Researchers say the number of food allergy diagnoses in England has doubled in a decade

Research has shown that the number of people in England diagnosed with a food allergy has more than doubled in the last ten years, and a third of people with life-threatening reactions do not carry adrenaline pens.

Experts from Imperial College London analysed GP records of 7 million people. The number of new cases of food allergy rose from 76 per 100,000 people in 2008 to 160 per 100,000 people in 2018, they found. The overall prevalence increased from 0.4% to 1.1% over the 10-year period.

The highest prevalence of food allergies was seen in children under five, with 4% affected. The figure was 2.4% for children aged five to nine, 2% for 10-14 year-olds, 1.7% among 15-19 year-olds and 0.7% for adults aged 20 or older in 2018, the data showed.

The rise in cases in England was likely reflected across the UK as a whole, the researchers said. They also found that one in three patients who had previously experienced anaphylaxis – a life-threatening allergic reaction – did not have their own adrenaline auto-injectors (AAIs).

The findings were published in the journal Lancet Public Health.

Lead researcher Dr Paul Turner, professor of paediatric allergy at Imperial’s National Heart and Lung Institute, said the results showed there was an “urgent need” to “better support GPs and primary care staff” in caring for patients with food allergies.

“Food allergies can have a huge impact on people’s lives and in some tragic cases even shorten their lives,” he said.

Food allergies occur when the immune system overreacts to certain foods, such as cow’s milk, peanuts, eggs, or shellfish. In severe cases, they can lead to anaphylaxis, which can cause swelling of the airways, difficulty breathing, and cardiac arrest.

The study did not investigate why the number of cases had increased, but experts said there were likely to be many different factors behind the rise. For example, increased awareness of food allergies likely led to more people seeking help on the NHS.

Parents who followed outdated advice to keep certain foods from their babies until they were older were also likely to blame, experts said. If a child was banned from eating peanuts, exposure through dust, contact with furniture or creams containing peanut oil could trigger a reaction in their immune system.

Increased use of detergents, creams and body lotions may also play a role, as they can break down the skin barrier, experts say. This allows food to enter the immune system through the skin instead of the gut, increasing the risk of food allergies.

Previously, it has also been suggested that poorer diet, genes, vitamin D deficiency, pollution and environmental factors could explain the increase in the number of cases.

Imperial said that while more doctors have diagnosed food allergies in the decade studied, the incidence of new cases may be declining. It was unclear why newly diagnosed food allergy cases may be leveling off, they said.

One possibility was changes in infant feeding guidelines that no longer recommend delaying the introduction of foods such as peanuts into a child’s diet, Imperial said. In children at higher risk for food allergies, earlier introduction of eggs and peanuts are now standard recommendations.

Turner said the research “paints an important, albeit mixed, picture of food allergy in the UK”.

He added: “The good news is that although the prevalence of food allergy has increased, the number of new cases occurring each year appears to have stagnated. However, more than a third of patients at risk of severe reactions do not carry potentially life-saving adrenaline auto-injectors, such as EpiPens.”

Prescriptions for AAIs – devices given to people at risk of anaphylaxis – were also less common among people living in more deprived areas of the country, researchers found. Only 55% of adults and 64% of children who had previously experienced anaphylaxis had an AAI prescription.

Nadim Ednan-Laperouse, co-founder of the Natasha Allergy Research Foundation, said: “It is shocking and alarming to discover that more than a third of people who have experienced anaphylaxis – the most severe allergic reaction – have not been prescribed an adrenaline auto-injector, and the poorest people in society are less likely to be prescribed this life-saving medicine.

“This is totally unacceptable and inevitably puts lives at risk. Anyone with a severe food allergy should carry two AAIs at all times.”