Sublingual Immunotherapy (SLIT)
Immunotherapy has changed in recent years with the emergence of
sublingual immunotherapy (SLIT)-where drops or a tablet are placed
under the tongue- instead of the injected subcutaneous
immunotherapy. This new treatment is painless, safe and much more
convenient than weekly trips to hospital for injections. Evidence
suggests that for hay fever it is equally effective.
SLIT is a useful treatment for severe spring or summer hay fever
in patients allergic to just one type of allergen, for example
grass pollen alone, or tree pollen alone. Rarely, it can be used
for allergy to two different allergens, eg grass and birch pollen.
It can also be used for desensitisation to house dust mite or
animals in patients with very severe nasal and / or eye symptoms
all year round causing significant disability. To qualify for
treatment, patients should have failed to respond to strict
avoidance of the allergen (or they may be unable to avoid it) and
should already be using all recommended standard treatments,
including continuous double-dose antihistamine tablets and
continuous steroid nasal spray. For animal allergy, immunotherapy
is usually only considered in those with occupational allergy. SLIT
is not suitable for patients with severe asthma.
The objective of immunotherapy is to reduce disease severity,
improve quality of life and reduce the cost, inconvenience and any
side-effects of standard treatment. The average reduction in
symptom scores is 30-35% and average reduction in medication use is
40-60%. The effects often last for at least two years after
stopping the immunotherapy. In some patients the effects can last
much longer. Immunotherapy for pollen-induced hay fever can prevent
the later development of other allergies, and for children it has
the potential to prevent the development of asthma.
The allergy is first confirmed by prick testing, most commonly
on the forearms, with results after 10-20 minutes. The medicine is
prescribed and an appropriate start date agreed. The first
treatment is taken at the hospital, with observation for one hour
afterwards.
Many patients experience itching of the mouth and throat for
some minutes after they take the drops or tablet, especially during
the first few weeks of treatment. There may be slight lip swelling
or headache. Occasional patients have wheezing, hives or tummy
cramps (tummy cramps are more common in children). Serious side
effects are very rare.
Types of Sublingual Immunotherapy:
Staloral Drops Staloral sublingual drops (at
2011 prices) cost approximately £1,000 per year for house dust
mite, pets and moulds and about £500 per year for grass and tree
pollen. The drops are taken each morning for three years. In
the case of pollen allergy they only need to be taken for six
months a year. Children over the age of 5 years can be treated.
Grazax Tablets These are available for grass
pollen allergy only and are taken 4-5 months per year for 3 years.
At 2011 prices they cost £67.50 plus VAT per month or £335.50 plus
VAT per year. Grazax tablets contain fish gelatine so should be
avoided in those with severe fish allergy.
Oralair Tablets In 2012 a new tablet form of
immunotherapy called Oralair (containing five types of grass)
should receive its UK licence. The treatment will cost £500 plus
VAT per year for 3 years. Tablets are taken under the tongue for
5-6 months per year. The tablets do not contain fish gelatine.