Can u have a rice allergy?

Yes: Rice allergy is unusual in the us but can occur in Asian populations where rice consumption is much greater.

Unusual but possible: It is rare but allergies to certain types of grains is possible including rice

Maybe: It is very uncommon. Real allergy produces predictable, obvious illness whenever the food in question is ingested. Rise is especially rare -- in the old days, rice was used as the carbohydrate in elimination diets as almost no one was allergic to it.

Possibly: Unusual but can develop it. If within short period of time after ingesting rice one develops hives, wheeze, breathing troubles vomiting then this is possible. Also can get toxin poisoning from rice which can present with similar symptoms but if allergy will happen every time you have a serve of rice rather than once.