Children and adults who are allergic to peanuts should also avoid products containing lupin flour, doctors advise.

Farmers in Australia and some European countries are turning to growing lupins as a potential replacement for soybean flour in breads and other baked goods.

In this week's issue of the medical journal The Lancet, researchers describe the case of the 25-year-old woman who had an allergic reaction at a restaurant after eating onion rings made with lupin flour.

The woman had had a severe allergy to peanuts when she was 15, but tests ruled out that the legume caused her allergic reaction in August 2004.

Lupin flour is made from the crushed seeds of the lupin plant, which is often used in animal feed.

According to the journal, the first known case of lupin allergy occurred in 1994, and the first case of lupin anaphylaxis was in 1999.

Cases are on the rise in France, where bakers began adding lupin flour in 1997.

In November 2004, the European Union required food manufacturers to list 12 ingredients that can trigger allergic reactions: gluten, fish, crustaceans, eggs, peanuts, soy, milk and dairy products, nuts, celery, mustard, sesame seed and sulphites.

Lupins are not included.

It's estimated about 300,000 Canadians have peanut allergies. They must check food labels and restaurant ingredients to avoid potentially life-threatening shock from an anaphylactic reaction.