After years the GP has arranged allergy blood tests

[KatyMac]

I have many and varied foods that I react to and I have struggled for a long time alongside IBS - with my attitude to food becoming very negative along the lines of arfid

I have a very limited diet and I am trying to increase the foods I eat

I have asked for help as I'm being encouraged to reintroduce milk/dairy into my diet by a lipid consultant (complicated)

And they have forbthe first time ever agreed to do some blood tests

Do I need to eat the things I know will upset me in order for them to register on the blood test? Should I also stop taking antihistamines before the test?

My symptoms are not anaphalactic for foods although my tongue and lips swelled when taking trimethoprim

I'd speak to the secretary of the person arranging the blood tests for the answers to your questions.

Blood tests measure specific IgE to particular allergens. You don't need to stop taking antihistamines though you do for skin prick tests. The problem is that a lot of reactions to food are not IgE mediated so it is perfectly possible to have very real reactions but negative tests. If you're not getting classical IgE mediated signs and symptoms the blood tests may not be that helpful unfortunately. My DS has classic features of CMPA that cleared totally on an elimination diet but it's non IgE so blood tests didn't pick it up. This page from allergy UK may be helpful.
https://www.allergyuk.org/information-and-support/support-for-you/self-help-hub/allergy-testing/

Don't think my gp has a secretary @TroysMammy

Thanks @MrsAvocet , so for years I've said i have food/contact allergies/intolerances (with pretty severe symptoms) & I've been told im imagining it, its all in my mind/ allergies don't work like that

and now I've been reflecting and asking for phychologocal help through a dietician and the eating disorder clinic to be told well we will test for it now!

I read the body of your post as it mentioned the consultant. Either contact the Consultant's Secretary, they may have sent the letter to the GP to contact you to arrange bloods. I doubt a GP would arrange allergy tests themselves. It's known for consultants to contact the GP for bloods so they don't have to do the donkey work. So whoever requested you get specific bloods done, contact the originator.

Yeah consultant is for lipids - the GP is doing the testing

If you're getting IgE blood tests but don't have IgE reactions to foods (hives, swelling, immediate vomiting, trouble breathing), it isn't advised.

Many people get false positives with these tests and you'd then be excluding important food groups for no reason.

My son was positive to wheat, peanut, egg, milk and soya. He eats wheat, peanut and soya daily without issue and is definitely not allergic to them, nor ever was.

An allergist should only do IgE blood tests for foods you've potentially had IgE reactions to, although they're only recently

I'd recommend talking to an allergist, rather than GP. You may be luckier than me, but IME GPs are next to useless when it comes to allergies sending out this msg.

If you are having ige symptoms (swelling/vomiting/ rash within 5 min of eating) is blood test will confirm the allergy. If you have a non ige allergy (delayed reaction- eczema/ gastro issues/ rash etc) then it won’t show in blood tests.

I'm not sure that's true. My DD had eczema and blood tests shower severe dust mite allergy. Now we've taken preventative action she has no eczema any more.

Yeah externally foods and plants cause blisters and bleeding immediatley and foods sometimes cause internal bleeding but that is often only visible when i go to the loo after a few hours

I was referred to the allergy clinic in August 22 and I'm not near the top of the list yet

Do you know what your GP is testing for? As others have said there’s no blood test for intolerance, and IgE isn’t really appropriate if you haven’t had any symptoms pointing to an IgE mediated reaction (as above). Are they testing for coeliac? If so yes you do need to be eating gluten containing food daily for at least six weeks before the test.

Tested about 4 times for coeliac including 2 biopsies

No idea what they are testing for - but I can't see a dietician until I'm tested

I've asked for counselling support andbthey sent me an online link for binge eating!

Found out what they are testing

Milk, egg, peanut, wheat, coeliac, potato and tomato

So I'm intolerant to egg and milk, not allergic

And i seem to have coconut and almond allergies - the oil when used in toiletries causes blisters and bleeding and similar if I eat them (in my gut)

Results are in i have no IgE type food allergies

Just ones that cause skin rashes upset tummies and bleeding out my bum!

Nope I got it wrong I have no iga responses