Severe and persistent allergies can really get you down and zap your energy, interfering with daily life. If you and your doctor feel you’ve tried everything for your severe hay fever, animal allergies or wasp and bee stings, and other treatments aren't working for you, immunotherapy may be worth exploring.
Immunotherapy isn’t a common treatment but it can be an option for the small number of people with severe and persistent allergy symptoms they’re unable to control. It can also help some people who have serious life-threatening reactions to things like venom from insect stings that are harmless to others. Immunotherapy isn’t a quick treatment - it can take 3 years to complete - so read on to find out if it might be an option for you.
How does immunotherapy work for allergies?
Immunotherapy aims to help your body get used to the thing that’s causing your allergy, whether that’s pollen or house dust - doctors call these things allergens. The idea is that getting used to an allergen stops you reacting so badly. This process is sometimes called desensitisation.
What are the different types of immunotherapy?
There are 2 main types of immunotherapy treatment - both involve giving you occasional small doses of the allergen:
- an injection in a specialist clinic under the supervision of a doctor, because of the risk of a severe reaction (anaphylaxis)
- drops or tablets under your tongue that can usually be taken at home
What are the benefits and drawbacks of immunotherapy?
- immunotherapy might not completely cure your allergy but it can make your symptoms milder and may mean you can cut down on the amount of allergy medicine you have to take at the moment
- it’s not a quick solution: both types of treatment usually take 3 years to complete
- the benefits last for 5 to 10 years after treatment is stopped
- there’s some evidence it can reduce the chances of asthma or new allergies developing
Who can have immunotherapy?
Immunotherapy doesn’t work for every case, although new treatments are in development for food allergies such as peanut allergy. At the moment, doctors know it can be suitable in some situations.
Severe hay fever: what you need to know
- immunotherapy might be worth a go if you’ve tried allergy treatments at maximum doses and you’re taking them the right way, but you still have severe symptoms or regularly need short courses of oral steroids (in the US, immunotherapy is often used for less severe cases if you want to try it)
- pollen immunotherapy has been shown to lessen hay fever or rhinitis symptoms such as constant eye itching and watering, fatigue, continuous sneezing and coughing and headaches – and may also reduce the need for medication
- treatment can’t be started during a pollen season and will need to kick off several months before the next pollen season. It will take 6 months or more before your hay fever symptoms improve
Wasp and bee stings: what you need to know
- immunotherapy is only considered for people who are at risk of a sting causing anaphylaxis - a potentially fatal reaction that may result in collapse, body shock and swelling and obstruction of the airways
- venom immunotherapy works well, giving around 98% protection against serious reactions to wasp stings and 90% protection against bee stings
- the more common minor reactions to wasp and bee stings - such as itching, pain and swelling - are normal and don’t need immunotherapy. They can be treated simply with antihistamine tablets, creams and cold compresses
Animal allergies: what you need to know
- you may be able to have immunotherapy if you have a severe animal allergy that puts you at high risk of developing anaphylaxis, or you react to tiny amounts of pet allergen - even in public places or on people’s clothes
- if you have a severe animal allergy and work in a veterinary surgery or have a job visiting homes where people have animals, you may also be suitable
- allergic to your pet? You’re unlikely to be given immunotherapy treatment as it’s less likely to work if you’re constantly being exposed to the allergen in your home. Research is exploring this area more so advice may change in the future - but at the moment the data’s limited
Asthma: what you need to know
- very rarely, immunotherapy can cause a severe allergic reaction and that can be dangerous in people with asthma - so it isn’t suitable for most
- but if you’re someone with asthma who also has severe allergic reactions to insect stings, the risk from a sting is greater than the risk of an immunotherapy side effect - so immunotherapy may be worth considering
- if you only have asthma symptoms during the pollen season (typically spring and early summer) you may also be considered for immunotherapy, starting well before that time of year
- the more severe your asthma is, the less likely you are to be offered immunotherapy because of the risk of an allergic reaction to it
Multiple allergies: what you need to know
- if you have severe symptoms that are caused by more than 1 allergen, you may be able to have immunotherapy to help with 1 or 2 of them
- but it’s very unlikely you’ll be given immunotherapy to help with all your allergies
- however, having immunotherapy to treat 1 or 2 can ease your symptoms so you can manage them with standard treatments
Allergic rashes: what you need to know
- allergic rashes like atopic eczema can’t usually be treated with immunotherapy
- ongoing research is looking into whether some forms of immunotherapy might help severe atopic eczema - but scientists don’t have the answers yet
Who can’t have immunotherapy?
