Asthma

 

What is Asthma?

Asthma is a condition of the lungs that causes a variety of symptoms, which vary from person to person according to the severity of the illness. Symptoms usually include coughing, wheezing and shortness of breath.

The difference between asthma and other lung conditions that cause similar symptoms is that in asthma these symptoms tend to occur in episodes with gaps of improvement or disappearance of symptoms for periods of time. Also, the symptoms caused by asthma are usually reversible, ie the correct treatment will lead to a significant improvement in the condition in a short space of time. This is not true of other chronic lung conditions, such as what used to be called chronic bronchitis or emphysema, in which the reversibility of the symptoms is not nearly so great.

For reasons that are not fully understood asthma is becoming more common and it now affects about 10% of people in the UK. In children it is even more common, affecting about 20% of the under 5's.

Part of the reason for the increase is that it is now diagnosed more often than it used to be. This is a good thing if this then leads to appropriate treatment. Asthma, especially if mild, tends to improve throughout puberty. However, later-onset asthma is more common than is often supposed: half of asthmatics start to suffer in childhood, a third start between the ages of 15 and 44 years, and the other sixth start after age 45 years.

When people are diagnosed as asthmatic they are often frightened of the diagnosis but it is important to realise that, although it is a condition that needs to be taken seriously, it varies tremendously in its severity. Most people have mild to moderate symptoms that can be well controlled with modern medication. Severe cases are rarer and, if uncontrolled, can lead to death but there now exist a large number of treatments that can prevent most cases from becoming life threatening.

 

How does it occur?

Inside the chest there is a system of branching tubes that carry air to the lungs. These are called the bronchi and (as they get smaller) the bronchioles and it is these that are affected in asthmatics. In asthma three main processes occur that combine to cause narrowing of these airways thereby making breathing more difficult and resulting in the symptoms typical of this condition.

Firstly there is inflammation of the lining of the airways; secondly there is an over-production of mucus inside the tubes and thirdly the muscles inside the walls of the airways contract causing a narrowing of the diameter of the bronchi and bronchioles.

Moving air through these airways becomes more difficult and the individual usually develops a cough, breathlessness and a wheeze as a result.

Why does it occur?

The basic cause of asthma in an individual is an over-sensitivity of the person's airways which therefore become inflamed far more easily than in a non-asthmatic person. The reason why this occurs is not fully understood. It is probably due to a number of factors such as family history, an increase in air pollution and, it has been suggested, an improvement in general living conditions so that the immune system gets 'bored' with nothing to fight and therefore starts to become over active.

 

What can trigger an asthma attack?

Triggers of asthma symptoms vary tremendously from one person to the next but they include:

  • Infections, particularly viral such as coughs and colds
  • Allergens, e.g. house-dust mite, pollens (hay fever), animal fur.
  • Occupational agents, e.g. certain chemicals, flour, smoke.
  • Environmental pollutants, e.g. cigarette smoke, sulphur dioxide.
  • Certain drugs, e.g. the so-called beta-blockers (e.g. Atenolol, Propranolol) and anti-inflammatory drugs such as Ibuprofen (Nurofen) and many others in this group of drugs.
  • Exercise.
  • Cold air.
  • Hyperventilation.
  • Foods such as seafood, nuts and occasionally certain additives.
  • Psychological factorssuch as stress or anxiety.
 

What are the symptoms?

Symptoms of Asthma usually include some or all of the following:

  • Coughing
  • Wheezing
  • Chest tightness
  • Shortness of breath
  • These symptoms are often worse at night.
  • In addition young children may not have typical symptoms and it may be difficult to differentiate between asthma and recurrent viral chest infections in young children.
 

How is asthma diagnosed?

Asthma is usually suspected from the 'history' given by the patient i.e. the symptoms they have been experiencing along with any family history or trigger factors.

Often the patient will complain that whenever they get a cold it "goes straight to my chest" and lasts much longer in them than in other people.

