptom free. A severe asthma attack can be life threatening if treatment is not sought immediately. Common signs and symptoms of asthma include:
- Coughing – which may worsen at night
- Chest tightness
- Shortness of breath
- Difficulty speaking (in more severe attacks)
- Blueness around the mouth (in more severe attacks).
The exact cause of asthma is not fully understood. It is believe to be caused by a combination of genetic (inherited) and environmental factors. It may be related to modern living, including environmental changes, diet or exposure to some infections.
It is known that most people with asthma constantly have some degree of inflammation in their airways. Their airways are also sensitive to certain irritants, known as triggers. Triggers can cause tightening or constriction of the already inflamed airways, thus provoking an asthma attack. Each individual tends to have different asthma triggers. Common asthma triggers include:
- Pollens or moulds
- House dust mites
- Air pollution
- Certain foods or food additives
- Strong perfumes
- Cigarette smoke
- Some medicines eg: aspirin, non-steroidal anti-inflammatory drugs, beta blockers
- Respiratory infections such as colds and influenza
- Changes in temperature and humidity
- Psychological influences eg: extremes of emotion
- Workplace irritants eg: paint and varnish fumes, flour, wood dust.
If asthma is suspected, the following may be undertaken by a doctor to assist with diagnosis:
- A full medical history including any family history of asthma
- Discussion of current symptoms
- Physical assessment
- A chest x-ray may be ordered
- Measurement of how quickly air can be exhaled using a peak flow meter.
While asthma cannot be cured, it can be controlled by avoiding triggers and through the use of medications. There are a variety of asthma medications available. A doctor will be able to discuss which may be most appropriate for the patient. The main types of medications used to control asthma are:
These are usually an inhaled corticosteroid medication which has the effect of reducing swelling and decreasing the body’s reaction to triggers . It takes time for preventers to start acting (up to three months of regular use). They are taken on a regular basis each day to prevent symptoms. Examples of preventers are fluticasone (Flixotide), budesonide (Pulmicort) and beclomethasone (Beclozone).
These inhaled medications cause the airways’ muscle to relax thus reducing constriction and relieving the symptoms of asthma. They are often referred to as bronchodilators. The are quick acting and are used to relieve symptoms once they have started. Examples of short-acting relievers are terbutaline (Bricanyl) and salbutamol (Ventolin).
These are long-acting inhaled relievers and are used in conjunction with a preventer. They work by keeping the airway muscles relaxed and are usually used twice a day. The use of a symptom controller should reduce the need to use a short acting reliever. Examples of symptom controllers are formoterol (e.g. Foradil) and salmeterol (e.g. Serevent).
Combination inhalers contain both preventer and symptom controller medicine in one device. Examples of combination inhalers are fluticasone and salmeterol (Seretide) and budesonide and formoterol (Symbicort).
Management of asthma
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Advocacy & Education Committee of the Asthma Foundation (2013). What is asthma? (Booklet PDF). Wellington: Asthma and Respiratory Foundation of New Zealand. https://s3-ap-southeast-2.amazonaws.com/assets.asthmafoundation.org.nz/documents/What-is-Asthma-Resource.pdf
Asthma and Respiratory Foundation of New Zealand (2014). Key statistics: Respiratory disease in New Zealand (Web Page). Wellington: Asthma and Respiratory Foundation of New Zealand. https://www.asthmafoundation.org.nz/research/key-statistics [Accessed: 12/05/17]
Advocacy & Education Committee of the Asthma and Respiratory Foundation (2013). Triggers in asthma (Booklet PDF). Wellington: Asthma and Respiratory Foundation of New Zealand. https://s3-ap-southeast-2.amazonaws.com/assets.asthmafoundation.org.nz/documents/Triggers-in-Asthma-Resource.pdf
Ministry of Health (2014). Asthma (Web Page). Wellington: Ministry of Health. http://www.health.govt.nz/your-health/conditions-and-treatments/diseases-and-illnesses/asthma [Accessed: 25/02/17]