Gluten Allergy: Symptoms and How to Test for It

In recent years the word "gluten" has become almost a term of abuse, and many readers use it to explain any digestive or skin problem. Yet similar complaints can stem from different conditions with different mechanisms, and therefore different testing. Understanding what is allergy, what is celiac disease, and what is simply sensitivity is the first step toward a well-informed conversation with a doctor.

What is called gluten allergy

Strictly speaking, gluten is a protein found in three grains: wheat, barley, and rye. Oats do not contain gluten but can trigger a reaction if they are produced in the same facility as wheat, barley, and rye. Wheat allergy is a food allergy: the immune system reacts to wheat proteins, and this can manifest as itchy eyes or difficulty breathing. Importantly, this allergy does not damage the small intestine long-term, which is a fundamental difference from celiac disease.

Allergy, celiac disease, and gluten intolerance: what is the difference

Celiac disease is an autoimmune condition: the immune system mistakes substances within gluten for a threat and attacks them, damaging the surface of the small intestine and impairing nutrient absorption. Non-celiac gluten intolerance causes similar symptoms — abdominal pain, fatigue — but does not damage the small intestine. The exact cause of celiac disease is unknown; a combination of genetics and environmental factors is suspected, and the risk is higher in people with a family history, Down syndrome, Turner syndrome, and certain autoimmune diseases.

Symptoms and signs of gluten allergy in adults

In adults, celiac disease can manifest as diarrhea, abdominal pain, bloating and increased gas, indigestion, and constipation. General symptoms also occur: fatigue due to nutrient deficiency, unintentional weight loss, itchy rash (dermatitis herpetiformis), fertility problems, nerve damage, and impaired coordination, balance, and speech. Some people have no symptoms at all, while in others extraintestinal manifestations predominate — iron deficiency anemia, aphthous stomatitis, osteoporosis.

Gluten allergy in children

In children, digestive symptoms are more common than in adults: bloating, chronic diarrhea or fatty, bulky, unusually foul-smelling stool, constipation, gas, nausea and vomiting, abdominal pain, poor weight gain. Children with celiac disease may grow more slowly than expected and have delayed puberty, and irritability is noted as a separate symptom in them.

How to test for gluten allergy

Diagnosis begins with a medical history and family history, examination, and assessment of symptoms. When celiac disease is suspected, blood tests and a biopsy of the small intestinal mucosa are most often used; the biopsy is taken during esophagogastroduodenoscopy — examination of the esophagus, stomach, and small intestine with a flexible tube with a camera. Serological tests for antibodies to tissue transglutaminase have high sensitivity and specificity, but the final diagnosis is confirmed by histological examination. Testing is recommended when symptoms are present or risk is increased, and first-degree relatives of patients are recommended to be screened.

When to see a doctor

Reasons for consultation include persistent changes in stool, abdominal pain and bloating, unexplained weight loss, constant fatigue, itchy rash, anemia, or slowed growth in a child. The doctor will assess symptoms, family history, and decide which tests are needed specifically for you.

Suspicion of gluten alone is not a reason to call emergency services; 103 or 112 — if difficulty breathing or other life-threatening signs appear.

• Persistent diarrhea, constipation, or fatty, foul-smelling stool
• Bloating, gas, abdominal pain, and nausea
• Fatigue, weight loss, anemia without an obvious cause
• Itchy rash with blisters

This material is for reference purposes and does not replace consultation with a doctor: only a doctor can correlate complaints, history, and test results.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer