A rice allergy is due to an immune system reaction after contact with and/or ingestion of rice and rice products.
The rice plant is a grass; should I avoid other grasses?
Usually the allergy to a food is protein based. Therefore, grasses that do not share the same protein should not effect you unless you are allergic to other proteins and/or pollens that are on the grass. Contact your allergist to discuss and possibly test for additional allergies.
What foods should I avoid?
Rice comes in all varieties such as white (short or long grain, jasmine, sushi, and so on), brown (short or long grain), red (Bhutanese for example), purple/black (Forbidden rice for example). There are dozens of rice varieties. Avoiding rice flours, puffed rice, sushi, rice wine, rice vinegar, rice cereal and other foods cooked with rice is also recommended. Always read the label before purchasing any processed or prepared food and when going to a social event discuss menu options with the wait staff and manager.
If you suspect you have food allergies, see your doctor or allergist for testing and diagnosis. Knowing what foods to avoid and carrying emergency medicine like epinephrine, if needed, can save your life if you have a serious allergy.