This becomes an important question when someone realizes how much they benefit from avoiding gluten due to celiac disease or non-celiac gluten sensitivity. The evidence suggests that corn (maize) has to be considered on an individual basis. It is possible, but not certain, that you may react to corn when you are sensitive to wheat gluten.
Consider this study that was published in the journal GUT, An International Journal of Gastroenterology and Hepatology. The authors investigated how nitric oxide is part of the intestinal inflammatory reaction reaction to gluten, and how it relates to the white blood cell response. They noted this in their conclusion:
“Mucosal activation of neutrophils and eosinophils [white blood cells] precedes pronounced enhancement of mucosal NO [nitric oxide] production after rectal wheat gluten challenge in patients with coeliac disease. Some of our coeliac patients displayed signs of an inflammatory reaction, as measured by NO and granulocyte markers, after rectal corn gluten challenge.”
So it depends on the individual. The more serious your condition the more important it is to check yourself for corn sensitivity with the immunological ‘gold standard’—a properly managed elimination-provocation protocol.
We are also bereft of a perfectly decisive indication for oats because rare individuals can react, though this study published in the Scandinavian Journal of Gastroenterology indicates that most celiac patients can tolerate them. First the authors note that…
“We have…identified three adult coeliac disease patients who developed a flare of active coeliac disease after ingestion of oats, which suggests that oats might not be entirely innocent in coeliac disease.”
They set out to compare the immune response to oats and wheat by comparing production of the main intestinal antibody (IgA) that participates in the reaction. Although other immune activity was observed,…
“No significant differences were found in IgA against oats in oats-eating and non-oats-eating coeliac disease patients.”
Their conclusion:
“Ingestion of oats does not cause increased levels of IgA against oats in adult coeliac disease patients on a gluten-free diet. The findings support the notion that most adult coeliac disease patients can tolerate oats.”
Note the “most”. And even if you are not sensitive to oats, it is important to be sure that they are certified gluten-free. Otherwise they can be contaminated with gluten during storage, transport, processing and packaging.
What about blood tests for food allergies? Too many variables influence antibody tests for them to give a reliable indication. If you have a serious condition with an autoimmune basis, it’s best to consult with a functional medicine practitioner who can help you through an elimination-provocation protocol (eliminating and re-introducing foods), and who knows how to use objective lab tests to profile your immune imbalance.
It may come as a surprise to you there are many who consider food allergy primarily a pediatric problem, which of course is incorrect. “Epidemiologic studies report an increase in food allergies in industrialized countries, but mainly focus on children and young adults. This leads to the impression that food allergies do not occur in the older population.” This 
Food allergy and food sensitivity are common aggravating factors for chronic inflammation of many kinds. If you think food allergy or sensitivity may be contributing to your problems, be sure to find a doctor who has the right knowledge and experience. This 