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What is allergy?

What is allergy?

The term 'allergy' is used to describe the body's immune response when it detects a particular substance in the body. The substance may not necessarily be harmful (for example, hayfever is a response to pollen) but the body detects it as a foreign substance and produces an immune response in reaction to it.

Allergy is widespread and affects approximately one in four of the population in the UK at some time in their lives. Each year the number of people suffering from allergies increases by 5% and as many as half of those affected are children.

Most allergies can be successfully diagnosed and treated by GPs. We aim to provide a service for patients when the diagnosis may not be clear or when more specialised treatment is required.

  • Hayfever  or allergic rhinitis - Nasal and eye symptoms due to pollen, house dust mite, pets or other allergens in the atmosphere
  • Hives/urticaria ('nettle rash')
  • Allergic swelling (angioedema)
  • Food allergy
  • Antibiotic, anaesthetic and other drug allergies
  • Bee or wasp allergy
  • Latex allergy

Patients with dermatitis may have an allergy (e.g. hair dye), but this is caused by a different mechanism. The testing for this kind of allergy is done in dermatology (patch testing).  Sometimes patients are referred to dermatology for patch testing after being seen in our clinic.  We endeavour to make sure that only appropriate patients are seen in the clinic and referral letters are checked by the consultants before an appointment is confirmed. 

  • Food intolerance
  • Eczema and dermatitis
  • Eosinophilic Oesophagitis
  • Orofacial Granulomatosis

Food Challenge Patient Information

Introduction 

You have been referred for investigation of a suspected allergy. As part of this investigation, you may be offered an oral challenge. This leaflet aims to tell you what to expect. 

What is an allergy?

Adverse reactions to foods can be allergic and non-allergic (intolerance). Allergic reactions are caused by the immune system.

What happens after I have had a reaction? 

You will be referred as an outpatient to a centre specialising in allergy, where you may have a blood and / or skin prick test. This can help to identify what caused your reaction. If your test results are positive, you will be advised to avoid that particular food.

Often if the reaction was typical of an allergic reaction you may be advised to avoid that food, even if the test results are negative. 

If the symptoms were not typical, the tests were negative and you would like to reintroduce that food back into your diet, then a ‘challenge’ may be offered. 

A challenge is the best way to determine how you will react to a particular food. 
 
What happens in a challenge?

An appointment will be made for you to attend the allergy challenge clinic. 
The challenge is performed in hospital, in order that you can be closely monitored.  You will be asked to bring with you the food that may be causing your reaction.  You will be asked to sign a consent form.

You may have an allergy skin prick test  prior to the challenge.
 
Increasing amounts of the food are given over time, with close observation for reactions. Observations may include pulse, blood pressure and peak flow (a breathing test). 

The exact duration and number of stages will depend on previous reactions and symptoms during your test, but typically a challenge to a food will take 2 - 3 hours. 
The amount of food required will vary, but the aim is to have taken a sufficient quantity to   exclude allergy.

After the final amount, you will be observed for at least 1hr before you can be discharged.

Challenges carry a risk. If you have any symptoms, however mild let the doctor or nurse know. We can then treat the symptoms quickly and prevent the reaction progressing. A cannula may sometimes be placed in a vein. Such symptoms usually occur within an hour of exposure to the food. The allergy team will write to your GP advising them of the outcome.

What kind of reaction may I have?  

The most common reactions are:

Flushing or rash 

Itching 

Lip swelling and facial swelling

Less common reactions are:

Wheezing 

Itchy watery eyes and nose 

Nausea

Rarely more severe reactions can occur causing faintness and anaphylaxis.

What happens if I react to the food? 

The challenge will be stopped and treatment given if necessary. 

Rarely ward or A&E admission may be required if a severe reaction occurs in order to monitor you closely and provide additional treatment. 
You will be advised to avoid this food in the future.

What do I need to do before the challenge?
  • Bring the food for the challenge 
  • Stop taking anti-histamines for 5 days before appointment   
  • Avoid aspirin or similar non-steroidal antiinflammatory drugs on day of the challenge. 
  • Expect to be in outpatients for the majority of the morning 
  • If possible bring someone with you 
  • Eat and drink normally prior to the challenge

Inform a member of the immunology team if you:  

  • are taking prednisolone  
  • Are taking beta blockers eg atenolol   
  • are unwell  
  • have asthma and are using your blue inhaler more frequently 
What happens if I become unwell after I leave hospital?