The main test for asthma is the Peak Flow Rate (PFR), which involves the patient blowing as hard as they can into a hand held meter. The PFR measures the fastest rate of flow of the air leaving their mouths as they blow. This is compared with the rate that they should be able to achieve for their age and height. In an asthmatic their PFR is usually found to be significantly lower than it should be. However because asthma, by its nature, can vary from hour to hour several readings may need to be done over a period of time to see if the PFR varies.

If there is still doubt about the diagnosis the doctor or nurse may perform a test called the 'reversibility test'. Since the symptoms of asthma are generally reversible with treatment the patients' PFR is measured whilst they have symptoms and then re-measured after receiving treatment of some sort. In an asthmatic there is usually an appreciable improvement in the before and after PFR.

Sometimes the only way to satisfactorily diagnose the condition is to give treatment for asthma to see if it improves the symptoms over a period of time. Most patients can be taught to monitor their own PFR at home (since the PFR meters are easily available on prescription) and this can be very useful not only for diagnosis but also for monitoring their condition to provide early warning of a deterioration in their breathing.

A chest x-ray is occasionally performed but this is usually only done to exclude other possible causes of breathing problems since a chest x-ray is normal in most asthmatic patients.

 

How is asthma treated?

Most asthmatics will be treated with one, two or more types of inhaled drug along with advice about avoidance of trigger factors, how to recognise deterioration in their breathing and what action to take. Obviously the treatment of very young children and acute asthma attacks requires special measures but inhaled medication through metered dose inhalers (MDIs or what most people call 'puffers') provides the treatment for the vast majority of asthmatics.

There is now a vast array of different MDIs available and it is beyond the scope of this factsheet to describe them all, but some basic principles can be mentioned. Firstly the treatment will be tailored to the age and severity of the asthmatic and the different types of inhaler now allow the most appropriate and easiest method to be chosen.

Mild asthma with intermittent symptoms can usually be controlled with the use of a reliever given via a MDI which is used by the patient as and when they need it. Examples of relievers are Salbutamol and Terbutaline and they act by opening up the airways by relieving the spasm in the muscles of the airway walls as described above. These are always blue in colour.

If an asthmatic is using their reliever more than once a day they are usually advised to use a preventer as well. These are given regularly every day and act by reducing the inflammation within the airways. These contain a steroid. Examples of preventers are Beclomethasone and Budesonide and again are administered via an MDI. These are brown in colour.

If this combination is not working sufficiently medication is added to the regime in the form of other drugs via an inhaler of some type or the addition of medication by mouth. The aim being that the individual can lead a normal life and take part in all their normal activities as far as possible.

One advance in recent years has been the development of a new type of medication that can be taken by mouth called the leukotriene receptor antagonists (Montelukast (Singulair) and Zafirlukast (Accolate). These can be useful in some cases of asthma.

 

How should an asthma attack be treated?

The short answer to this question is "calmly but with respect" since severe, acute asthma can be very serious. It is important that asthmatics ask their doctor or nurse to give them instructions about how to recognise a deterioration in their condition and what to do about it along with guidelines as to when it is appropriate to call the doctor or ambulance.

If an asthmatic has difficulty breathing and their usual medication is not relieving their symptoms, or is only relieving them for a very short time urgent medical advice or assistance should be sought.

Can someone with asthma lead a normal life?

In almost all cases the answer to this is an emphatic "Yes". There have been many asthmatic Olympic sportsmen and women and, apart from the most severely asthmatic individuals, the aim of treatment is that they can lead a normal life. However, it is up to each person to take the recommended treatment, not to smoke, to monitor their asthma wherever appropriate with a peak flow meter, and to make sure they have a supply of their treatment to cover weekends and Bank Holidays.

 

Where can further information be obtained?

Apart from contacting your own GP the following organisations may be of help:

Action Asthma Patient Service
Dept G
Freepost DR83
Ashford
Kent
TN24 OYX
Telephone: 020 8990 3011

National Asthma Campaign (Asthma UK)
Summit House
70 Wilson Street
London
EC2A 2DB
Telephone: 08457 010 203
Website: www.asthma.org.uk