Wheat allergy vs gluten sensitivity
Both food allergies and gluten sensitivity disorders are increasing through better recognition by healthcare providers and a true increase in these disorders. So, how do you tell the difference between the two?
Wheat allergy is one of the top 8 common foods that trigger allergies. Wheat shares many proteins with other cereal grains (rye, barley) that can also cause symptoms. The main proteins causing allergy are globulin and glutenin fractions (different than celiac).
Symptoms: if ingested, wheat can result in hives, angioedema (swelling), itching, worsening eczema or anaphylaxis. If wheat flour is inhaled, like tossing pizza dough in the air, it can result in asthma. Symptoms can occur quickly and be severe.
Testing: allergy skin test to wheat with a reading at 15-20 minutes or specific IgE blood test to wheat can assess if the reaction is a true allergy. There is cross reactivity with grass, so a positive wheat skin test may be a clinically irrelevant test in a person with grass allergy. Sometimes a food challenge (eating wheat) in the office under supervision is necessary when testing is inconclusive.
Prognosis: most cases of wheat allergy are outgrown.
Gluten sensitivity: gluten is found in many grains including wheat, barley, and rye. Celiac disease is common and increasing. It affects about 1% of children in U.S. (1-3% of children in Denver, CO). This is likely due to more awareness and more testing, but also the incidence is increasing. It’s currently believed that celiac disease is under-diagnosed. Gliadin is felt to be the protein responsible for symptoms–this is a non-IgE mediated reaction and therefore not a true allergy. Celiac disease is associated with other autoimmune disorders: type I diabetes and thyroid disease
Genetic: gene testing positive for HLA-DQ2 or DQ8 is essential for celiac disease
Screening tests: tTG IgA and total IgA. This tissue transglutaminase antibody (tTG) is the single best test! It’s important to have a total serum IgA, as 1:300 people lack IgA and the test would therefore be useless. Anti-gliadin antibodies are NO longer recommended. Also thyroid antibodies and liver function tests are checked.
More than a gut problem:
- Skin: hair loss, apthous stomatitis (canker sore, mouth ulcers), dermatitis herpetiformis (itchy blistering skin rash usually on buttocks or both knees and elbows.
- Nervous system: seizures, depression, and ataxia (inability to walk straight)
- Hepatitis: inflammation in the liver
- Bone: osteoporosis, fractures, arthritis, dental abnormalities
- Reproductive Tract: miscarriage, infertility, delayed puberty
- GI: abdominal pain, diarrhea, bloating, constipation, irritability, growth failure and malnutrition.
Who needs a biopsy by the GI doctor?
- Patient with symptoms and positive tTG blood test or no symptoms but HIGH or increasing tTG blood levels
Who needs screening for celiac?
- Any child with symptoms who has been exposed to gluten, where celiac is suspected
- Children at risk include those with Type I diabetes, autoimmune thyroiditis, Down Syndrome, Turner Syndrome, Williams Syndrome, selective IgA deficiency and first degree relatives with celiac disease. tTG screening should start at age 3 and be repeated every 1 to 3 years or when symptoms develop.
Prognosis: celiac disease is life-long.
At Family Allergy & Asthma Care of Montana, we can test for wheat allergy and assist in differentiating wheat allergy from gluten sensitivity causing celiac disease.
This information is solely for informational purposes and not intended as a substitute for consultation with a medical professional.