Understanding asthma
by Associate Professor Jessie Anne de Bruyne
Did you know that the term asthma is derived from a Greek
word meaning to breathe hard? According to the World Health Organization, asthma
is a serious public health problem, affecting over 100 million people worldwide,
especially children. As such, it is the most common childhood ailment after the
common cold.
What is asthma? How does it occur and how do we manage it? To answer these questions
and many more, we have an expert, Associate Professor Jessie Anne de Bruyne, who
will enlighten us on matters concerning this common, but chronic disorder.
Associate Professor Jessie Anne de Bruyne is currently the Head of the Respiratory
Unit at the Department of Peadiatrics at University Malaya (UM), Kuala Lumpur. She
graduated from UK with her MBChB and MRCP and worked in UK for 6 years before returning
to work at UM in 1991. She is the founder member and Hon Secretaray of Kelab Asma
Kanak-Kanak Selangor & Wilayah Persekutuan - a club for families of children
with asthma. Her research interests are in the epidemiology and treatment/education
of asthma.
Q1) What is Asthma?
Asthma is a chronic inflammatory disorder of the airways in which many cells and
cellular elements play a role. The chronic inflammation causes an associated increase
in airway hyper-responsiveness that leads to recurrent episodes of wheezing, breathlessness,
chest tightness and coughing, particularly at night or in the early morning. These
episodes are usually associated with widespread but variable airflow obstruction
that is often reversible spontaneously or with treatment.
Gina guidelines 2002
Asthma is a condition that affects the airways leading to the lungs making them
smaller and therefore making it harder to breathe. This occurs in 2 ways - firstly,
the airways are inflammed ie the walls of the airways are swollen and red and produce
more mucous than usual.
This makes the smooth muscle in the airway wall very sensitive so that certain triggers
like upper respiratory chest infections (ordinary coughs and colds), animal fur,
cigarette smoke, etc. will make them tighten up - when the muscles tighten up, the
airway gets narrower. This leads to repeated episodes of wheezing, breathlessness,
chest tightness and coughing, particularly at night or in the early morning.
This narrowing due to the muscle tightening can improve by itself or with certain
medicines called bronchodilators (bronchi = airways, i.e. medicines that make the
airways bigger) or by itself. The underlying inflammation that makes the airways
hypersensitive, however, needs to be treated with anti-inflammatories that are taken
on a regular basis.
Q2) Are they various forms or severity of asthma?
The severity of asthma is based on the frequency and severity of attacks
and also on interval symptoms like coughing at night, coughing or wheezing on exercise.
It also is determined by respiratory function tests (breathing tests) that can be
done by a doctor. A child who has frequent attacks with interval symptoms nearly
every day with abnormal lung function has severe persistent asthma. A child with
infrequent attacks, minimal interval symptoms and normal lung function has mild,
intermittent asthma. And there are gradations between the two. A child may go from
one degree of severity to another.
Q3) How common is Asthma among Asian children?
These are the results of ISAAC (International Study of Asthma & Allergy)
which has been conducted around the world. The first row of figures reflects presence
of wheeze (a cardinal symptom of asthma) in the last 12 months. The 2nd row indicates
severe wheeze and is an indication of the prevalence of severe asthma in Asia.
Q4) What is its prevalence in boys versus girls?
In general, there are more boys with asthma in infancy but this tendency
decreases as they get older so that by puberty the prevalence is roughly equal in
both sexes.
Q5) At what age does asthma usually occur in children?
Asthma can occur at any age. Babies who wheeze do not necessarily have asthma especially
if there is no family history of atopy (ie asthma, eczema, hayfever) and they tend
to stop wheezing by the end of the 2nd or 3rd year of life. Those 'infant wheezers'
with a family history of atopy are more likely to have asthma and continue to have
symptoms of asthma as they grow older. Children who start wheezing at an older age
are more likely to have asthma than those who start in infancy.
Q6) What causes asthma?
