Extrinsic or allergic asthma
About 80 per cent of children with asthma, and more than half of adult
sufferers, have allergic asthma, which means their asthma is caused by
coming into contact with a substance in their environment.
No one doubts that the hypersensitivity causing the muscles of the
little bronchioles to constrict (and the tubes to become inflamed and
filled with mucus) has to do with allergies. The conventional view
maintains that the main culprits are grass pollen and the housedust
mite Dermatophagoides pteronyssinus.
This little creature is much more prevalent in homes today because of
fitted carpets, heat and insulation. This type of asthma is also
believed to be genetic. One-third of patients have a relative who has
suffered from asthma.
Intrinsic or non-allergic asthma
This represents about 10 per cent of cases and usually develops after
the age of 30. This form of asthma is not typically associated with
allergies. The condition tends to affect women, and many cases seem to
follow a respiratory tract infection. The condition can be difficult to
treat and symptoms are often chronic and last all the year round.
Exercise-induced asthma (EIA)
Exercise has undeniable health benefits but, for a significant
proportion of individuals, including professional athletes, exercise
can be a trigger for breathing difficulties known as exercise-induced
bronchospasm or, more commonly, exercise-induced asthma.
EIA is especially common in children and young adults, and comes on most often during intense exercise in cold, dry air.
EIA is not necessarily linked to an allergic reaction and you don’t
have to be asthmatic to have it, although many asthmatics do. US data
suggest that asthma affects four to seven per cent of the population,
and studies. People who only have EIA don’t usually require long-term
maintenance therapy. The condition tends to resolve itself shortly
after exercise activity stops.
Adult or late-onset asthma
Asthma can start at any age, although it occurs more often in women,
mostly middle-aged, and frequently follows a respiratory tract
infection. Some people have symptoms during childhood, which then
disappear in later life. Others develop late-onset asthma in adulthood
without ever having had symptoms as a child.
Asthma can be difficult to detect in older people as some of the
symptoms—cough, wheeze and shortness of breath—are shared with other
conditions such as chronic bronchitis, emphysema, chronic obstructive
pulmonary disease (also known as COPD) and heart disease.
Late-onset asthma is usually not caused by allergies, but can be
brought about through infection. Doctors diagnose late-onset asthma
when an adult develops chronic coughing and wheezing that does not
appear to be caused by allergy, irritants or an obvious infection.
Back to How You Beat Asthma
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