Immunotherapy Treatment

Introduction

The great majority of insect sting allergic responses are mild inconveniences that can be controlled by taking anti-histamines. For some, like myself, the response is so aggressive that it needs to be treated and the traditional approach to this routine is Venom Immunotherapy, or desensitization.

If the medical professional were totally honest, they don't know why this treatment works! But the fact is that it does and hundreds of thousands of people around the world are very grateful that it does. The principle behind venom immunotherapy is that you are injected on a regular basis with gradually increasing doses of venom until you reach the maintenance level of 2 wasp stings. You therefore start off with a tiny dose (in my case 1/5000th of a sting) and over the period of the immunotherapy one somehow reaches the 2 wasp sting injection without any major allergic response. You are then "cured" of your allergy but have to be dosed up for the next few years just to keep de-sensitized. Eventually you don't need the maintenance injections and you are "cured" of the allergy!

The Risk

The major risk is precisely what happened to me - anaphylaxis. The immunotherapy can cause a serious allergic reaction which is why it should always take place in hospital next to the Emergency Room. As I write this I still find it difficult to believe the effect such a tiny dose of venom had on me - if you are considering immunotherapy then please make sure that it takes place near to the Emergency Room!!

The Treatment - (click here to see the Patients Notes from the Manufacturer ALK and click here to see the Technical Leaflet for the Doctors both of which make interesting reading)

Testing The treatment normally starts off with a skin prick test or a blood test which in theory determines to which insects the patient is allergic; once established then the patient starts off a course of build up injections with the venom specified by the blood test. In the opinion of most doctors, immunotherapy should not start without a specific IgE identified by the relevant testing.

However, there have been a significant number of cases of people who have had systemic life threatening reactions but have had negative test results - particularly skin test results. So what does the poor doctor and patient do?!

Immunotherapy Injections: The strength, number, frequency and duration of these injections varies according to country, the immunologist, government advice, financial conditions and the general fashion at the particular point in time. Once again, there are no hard and fast rules about this treatment although my own experience and those of others who have contacted me from this website are:

Duration and Frequency - The venom immunotherapy course typically aims to get people up to a maintenance dose of venom within 12 weeks - one injection per week. Some doctors advocate "rush immunotherapy" whereby the maintenance dose is achieved during a few days stay in hospital - injections are given every three to four hours and the 12 injections are therefore compressed into a smaller time period. The jury is still not decided as to whether rush immunotherapy is more risky than traditional 12 week immunotherapy - it is certainly more convenient and I know of a number of visitors to this site that have successfully had this treatment in Continental Europe. It is important that following each injection you stay in the hospital for up to an hour - allergic reactions are not always immediate, so don't be lulled into a false sense of security if nothing happens immediately!
Strength of Injections - Whilst everyone seems to agree that two wasp stings (100 mg of venom) is the appropriate target dose for the end of the course, the starting dose depends on many factors - usually completely unrelated to the patient but more determined by the established practice in the particular country of treatment. Thus Americans seem to start their injections at much lower levels of venom than Europeans - quite why I am unsure, but it may have something to do with higher levels of litigation in the US than Europe! In the UK at least, we usually look to start at around 1/5000 of a wasp sting. The key to success is to use the potency of the injection to ensure that desensitisation starts before an allergic reaction takes place.
I have a copy here of the ALK patient guide on their venom immunotherapy treatment - it is well worth reading through!

Once the 2 wasp sting level has been achieved then you are "cured" but still have to have maintenance injections for a period of time to keep desensitised.

Venom immunotherapy is serious stuff - but professionally conducted is relatively safe and offers the patient a wonderful way to sort out what is one of the most dangerous allergies of them all. A recent paper shows quite clearly that simply carrying an epipen does little if anything to improve the quality of life of an insect sting allergic patient. Venom Immunotherapy on the other makes a huge difference - as I can personally testify.