What is immunotherapy?
Immunotherapy (also called desensitisation) is a treatment offered in the allergy clinic for allergic rhinitis (for example hayfever) and bee/wasp allergy. The treatment aims to change the response to these items so they are tolerated better. In the case of bee and wasp venom allergy this decreases the likelihood of a severe allergic reaction (anaphylaxis) if stung again. In allergic rhinitis it aims to reduce the severity of the rhinitis symptoms. We offer this treatment for people who have had severe allergic reactions to bee or wasp stings or where allergic rhinitis has not responded to maximum medical treatment (daily use of an antihistamine and a nasal steroid spray)
How is it given?
For allergic rhinitis, immunotherapy can either be given as an injection into the subcutaneous tissue (fatty area under the skin) of the upper arm or via the sublingual route (a tablet placed under the tongue). Venom Immunotherapy is only given through the subcutaneous injection route.
The exact details will be discussed with you if you are suitable for immunotherapy after assessment in the service.
Preparing for immunotherapy
Your first appointment will take slightly longer as we need to go through consent with you, explaining the risks and benefits of the treatment.
If you take antihistamines you can continue to take these as normal throughout your treatment. Certain medications may need to be stopped before starting immunotherapy and this will be discussed with you if needed.
For subcutaneous immunotherapy on the day of the injection, you should avoid very hot baths/showers, excessive alcohol and excessive exercise. If you feel unwell on the day of injection it is important you contact the department to discuss if you should attend the appointment. If you need a vaccination this should be given a week apart from your immunotherapy injection.
What are the risks and side effects of subcutaneous immunotherapy?
The main risk is an allergic reaction. After injection, patients are generally monitored for 30 minutes in the clinic so if any symptoms occur, they can be assessed. The symptoms of a mild allergic reaction can involve sneezing, runny nose, coughing and itchy raised rash (urticaria). There is a risk of a severe allergic reaction (anaphylaxis), but this is very rare.
It is common to experience swelling, itching and redness at the site of injection. If this occurs it can be treated with antihistamines. An antihistamine can also be taken prior to the injection if required. We will give you more advice on this when you attend for your first injection.
What are the risks and side effects of sublingual immunotherapy?
The main risk is an allergic reaction. Patients taking sublingual immunotherapy should expect mild to moderate local reactions within the first few days and subsiding again with continued treatment (1-3 months). For most events, the reaction will start within 5 minutes of placing the tablet under the tongue and settle within a few hours at most. It is very rare to have more severe reactions with SLIT.
What happens if I miss an injection?
This varies depending on the type of immunotherapy you are having and the product being used but it is important you try and stick to your scheduled appointments as much as possible. Missed injections may mean the next dose would need to be reduced or if many injections are missed the treatment may need to be restarted from the beginning.
What happens if I miss a tablet?
It is very important that one tablet is taken every day without interruption. If you stop treatment for any reason you should let us know as soon as possible so we can discuss this with you.
Can Immunotherapy be given in pregnancy?
We would not start immunotherapy if you were trying to conceive or are pregnant. Immunotherapy does not need to be stopped if you unexpectedly become pregnant during treatment, but we would discuss the risks and benefits with you at the time to allow you to make a decision that is best for you.
If you have any questions please discuss this with Immunology nurses or your Immunology consultant.