Desensitisation Therapy

Desensitisation is also known as immunotherapy.  It is when we give gradually increasing doses of an allergen extract to reduce or alleviate the symptoms of the condition that it causes (e.g. hayfever or specific food allergies).  It was carried out initially about 100 years ago to pollens and now is in use across the world as a safe and effective treatment for allergies.  Having been widely used for hayfever, pet and house dust mite allergies, it is now available for certain food allergens, aiming to improve the quality of life for children and their families.

What is Allergy Immunotherapy (desensitisation)?

Allergen immunotherapy treatment (often referred to as desensitisation) is regarded as a safe and effective treatment for allergies.  The treatments all work by administering the patient with regular high doses of the relevant allergen, which dampens the immune response and reduces the severity of symptoms.  It has been in widespread use for hayfever and allergies to house dust mite and pets, but more recently the same principles have been applied to help treat food allergies, which can be potentially life threatening.

Aeroallergen Immunotherapy

Immunotherapy is backed by extensive research, and we can offer treatments for tree and grass pollen as well as house dust mite.  We are also able to offer treatment for allergy to animal dander.  The treatments all work by administering the patient with regular high doses of the relevant allergen, which dampens the immune response and reduces the severity of symptoms.

While medications such as antihistamines and steroid based medications can help alleviate some of the suffering, many patients still have bothersome symptoms.  These patients can often benefit from immunotherapy.  It is the only treatment which can impact on the underlying cause of the allergy symptoms by retraining the immune system to become less allergic.  Because of this the effect of the treatment can last for years after it is stopped.  This effect cannot be obtained through conventional treatments as they only supress the symptoms.

How does immunotherapy (desensitisation) work?

The treatment works by administering the patient with regular doses of an allergen extract to try and reduce allergic symptoms in the longer term. This in turn can lead to a reduction, or no further need, for medication.

The effects of immunotherapy can last for many years after the treatment is complete as the immune system has a memory.  There are therefore long-term benefits, especially for children, where it has been shown to prevent the future development of additional allergies and asthma symptoms.

Allergen immunotherapy can take the form of either tablets or oral solution placed under the tongue (sublingual), or in the form of injections (subcutaneous).

What are the benefits of allergen immunotherapy?

Scientific studies have shown that immunotherapy can be used to reduce the symptoms of hayfever and seasonal asthma caused by grass or tree pollen, as well as house dust mite.  The treatment can be so effective that many patients report needing to use less, or no medication.  As the immune response is altered, the beneficial effects last longer than the 3 years the treatment is given for.

If treatment is started at an early age, then it may prevent new allergies developing and reduce the chance of getting asthma in later life.  It is important to note that immunotherapy only works against a specific allergen and will not improve symptoms caused by other allergens.

What are the different ways of performing desensitisation?

Subcutaneous immunotherapy (SCIT):  This involves giving a series of injections to help desensitise the patient.  This is currently available for both grass and tree pollen.  This involves giving 6 injections over 6 weeks before the pollen season each year for 3 years.  SCIT has been shown to be very effective and suitable for most patients with severe hayfever.  Unfortunately, it is possible, although rare, to have severe allergic reactions to the injections, particularly in children with asthma, and therefore this treatment is not suitable for asthmatics.  It is only given under careful supervision in the hospital setting, with each injection followed by a 1-hour period of observation.

Sublingual immunotherapy (SLIT): This involves placing the allergen extract under the tongue either by tablets or drops.  This is a very safe method, and severe reactions are extremely rare, although the first dose of treatment is always given under close medical supervision.  This treatment is therefore more suitable for well controlled asthmatics.  The treatment dose is then taken daily for 3 years and again has been shown to have a long-term impact on the immune system.

Are there any side effects of immunotherapy?

As with all medications, SLIT can potentially cause side effects, and in the early stages of the treatment it is common to experience the following within a few minutes of taking the dose:

• Mouth itching
• Irritating sensation

In most cases this settles within 20 minutes of starting treatment but can be alleviated with simple over-the-counter antihistamines.