There are a few situations where immunotherapy isn’t suitable:
- if you’re pregnant or trying to conceive, immunotherapy isn’t normally recommended. But you can start treatment while you’re breastfeeding
- if you’ve had surgery for breast cancer that’s caused swelling to your arm (lymphoedema) you can’t have injections into the affected arm. But you should be able to have the injections in another area, such as your leg or tummy
- children under 5 can’t normally have immunotherapy
When to see a doctor
If you feel your allergies to animals, pollen or wasp and bee stings are severe, and self-care, pharmacy and prescription treatments aren’t working for you, talk to your doctor to see if you can be referred for immunotherapy.
Immunotherapy for allergies is only considered for people with specific and severe allergies where other treatments haven't worked.
In the UK, immunotherapy is available on the NHS but it’s a specialist service and immunotherapy clinics aren’t yet set up in every area. This means you may need to pay to have the treatment privately if you want to try it, and that can be very expensive.
In other countries, including the US, immunotherapy for allergies is more widely available, either privately or through health insurance.
How do I get referred for immunotherapy?
Your doctor can refer you to an allergy specialist if they think you’d benefit from the treatment. Not all hospitals have these specialists so having the treatment may mean you have to travel.
You’ll need to have a skin prick test to identify your allergy, and in some cases a blood test to look for allergic antibodies. Your doctor may also check your general fitness, because health issues such as high blood pressure and asthma must be under control before you have treatment.
Types of immunotherapy
There are two types of immunotherapy: tablets/drops you take under your tongue (sublingual) and injections, which are done under medical supervision.
A 3-year course of treatment is currently recommended but in future, research might show a shorter course could be almost as effective. Large studies have shown that drops/tablets work for hay fever. More studies are needed to compare drops and tablets with injections to see which works best. Not all forms of immunotherapy are available as tablets, so you can chat through the options with your doctor.
In both types of immunotherapy, you’ll have tests to show which allergen is affecting you. An extract of the allergen is then prepared, ready to either be injected or taken as drops or tablets.
Allergy injections (subcutaneous immunotherapy, or SCIT)
This is the most common type of immunotherapy. One benefit is you don’t have to remember to take pills every day - but you can spend a lot of time going to appointments.
What happens with immunotherapy injections?
A specialist allergy doctor will give you injections into your upper arm. Usually, the first injections are given each week while the allergen dose is increased to a maintenance dose. After that, you’ll have injections every few weeks for at least 2 years. You’ll need to wait for up to an hour after each one so that if you get any serious side effects, these can be quickly treated in the hospital.
In general you can expect to:
- stay in the clinic until you’re advised it’s safe for you to leave
- avoid exercising for at least 3 hours after having the injection
- avoid some heart or blood pressure medication such as beta blockers - if you take these medicines, your specialist will discuss it with you and may suggest you change to a different type of treatment
- take a simple non-sedating antihistamine tablet before each injection to help minimise any side effects
Side effects from immunotherapy injections
Most people can easily manage any side effects or reaction to the injections if they happen.
- you may have itching and swelling on your skin where you have the injection, and these symptoms can get worse for hours or days afterwards. Simple antihistamine treatment and putting an ice pack on the area can help
- you may feel tired or as if you have mild flu symptoms after an injection. You’ll usually be advised to avoid alcohol and take it easy on the day of each injection to help minimise this risk
- There’s also a low risk of wheezing, dizziness and a severe allergic reaction called anaphylaxis, which is why the injections are done in a clinic and not at home
Allergy drops/tablets (sublingual immunotherapy or SLIT)
This type of immunotherapy is more convenient as it doesn’t involve lots of hospital visits. There’s a very low risk of severe reactions - plus you’ll prefer this option if you don’t like needles, and it’s often more convenient than having to go to hospital for injections. But you will need to get into a good routine as missing doses regularly can mean the treatment won’t work.
What happens with immunotherapy drops and tablets?
After you’ve taken the first dose in hospital, under supervision by an allergy specialist, you can carry on taking your drops or tablets at home.
You take the extract in a tablet or drop form anywhere from 3 times a week to every day. You’ll be advised to:
- take it in the morning on an empty stomach
- keep the drops or tablet under your tongue for at least 2 minutes, then swallow
- avoid eating or drinking anything for 15 minutes after this
- take your dose as usual the next day if you forget it
Side effects from immunotherapy drops or tablets
Side effects can include irritation or itching inside your mouth, and sometimes nausea. You can usually manage this by temporarily lowering the dose you take or by taking a non-sedating (non-drowsy) antihistamine beforehand. Any side effects generally clear up after the first few weeks of treatment.
Watch this space
Scientists have recently trialled a promising new treatment for children with peanut allergy, which affects around 1 in 50 children in the UK and is the most common cause of food-related death.
The tablet treatment, called Palforzia, is given every month and helps the immune system gradually build up acceptance to peanuts. The UK’s National Institute for Health and Care Excellence (NICE) has now recommended it for treating peanut allergy in children aged 4 to 17. It can be continued in people who turn 18 while on treatment. Palforzia should be used with a peanut-free diet.