Over the past 20 years there has been a 500% increase in children being admitted to hospital for food allergies, NICE has revealed.
The watchdog voiced concern over children being incorrectly diagnosed with unreliable testing kits available on the internet.
In Europe and North America there has been a large increase in food allergies since 1990 with between 6% and 8% of children now suffering.
Reactions to food can be severe and are recognised as a major paediatric problem in the UK and other Western countries.
In a bid to help GPs spot the signs and symptoms, the National Institute for Health and Clinical Excellence (NICE) issued its first guidelines on food allergies in children.
The draft guidance also warns against allergy tests sold over the internet and offered by alternative practitioners.
These tests which include hair analysis and kinesiology can wrongly diagnose food allergies, leading to children being put on restrictive diets lacking in nutrients, it says.
The guidance tells GPs when to consider the possibility of a food allergy and when to carry out further testing.
Dr Judith Richardson, Associate Director of NICE's Centre for Clinical Practice, said: "This will be the first evidence-based guideline on how health professionals and others who work with young children should diagnose and assess food allergies in children."