Asthma tends to run in families so that a person with relatives who have
asthma is more likely to have asthma than one who does not. Various things have
been thought to 'turn on' asthma including the house dust mite, cockroaches and
certain viral infections. In a child who already has asthma, exposure to animal
fur especially cat fur, can trigger off an attack or make the asthma control worse
but various studies suggest that early exposure to animals reduces sensitivity to
them. Air pollution does not seem to 'turn on' asthma in those who do not have it
- on the contrary, asthma is less prevalent in many 'polluted' areas when compared
with less polluted areas eg East vs West Germany. Understanding about what causes
asthma is still evolving.
Q7) Is asthma curable?
Asthma is not curable but it can be controlled.
Q8) Do most children eventually outgrow asthma?
This depends on the severity of the disorder and the frequency of the attacks.
Research findings reported that 50 to 60% percent of people with episodic asthma
stop wheezing before they reach adulthood, 25 percent of those with frequent attacks
outgrow asthma in adult life whereas those with the chronic severe form of asthma
will continue to be asthmatic throughout life, as depicted in the pie chart below.
Q9) What are the signs and symptoms of asthma?
Asthma usually presents with recurrent coughing and/or wheezing. During an
attack parents may notice that the child has difficulty breathing and the suprasternal
notch recesses ie the space at the top of the breastbone tends to go in during breathing;
they may also notice that the tummy seems to go in and out while breathing; they
may hear a wheezing sound. If the child has difficulty breathing or is unable to
speak because of breathing difficulties they should use the reliever medication
and seek medical help immediately.
Q10) What are the current treatments for asthma?
Avoidance of trigger factors remains basic to the treatment of asthma. Asthma drugs
are divided into 2 main groups - preventers and relievers.
• Preventers are anti-inflammatory medicines like inhaled steroids, inhaled sodium
cromoglycate and oral leukotriene antagonists.
• Relievers relax the smooth muscle around the airways and make you feel better
during an attack. They consist of bronchodilators and are taken only when necessary.
Relievers are best taken by the inhaled route as they go directly to where they
are needed and therefore will work much faster than if they are swallowed. Sometimes,
long-acting bronchodilators are added to anti-inflammatory medicines to help in
the long-term control of the asthma. They should never be taken by themselves.
Q11) How do i know my child's asthma control is getting worse?
He or she will start having more interval symptoms like coughing at night
or coughing or wheezing while running around. He or she may also start needing his
rescue or bronchodilator medicaiton more frequently.
Q12) What's your advice to parents in order to minimize asthmatic
attacks in their children?
They should try to identify the child's trigger factors eg animal fur, and
avoid them.
The commonest trigger factor is the common cold and it is impossible to avoid -
however, if the child starts to develop asthmatic symptoms with the cold, he can
be given bronchodilators like ventolin or bricanyl to relieve the symptoms.
If the doctor has prescribed prophylactic or preventive treatment, this should be
taken every day, not just when there are problems. Adherence to preventive anti-inflammatory
treatment means that the inflammation in the airways is kept under control, the
airways are not so sensitive and asthmatic attacks are less likely to occur.
Q13) What are the common do's and don'ts that asthmatic children
should observe?
Don't smoke and avoid environments with lots of tobacco smoke.
The child with asthma is encouraged to lead as normal a life as possible and, with
proper control, he or she should be able to do just about anything that a child
without asthma can.
Q14) Are there types of food that asthmatic children have to avoid,
in order to prevent the onset of a sudden attack?
Not really. Parents often comment that they have been told to avoid a variety
of foods but, on direct questioning, their child's asthma is not really precipitated
by any food. There are some foods where artificial additives like colourings and
preservatives can trigger an attack; monosodium glutamate is a trigger for some
producing 'Chinese takeaway asthma' certain medicines like aspirin and anti-hypertensives
(Beta-blockers) should also be avoided.
Q15) Would asthmatic children be compromised in terms of their
physical and mental development, than other children without asthma?
Should not be if they look after themselves properly - avoid triggers, comply with
treatment.