Allergic rhinitis (hay fever) is one of the most common allergies, affecting 1 in 4 young people in Britain. In a small proportion of patients, maximum treatment (with antihistamines, nasal steroids and eye drops) is not effective. Some of these patients may benefit from immunotherapy.
Allergies occur when the body reacts to foreign proteins (allergens). In allergic rhinitis, nose symptoms (runny, itchy or blocked nose) or eye symptoms (itchy watery eyes) occur after contact with these allergens e.g. grass or tree pollen, house dust mite, dogs and cats. In children, house dust mite and pollen allergies are important causes of hay fever.
Immunotherapy is the only treatment that can change the underlying allergic disease. The alternative is to continue with medicines that dampen down the symptoms such as antihistamines and steroids.
Immunotherapy is given by either injection under the skin (subcutaneous immunotherapy [SCIT]), or as a drop under the tongue (sublingual immunotherapy [SLIT]). Giving increasing amounts of the allergen trains the immune system to ignore the allergen (immune tolerance).
Sublingual immunotherapy (SLIT) with drops under the tongue, or a fast dissolving tablet is used by our allergy service, particularly for children with grass and tree pollen allergies, or those with house dust mite allergy.
The first dose will be given in hospital under close supervision and you will be shown exactly how to take the treatment. After that, you can take the medicine at home, but you will need to do this regularly every day for three years.
For the treatment to work best, it is important that you take the SLIT as prescribed by the allergy team, every single day. Missing doses may also result in a return of your rhinitis/asthma symptoms.
Should you forget to take your drops / tablet, take it later in the day if possible, but otherwise just continue with your normal once daily routine. Do not take a double dose to make up for a forgotten one.
The treatment needs to be given for three years.
Nose and eye symptoms improve. Patient’s often feel better, are less sleeping and are able to concentrate more on their school work and outside activities.
Allergen immunotherapy may also reduce the likelihood of getting asthma.
Sublingual immunotherapy (SLIT) is very safe. Large studies on thousands of children have never found any serious reactions (which do sometimes occur with SCIT).
The most common side effects were itchiness and swelling in the mouth after taking the drops or tablet. This can be prevented by taking antihistamines beforehand, or if the symptoms are recurrent, reducing the dose.
Studies from Europe report that side effects are very rarely troublesome enough for the patient to stop the treatment.
If your doctor thinks that SLIT might help you, then you will be offered an appointment in a specialist allergy clinic. SLIT works best if you are sensitised to one allergen and agree to regularly take medication every day. Thus during the clinic appointment, a detailed history will be taken and skin prick tests will be performed to a range of pollens and other allergens. We will also ensure that, if you have asthma, it is well controlled so that you can have the treatment.
SLITwill not work for everybody. It leads to “very good” or “good” improvement in three out of four pollen allergic patients. It is also reduces the use of hay fever medicines. If it doesn’t work, patients usually have to rely on avoidance strategies and symptomatic treatment. Sometimes there are other allergies e.g. pet allergy or dust mite allergy that need to be sorted.
You will have the opportunity to discuss any issues during your visit to the Allergy clinic.