Oat vary among oat varieties. Also, oats products are frequently cross-contaminated with other gluten-containing cereals during grain harvesting, transport, storage or processing. Pure oats contain less than 20 parts per million of gluten from wheat, barley, rye, or any of their hybrids. Use of pure oats in a gluten-free diet offers improved nutritional value from the rich content of oat protein, vitamins, minerals, fiber, and lipids, but remains controversial because a small proportion of people with celiac disease react to pure oats. Some cultivars of pure oat could be a safe part of a gluten-free diet, requiring knowledge of the oat
Wheat allergy comes from the progenitor species "Aegilops speltoides". This indicates that nascent mutations on the B genome of wheat are from a small number of cultivated Triticeae species. Recent study of WDEIA shows that both aspirin and exercise increase the presence of gliadin in the blood stream and the chronic induced response may extend to NSAIDs, MSG, Benzoate and other synthetic chemical food additives. Baker's allergy has a ω-gliadin component and thioredoxin hB component. In addition, a gluten-extrinsic allergen has been identified as aspergillus amylase, added to flour to increase its baking properties. Contact sensitivity, atopic dermatitis, eczema, and urticaria appear