Every type of grain, including wheat, barley oats and rye, but also corn, rice, sorgum and other grains, contains one or more forms of gluten. However only specific types of gluten found in wheat (gliadin), barley (hordein), rye (secalinin) and possibly oats (avenin – open to debate, I suggest avoiding it for now) are of interest to celiac disease.
Even the above broad statement is open to debate; some people recommend avoiding all grains for celiacs when recovering from celiac disease symptoms associated with eating wheat, barley, rye and oats.Rice consists of about 5% orzenin by weight. Compared to the amount of prolamine found in other grains, this is very low. Like all prolamines, orzenin helps the rice grain sprout.
Assuming you are celiac and have been diligent in your diet, current thinking assumes that you are safe with rice since orsenin has not been found to cause inflammation in the body for celiacs.
If you have a gluten allergy, you may need to be more cautious. Celiac disease has been closely studied, where as gluten allergy much less so. Besides the possible confusion between the two (you may think you have gluten allergy but really are celiac), it is possible to have a gluten allergy that reacts to different types of gluten than those that trigger celiac. So if you suspect gluten allergy, you should cut out all grains at first until you are sure what you react to.
A study from The Children’s Hospital at Westmead, Sydney, Australia indicated that more people have an allergy to rice than you might expect.