Food allergy diagnoses in England doubled in a decade, say researchers

The number of people diagnosed with food allergies in England has more than doubled in a decade and a third of those with life-threatening reactions are not carrying adrenaline pens, research has revealed.

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

The highest food allergy prevalence was seen in children under the age of five, 4% of whom were 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 over in 2018, the data showed.

The surge in cases in England was likely reflected across the UK, 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 Lancet Public Health journal.

The lead researcher, Dr Paul Turner, a 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” to care for patients with food allergies.

“Food allergy can have a huge impact on people’s lives, and in some tragic cases, can cut lives short,” he said.

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

The study did not investigate why cases had surged, but experts said there were likely to be many different factors behind the increase. For example, increased awareness of food allergies was probably leading to more people seeking help from the NHS.

Parents following outdated advice not to give their baby certain foods until they were older was also likely to blame, experts said. If a child was prevented from eating peanuts, then exposure through dust, contact with furniture or creams containing peanut oil could trigger a response in their immune system.

Increasing use of detergents, creams and body lotions may also play a part because they can break down the skin barrier, experts said. This allows food to get through the skin into the immune system, rather than through the gut, which increases the risk of food allergies.

Poorer diets, genetics, vitamin D deficiency, pollution and environmental factors have also been previously suggested as potential explanations for the rising number of cases.

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

One in three people in England who had previously had a severe allergic reaction to food did not carry an adrenaline pen. Photograph: Jim Bourg/Reuters

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

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

He added: “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 life-saving rescue adrenaline auto-injectors, like EpiPens.”

Prescriptions for AAIs – devices given to those at risk of anaphylaxis – were also less common for 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 AAI prescriptions.

Nadim Ednan-Laperouse, the 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 in society are less likely to have prescriptions of this life-saving medicine.

“This is totally unacceptable, and will inevitably put lives at risk. Anyone who has a serious food allergy should carry two AAIs with them at all times.”