Alternative Names CRS, MSG allergy, MSG symptom complex
Definition Chinese restaurant syndrome (CRS) occurs in some people after they eat foods containing the food additive monosodium glutamate (MSG) - a common ingredient in Chinese food.
What is going on in the body? MSG is a commonly used flavour enhancer. It is found in a variety of foods, including Chinese dishes. In 1968, a researcher identified a set of symptoms that occurred in certain people after they ate foods containing MSG. Thus, the term Chinese restaurant syndrome was coined. Although similar to an allergic reaction, CRS is more of an intolerance to or side effect of MSG. True life-threatening symptoms are extremely rare. MSG is not an allergen. A small percentage of people may be sensitive or intolerant to MSG, as they may be to other naturally occurring foods and ingredients.
What are the signs and symptoms of the disease? Symptoms of CRS can include:
burning sensation on the back of the neck, chest, shoulders, abdomen, thighs, and forearms
What are the causes and risks of the disease? CRS is caused by eating foods containing high amounts of MSG. A person who eats foods containing MSG on an empty stomach increases the amount absorbed into the bloodstream. This results in an increased risk of CRS. The intensity and the duration of symptoms are directly related to the amount of MSG ingested.
What can be done to prevent the disease? People with CRS should avoid foods containing high amounts of MSG. Symptoms of CRS can sometimes be avoided by eating food prior to eating MSG.
How is the disease diagnosed? With symptoms so similar to an allergic reaction, the first experience often results in a trip to the emergency room. CRS is diagnosed when typical symptoms occur within 30 to 60 minutes of eating foods with high concentrations of MSG. The symptoms usually go away without treatment in about 2 to 3 hours.
What are the long-term effects of the disease? The condition goes away by itself without causing long-term effects. But the concern for someone with CRS is how much MSG, if any, can be consumed without causing symptoms. Before changing eating habits, a person should talk with his or her doctor.
What are the risks to others? There are no risks to others.
What are the treatments for the disease? With symptoms so similar to an allergic reaction, treatment is sometimes given before the diagnosis is made. Antihistamines are the most frequently used medication. However, if CRS is diagnosed, the symptoms will usually go away without treatment within 2 to 3 hours.
What are the side effects of the treatments? Some antihistamines cause drowsiness.
What happens after treatment for the disease? After the symptoms resolve, a person with CRS often feels weak and tired for a day or two. Afterward, their activity level and appetite return to normal.
How is the disease monitored? Avoid foods containing high levels of MSG. However, MSG is in many foods other than Chinese foods, and it would be difficult to avoid it completely. Because the symptoms are related to the amount of MSG ingested, very mild symptoms are often more of a nuisance than an illness. A person should read food labels and order Chinese food prepared without MSG.
Author: Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 18/09/2004 Contributors Potential conflict of interest information for reviewers available on request
