Asking people four simple questions could rule out those who mistakenly believe they have an allergy and pursue costly tests, researchers in UK say.
A new study found that asking four questions helps identify those who are not allergic with an accuracy of almost 90 per cent.
Experts from the University of Edinburgh said "a significant number of people mistakenly believe they have allergies and use both NHS and their own time and resources pursuing unnecessary investigations".
These include skin prick testing and specific blood tests, both of which offer a high level of inaccurate results.
A significant number of people mistakenly believe they have allergies
People then spend money on treatments and avoid "presumed triggers" when they are "not, in fact, allergic", they said.
In a study of 143 people, published in the British Journal of General Practice (BJGP), skin prick and blood tests were compared with the results of a questionnaire aimed at identifying people who had an allergy.
The results meant experts were able to boil down the questionnaire to just four simple questions.
These were: Do you have, or have you ever had, hayfever? Do any of your parents or siblings have, or have they ever had, hayfever? Do your allergy symptoms vary when you go from place to place (for example, on holiday)? Is there a specific trigger that always sets off your allergy symptoms?
The authors concluded that, for those who answered no to the four questions, most had no allergy.
They said: "Most (87.5 per cent) of those who gave negative responses to all the questions were non-atopic (had negative skin tests)."
They said the findings may help family GPs work out the risk of allergy, although they said larger studies should be carried out.
The researchers said that 10 per cent to 12 per cent of the general adult population think they have some type of food allergy or intolerance.
But tests show only 1 per cent to 2 per cent actually do.
"This represents a fivefold overestimation of food allergy, which is likely to have significant cost and societal implications," they said.
Allergy UK's head of clinical services, Amena Warner, said: "We do know, however, that a good allergy clinical history is the important first step in accurately identifying allergy and allergic triggers."
"We are also aware that certain reported 'allergy testing', such as hair analysis or vega testing, is not validated so should not be used."
"There are clear Nice (National Institute for Health and Care Excellence) guidelines on recommended testing using the appropriate allergy tests of either a specific IgE blood test or a skin prick test."
"Of course, as a national charity committed to helping improve the prompt diagnosis and treatment of allergic disease, Allergy UK welcomes new research and we await the outcomes of a larger study to validate the screening questionnaire."