Coeliac disease🎥
Coeliac disease
Introduction
Coeliac disease is a chronic autoimmune condition in which exposure to gluten—a protein found in wheat, barley, and rye—triggers an immune-mediated inflammatory response in the small intestine. This results in villous atrophy and malabsorption of nutrients. It affects individuals genetically predisposed via HLA-DQ2 and HLA-DQ8 alleles.
Peak Incidence
- Most commonly presents between 15 and 30 years of age, but can occur at any age, including in childhood or late adulthood.
- More common in females and those with associated autoimmune conditions (e.g. type 1 diabetes, autoimmune thyroid disease).
Pathophysiology
- Ingestion of gluten leads to deamidation of gliadin peptides by tissue transglutaminase (tTG).
- These modified peptides are presented by HLA-DQ2 or HLA-DQ8 molecules to T cells, triggering an inflammatory immune response.
- This results in villous atrophy, crypt hyperplasia, and increased intraepithelial lymphocytes, leading to malabsorption.
- Associated with IgA anti-tTG antibodies, which are useful in diagnosis.
Symptoms
- In children:
- Failure to thrive
- Abdominal bloating and pain
- Chronic diarrhoea
- Irritability
- In adults:
- Chronic or intermittent diarrhoea
- Fatigue
- Weight loss
- Iron-deficiency anaemia
- Bloating, flatulence
- Aphthous ulcers
- Silent or atypical coeliac disease may present with non-gastrointestinal features alone.
Signs
- Abdominal distension
- Dermatitis herpetiformis – pruritic, vesicular rash (usually elbows, knees, buttocks)
- Angular stomatitis, glossitis (due to nutrient deficiencies)
- Pallor from anaemia
- Short stature or delayed puberty in undiagnosed children
Diagnosis
Important: Patients must continue eating gluten (minimum one gluten-containing meal per day for at least 6 weeks) before testing to ensure diagnostic accuracy.
Blood Tests
- IgA tissue transglutaminase (tTG) antibodies – first-line test
- Total serum IgA – to rule out selective IgA deficiency
- If IgA deficient: test for IgG anti-DGP (deamidated gliadin peptide) or IgG anti-tTG
Small Bowel Biopsy (Gold Standard)
- Performed via upper GI endoscopy with duodenal biopsies
- Findings:
- Villous atrophy
- Crypt hyperplasia
- Increased intraepithelial lymphocytes
Genetic Testing
- HLA-DQ2/DQ8 testing may be helpful in excluding coeliac disease if serology or biopsy results are inconclusive.
Complications
- Malabsorptive complications:
- Iron, folate, and vitamin B12 deficiency
- Hypocalcaemia, vitamin D deficiency → osteoporosis
- Weight loss, protein–energy malnutrition
- Haematological:
- Anaemia (microcytic or macrocytic)
- Hyposplenism – increased risk of encapsulated bacterial infection
- Neurological:
- Peripheral neuropathy
- Cerebellar ataxia
- Epilepsy ± cerebral calcifications
- Dermatological:
- Dermatitis herpetiformis
- Malignancy:
- Enteropathy-associated T-cell lymphoma (EATL)
- Small bowel adenocarcinoma
Management
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Lifelong gluten-free diet – strict avoidance of wheat, barley, and rye.
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Dietitian referral for patient education and dietary planning.
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Pneumococcal vaccination and booster every 5 years due to functional hyposplenism.
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Annual review: monitor weight, symptoms, nutritional markers (iron, folate, vitamin B12, calcium, vitamin D).
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Bone mineral density (DEXA) scan at diagnosis and as clinically indicated.
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Influenza vaccine recommended.
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Support groups (e.g. Coeliac UK) may assist with education and adherence.
FAQ from our users
What is dermatitis herpetiformis?
- A chronic skin condition characterised by intensely itchy and blistering skin eruptions. It is strongly associated with coeliac disease.
Why do you check for IgA deficiency?
- If patients are deficient in IgA, this may give a false negative result for anti TTG antibody test.
What is functional hyposplenism?
- This is when the structure of the spleen is intact however its function is compromised. In coeliac disease, the chronic inflammation and immune system dysregulation can impair spleen function.
Common pitfalls in a clinical setting
Common pitfalls in a clinical setting
- Dermatitis herpetiformis is a common medical school question, so always consider coeliac disease if a patient presents with a rash primarily on their elbows and knees.
- Tissue transglutaminase antibodies may be checked to monitor compliance with a gluten-free diet.
- NICE released guidance on who should be screened for coeliac disease & it includes:
- persistent unexplained abdominal or gastrointestinal symptoms
- faltering growth
- prolonged fatigue
- unexpected weight loss
- severe or persistent mouth ulcers
- unexplained iron, vitamin B12 or folate deficiency
- type 1 diabetes, at diagnosis
- autoimmune thyroid disease, at diagnosis
- irritable bowel syndrome (in adults)
- first‑degree relatives of people with coeliac disease.
- NICE also states that coeliac should be considered in patients with any of the following:
- metabolic bone disorder (reduced bone mineral density or osteomalacia)
- unexplained neurological symptoms (particularly peripheral neuropathy or ataxia)
- unexplained subfertility or recurrent miscarriage
- persistently raised liver enzymes with unknown cause
- dental enamel defects
- Down’s syndrome
- Turner syndrome