What is the difference between coeliac disease, wheat allergy and non coeliac gluten sensitivity

(For more information, see the Coeliac Society of Ireland website: www.coeliac.iehttp://www.coeliac.ie/)

What is Coeliac Disease?

Coeliac disease is an autoimmune condition where the ingestion of gluten leads to damage in the small intestine. Gluten is a protein found in wheat, barley, and rye. For those with coeliac disease, eating gluten triggers an immune response that damages the small intestine's lining, leading to malabsorption of nutrients.

Wheat Allergy

A wheat allergy is an allergic reaction to proteins found in wheat. This reaction is mediated by the immune system and can cause symptoms ranging from mild (such as hives or gastrointestinal discomfort) to severe (like anaphylaxis). Unlike coeliac disease, wheat allergy does not cause long-term damage to the small intestine.

Non-Coeliac Gluten Sensitivity

This term refers to a condition where individuals experience symptoms similar to those of coeliac disease, such as bloating, diarrhea, and abdominal pain, but do not have the autoimmune response or intestinal damage seen in coeliac disease. Diagnosis of non-coeliac gluten sensitivity is typically made after coeliac disease and wheat allergy have been ruled out.

What are the signs and symptoms of coeliac disease?

Diarrhea or constipation
Abdominal pain or bloating
Weight loss or failure to thrive in children
Fatigue or weakness
Dermatitis herpetiformis (itchy skin rash)
Anaemia
Infertility or recurrent miscarriages
Osteoporosis or osteopenia
Neurological symptoms, including headaches and numbness or tingling in the hands and feet

How do you diagnose Coeliac Disease?

The diagnosis of coeliac disease involves a combination of blood tests and a biopsy of the small intestine.

Interpretation of Tests:

1. Positive Blood Test: If your blood test shows high levels of specific antibodies (e.g., tTG-IgA), this suggests you may have coeliac disease. A biopsy is often recommended to confirm the diagnosis.
2. Negative Blood Test with Symptoms: If the blood test is negative, but symptoms persist, further investigation is required, which may include genetic testing or an endoscopy.
3. Positive Biopsy: A positive biopsy will show damage to the villi in the small intestine, confirming a diagnosis of coeliac disease.
4. Negative Biopsy: If the biopsy is negative, but symptoms continue, you may need to explore other potential diagnoses, such as non-coeliac gluten sensitivity or irritable bowel syndrome.