Patients have been advised to get a professional diagnosis from a doctor if they are concerned that they have a food allergy.
Mandy East from the Anaphylaxis Campaign said that misdiagnosis at home can result in dangerous complications, such as malnourishment.
Her comments come as NICE has issued new guidance to support GPs and other health professionals when it comes to recognising the symptoms of food allergies.
Ms East added: "You are cutting out all these food groups, you are not feeling any better, you have still got the symptoms, you still have got the condition so you're at risk of being malnourished and you're still not actually treating the underlying condition."
Earlier this year, research company Mintel revealed that 44 per cent of UK adults suffer from at least one allergy, although this is predicted to rise.
Allergies to dairy, fish or seafood products were the most common complaint.