Other side effects which may affect up to 1 in 10 people are noted below.  These tend to occur in the first week of taking the medication and generally mild to moderate and short lived:

• Eye or ear itching
• Numbness of skin, mouth or tongue
• Asthma symptoms
• Eye, nose or mouth inflammation
• Cough or sneeze
• Shortness of breath
• Nasal discomfort
• Dry throat
• Swelling of lips or tongue
• Stuffy or runny nose
• Mouth blisters
• Stomach pain or discomfort
• Heartburn
• Tiredness
• Itching
• Chest discomfort
• Fever

How successful is immunotherapy (desensitisation)?

The patients I have treated with immunotherapy report an improvement in symptoms and less use of traditional treatments, such as antihistamines and steroid nasal sprays.  As also mentioned, using immunotherapy from an early age may prevent new allergies developing and reduce the likelihood of getting asthma, which we know is 8 times more likely in child who suffer from hayfever.

Food Immunotherapy / Desensitisation

Desensitisation is also known as immunotherapy.  It is when we give gradually increasing doses of an allergen extract to reduce or alleviate the symptoms of the condition that it causes (e.g. hayfever or specific food allergies).  It was carried out initially about 100 years ago to pollens and now is in use across the world as a safe and effective treatment for allergies.  Having been widely used for hayfever, pet and house dust mite allergies, it is now available for certain food allergens, aiming to improve the quality of life for children and their families.

What is food immunotherapy?

Oral tolerance induction (OIT), also known as oral desensitisation therapy (OD), involves giving very small, but gradually increasing, amounts of food that the child is allergic to.  The idea is that the treatment increases the tolerance of the food so that larger amounts of the food can be consumed without causing symptoms, and therefore accidental exposures to small amounts should not cause reactions.  This treatment has been mainly studied with milk, egg and peanut.  Most recently Palforzia®, a peanut containing capsule, has become the first licensed food immunotherapy treatment.  We have been offering both milk and egg desensitisation in our NHS service for many years but can now also offer treatment privately, including with Palforzia®.

How does food immunotherapy work?

There has been an increasing body of research which has been looking at how the treatment impacts on the immune system.  It has shown that the regular exposure to the food causing allergy, but at a level below that which causes a reaction, leads to the production of an antibody called IgG4.  This antibody has a blocking effect on IgE antibody, which is the antibody that is responsible for causing allergic reactions.

Which food allergies can be treated with immunotherapy?

Most research has been done on desensitisation to milk, egg and peanut.  As noted, we have been offering desensitisation to milk and egg on the NHS for some time but can also offer desensitisation to peanut using Palforzia®.

How long does the process for food immunotherapy take?

This will depend on which food immunotherapy is being given and which protocols are used.  Some are faster than others, but a typical protocol takes 8-12 weeks, although Palforzia®’s protocol takes 6 months to reach the top dose.  The doses are increased with specific gaps between doses but reactions or other factors such as incidental illness or missed doses may require a longer gap between doses.  Once we have reached the top dose (maintenance) then the patient needs to continue to take this regularly to maintain effect.  The frequency of this dosing can be reduced, but not stopped, over time without apparent loss of effect.

Is food immunotherapy the right treatment for my child?

Although a child may be suitable for immunotherapy, it may still not be the right treatment option for them.  For many patients, continuing to avoid the food they are allergic to, coupled with an appropriate emergency action plan is still the most appropriate way to manage the allergy.  Food immunotherapy is associated with a risk of reaction and can impact on day-to-day life during up dosing and beyond.

To decide if immunotherapy is right for your child there is an important process of shared decision making, which together with detailed information about the treatment, will help us decide if it is the right thing to do.  We will only consider your child for treatment once this process has been completed and you will be required to sign a consent form to confirm that you understand the risks and benefits of each approach.

How do I get further information and make an appointment to discuss further?

Please use our contact form, or give us a ring or email, and we can arrange an appointment to discuss further.