What is Coeliac Disease?
Coeliac disease is caused by Inflammation of the lining (mucosa) of the small intestine is caused by sensitivity to gluten. The treatment is a gluten-free diet.
How is Coeliac Disease Diagnosed?
A word of caution about the symptoms of Coeliac Disease! It was estimated in 2017 that as many as 80% of people with coeliac disease in Australia have not been diagnosed.
Many of the symptoms of coeliac overlap with those of Irritable Bowel Syndrome (IBS) & other common conditions like chronic fatigue syndrome. Coeliac disease is found in approximately 1 in 150 people, and IBS in around 1 in 5 people. Therefore, many people have both coeliac and IBS – so it’s often difficult to know at the beginning (before the coeliac exclusion diet) which symptoms (if any) are related to coeliac and which symptoms are related to other conditions such as IBS.
The symptoms of coeliac disease almost always respond to a gluten-free diet, with improvement taking place most often within a few weeks (but may take longer).
Coeliac Disease Symptoms may include some of the following (the list isn’t exhaustive!)
- Gastrointestinal: Loose bowel motions … or Constipation, Flatulence, bloating, Nausea.
- Recurrent mouth ulcers
- Fatigue (very common)
- Weight loss, joint pains, Skin rash (very itchy over extensors), Neurological Symptoms, Depression – all less common
Coeliac may also be the cause of Iron deficiency anaemia, premature osteoporosis, or abnormal liver blood tests. There is also an association with recurrent miscarriage and dental enamel defects.
It’s fair to say also that a GP will probably test for coeliac disease a lot more frequently than actually pick up new cases. Why is this?
- It is estimated that as many as 4 out of 5 people with coeliac disease remain undiagnosed – so The GP needs to be vigilant.
- The symptoms are usually vague and non-specific – so the likelihood of coeliac in an individual is often quite low.
The first test for Coeliac Disease is usually a blood test: The anti tissue Transglutamase antibody test (atT test). This is a much better test for most people than the old anti gliadin antibody.
The atT test is a great development in the diagnosis of coeliac disease but it still not 100% accurate. No blood test is perfect, and the issues even with This test are:
- atT test may be negative when coeliac disease is present – most often when a gluten free diet has been followed. It’s therefore important to make sure you’re taking gluten for at least 6 weeks before this blood test.
- atT test may be positive when coeliac disease is not present. Uncommon scenario though this is the reason why Australian guidelines still recommend an endoscopy (in most people) to confirm the diagnosis.
- The test is less sensitive in young children.
What should I eat during the gluten challenge? Four slices of bread a day, or 4 wheet-Bix, or a cup of pasta. The amount of gluten may be better tolerated when spread over the course of the day (eg. breakfast, lunch, dinner). You really need to ‘do’ the challenge properly because the blood test will only be reliably positive after a good dose of gluten over the 6 week period.
Not everyone will agree to taking gluten for several weeks before the atT blood test. In this situation, there is a second-best test called a blood tissue typing test. The huge majority of people with coeliac disease are either tissue type DQ2 or DQ8. So a negative DQ2 & negative DQ8 does effectively rule out Coeliac. But a positive DQ2 or positive DQ8 is still found in 30% of the Australian population – so a positive test doesn’t mean much. (It’s also useful test, say, in someone with down’s syndrome because those with negative DQ2/DQ8 won’t need long term screening for coeliac).
The bottom line is that The GP will arrange a blood test work-up and refer for direct upper Gastrointestinal endoscopy testing when indicated.
Does the diagnosis of Coeliac Need Confirming?
Guidelines do still indicate that the diagnosis needs confirming with histology – in other words, by taking a biopsy via an endoscopy. The normal lining of the small intestine shows finger-like projections called villi (nutrients are absorbed across these). With Coeliac, the villi are flat and they are inflamed.
I feel better on a gluten-free diet but don’t have Coeliac
Gluten is of course found in wheat (and other cereals). Intolerance to wheat is common in people with Irritable Bowel Syndrome – because wheat is one of the FODMAP foods. The symptoms of IBS and Coeliac overlap a lot.
The practical difference is that there’s a need to be completely gluten-free with Coeliac (to avoid complications like anaemia). Those with IBS will tolerate different “doses” of wheat (from normal amounts to none) – and will discover this through elimination and re-introduction of the wheat.
Even a few crumbs of bread can cause inflammation. Accidental exposure to gluten is common and many people with coeliac will experience acute symptoms within a few hours of exposure. Abdominal symptoms may include nausea, vomiting, bloating, diarrhoea, reflux or abdominal pain.
Many foods contain hidden gluten, for example:
- Wheat protein additives
- Barley malt flavouring
- Wheat-based thickeners
It is safe to eat meats, corn, rice, dairy products, fruit and vegetables. It is recommended to avoid oats because most commercial brands are contaminated with wheat.
Gluten-free diets are naturally low in fibre and can be higher in fat and/or carbohydrate.
The Coeliac Society of Australia have produced a very useful App for both IOS & Android, and contains details of over 800 foods.
Support from a dietician is a good idea.
Medical Management with your GP
- Blood Tests: Periodic checking of some blood parameters is often sensible – for example for anaemia, B12, folate & Iron studies, atT and other tests as required.
- Older adults with a first diagnosis of Coeliac may have osteoporosis – The risk is increased. A bone mineral density may be required.
- There is said to be increased risk of pneumococcus & there is probably a role for pneumococcal vaccine. There is no consensus in international guidelines. The UK department of health for example “recommends that clinical assessments are made on an individual basis.” The basis for considering pneumococcal vaccine is that the spleen not functioning completely normally in 30% of people with coeliac disease.
- Family members have a 10-20% risk of developing coeliac disease and should be tested.
- Increased risk of type 1 diabetes (though it’s normally the other way round – testing is recommended in people with type 1 diabetes), and thyroid disorder.
- An associated skin condition may occur (usually responds to the gluten-free diet) called dermatitis herpetiformis (Primary care dermatology society link).
- Some people get recurrent painful mouth ulcers (apthous ulcers).
Iron supplements should be taken for Iron deficiency. An Iron Infusion may be suggested if oral Iron is causing side effects or not working.