Allergy IgE testing “RAST Test” Allergy Blood Test

Allergy IgE testing Specific IgE RAST test Blood allergy test for adults and children in London.

Why do we use a blood allergy test and what is the difference with prick test and other types of allergy tests?

Allergy IgE testing ImmunoCap measures free specific IgE to an individual allergens that you and your allergy consultant suspect to be related to your symptoms. This allergy blood test can be done for more than 400 different allergens (developed by our partner – Phadia – division of Thermo Fisher scientific).  In our allergy centre you can get access to the cutting edge technology.

Our allergy consultants will help to interpret results for you and your children.

Please register as a new patient.

I want to have all available allergy tests done?
Very often we get request to do all possible tests and from technical side this can certainly be done.  Our consultants encourage to start from symptoms and do a limited number of tests for those allergens that actually can be responsible for symptoms and help with diagnosis.

Will a positive or negative test confirm or exclude allergy?

Unfortunately in many cases getting positive or negative result of an allergy test will not  answer the main question if the particular allergen is responsible for causing the symptoms or not.

We see many patients who have positive IgE tests to several allergens and don’t have any symptoms and on the opposite negative tests sometimes can be questioned by positive provocation tests when suspected allergen is applied on the skin or mucosa and actually cause symptoms. For example this is relevant in newly established condition called local allergic rhinitis, when people with negative allergy tests suffer from very bad hay fever (running nose, sneezing and itchy eyes).  This is why these tests need interpretation by experienced allergy consultants and are not recommended without a consultation with allergy specialist before of after testing.

In complex cases both skin prick testing IgE testing and component testing might be required

Appointment with allergy consultant can be booked via Electronic Appointment System

List of allergens for an allergy blood IgE test in London:

If I live at a distance or have other reasons and can not attend allergy clinics in London?

Our London Laboratory can do allergy testing from a sample sent in the post. We provide all necessary for a blood sample collection by a healthcare professional locally and special transport container with prepaid envelope. Results will be sent to the patient and their GP (if they consent for this).

London Allergy and Immunology Centre together with our partners have developed a program for remote allergy testing using technology of simultaneous IgE detection to 112 different allergens in one test from a finger prick. This is similar method of IgE testsing to ImmunoCAP.  This type of Private Allergy Testing is done with Allergy Consultant’s interpretation of results and is available as an allergy UK wide test in any part of  England, Scotland, Wales and Northern Ireland.

Individual allergy tests to food can be requested remotely (up to 3 allergens can be done from one tube of blood collected from a finger prick), If you want to have more than three allergens done you will either need to attend the appointment or request two sample kits.  Individual tests for food allergens can be accessed from the website Food Allergy Test  https://foodallergytest.co.uk 

We have developed a history questionnaire that can be filled out on our website and then our consultants will determine if based on your symptoms, doing an allergy test can bring any new information helpful in diagnosis. If yes you will be sent a form and a collection kit (for adults only) or you can attend our laboratory in London with your child where a sample can be collected by a professional phlebotomist (trained to take samples at any age).  This test is called ISAC and it is also a specific IgE test but it only includes some allergens.

Allergens described below (the layout of the ISAC biochip is predetermined and it is not possible to add or remove anything (please see ISAC test information and list of allergens).

Allergy IgE testing ImmunoCAP is a very sensitive blood test for allergies. It measures the concentration of immunoglobulin E (IgE), which is an indicator of allergic sensitisation. ImmunoCAP is a laboratory test that can detect sensitisation to one allergen at a time (comparing to Immunocap ISAC (above) that tests for multiple allergens in one test). ImmunoCAP can test for hundreds of allergens, such as weeds, trees, pollen, mould, food, and animal dander—all with just one blood sample taken during a single appointment. The list of allergens that we can test is given below. Multiple tests can be done using the same sample. This test can be done for adults and children.

Results usually take under 2 weeks to be ready and are sent to the consultant who requested the test for you. You also can get a copy of the test result by e-mail. Our consultants will interpret results for you during the follow-up consultation (consultation is not included in the price). Results  can help your doctor determine your or your child’s individual allergy profile that can help to create a  treatment plan. This might include medications and tips to help you reduce exposure to your child’s specific allergic triggers, including rhinitis triggers, asthma triggers, and food allergy triggers. Accuracy: Among allergy blood tests, ImmunoCAP is widely considered to be the most accurate and precise—the best test, the gold standard.(1-4)