What's The Differnce Between An Allergy And An Intollerance?

[Marijn]

What's the difference between an allergy and an intollerance/hypersensitivity? I read something about Icg and Ice (I think those were the terms used), but can someone give me a layman's explanation, please.

[daffy654]

An allergy triggers an immune system response and can be very serious/fatal, an intolerance tends to cause digestive problems and is much less serious.

[ChillDoubt]

An intolerance may cause a little discomfort, but nothing serious.
An allergy may cause(in extreme cases i.e. nuts, bee sting etc) anaphylaxis, which is altogether far more serious and can result in death.

[Marijn]

Thanks for your answers. I have food intolerances/hypersensitivities and it causes fatigue, bloating etc. I have just found out the main culprits are milk and eggs. I wondered why the test for the intolerances wouldn't pick up on allergies (that's what the literature said anyway).

[Sqad]

An Allergy in medical terms necessitates the production of antibodies in the blood stream in response to proteins either inhaled or ingested.

An example is antibodies in the blood to grass pollen. These antibodies are immunoglobulins either IgE or IgA.

Hypersensitivity is often used by the lay person to be synonymous with allergy....it might be.......it might not be.

Intolerance is the same...... a laymen's term for allergy.

[gness]

Notafish. I am very allergic to peanuts. I carry two epi pens and my reaction to peanuts (daughter says it was an accident) is immediate and serious. Mouth, tongue and throat swell and breathing becomes difficult. Epi and trip to hospital.
I have a slight intolerance to anything in the peanut family. Peas and anything that is/was a bean. Not serious just a slight tingling and swelling of my mouth and hands. I know as soon as I take a bite if bread contains soya flour.
Some intolerances, I believe, are much slower and cause digestive problems......I'm told.

[gness]

And what Sqad says. Hi Sqad. x

[joko]

an allergy can potentially kill you

and intolerance is usually just some unpleasant and uncomfortable symptoms like diarrhoea, bloating, redness, nausea, itching etc

[Sqad]

Hi! gness.

[Marijn]

Thank you all. The test I had done for intolerances said it didn't check for allergies. So if you came up as NOT having an intolerance to nuts, for example, you didn't necessarily NOT have an allergy to them. It also said it didn't check for coeleiac disease (sp), so you might not have a positive result to gluten as far as the test results were concerned, but you could still actually have coeliac disease. I don't understand that bit.

[daffy654]

Who tested you notafish? If it was a shop bought test then I would be very wary of relying on the results. If you feel you have allergies then it would be best to ask your GP to refer you to an allergist at the hospital for proper testing.

PS. My daughter has severe allergies to wheat, barley, grass and grass pollen and has been hospitalised on many occasions because of anaphylaxis, she has to carry an Anapen (same content as Epipen but easier to use) everywhere.

[Sqad]

notafish....intolerance depends upon the absence of IgE in the blood. If they are there (in the blood) then it is an allergy and it is the combination of the antigen (what you are allergic to) and the antibody (IgE) which does the damage.

Coeliaic disease sufferers have antibodies in the blood...IgA and IgG.

[Marijn]

Thank you Sqad, could you explain that another way, I've left my brain at home. Daffy, my blood was tested by York Laboratory, it was private. I'm reasonably confident they are legitimate. Thanks again.

[Sqad]

notafish

\\\Thank you Sqad, could you explain that another way\\

If there are higher than normal levels of IgE or IgA'a in the blood it is an allergy.

If there aren't........it's not an allergy.

That is as simple as i can put it.

[Marijn]

Righto. Cheers

[LazyGun]

@ Notafish - You might find the following link a useful guide in distinguishing between an allergic response and a food intolerance.

http://www.webmd.com/allergies/features/food-allergy-myths

As sqad has already mentioned, a food allergy requires an antibody mediated immune response, specifically an IgE (Immunoglobulin E) response, which in turn triggers the release of large quantities of histamine, whereas a food intolerance tends to be a lack or deficiency, often genetically moderated of a specific enzyme required to digest that particular food group.

As for York Laboratories - I am somewhat sceptical of the value of their results. For instance, they will often talk about food allergy tests - but they test for an IgG response, not an IgE response - and this is a clinically significant difference.

So, take the results from York Laboratories with a pinch of salt - unless, of course, salt is one of those food groups you are intolerant of! :)

[Marijn]

Thanks Lazy gun, I should've said they are York TEST Laboratories. They specifically said they do NOT test for allergies, only intolerances. The results showed the IgG or IgE, I can't remember which it is (but not both). Anyway what I don't understand is that you may not get a positive result for a nut intolerance for example, but you MAY actually have a nut allergy. And you may not show up as having a gluten intolerance even though you may have coeliac disease. Also I don't know why they don't just check for allergies as well, while they've got a sample of your blood there.

[EcclesCake]

I suspect that for them to test for allergies would be extremely costly.

To give feedback regarding allergies (which can be fatal) they would have to have pretty stringent testing in place backed up by comprehensive insurance for when they make a mistake. In all probability their business model is more suited (and profitable) if they make loose assessments that will satisfy the expectations of their clientele.

[Marijn]

Thanks EcclesCake

[LazyGun]

Notafish - Allergies and the bodies immune response is a complicated thing, not easily explainable in one of these texts :)

Suffice to say - The most serious allergic response is the IgE- mediatated immune response, which is the one that causes the immediate, dangerous response. Non-IgE mediated responses can also occur, but they tend to take place some hours after the supposed exposure.

Now, what the York Test Laboratories offer is a blood test which looks for IgG antibodies - but these do not typically cause an immune response such as allergy or "intolerance" - quite the opposite actually, IgG antibodies only indicated exposure to a particular component within a food. An IgG marker does not indicate a food intolerance or an allergy.

It is difficult to test for the true allergic response - the IgG mediated response, because it is so rapid acting, and it can often be difficult to obtain a blood test when such a reaction occurs - so an IgE test, unless blood has been taken during the response, is fairly useless.

A proper analysis of allergy or intolerance is, I am sorry to say, much more laborious than a blood test - requiring controlled exposure to particular reactants, coupled with observation, blood tests etc.

If you have an interest in the science behind all of this, take a look at the following link - very good overview of the different tests available, and why an IgG test is not really all that useful.

http://www.sciencebasedmedicine.org/index.php/igg-food-intolerance-tests-what-does-the-science-say/

[LazyGun]

Doh this sentence in my last post is wrong -
"It is difficult to test for the true allergic response - the IgG mediated response, because it is so rapid acting,"

It should be IgE= mediated. not IgG mediated... :)