Treat  reactions according to your management sheet

Make a note of the symptoms and when they happened and let the immunology team know

Further Information

AllergyUK www.allergyuk.org 01322 619898

The Anaphylaxis Campaign 1 Alexandra Road Farnborough Hampshire.  GU14 6BU 01252 542029  www.anaphylaxis.org.uk 

The MedicAlert Foundation 1 Bridge Wharf 156 Caledonian Road London N1 9UU Monday to Friday 9am to 5pm Freephone 0800 581420 (UK) or 1800 581420 (Ireland)  Fax 020 7278 0647  info@medicalert.org.uk  www.medicalert.org.uk

Drug and Vaccine Challenge Patient Information

Introduction

You have been referred for investigation of a suspected drug or vaccine allergy. As part of this investigation, you may be offered an oral drug or vaccine challenge. This leaflet aims to tell you what to expect.

What happens after I have had a severe reaction?

You will be referred to a centre specialising in allergy as an outpatient where you may have a blood and / or skin prick test. This can help to identify which drug or drugs caused your reaction. If your test results are positive, you will be advised to avoid that particular drug and advised to wear a medical alert emblem at all times (see Further Information).

Most often if there is a possibility that someone is allergic to a particular drug then they can just avoid it. However, sometimes it is important that patients are able to use a particular drug if possible e.g. antibiotic. If it is important that you know whether it is safe for you to take a particular drug and the tests for allergy are negative then a ‘challenge’ may be offered. This is the best way to determine how you will react to a drug or vaccine.

What happens in a challenge?

An appointment will be made for you to attend the allergy challenge clinic.
Drug challenges carry a risk. We do the challenge in hospital to minimise the risk. You will be asked to sign a consent form.

  • You may have an allergy skin prick test prior to the challenge.
  • Increasing doses of the drug or vaccine are given over time, with close observation for reactions. Observations will include pulse, blood pressure and peak flow (a breathing test).
  • The exact duration and number of stages will depend on previous reactions and symptoms during your test, but typically a challenge to one drug will take 2 - 3 hours.
  • The amount of drug required will vary, but the aim is to have taken one standard dose of the drug by the end of the challenge.
  • After the final dose, you will be observed for up to 2 hours before you can be discharged.
  • Sometimes, e.g. antibiotics, you are advised to complete a course of treatment at home at the end of the challenge. This is to look for delayed reactions.

If you have any symptoms, however mild, let the doctor or nurse know. We can then treat the symptoms quickly and prevent the reaction progressing. A cannula may sometimes be placed in a vein.

If you have no reaction during the challenge, the allergy team will write to your GP advising them that you are able to take that particular drug.

What kind of reaction may I have?

The most common reactions are: 

Flushing or rash 

Itching 

Lip swelling and facial swelling

Less common reactions are:

Wheezing 

Itchy watery eyes and nose 

Nausea Rarely more severe reactions can occur causing faintness and anaphylaxis.

What happens if I react to the drug or vaccine?

The challenge will be stopped and treatment given if necessary.

Ward or A&E admission may be required if a severe reaction occurs in order to monitor you closely and provide additional treatment.

You will be advised to avoid this drug completely.

What do I need to do before the challenge? 
  • Stop taking anti-histamines for 5 days before the appointment.
  • Avoid aspirin or similar non-steroidal antiinflammatory drugs on day of the challenge
  • Expect to be in the outpatients clinic for the majority of the morning   
  • Eat and drink normally on the day of the challenge

If you are not sure about this please ask. 

Inform a member of the immunology team if you:   

  • are taking prednisolone   
  • are taking beta blockers eg atenolol    
  • are unwell  
  • have asthma and are using your blue inhaler more frequently 
What happens if I become unwell after I leave hospital? 
  • Treat  reactions according to your management sheet 
  • Make a note of the symptoms and when they happened and let the immunology team know
Further Information

AllergyUK www.allergyuk.org 01322 619898

The Anaphylaxis Campaign 1 Alexandra Road Farnborough Hampshire.  GU14 6BU 01252 542029  www.anaphylaxis.org.uk 

The MedicAlert Foundation 1 Bridge Wharf 156 Caledonian Road London N1 9UU Monday to Friday 9am to 5pm Freephone 0800 581420 (UK) or 1800 581420 (Ireland)  Fax 020 7278 0647  info@medicalert.org.uk  www.medicalert.org.uk

 What is immunotherapy?

Immunotherapy, often referred to as desensitisation, is the only proven treatment that can reduce allergy symptoms in the long-term. Immunotherapy is a well-established treatment for certain severe allergies, and involves the administration of gradually increasing doses of allergen extracts over a period of years. It is given to patients by injection or drops/tablets under the tongue (sublingual).

