Immunomodulatory therapy
Specific allergen immunotherapy
(desensitisation)
Specific allergen immunotherapy is
effective in the management of rhinitis and
asthma and can achieve a durable remission
of allergic symptoms.
37,
38, 39
<LevelI> Evidence from a randomised
clinical trial suggests that it may reduce
the risk of childhood rhinitis progressing
to asthma.14, 15
<Level II>
This treatment should be considered only
when there is evidence that allergic
rhinitis is predominantly due to exposure to
a single allergen, and where it is not
possible to avoid the allergen (e.g.
pollens, house dust mite, occupational
allergens). It should be considered in
consultation with an allergist.
Oral (sublingual) and injectable
(subcutaneous) forms of immunotherapy are
available:
-
Subcutaneous allergen
immunotherapy involves a course of
injections given weekly to monthly over
2–3 years. It is well tolerated in
adults and children when administered
and supervised by an allergist.40
Potential adverse effects include
injection-site reactions, sneezing,
bronchospasm, urticaria and anaphylaxis.
Subcutaneous immunotherapy can only be
attempted while asthma symptoms are well
controlled. The risk of a fatal allergic
reaction is increased in patients with
marked airflow limitation (e.g. when
forced expiratory volume in one second
is less than 70% of the predicted
value).41 Immunotherapy is
contraindicated in patients with severe
or unstable asthma and those using beta
blockers.
|
 |
Practice
points |
 |
-
Discuss
immunotherapy early in
the course of allergic
rhinitis, if suitable.
-
Explain
to patients that
immunotherapy:
- has not been shown to
be effective in patients
with multiple allergens,
so is most likely to
benefit those with a
well-defined single
allergen (e.g. pollen,
house dust mite, cat
allergens)
- offers no benefit if
triggers are
substantially
non-allergic
- can cause local and
systemic adverse
effects.
|
|
|
