Rast Tests for Allergies

[sylvm]

I have posted before regarding my DD's suspected dairy intolerance. Took her to the GP yesterday and he took it all on board. He wants to have a Rast Test done on her blood in preference to the skin pin prick tests - said they don't always show these things up. Does anyone know what the difference is between the two sorts of test - I suppose I just want reassurance that this is a reliable way of confirming what we already know!

I don't know about these tests and I couldn't get my gp to refer my sons for any sort of intolerance tests despite clear evidence and symptoms. Evewntually my homeopath put me in touch with a food intolerance man who tests with a rare machine which uses an electric circuit to test for reactions to different sorts of food. It was brilliant. All of my suspicions were confirmed, which is great as it takes the guessing out. I now know my sons and I are intolerant to milk from cows, sheep and goats and all related products.

My results showed a couple of surprises. I'm intolerant to yeast (so wine and bread) and also sugar. It makes sense of my thrush and asthma.

The strategy is to cut out all the offending foods for four weeks then re-introduce one, eating lots of it, and see if there's a reaction just to confirm the test. He says there's usually a fairly pronounced reaction and often within half an hour!

The problem with the blood tests is that they test for antibodies. There may well be intolerances which are not severe enough to produce antibodies but then still have a deleterious effect on health especially when those foods accumulate.

My dd1 has the blood tests but couldn't pick out what she was allergic to, when we saw th consultant he said he didn't like the RAST as they were inaccurate.She was then skin pricked but nothing they tested for showed as allergic so we still don't know [rolls eyes]
Her allergy is an environmental one so not sure which testing is any more/less accurate for food ones?

The thing is nikkie often there are many factors which combine to create allergic response, environmental and dietary. The immune system becomes overloaded then you get snot or rashes or asthma etc.

If you take away a major source of immune response, and it's best to start with the dietary ones, you may well find the immune system can cope with the odd environmental allergen or irritant when it couldn't before.

This has been my experience and that of my ds. The blood tests, as I've said, show accurate allergy readings but don't detect intolerance so they're of limited use really.

All the blood tests showed for her was that she was very allergic to........Something, her reactions to everything was the same so they couldn't distinguish.
When they did the skin prick test she had all the common food and environmental ones but nothing showed.ATM she is fine whilst she is on anti-histamines.

am I right in thinking that RAST shows intolerances and looks for antibodies in teh blood and skin prick shows allergy. My dd2 had RASTs for everything which came back negative, but the paed said that RASTS are conclusive for a positive...but mean nothing if negative. She was taken off everything in the end and showed a good improvement. The best way of confirming intolerance is to take her off and then do a food trial (under dr guidance)

RAST tests don't pick up intolerances at all, only true allergies. My youngest ds had a RAST test when he was 19 months old as his skin wasn't suitable for skin prick tests. It showed him to be highly allergic to milk & eggs, which we already knew, highly allergic to nuts * mildly allergc to wheat. I can honestly say that ds is definately allergic to milk, eggs & wheat, but can't say about nuts as he has never had any and we have always been careful. He is allergic to peanut, hazelnut, brazil nut, almonds and coconut mixture.

I was lead to believe that there isn't any test that can prove intolerances, except an avoidance trial. Basically a RAST test picks up on IgE antibodies in the blood produced from mast cells. The doesn't happen in intolerances

DD is only being tested for dairy intolerance. Would the fact that she is on Ceretrizine for hay fever affect the result at all. I know she is reacting to dairy - I don't need a test to tell me - I do think it might make life more clear cut if we got a positive result ... should I let her sniff for the couple of days before the test or won't it make any difference?