COELIAC DISEASE - Can you trust your symptoms or blood tests?
Updated: Jun 10, 2020
Suffering from; Headaches, Joint Pain, Reflux, Itching Blistering Skin Rash? ... You may have coeliac disease! Coeliac disease may go undiagnosed for years, in fact one of my client's Gastroenterologists said that "trying to diagnose coeliac disease is the bane of my professional life". That's a gut specialist speaking! Why then, is this common disease so hard to diagnose? There are 2 main reasons;
1) TESTING PROBLEMS
Incorrect 'loading' - for a coeliac blood test to be valid, an adult needs to eat 4 slices of wheat based bread for 6 weeks before the test, while a child needs at least 2 slices per day 6 weeks. The Australian Coeliac Society recommends this level, and some of the pathology laboratories note on results that a lack of eating gluten prior to the test may lead to a false negative test. I've met countless people who've never been instructed to eat the required amount of gluten, and have thus had a false negative test. When I recommend some people to have a correct retest, their results prove coeliac disease.
Low Immunoglobulin levels - if a person has naturally low immunoglobulin A or G levels, eating gluten may raise the levels into the normal reference range instead of the high reference range, thus giving a false negative test. If you've had a coeliac test done, and the Immunoglobulin A (IgA) level is lower than the reference range, your test may not be valid. In children under 4 years of age, the Immunoglobulin levels can fluctuate, making diagnosis in this age group less reliable. A positive blood test for coeliac disease must be followed up by an endoscopy & biopsy to help confirm the diagnosis.
Endoscopy & Biopsy - regarded as the gold standard for coeliac disease diagnosis, this may not identify coeliac disease that occurs beyond the reach of the endoscope. In such cases, diagnosis may be possible with a capsule endoscopy, using a swallowed capsule camera that takes photographs throughout the gastrointestinal tract (GIT)
Gene test - Almost all coeliac sufferers have all or part of 1 or 2 genes (HLA DQ2 or HLA DQ8), but only about 3% of people with these genes will develop coeliac disease. This means that a negative gene test almost totally rules out coeliac disease, but a positive gene test doesn't necessarily mean the person has coeliac disease! Confusing? Uh-Huh.
2) VARIABLE SIGNS & SYMPTOMS
There's a long held myth that a person suffering coeliac disease will be underweight and malnourished, and will have stomach/bowel pain, bloating, excess gas and diarrhoea if they eat gluten. This classic presentation may be true of some people with coeliac disease, but the majority of sufferers have no gastrointestinal symptoms at all. And while ~50% of sufferers will be underweight,
about 10% are obese. Diarrhoea will be a sign in about 1/3 of those with Coeliac Disease, but around 20% will have constipation!
As you can see, the symptoms vary so widely in Coeliac Disease that they're unreliable for diagnosis. Other possible symptoms include;
Chronically low iron levels (anaemia)
Weak teeth and dental enamel loss
Failure to thrive or reach height potential in children
An itching, blistering skin rash called Dermatitis Herpetiformis (see image below)
This rash occurs in about 15-25% of coeliac sufferers, and is usually equilateral (occurs on both sides of the body in an equal pattern).
Having dermatitis herpetiformis doesn't mean a person has coeliac disease, but when checked by endoscopy, more than 90% of people with this rash have damage to their gut lining from gluten products.
Why Correct Diagnosis Matters
Although diagnosis is difficult in coeliac disease, for all the reasons I've mentioned, its' still worth testing if at all suspected, for the following reasons;
Diagnosis allows people to take coeliac disease seriously, avoiding gluten completely
An undiagnosed coeliac sufferer has an increased risk of some cancers including intestinal lymphoma and cancer of the small bowel if they continue to eat gluten
Malnutrition is more likely in undiagnosed coeliac disease, leading to an increased risk of low bone density, Vitamin B12 deficiency, copper deficiency, zinc deficiency and iron deficiency anaemia
Diagnosis provides a basis to check for associated diseases, especially autoimmune diseases as coeliac is connected with increased risk of many autoimmune conditions
Diagnosis means that family members may also have the disease, with associated risks of other diseases. The sooner they're checked and if diagnosed, off gluten, the better their lifelong health may be.
If you suspect you have coeliac disease, I recommend you talk to your health professional and make sure that testing is correctly done. If the disease is confirmed, the only treatment is to make sure your diet is completely gluten free for the rest of your life.
And there's some good news! Many people suffer from abdominal pain, cramping, bloating and wind when eating gluten, but may not have coeliac disease. For these people, I usually examine their diet carefully, and look for other possible culprits such as yeast, mould inhibiting preservatives or other compounds in what they're eating. If this is your situation, trying to analyse what's going on can be a virtual nightmare, and it's probably highly worth your while talking to a health professional who has more nutrition/dietetic education than the average GP. Find out the culprit for your tummy trouble, and you can move towards enjoying eating without the negative results!