What is Allergovit desensitisation?
Pollen desensitisation (also known as immunotherapy) is a treatment used for severe hayfever. It involves giving regular injections of pollen allergen in order to ‘reset’ the immune response. Over time the symptoms improve in most people.
Does the treatment work?
The treatment doesn’t cure hayfever, but rather reduces the symptoms. Pollen counts can be higher in some years and you may still have bad days even after successful treatment. Desensitisation is a very effective treatment for severe hayfever. In our clinic, nine out of ten people report significant improvement. In clinical trials, the average improvement was 30% in year one, 50% in year two and 70% in year three. The benefits are long term, even once the treatment is complete. During the pollen season, please continue taking your usual medication; hopefully you won’t need as much once the treatment is working.
What does the treatment involve?
Allergovit is the brand name for the pollen products that we use. Different products are available for different types of pollen. We will choose the best product for you based on your symptoms and allergy test results. Allergovit is made from natural pollen, and doesn’t contain any additives. Allergovit is given by injection in the upper arm.
The first phase of the treatment is known as ‘updosing’. We start with a very small dose, which is increased at each visit. You will need to attend every one or two weeks. It takes seven sessions to reach the maximum dose.
The next phase of the treatment is known as ‘maintenance’. You attend once at four weeks and then every eight weeks for top ups.
The treatment always starts out of the pollen season, in the autumn or winter. It is completed after around 30 months, which provides long term protection.
Are there any side effects or risks?
Because you are allergic to pollen, the treatment can cause allergic reactions. The main time that we see reactions is during the updosing phase, but they can happen at any point during treatment.
You must stay in the clinic for 30 minutes after the injection. If you do get an allergic reaction we will assess and treat anything that happens. Severe allergic reactions to Allergovit are extremely rare, estimated at one in one million injections.
These reactions can include:
• Local reactions: The injection site may itch, swell and go red: taking an antihistamine before you come can help.
• Anaphylaxis: This is a severe reaction and includes rashes, swelling (for example, of the lips) and breathing problems or fainting.
• Milder generalised allergic reactions: These affect the skin only, causing itching and hives. This is more common, estimated at one in 10 000 injections. Skin reactions usually happen within 30 minutes, but can be delayed out to a few hours. Delayed rashes are not dangerous and can be treated with anti histamines.
• Delayed hayfever: Around one in 20 people experience hayfever symptoms some hours after the injection. Occasionally people get a bit wheezy too: this is usually seen in people who get wheezy during the pollen season. It gets better within a few hours and responds to usual medication.
• Fatigue and tiredness on the day of treatment are another reported side effect.
Are there any precautions?
• You should stay in the department for 30 minutes after injections, as this is the risk period for severe reactions.
• Please don’t come for immunotherapy if you are not well e.g. with infection.
• If you have asthma, it should be well controlled. If your asthma isn’t controlled on the day we may advise on treatment and delay the immunotherapy.
• Vigorous exercise such as running, gym or exercise classes is not recommended straight after the dose.
• Please let us know if you are taking B Blocker tablets.
• Some people take an antihistamine tablet before the appointment, which can help with the local reactions at the injection site.
What if I am pregnant or become pregnant during the treatment?
Pregnancy should be avoided during the updosing phase. However, if you become pregnant during the maintenance phase it’s not a problem.
Where do I need to go for my treatment?
Desensitisation clinics are held in Main Outpatient Department, Royal Sussex County Hospital on Monday and Wednesday mornings. You will be given an appointment, but you don’t need to stick to the stated time: you can turn up whenever convenient between 8am and 11.30am.
Who can I contact for further information and advice?
For general enquiries and appointment changes [email protected]
For appointments 0300 303 8360
Medical Secretaries for more urgent questions 01273 523107
The information in this leaflet is for guidance purposes only and is in no way intended to replace professional clinical advice by a qualified practitioner.