Introduction
Hay fever lasts 10-20 years in most patients. Medicines do
not cure the problem, and it is not always possible to avoid the
cause, such as with grass pollens. Desensitisation (immunotherapy)
is the only way of "teaching" the immune system to tolerate
allergic triggers. It is effective in most people with hay fever
and often helps those with asthma. Unfortunately, it has not
definitely been shown to help people with eczema, and there is
no evidence that food or stinging insect allergy can be controlled
in this way.
How the treatment works
Our immune system responds to substances in our environment
that we eat, drink or inhale, but only allergic people develop
an "allergic" immune response. By giving small but increasing
amounts of allergen at regular intervals a few times/week, tolerance
to inhaled allergen increases. Exposure results in fewer or no
symptoms.
How can this be done?
Injected immunotherapy has a long tradition of use
for over 60 years. A number of studies published in the last 5
years have shown that sublingual and oral immunotherapy,
where the allergen extracts are taken by mouth, can also be effective.
This form of treatment has a long tradition of use in Europe,
where it is used more commonly than injected immunotherapy. The
allergen extracts available in Australia for oral and injected
treatments are made by the same European manufacturer. It is important
to note that these extracts are very potent, and NOT the extremely
weak and ineffective extracts used by some medical practitioners
10 or more years ago.
Who should have immunotherapy?
o The allergy is severe, or
o It is hard to avoid the cause, or
o Medicines don't work, or
o Medicines cause side-effects, or
o You are tired of taking medication
How well they work
Injected immunotherapy has a long tradition of use
for over 60 years, and about 3 in 4 patients with hay fever experience
significant improvement with immunotherapy. Sublingual and
oral immunotherapy, where the allergen extracts are taken
by mouth, has a much shorter history of use, but a number of studies
published in the last 5 years show evidence of effectiveness.
It is difficult to advise exactly HOW effective this form of treatment
may be until more local experience is obtained. In particular,
it is unclear whether it will be as effective as immunotherapy
given by injection. Sometimes symptoms are reduced rather than
abolished. In that case you may need medication as well.
Why chose sublingual /oral instead of injected immunotherapy?
The potential advantages of oral treatment are those of NO
injections, NO regular doctor visits, NO waiting periods after
the injections and a higher safety margin. The main disadvantage
of the oral treatment is cost; much more allergen needs to be
swallowed than injected, resulting in the cost of allergen being
5-6 times that paid for injected treatments (ie. approx Aust $1200/year,
compared to around $200/year for the injectaed extracts). On the
other hand, this needs to be balanced with the time and cost saved
in avoiding doctor visits. In practice, those more likely to chose
oral immunotherapy will be those who hate needles, people who
don't have time to wait in doctors rooms after injections, and
parents of young children, who are not going to tolerate lots
of injections.
How long does it take to work?
Improvement does not occur immediately. It usually requires
at least 4-5 months before hay fever improves, sometimes
longer. If you are having treatment because of Spring / Summer
hay fever, you usually know quite clearly in the first season.
Can you still use medicines as well?
Yes. You can still use your usual allergy medicines as well.
Common methods for taking the allergen extracts
Take in the morning on an empty stomach
Keep them under the tongue for at least 2 minutes, then swallow.
Do NOT eat anything for 15 minutes.
Avoid crunchy cereals as these may cut the tongue and increase
the likelihood of mouth irritation from the extracts
If you forget to take them in the morning, take them before bedtime
instead
How long does the treatment go on for?
Immunotherapy is not a "quick fix". You need to be committed
for it to work, and to cooperate with you doctor to reduce the
risk of side-effects. If you find it helps, the minimum duration
recommended is 3 years (5 is better) to reduce the chance of your
allergy returning once you stop.
Risks and side-effects of oral immunotherapy:
COMMON
Salty or unpleasant taste. Children can suck a lollie at the same
time
UNCOMMON ~ 5 - 10 %
Irritation or itching inside the mouth. This can be controlled
by temporarily reducing the dose or talking an antihistamine beforehand.
RARE ~ 3-5%
Stomach upset
*Dangerous side-effects such as difficulty breathing or rashes
have not been reported with this form of treatment at the time
of writing. One brand claims 100 million does administered without
a single case of serious allergic reactions thus far.
