Gluten allergy
Reaction to gluten (coeliac disease is autoimmune, not a classic allergy).
About gluten allergy
Gluten is a group of proteins found in wheat, barley and rye that give dough its stretch. It is important to separate three different conditions. Coeliac disease is an autoimmune illness, not a classic allergy, in which gluten triggers the immune system to damage the lining of the small bowel. Wheat allergy is a true IgE-mediated allergy to wheat proteins. Non-coeliac gluten sensitivity describes symptoms after gluten without the antibodies of coeliac disease or the mechanism of allergy. Because the label "gluten reaction" covers all three, getting the right diagnosis matters.
How it presents depends on the condition. Wheat allergy tends to cause rapid symptoms within minutes to a couple of hours, such as hives, swelling, wheeze, vomiting and, occasionally, anaphylaxis. Coeliac disease usually causes slower, ongoing problems such as diarrhoea, bloating, fatigue, weight loss and nutrient deficiencies. Gluten sensitivity typically brings bloating, discomfort and tiredness without intestinal damage or allergic antibodies.
Diagnosis differs too: coeliac disease is confirmed with specific blood tests and a gut biopsy, and it is important not to cut out gluten before testing, as this can hide the diagnosis. Wheat allergy is confirmed with skin-prick or specific-IgE tests and sometimes a supervised challenge. Management for coeliac disease and confirmed sensitivity is a strict, lifelong gluten-free diet with careful label-reading. For wheat allergy, avoidance plus any prescribed emergency medicine applies. A severe allergic reaction is a medical emergency: call 999.
Common triggers
- Wheat, barley and rye\nBread, pasta and baked goods\nMany processed foods and sauces
Symptoms
- Itching or tingling in the mouth
- Hives, itching or eczema
- Swelling of the lips, face, tongue or throat
- Stomach cramps, nausea, vomiting or diarrhoea
- Wheezing or trouble breathing
- In severe cases, anaphylaxis
Avoidance & management
- Read ingredient labels every time
- Ask about ingredients and cross-contamination when eating out
- Keep the food out of shared cooking areas
- Carry prescribed antihistamines or an adrenaline auto-injector
- Seek emergency help for any severe reaction
Sources & references
Allergy safety: what everyone should know
Mild-to-moderate reaction signs
- Itching, hives or a raised rash
- Swelling of lips, face or eyes
- Tingling mouth, sneezing, runny nose
- Stomach pain, nausea or vomiting
Anaphylaxis — call 999 (UK) or 112 (EU) immediately
- Difficult or noisy breathing, wheeze, persistent cough
- Swelling of the tongue or tightness in the throat
- Dizziness, collapse, pale and floppy (young children)
- Use an adrenaline auto-injector (e.g. EpiPen) at once if prescribed, then call an ambulance even if symptoms improve
Allergy or intolerance? A true allergy involves the immune system and can escalate quickly; an intolerance (e.g. lactose intolerance) is unpleasant but not life-threatening. The symptoms overlap, so self-diagnosis is unreliable.
Getting tested: home-testing kits based on IgG are not diagnostically valid. If you suspect an allergy, ask a GP for referral to an allergy clinic for skin-prick or specific-IgE testing and a supervised food challenge where appropriate.