Key takeaways

  • Coeliac disease is autoimmune, wheat allergy is allergic, and non-coeliac gluten sensitivity is diagnosed only after other causes are considered.
  • Testing for coeliac disease is most accurate before starting a gluten-free diet.
  • The level of avoidance, medical risk and follow-up differs between these conditions.

Coeliac disease, non-coeliac gluten sensitivity and wheat allergy are different conditions, even though some symptoms overlap. Coeliac disease is an autoimmune condition that damages the small intestine. Wheat allergy is an immune allergy that can cause an immediate and potentially severe reaction. Non-coeliac gluten sensitivity is considered only after coeliac disease and wheat allergy have been excluded.

What is coeliac disease?

In coeliac disease, eating gluten—proteins found in wheat, barley and rye—triggers an immune response that damages the small intestine. Symptoms may include diarrhoea, bloating, abdominal pain, fatigue, anaemia, weight loss or an itchy blistering rash. Some people have few obvious digestive symptoms.

Treatment requires a strict lifelong gluten-free diet after diagnosis, including attention to cross-contact.

What is wheat allergy?

Wheat allergy is a reaction to proteins in wheat. Symptoms can include hives, swelling, vomiting, wheezing or breathing difficulty and may occur quickly. Wheat allergy does not cause the same long-term intestinal damage as coeliac disease, and a person may not necessarily need to avoid barley or rye unless separately advised.

What is non-coeliac gluten sensitivity?

This term describes symptoms linked with gluten-containing foods in someone who does not have coeliac disease or wheat allergy. Symptoms may include abdominal discomfort, bloating and tiredness. There is no single diagnostic test, and another component of wheat may sometimes be responsible.

Do not stop gluten before coeliac testing

Coeliac blood tests and intestinal biopsies look for changes caused by ongoing gluten exposure. Starting a gluten-free diet first can affect the results. Speak with a doctor before removing gluten if coeliac disease is possible.

What you can do while waiting for an assessment

  • Keep a food and symptom diary without changing several foods at once.
  • Write down family history of coeliac disease or autoimmune conditions.
  • Note non-digestive symptoms such as fatigue, mouth ulcers, rash or anaemia.
  • Continue your usual gluten intake unless a clinician advises otherwise.
  • Photograph ingredient labels of foods linked with reactions.

If you are diagnosed

A registered dietitian can help replace nutrients and explain labels, eating out and cross-contact. Naturally gluten-free foods—rice, potatoes, corn, quinoa, beans, fruit, vegetables, eggs, fish and unprocessed meat—can form the basis of varied meals.

Do not deliberately retest wheat at home after breathing difficulty, throat swelling, faintness or another serious reaction. Seek emergency help for those symptoms.

Sources and further reading

NIDDK: Coeliac disease definitions and NIDDK: Diagnosis of coeliac disease.

This article provides general information and is not a diagnosis.