Allergy to rye, but negative to celiac testing?
July 2, 2016 8:33 AM   Subscribe

I was recently tested negative for a celiac blood test, yet an allergist applied skin testing and it appears that I'm allergic to rye. What does this mean? Should I avoid all breads, crackers, and pastas in general? I haven't eaten breads, crackers, or pasta in two years. I wonder if the celiac blood test could be a false negative, since I haven't eaten breads in a few years?

Should I call an allergist and find out what I should do to take the next step?
posted by RearWindow to Health & Fitness (12 answers total) 1 user marked this as a favorite
Just because you haven't been doing something doesn't mean that you can't do something.

What's the real cause for concern?
posted by oceanjesse at 8:46 AM on July 2, 2016 [1 favorite]

My understanding is you have to have recently eaten gluten in order for a test of celiacs to give a reliable result.

Why don't you just call your allergists office and ask these questions.
posted by a strong female character at 8:47 AM on July 2, 2016 [5 favorites]

Could it be from beverages? Whiskey or beer?
posted by Rube R. Nekker at 8:58 AM on July 2, 2016

My understanding is also that you need to have recently eaten gluten for serological testing for coeliac disease to be reliable. Equally, as far as I understand, being allergic to rye is not the same thing as coeliac disease - so your positive skin test to rye doesn't mean that your negative coeliac result has to be false.

This page (which is aimed at health professionals), explains coeliac disease and its diagnosis in a little more detail. The blood test is looking for antibodies that the body makes in response to gluten. If you haven't eaten any gluten, there will be no antibodies to find - and so the test could give a false negative. However, gluten is found in plenty of things apart from breads, crackers and pasta - have you cut out all gluten, or just these specific foods? Before cutting out these foods, did you have symptoms consistent with coeliac disease?

The best thing to do is almost always to talk this through with your doctor! Can you call the allergist who applied the skin test and ask her/him to explain the result?
posted by bored_now_flay at 9:07 AM on July 2, 2016 [4 favorites]

If you're allergic to rye, the thing to do would be to avoid rye. All grain isn't rye. The celiac test -- assuming it was the right test, done the right way -- indicates that gluten is not a problem, so why would you avoid other grains besides rye?

Yes, talk to your doctor. But first, make sure your doctor is an actual doctor, and not a naturopath. I say this because naturopaths tend to run with allergists to seem legitimate. Naturopaths are scammers and quacks. Avoid, avoid, avoid. Don't get fleeced.
posted by Sys Rq at 9:55 AM on July 2, 2016 [3 favorites]

If you're allergic to rye it means no rye IPA, no rye whiskey, no rye bread. You can eat or drink barley, wheat, etc.
posted by fixedgear at 10:09 AM on July 2, 2016

I think usually doctors will have you do a gluten challenge (i.e.: eat some crackers) for a few weeks before a blood test for celiac disease. But as others have pointed out, it's not clear whether you've followed a gluten-free diet or just haven't been eating the things you say. Gluten is in a lot of things.

You can be both allergic to rye and celiac, or you can be one but not the other. They are two separate things. The allergen that you're allergic to in the rye isn't necessarily the gluten in the rye - there are lots of other proteins in rye that could trigger your allergic response.
posted by mskyle at 10:19 AM on July 2, 2016 [3 favorites]

I was told by my doctor and several celiac disease experts that one has to be consistently eating gluten daily for at least 3 weeks in order for the antibody blood tests to actually detect anything. I was told this after I had stopped eating gluten for quite a long time, and my reaction to anything containing gluten is pretty severe, so I did not re-introduce it in order to do the blood tests. The only treatment for celiac disease is to not eat gluten anyway, so I'd rather not put myself through three weeks of GI hell to get a confirmation that I'm already doing the right thing for myself.

TL; DR: If you have been avoiding gluten (and not just the specific foods you listed) for 2 years, even if you were celiac, it would be unlikely that the antibody blood test would come out positive.
posted by bedhead at 10:27 AM on July 2, 2016 [1 favorite]

Just to clarify one more time: Allergies and Celiac are not related at all. Most people with Celiac are not allergic to wheat or gluten and would not test allergy positive in a skin prick test. Allergy is IgE immune response to any protein, Celiac is a T-cell autoimmune response to a very specific protein.

Allergy to rye (as grain, grass, or grass pollen) has no relationship to Celiac. Unfortunately, rye as grain is added to a lot of things, especially wheat products. It would probably be good to know whether you were tested for grain (food) or pollen allergy, because having a reaction to one does not mean you would absolutely react to the other.

And no, you might not test positive for Celiac if you haven't had any wheat for a while.

I know it is confusing, and frustating. Do go back to the allergist and ask whatever questions you need to ask so that you know what is going on.
posted by monopas at 3:51 PM on July 2, 2016 [2 favorites]

> I was recently tested negative for a celiac blood test, yet an allergist applied skin testing and it
> appears that I'm allergic to rye

Being allergic against Rye/Wheat and being a Celiac are two very different things.
Out of curiosity, did they test wheat too?

> I haven't eaten breads, crackers, or pasta in two years.
Then it is very unlikely that the celiac blood test would show up positive. Most reliable option would be a gene test. Not sure about the cost/health insurance coverage.

If you are gluten intolerant than going off gluten is obligatory (to avoid other diseases).
posted by yoyo_nyc at 5:47 AM on July 3, 2016

The "gene test" can only rule out celiac disease, not confirm it (a negative test means that you don't have celiac disease but a positive test doesn't really mean anything - lots of non-celiacs test positive). A small intestine biopsy is generally considered the gold standard for a celiac diagnosis.
posted by mskyle at 8:46 AM on July 3, 2016

I was not talking about Celiac disease but about gluten intolerance. If the gene test is positive you should stop eating gluten. Period. FYI, there are other forms of gluten intolerance, like DH and more that are suspected.

Having this allele and keep eating gluten also increases your risk of other autoimmune diseases. Wikipedia is your friend...
posted by yoyo_nyc at 7:42 AM on July 10, 2016

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