WESTERN VIEW DESCRIPTION: A temporary narrowing of, and excess production of phlegm in, the small airways (bronchioles) through which air flows into and out of the lungs. The narrowing is caused by a spasm in the tiny muscles which surround the bronchioles.
CAUSE: The absolute cause is unknown, but certain triggers (eg.colds and other viral infections, temperature changes, allergies, exercise, smoke, dust and other irritants) may start an attack in susceptible individuals. The tendency to develop asthma runs in families along with hay fever and some forms of eczema to give a 15 times greater chance of developing the condition.
SYMPTOMS: Attacks may build up slowly over many weeks and the individual may be barely aware of the deterioration in lung function, or a severe attack may start within a minute or two of exposure to a trigger. The narrowing of the airways causes shortness of breath and wheezing, coughing, particularly in children, and tightness and discomfort in the chest. Asthmatics have more trouble breathing out than breathing in.
INVESTIGATIONS: Diagnosed by respiratory function tests which involve blowing into a number of different machines which either draw a graph or give an electronic reading. The patient’s response to medication is also checked on these machines. Once diagnosed it is important to identify any trigger substances if possible by trial and error, or with blood and skin tests.
TREATMENT: Prevention – all but the mildest asthmatics should be using steroid or anti-allergy inhalations to prevent attacks. Severe asthmatics may need to use prednisone tablets to both prevent and treat their attacks. Those who react to specific substances may benefit from allergen desensitisation. Treatment – best method is by aerosol sprays which take the medication directly into the lungs where they act to dilate the airways and liquefy the thick mucus. Many of these can have their effectiveness and ease of use improved, particularly in children, if a spacing device or machine nebuliser is used. Mixtures and tables are also available, but they work more slowly and have greater side effects. Very severe attacks may require oxygen by mask and injections of adrenaline, theophylline or steroids.
COMPLICATIONS: Prednisone and other steroids may have significant side effects if used for a long time. People can die rapidly from a sudden, severe asthma attack.
PROGNOSIS: Asthma cannot be cured, but doctors can control the disease very effectively in the vast majority of patients.