Food allergy testing

[edprush]

Has anyone had this done by a medical doctor?

Is it even possible to test for food allergies in any other way than food-elimination?

 

[edprush]

^

 

[OutHouse]

when i was a kid i got tested by getting like 40 shots on the underside (needle just under the skin and just enough liquid injected to cause a blister to form) of both arms. then i went back a few days later for the doc to see which ones i had a reaction to.

 

[Gibsons]

Originally posted by: edprush
Has anyone had this done by a medical doctor?

Is it even possible to test for food allergies in any other way than food-elimination?

Either ELISAs or a pin-prick test should detect them in most cases.

Also a few other ways that I can think of, but aren't commercially available.

 

[Kaido]

I did a pin-prick test, which showed nothing. Keep in mind that it isn't a very accurate test; not all allergic reactions show up as a bump on your skin. I discovered that I am gluten-intolerant and possibly lactose-intolerant simply through eliminating foods. The most comprehensive test that I know of is the York Test FoodScan test, which tests your blood against 113 different foods:

http://www.yorktest.com/html/testing-and-services/food-intolerance-testing/

PM me if you're interested on getting it in the states or Canada. They can do it via mail if you want to deal with the main UK place. It runs about $500 USD for the full-on test.

 

[SoulAssassin]

Originally posted by: Kaido
I discovered that I am gluten-intolerant and possibly lactose-intolerant simply through eliminating foods.

Gluten intolerant or you have celiac? My girl has celiac and it's life changing thing...she just found out a couple years ago.

 

[Kaido]

Originally posted by: SoulAssassin

Originally posted by: Kaido
I discovered that I am gluten-intolerant and possibly lactose-intolerant simply through eliminating foods.

Gluten intolerant or you have celiac? My girl has celiac and it's life changing thing...she just found out a couple years ago.

Gluten-intolerant, not a celiac thankfully. I actually found out through my dad, who discovered he had a gluten intolerance and mentioned it to me. I eliminated wheat from my diet and felt 110% better. I do have a friend who is a celiac though, fortunately I can have wheat products about once a week if I am careful.

 

[Mark R]

It's important to be clear as to what a food allergy is.

An allergy is an immediate (or prompt - within a minutes) reaction to a substance, which causes symptoms like skin rash, swelling of lips or tongue/mouth, wheezing or difficulty breathing, diarrhoea, watery eyes or nose, etc. Irregular bowel habit, abdominal cramps, constipation, nausea, bloating, etc. are not symptoms of allergy.

There are a series of well recognised and understood food intolerances - e.g. lactose intolerance, where some people lack the ability to digest milk sugar, causing it to ferment and produce gas and bloating, etc. Coeliac disease is another common intolerance to gluten - a non-allergic reaction to gluten (found in wheat and other cereals) causes the intestine to become inflamed and work poorly.

Many people report symptoms that don't fall into these definitions. These non-specific conditions are often loosely called 'food intolerances', and lumped in together with 'irritable bowel syndrome'. These conditions are poorly understood - in particular, no one knows how or why they occur.

In terms of allergies - there are recognised tests for them, although the tests are not extremely accurate. They include skin prick testing, where extracts of various substances are applied to the skin, and then a pin prick made at each spot, injecting a tiny amount of the substance into the skin. A few days later the skin is examined - the formation of a blister suggests an allergic type response to that substance. There are also blood tests available (so-called RAST tests), again they aren't fantastically accurate - but they can support a diagnosis of genuine allergy. RASTs are expensive, and a seperate test must be run for each substance suspected - before a doctor orders such a test they will normally attempt to narrow down the list with you before ordering only 2 or 3 tests.

Coeliac is easily, and relatively accurately, diagnosed on blood tests - but the most reliable test is an endoscopy to take a biopsy sample of the intestine.

For other intolerances, nothing has been shown to work other than food-elimination diets. People have tried all sorts of blood tests (and there are a number of commercial labs who offer such tests) but the scientific evidence is that they are less accurate than elminiation diets, and much more expensive - few doctors believe there is any role for blood tests in diagnosing 'intolerance', expect to test for diseases which may have similar symptoms.

 

[edprush]

Originally posted by: Gibsons

Originally posted by: edprush
Has anyone had this done by a medical doctor?

Is it even possible to test for food allergies in any other way than food-elimination?

Either ELISAs or a pin-prick test should detect them in most cases.

Also a few other ways that I can think of, but aren't commercially available.

Is ELISA the same thing as RAST (RadioAllergoSorbent Test--In the test, the sample of blood is mixed with substances known to trigger allergies. The test measures the level of allergy antibodies (specific IgE antibodies) in the blood which are present if there is a allergic reaction).

 

[edprush]

Is there a method/process to for the elimination diet? For example, are there foods that a person should eliminate first because they have a great likelihood to be an allergen?

 

[Mark R]

Originally posted by: edprush
Is ELISA the same thing as RAST (RadioAllergoSorbent Test--In the test, the sample of blood is mixed with substances known to trigger allergies. The test measures the level of allergy antibodies (specific IgE antibodies) in the blood which are present if there is a allergic reaction).

They are both tests that can be done on a blood sample to detect the allergy antibodies. They measure the same thing using different methods.

The RAST name is actually a trademark for a very old, specific test kit for allergy antibodies. The original RAST kit was based on RIA (radio-immunoassay) technology. However, due to market dominance, the name RAST quickly became synonymous with allergy antibody tests.

The original RAST kit has been superceded by more modern kits, and RIA technology has been virtually obsoleted by ELISA (enzyme linked immunosorbent assay) technology. ELISA is simple and cheap, and virtually all current test methods are based on ELISA technology. However, the old name has stuck, and many people (including doctors) still call them RAST tests.

The key point is that allergy tests must measure specific antibodies, called IgE, and any test that can detect IgE reactive against specific substances can be used. The method doesn't really matter.

Be aware that some labs offer ELISA tests for all sorts of other antibodies (most commonly IgG). Although these tests measure what they say they measure, no one actually knows what the results mean. Only 'IgE' tests have proven to give useful results.