On average people with hay fever have about 30% improvement in symptoms following immunotherapy. The success of the treatment can vary between individuals. Some people will be almost free of symptoms, most will still need some medication, and a small number of patients will not show any improvement at all.  We will review your symptoms after the first year.

Can everyone have immunotherapy?

No. Not all individuals with hay fever are suitable for this treatment. Your consultant will decide whether or not you are a good candidate to receive this treatment.

Immunotherapy is not recommended in patients with poorly controlled asthma as they are more likely to experience severe reactions. It should also not be commenced during pregnancy.

Subcutaneous Immunotherapy How is the treatment given?

Immunotherapy should take place before the tree or grass pollen season starts. The injection has to be administered in hospital so you can be closely monitored.

Immunotherapy involves a total of 6 injections per year being administered just under the skin on your arm. The dose will be slowly increased every 7-14 days for 3 injections and then 3 further injections every 14-28 days. Treatment is continued for 3 years. You will have to be observed for at least 1 hour after the injection. Injections time frame in non pollen season diagram

What you should know about the injections. 

You should let us know if you have:

  • been feeling unwell in the 24 hours preceding the treatment
  • started new medication or have had vaccinations since your last injection.

You should not eat a large meal immediately before the injection is administered and limit alcohol consumption

You should not take any strenuous exercise for 12 hours after the injection.

What happens if I miss my injection? 

It is important that you try and attend your appointments as per the schedule.

If you are 2 weeks late for having an injection, the treatment regime would have to start from the beginning.

Side effects

Common

Redness and slight swelling at the injection site. These can be treated by applying ice packs and/or taking an antihistamine (e.g. Cetirizine 10 mg tablet) 

Feeling tired and lethargic– this is often temporary and should resolve within a few hours

Less common 

Symptoms of hay fever or nettle rash/ hives (also called urticaria).

Rare 

Chest tightness and wheeze 

Anaphylactic shock

If you develop any side effects, please inform the allergy team.

Sublingual Immunotherapy (SLIT)

How is the treatment given?

This treatment involves a daily dose of allergen being administered as a tablet or drops under the tongue. It is important to take the medication every day.  The first dose is given in hospital and  subsequent doses at home.  An improvement in symptoms occurs in the first season, but it is necessary to continue for 3 years to get lasting benefit.

Side effects

Common

Local symptoms such as itching in the mouth, but this improves during the first few weeks. 

Indigestion symptoms 

Throat discomfort 

Rhinitis symptoms e.g runny nose

Rare

Tightness of the chest or wheeze 

Anaphylaxis

Pollen calendar

What is allergy?

Allergies occur when the immune system makes an inappropriate response to something harmless. In the case of bee and wasp allergy this is caused by an allergy antibody (IgE) reacting to bee or wasp venom. This can, in some people, cause severe reactions called anaphylaxis.

What is immunotherapy?

Immunotherapy, also called desensitisation, is the only treatment that can reduce the risk of anaphylaxis in individuals who are allergic to bees or wasps. The treatment involves administering small amounts of the protein which the person is allergic to (which is called an allergen) so that the body can slowly “get used” to it. This will reduce the chances of the person having a severe reaction if they are stung by the bee or wasp again.

This treatment is very effective, providing 98% protection against serious wasp venom reactions and about 90% protection against serious reactions to a bee sting.

What your treatment involves

Immunotherapy treatment is given as injections into the fatty layer of tissue just beneath the skin (subcutaneously).

Initially, you will receive slowly increasing doses of the venom allergen on a weekly basis for 12 weeks. We will then give a maintenance dose every 4 to 6 weeks for up to 2 years and then 68 weekly for the third (final) year.

The injections will be administered in the outpatient department under medical supervision. You will be asked to stay for one hour after your injection in case of any reactions. If you feel unwell after the injection you  will be asked to stay a little longer.

At each  visit we will record details of any symptoms you experience after the injection. This is so we can adjust your dose regime depending upon your symptoms.

What happens if I miss my injection?

It is important that you try and attend your appointments as per the schedule. 

If you miss your injections you may have to reduce the scheduled dose. If many treatments are missed, it may be necessary to re-start the treatment.

What side effects can occur?

The common side effects include:

  • Swelling and redness at the injection site, which may be quite large in cases. 
  • Nettle rash, tiredness, flushing.
  • Itchy eyes and runny nose or wheezing.

Most symptoms are mild and usually settle. This does not mean that treatment would have to be stopped. You may apply ice and take an antihistamine for injection site reactions. If you are concerned please contact your general practitioner. 

Serious allergic reactions (anaphylaxis) are very rare with immunotherapy treatment. 

Can I have immunotherapy if I am pregnant?

