TREATING ALLERGIES

WITH IMMUNOTHERAPY

What is immunotherapy?

Allergen immunotherapy is one of the most powerful tools available to help control, modify and reduce the severity of your allergies.

The treatment involves administration of small and slowly incremental doses of purified allergen extracts which then worked to induce a state of desensitisation or tolerance by invoking specific immune mechanisms, hence the term “immunotherapy”.

How can immunotherapy help?

Immunotherapy in principle applies to any allergy – for inhalant allergens, foods or drugs. Indeed, it is an area of active research for many other diseases including neurodegenerative problems and cancer.

However, in practice, the treatment is most commonly used for allergic rhinitis. This is especially with symptoms are moderate to severe, allergen avoidance is difficult and where patients are experiencing side effects or desire not to take medications long-term.

In carefully selected cases, allergen immunotherapy is also being increasingly used in the management of asthma and atopic eczema.

Venom immunotherapy is an established treatment in the management of stinging insect allergies for bees and wasps.

Immunotherapy for the treatment of food allergies shows promising early results. Significant side-effects can occur in some people however, research continues.

What can you expect?

Allergen immunotherapy for aeroallergens is recommended, typically for a duration of 3 years, though sometimes longer treatment courses are needed to reduce the risk of symptoms recurrence when stopping treatment.

Immunotherapy for aeroallergens are delivered via regular injection, or daily oral doses.

Insect allergy immunotherapy is given by regular injections for 5 years, sometimes longer. Sublingual immunotherapy is not yet available for insect venom immunotherapy.

Please note that immunotherapy is not a quick fix for allergies, and it is often many months before you’ll start to appreciate the benefits.

Immunotherapy is backed by scientific evidence to support the efficacy and safety and is utilised the world over in management of allergies.

Some people may confuse immunotherapy with homeopathy, but factually there is no relationship.

How is immunotherapy done?

There are 2 options available; Subcutaneous Immunotherapy (injections) and sublingual immunotherapy (oral drops, spray or tablets).

Immunotherapy injections

Start with a very low dose which is gradually increased on a weekly basis until a defined target dose. This may take up to 3 months and may vary between patients, though with newer vaccines that target dose can be achieved in as little as 3 to 4 weeks. Thereafter injections are continued on a monthly basis for the balance of the treatment, which is usually 3 years. The injections are done in a medical facility, under medical supervision.

Sublingual Immunotherapy

Is a daily treatment that you do yourselves at home. The vaccine comes in different forms including drops, spray or tablets. These are taken daily, usually in the mornings on an empty stomach.

Potential reactions to injection immunotherapy

Minor, localised swelling at the site of the injection can be treated with non-sedating oral antihistamines or ice packs/ paracetamol if there is discomfort. Serious reactions (such as anaphylaxis) is possible, but with proper care and attention is fortunately rare.

Injection immunotherapy must be done under the supervision of a trained physician such as a Clinical Immunologist and Allergist. Following is some general advice to help minimise the risk of a serious allergic reaction.

Remain at your Doctor's Surgery for at least 20 minutes after injection

Avoid exercising for at least 3 hours after treatment.

Certain blood pressure medications such as Beta blockers are contraindicated. It is important to discuss this with your Allergist before starting Immunotherapy to discuss any suitable alternatives.

A non-sedating oral antihistamine pre-injection may reduce the risk of side effects

Inform your doctor about any reaction or adverse symptoms from the previous injection even if these sound trivial. Also advise if you have been started on any new medications (including topical preparations such as eyedrops)

Adhere to the schedule, minimise any gaps in treatment

Potential reactions to sublingual treatment

Sublingual immunotherapy is usually very well tolerated.

The main side effect is irritation of the oral mucosa, sometimes minor swelling especially in the 1st few weeks after starting treatment. Approximately 10% of patients experience the side effects. These usually resolved within a few weeks, and if needed can be treated by taking an oral antihistamine.

Less commonly, some patients may experience stomach cramps and nausea, especially if medication is taken on an empty stomach. The symptoms can also be managed by dose adjustment and or taking an antihistamine

Risk of potentially dangerous side effects arising from this form of treatment, such as difficulty breathing; is extremely low

Are there cases when allergen immunotherapy should not be given?

Pregnancy

No evidence exists currently that immunotherapy causes abnormal growth or development in babies. It is however recommended not to start treatment if you are already pregnant or planning pregnancy in the near future. If you become pregnant while on treatment, you can generally continue treatment; but still discuss this with your allergy specialist first.

While Breast-feeding: treatment can be started or continued.

Age

Immunotherapy is not normally started in children less than 5 years of age, due to difficulty with taking injections/drops.

Severe uncontrolled asthma or atopic eczema

These are considered contraindications to starting Immunotherapy. Treatment for these conditions needs to be optimised before Immunotherapy can commence. Immunotherapy confers long-term prognostic advantage for both conditions

Cancer, Immune deficiency and autoimmune disease

These constitute relative contraindications. It is generally recommended not to commence Immunotherapy if these diseases are actively being treated.

Costs of Allergen Immunotherapy

Individual costs vary and will be advised at the time of prescribing treatment. Please consider the following

Allergen extracts - more expensive for oral than injection extracts

GP visit gaps - only applies to those having injections; check with your GP

Specialist review visit costs - to start treatment (most cases) and then after 6-12 months (to review)

Cost-effectiveness - The initial cost of immunotherapy may be substantial, but to take a long term view, many studies have shown that immunotherapy costs less in the long term than ongoing medicines many years to come

Note: There is no Medicare rebate for the allergen extracts for aeroallergens. If you have private health insurance and ancillary cover, you might get some money back but only for some extracts, do check with your Health Cover Provider.