A rice allergy is a potentially deadly response by a person’s immune system to rice or foods containing rice. After a susceptible person ingests rice, the immune system reacts with the release of histamines and other chemicals that trigger symptoms that can range from mild to life–threatening. While somewhat rare in the United States, rice allergy still affects a small portion of the population.

The low incidence of rice allergy in the United States has given rise to the myth that rice is a hypoallergenic food that will not cause allergies. In fact, rice allergy is not unusual in Japan and other nations where rice is a staple food. Rice pollen also causes allergies when inhaled, and the symptoms mimic those of hay fever.

There is no way to know whether a person with a rice allergy is likely to have a mild or severe reaction after eating rice products. Symptoms that begin as mild to moderate can quickly intensify and lead to potentially life–threatening anaphylactic shock. Therefore, those with this allergy must avoid the grain altogether. There are several foods that can serve as substitutes for rice. A person with a rice allergy who accidentally consumes rice must seek immediate medical attention.

Rice can cause an allergic reaction in sensitive individuals who consume the grain. Any food that uses rice – including those made with rice flour – has the potential to trigger a reaction. Unlike many food allergies, rice allergy afflicts adults more often than young children. In addition, dogs can be allergic to rice. The grain is found in many commercial dog foods.

The incidence of rice allergy in the United States and Europe is very low, because rice is not considered a staple food. In general, the more often a person is exposed to a food, the higher the likelihood that the body will become sensitized to it. For this reason, allergies to a particular food are highest in regions where the food is a staple of the local diet. In Japan, for instance, an estimated 10 percent of the population is believed to be allergic to rice. Rice allergy is also more common throughout East Asia, where rice is a staple of the local diet.

Rice pollen also causes hay fever (allergic rhinitis) symptoms in areas where it is grown commercially. Because it is a member of the grass family, its pollen becomes airborne and is easily inhaled.

Like all food allergies, rice allergy is the result of an immune system reaction. A food allergy develops when something is consumed and the immune system mistakenly perceives it to be a harmful foreign substance. In reaction, the body begins producing antibodies specifically designed to fight the invading substance, known as an antigen.

When enough antibodies have been created, the body becomes sensitized to the antigen. The next time the person consumes the food with the antigen, an allergic reaction will occur.

Unlike other food allergies, there are no unfamiliar synonyms used for rice in food labeling. However, those with a rice allergy should also avoid rice flour. In most meals, the presence or absence of rice is obvious. But it is hidden in a few foods, including:

• Indian and Japanese sweetmeats (made with rice flour)
• Spring rolls (made with rice flour)
• Some noodles (rice noodles are very white)

People who are allergic to rice also may react to other foods in the same botanical family. This is called cross reactivity, and it requires people with food allergies to be extra careful when making meals or ordering food in restaurants. Foods that can spark reactions in those allergic to rice include:

• Barley
• Maize
• Wheat
• Durum wheat
• Corn
• Soybean
• Triticale
• Oats
• Rye

Those with rice allergy are also frequently allergic to peaches and apples.  

A person who has a reaction to rice does not necessarily have a rice allergy. In some cases, the reaction may be triggered by a food intolerance, which does not involve an immune-system reaction. Food intolerance involves the inability of the body to digest a substance, leading to symptoms of discomfort (e.g., stomach cramping) but posing little danger. Food intolerance often allows the individual to eat small portions of a problem food without experiencing symptoms. With a food allergy, even a very small portion of a food allergen can cause an allergic reaction.

While primarily referred to as a type of food allergy, rice plants also produce pollens. In areas where rice is grown commercially, people may develop allergies to rice pollen. This may be linked to a number of allergic conditions related to the inhalation of rice pollen, including:

• Allergic rhinitis (hay fever). An inflammation of the mucous membranes that lines the nose causing nasal congestion, sniffling and sneezing.
  
  

  

• Allergic conjunctivitis. An inflammation of the tissue lining the inside of the eyelid that produces irritation and tearing of the eyes.
  

  

• Allergic sinusitis. An inflammation of the tissue lining the inside of the sinuses that leads to congestion and sinus pressure.
  
  

  

• Asthma. A condition in which breathing airways become blocked or narrowed causing shortness of breath and breathing difficulty. Some forms of asthma are triggered by allergies.
  

  

The signs and symptoms of rice allergies are the same as for other food and pollen allergies. Rice allergies can trigger symptoms that range from the relatively mild to the more potentially serious. Symptoms typically appear within minutes to a few hours after contact with rice protein.

Potential signs and symptoms include:

• Hives and eczema 
• Runny nose or nasal congestion
• Itchy or watery eyes
• Sneezing
• Swelling of the tongue, lips and throat (angioedema)
• Vomiting
• Nausea
• Abdominal cramps
• Diarrhea
• Cough
• Wheezing

Signs and symptoms of a more severe reaction include:

• Difficulty breathing
• Shortness of breath
• Tightness in the chest or throat
• Drop in blood pressure
• Rapid pulse
• Dizziness or lightheadedness
• Fainting

People experiencing any of the signs and symptoms of a rice allergy should seek immediate medical attention to prevent anaphylactic shock, a potentially life-threatening reaction.

Individuals who suspect that they are allergic to rice should consult an allergist/immunologist. In order to diagnose the cause of the patient’s symptoms, the physician will collect the patient’s medical history, perform a physical examination and employ allergy tests (e.g., skin tests, blood tests).

Once the diagnosis of rice allergy has been confirmed, the patient will be advised to avoid the grain. Those with a rice allergy must completely avoid rice because consumption can cause anaphylactic shock, a potentially life-threatening reaction. There is no way to predict whether a person will have a mild or severe reaction after consuming a food they are allergic to. People with rice allergies must carefully read the ingredient labels on food products and be cautious when eating at restaurants.

Those who avoid rice are unlikely to miss any essential nutrients. However, good rice substitutes can be found in the following:

• Sorghum
• Millet
• Quinoa
• Cornmeal
• Buckwheat

Wild rice can serve as a substitute for some who are allergic to rice. However, in others, it is likely to trigger a cross reaction. People with food allergies should consult a qualified physician before consuming an "alternate" food.

People with rice allergies will also be given instructions in case of accidental consumption. Individuals with a history of mild reactions may be instructed to take antihistamines. Those with a history of severe reactions may be prescribed an allergy kit.

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following rice allergy–related questions:

1. Do my symptoms suggest rice allergy or food intolerance?
   
   
2. What tests will you use to determine if I am allergic to rice?
   
   
3. If I have eaten rice in the past without any reaction, does that mean I am not allergic?
   
   
4. If I am allergic to rice, will I ever be able to eat rice again?
   
   
5. Is my rice allergy dangerous?
   
   
6. What may have caused me to develop a rice allergy?
   
   
7. What are my treatment options?
   
   
8. What should I do if I accidentally eat rice?
   
   
9. Are my children more likely to develop a rice allergy because I have the condition?
   
   
10. Are there other foods besides rice that I should avoid?