I think technically there is no such thing as "gluten allergy." There *is* wheat allergy and gluten *is* implicated in all sorts of other immunological problems - which for all intents and purposes amount to the same for the sufferer - but it's not quite the same as "allergy" in terms of what goes on below the surface.
And sometimes people let the term allergy ride to encompass all the problems, and sometimes they really mean allergy when they say allergy. So I guess the thing is, read close and understand a benadryl isn't gonna help, if you know what I mean. The treatments you'll want will depend on root causes.
Anyways, as I've now got 4 endocrine/autoimmune problems, I have my own theories. First, is the human-created environment filled with endocrine disruptors and so forth. All the fire-retardant on our clothes, in our furniture; all the plastic bottles and cans of ketchup; perfumes, a favourite holiday gift; processed soy; all the medicines we take and the tossed pills that leak into the environment at large; the pesticides ... Second is stress - and not the stress you feel, but all the stress reactions in your body. So much stress, and you burn out the system eventually. Stress from the disruption of biochronological rhythms with all our lights, sitting 10 hours a day at a desk and hoping an hour at the gym is gonna do something, etc. Third is highly processed food and fruit juice (but not table sugar; that's totally negligible), because these things hit your blood stream at a hundred miles per hour. Fourth is overwhelming plenty - constant eating, snacking, etc. Keeps the blood sugar even, but your body never gets a rest.
Well, I could go on. Could talk about the invention of agriculture as the fall of mankind, too. Lol.
Last comment - Oats are a no-go if you need to go gluten-free and not-so-hot if you are fighting diabetes. Not the same exact proteins, but very close and produce the same problems. Also, they are sooo slow on the bloodstream front, you are really taxing your system for an extended amount of time. You could be keeping your blood sugar even at the cost of your actual insulin-producing cells.
Ok. Just my half-penny.