Food allergies have more than doubled in a decade, new research shows.

Analysis of more than 13 million UK patients show rates have risen sharply yet around a third of sufferers do not have potentially lifesaving EpiPens.

Pre-school children carry the biggest risk with 4 per cent of under-fives having a suspected allergy, compared to around one per cent of adults.

Experts said its rising prevalence showed the importance of ensuring GPs and other community staff — such as nurseries — are sufficiently trained to care for those at risk of severe food allergy.

Food allergy occurs when the immune system overreacts to certain foods, such as peanuts, eggs, cows' milk or shellfish.

In severe cases it can lead to anaphylaxis, which can cause swelling of the airways, breathing difficulties and cardiac arrest if not treated urgently.

In the biggest real-world study on UK allergies, Imperial College London researchers analysed GP and hospital records for incidents involving allergies between 2008 and 2018.

They found the the number of new cases of probable food allergy doubled from 76 to 160 cases per 100,000 during this time, a jump from 0.4 to 1.1 per cent of the population, before starting to level off.

In children and young people under 20, it increased from almost one to 2.41 per cent, according to findings published in the Lancet Public Health journal.

Under-fives had the highest 'probable' allergy rates in 2018 at 4 per cent, compared with 2.4 per cent in those age 5 to 9, 1.7 per cent for 15 to 19-year-olds and 0.7 per cent in adults. 

This is up from 1.2, 0.9, 0.8 and 0.2 per cent respectively.

Scientists said new cases have started to slow, possibly due to changes in infant feeding guidelines which no longer recommend delaying the introduction of foods like peanuts to babies or those at risk of allergy.​

Lead author Dr Paul Turner, Professor of paediatric allergy at Imperial, said: 'This new analysis paints an important, if mixed, picture of food allergy in the UK.

​'The good news is that while the prevalence of food allergy has increased, the numbers of new cases occurring each year look to have plateaued.

'However, more than one-third of patients at risk of severe reactions do not carry potentially lifesaving rescue adrenaline autoinjectors, like EpiPens.

​'We urgently need to address this, and better support GPs and primary care staff who end up looking after the vast majority of food-allergic patients in the UK.'

Most patients — including those with previous anaphylaxis — were seen in primary care settings, such as at a GP surgery, with only one in ten seen at least once by a hospital specialist over a decade.

Prescriptions for adrenaline autoinjectors in those with previous anaphylaxis were estimated to be at 64 per cent for children and young people and just 55 per cent for adults, as well as less common for people living in more deprived areas of the country.

The findings come after recent high profile cases such as that of 13-year-old Hannah Jacobs, who tragically died within hours of taking a sip of a Costa Coffee hot chocolate, containing cow's milk in 2022.

Earlier this month, a coroner noted 'neither Hannah or her mother were carrying an epi-pen that had been prescribed' on the day she died.

Dr Turner added: 'Food allergy can have a huge impact on people's lives, and in some tragic cases, can cut lives short.

'By better understanding the prevalence of food allergy in the UK and working with affected people, their families, scientists and clinicians, we are working together to reduce that impact.'

The cause behind the rise is not known, with one theory suggesting it could be in part due to increased awareness while others suggest it could be down to decreasing exposure to germs and changes to gut bacteria.

Exposure advice has also changed over the years with parents now told to introduce allergenic foods as early as possible.

Until 2009, official was not to give peanuts to children with a family history of a peanut allergy until they were at least three - and to all others until they were at least one whereas experts now suggest they should be weaned on to small doses as early as possible.