More than half of Australians think people with a food allergy are over-cautious, a new survey has found.

Unrealistic reactions from a handful of parents taint all families trying to minimise the risks for people with a food allergy, says an expert.

A new study has found 56 per cent of Australians believe people with a food allergy are over-cautious, while 69 per cent do not know what to do in an emergency.

"Even consuming the tiniest amount of a food that you are allergic to can result in a life-threatening reaction in some, so it is essential that the community understands the importance of taking food allergy seriously," Maria Said says.

The Allergy & Anaphylaxis Australia president said social media sites could be scathing of people with a food allergy, sometimes in response to unrealistic parents.

"I have heard of parents asking schools to wipe down handrails," she told AAP.

"That is an extreme measure and that is totally unrealistic - people very rarely go into anaphylaxis from touching an allergen.

"We are all then tarred with the same brush because of the handful that are absolutely over the top."

Sufferers need to be cautious and always know what is in what they eat and drink, but can be affected by negative community reactions.

Ms Said said her adult son tends not to "make a fuss" or tell others about his peanut allergy, which can be risky.

"It's not something to hide, it's not something to feel ashamed of," she said.

"It is your lot and you have to check your food every time you eat as part of your everyday management."

The survey of 1050 people found 86 per cent do not know the signs and symptoms of a severe allergic reaction, and 98 per cent do not know the condition can be life-threatening.

"Australia has one of the highest rates of food allergy in the world and hospital admissions for severe allergic reactions have doubled in the last decade," Ms Said said.