Immunotherapy to Aeroallergens
What is immunotherapy?
Immunotherapy is the practice of administering gradually increasing doses of an allergen extract (e.g. pollen, dust mite, mould, pet dander) in order to reduce the symptoms of the allergic rhinitis (known as hayfever), eczema or asthma that it causes. Immunotherapy was first carried out almost 100 years ago and is now in widespread use around the world. It is sometimes referred to as ‘allergy vaccination’ or ‘desensitisation’.
Until recently, immunotherapy involved having a series of injections (subcutaneous immunotherapy) over a period of three to five years. Due to the advent of effective and safe oral products, we seldom provide injection immunotherapy
What is sublingual immunotherapy (SLIT)?
Sublingual immunotherapy entails placing an allergen extract under the tongue, either by tablets or drops. This method is safe and means that injections are not needed (unles treating venom allergies). However, SLIT does need to be taken on a daily basis.
What are the benefits of sublingual immunotherapy?
Most children receiving SLIT report an improvement in symptoms (allergic rhinoconjunctivitis, asthma, eczema) and need for less medication use. SLIT benefits are often evident even in the first year of treatment. There is some evidence that SLIT prevents new allergies developing and reduces the likelihood of developing additional allergic disease such as asthma.
What are the risks?
Large studies on hundreds of children (as young as 2 years of age) demonstrate that SLIT is a safe form of therapy. However, mild side effects are common. The most common side effects are itchiness and swelling in the mouth after taking the medicine. This can be helped by taking antihistamines beforehand, or if the symptoms are recurrent, reducing the dose. It is our experience that side effects are very rarely troublesome enough for a child to want to stop the treatment.
How long will the treatment last?
If your child has symptoms of hayfever in the spring/summer then they may be allergic to tree pollen, grass pollen or both. Which SLIT product you receive will depend on the clinical history and allergy test results.
Usually, your treatment will start a few months before the normal onset of your symptoms (if pollen allergic) and continue for a total of 3 years. This cycle of treatment will be repeated over 3 years.
SLIT can be commenced at any time of the year for non-seasonal allergens.
Improvements in symptoms would be expected from the first year of treatment but research suggests that this benefit will continue for some years beyond the last course of treatment. It has been shown that three years of treatment (pollen) is more effective than just two years.
What are the alternatives?
Immunotherapy is the only treatment with the ability to moderate the underlying cause of an allergy. The alternative is to continue with medicines that suppress the symptoms such as anti-histamines and steroid based medicines, but are not curative nor without side effects.
Will the treatment completely get rid of my allergy?
Unfortunately, whilst some patients do find they are greatly improved, for many the improvement is good but not complete. It is therefore important to have realistic expectations. Around 80-85% of patients report significant improvement in their hayfever symptoms in the first year of treatment.
How do I use sublingual immunotherapy?
SLIT products come either as a simple spray device, dropper or as tablets. The first dose will be given in Professor Du Toit’s private clinic under close supervision and you will be shown exactly how to use the treatment. Side effects & management will be discussed & written information will be supplied.
How old does a patient have to be to commence SLIT?
Most children can comply with the daily regimen of placing the product under the tongue for at least a minute before swallowing from about 6 years of age.
Where can I find more information on SLIT?
- AAAAI – American Academy of Allergy and Clinical Immunology
- WAO - World Allergy Organisation
- BSACI - British Society of Allergy and Clinical Immunology
- EAACI – European Academy of Allergy and Clinical Immunology
We currently make use of the following products, please check the company website for current licensing arrangements in the UK.
Duration each year, repeated over three years, annual follow up and assessment
- Acarizax (ALK Abello) Tablet. House Dust Mite (typically 12 months duration)
- Oraltek/Inmunotek Liquid formulation. Grass Pollen, Tree Pollen, Animal Dander, House Dust Mite (4-6 months duration for pollen, 12 months for House Dust Mite)
- Grazax (Alk Abello), Tablet. Grass Pollen (12 months duration, although a shorter 6 months course may also be used)
- Staloral (Stallergenes) Liquid formulation. Grass Pollen, Tree Pollen
- Oralair (Stallergenes) Tablet. 5 Grasses: Timothy, Cocksfoot, Rye, Sweet vernal and Meadow (4-5 months)
- Oralvac Compact (Allergy Therapeutics), Liquid formulation. Tree Pollen, Grass Pollen, Weed pollen, Moulds, Animal dander (4-6 months, allergen depending)