What is coeliac disease?
Author: Kathy Beck APD, Paediatric Allergy Dietitian
Coeliac disease is a chronic autoimmune condition that affects the small intestine in genetically predisposed people. It occurs when the immune system reacts abnormally to gluten, a protein found in wheat, barley and rye. This reaction damages the lining of the small intestine and interferes with the absorption of nutrients.
Cause
When people with coeliac disease eat gluten, their immune system attacks the small intestine, specifically damaging the villi which are tiny finger like projections that assist with nutrient absorption. Coeliac disease develops in response to genetic and environmental factors and can develop at any age. It is associated with specific genes HLA-DQ2 or HLA-DQ8. Simply having these genes does not mean that you have coeliac disease as around 50% of the community will have these genes. Only 1 in 40 will develop coeliac disease in their lifetime. Environmental factors play a role in triggering coeliac disease in those with the genetic predisposition.
Symptoms in Children
Symptoms vary widely and some children may have no obvious symptoms. Coeliac disease testing should be investigated in children with the following symptoms.
- Persistent, unexplained abdominal or gastrointestinal symptoms
- Faltering growth or failure to thrive
- Prolonged fatigue
- Unexpected weight loss
- Unexplained iron, vitamin B12 or folate deficiency
- A child who is regularly “out of sorts” or generally unwell
In addition, the following are indications for screening for coeliac disease.
- Type 1 diabetes
- Autoimmune thyroid disease
- Dental enamel defects
- Down’s syndrome
- Turner syndrome
- First-degree relatives with coeliac disease
Diagnosis
The first step towards diagnosis is to keep eating gluten which must be in the diet for at least 6 weeks prior to testing. If gluten has been excluded from the diet a gluten challenge is required to ensure the accuracy of diagnosis. For children, at least 5g of gluten per day is required as a gluten challenge. This is equivalent to 2 slides of wheat based bread, 2 Weet Bix, 1 cup of wheat based pasta or 8 – 10 crackers (eg. Jatz) per day.
A blood test called “coeliac serology’ can be arranged by a GP to measure the level of certain antibodies. These are either
- Transglutaminase-IgA (tTG-IgA) AND deamidated gliadin peptide-IgG (DGP-IgG) antibody tests
OR - Transglutaminase-IgA (tTG-IgA) antibody test AND the total IgA level
If these antibodies are above the normal range coeliac disease may be present.
The final step in diagnosis is a small bowel biopsy which is performed by a gastroenterologist during and endoscopy.
Sometimes another blood test to detect the presence of HLA-DQ2 or HLA-DQ8 may be used to support diagnosis.
Management
Coeliac disease requires lifelong adherence to a gluten free diet. This means no wheat, rye, barley (and sometimes oats). Safe alternatives include rice, corn, quinoa, buckwheat and certified gluten-free products
An individualised long term plan to maintain health and reduce the risk of complications. At diagnosis it is important to
- Learn the skills needed to follow a gluten free diet
- Screen for associated conditions
- Screen family members for coeliac disease
Children with coeliac disease often have nutrient deficiencies including iron, vitamin B12 and folate. In many cases growth is also affected.
Consultation with an Accredited Practicing Dietitian will provide individualised education about setting up a safe gluten free environment in the home, a gluten free diet and correcting nutritional deficiencies.
For more information go to https://coeliac.org.au/
About the author
Kathy Beck is a South East Queensland based paediatric dietitian who specialises in food allergy. Kathy is an active member of the Dietitian’s Committee of the Australasian Society of Allergy and Clinical Immunology (ASCIA). Kathy has been a dietitian for over 30 years with the last 15 years working in paediatrics in various clinical settings in Australia and England.