We would not start  immunotherapy  if you are trying to conceive or are already pregnant. If you become pregnant when you are established on maintenance injections, treatment can continue.

If you have any concerns, discuss them with your immunology consultant.

Preparing for your immunotherapy

So we can ensure that your treatment is safe, please inform someone from the clinic if you:

  • Have been unwell (e.g. a fever) within the 24 hours before treatment. 
  • Have experienced allergic symptoms within the 3-4 days before treatment.
  • Develop any side effects.
  • Are taking regular medications and have had any changes to these. 
  • Have received a vaccination within the last 7 days before treatment. 
  • Have any chronic conditions such as asthma, heart and/or lung disease, immune disorders.

Before your injection, avoid large meals and alcohol. We recommend that you take an antihistamine tablet (e.g. Cetirizine 10mg) one hour prior to your clinic visit/injection.

Antihistamines can be purchased from your local pharmacy who will be able to advise you on the one most suitable for you.

After the injection, please do not take any strenuous exercise for 12 hours and avoid having a hot bath. Alcohol should be avoided for at least 4 hours afterwards

Useful tips to avoid getting stung 
  • Move away slowly and don’t panic - avoid provoking bees and wasps. 
  • Wear clothing that covers most of the body (particularly the feet).  
  • Always wear shoes when outdoors. 
  • Avoid wearing bright colours, flowery prints and using products with strong scents – these can trick wasps and bees into thinking you are a flower!  
  • If gardening, wear long sleeves, long trousers and gloves. 
  • Keep food and drink covered when eating and drinking outside - wasps can crawl inside cans where they are not seen. 
  • Avoid flowering plants, outdoor areas where food is served, rubbish and compost  Regularly and carefully remove any fallen fruit in your garden and keep a well-fitting lid on dustbins. 
  • Keep doors and windows closed  
  • Drive with the windows up and the air conditioner on.
What is Urticaria?

Urticaria is a red, itchy rash sometimes called hives or nettle rash. It is thought to be caused due to release of excessive histamine from some immune cells, which is why antihistamines are commonly used to treat this condition.

What is Omalizumab and how does it work?

There is probably more than one mechanism or cause for chronic urticaria. Stimulation of some immune cells (called mast cells) causing release of histamine is likely to be one mechanism. Omalizumab is a man-made drug that reduces stimulation of these cells and thus, decreases the release of histamine.

Why am I being offered Omalizumab?

You have been offered this medicine since your urticaria has not improved despite taking high doses of antihistamines and other drugs.

80-90% of people taking Omalizumab get significant benefit and about a third of patients are completely free of symptoms after 12 weeks. 

It suppresses symptoms and is not a cure, so the symptoms can return once the treatment is stopped.

What does the course of Omalizumab involve?

There is a national guideline for the use of Omalizumab. We use a questionnaire that helps us understand how much improvement there has been in your symptoms. It is important that you fill this questionnaire at the correct time points, since it may be difficult for us to justify the use of the drug without this information.

Omalizumab is licensed to be given as a series of injections every month, lasting for 6 months.  In clinic we sometimes find that the injections work just as well given every 6 weeks.  There is a small risk of reaction so you need to stay in the clinic for 1 hour after the first injection and 30 mins after subsequent injections.

We initially provide 4 doses and reassess your symptoms to see if the medicine is working. After 6 injections we will stop the treatment, but if you have a flare up of symptoms and meet the criteria again for another course of treatment, then we will restart the Omalizumab.

What are the risks of taking Omalizumab?

Some people who have had Omalizumab for urticaria have described reactions at the site of the injection, such as swelling and redness. Some patients have had an increased number of  coughs and colds after starting the drug.

Are there any serious risks?

In asthma patients taking this medication, there have been rare cases of  a severe allergic reaction.  Although this has not been seen in patients with urticaria, we will monitor you for an hour after the first injection and for 30 mins after subsequent injections in the clinic.

In our clinic we provide you with an adrenaline autoinjector to carry for the first 24 hours so that in the unlikely event that you had a severe reaction you would be able to treat it quickly and effectively

Remember to bring your adrenaline autoinjector to clinic appointments.

What else do I need to know?

You should not have Omalizumab if you are at risk of a worm infection (e.g. travel to some countries), or if you are pregnant or breast feeding.

Please inform someone from the clinic if there are any changes to your other medication, if you develop any new illness, become pregnant or plan to become pregnant.

Further Information

British Association of Dermatologists www.bad.org.uk Willan House,  4 Fitzroy Square, London W1T 5HQ  Tel: 0207 383 026 
 
Novartis (who make omalizumab) Website to provide information: http://www.xolair.com/