The allergy epidemic: is a cure on the way?

A spiralling health crisis threatens countless children and makes parents’ lives intolerable—and nobody understands what’s causing it. But hope could be round the corner
August 28, 2021

Sarah Knight was stressed. She was home with a six-month-old baby, breastfeeding, adjusting to her new responsibilities as a mother. She was doing her best, but something seemed off. Her son Will was suffering from eczema, acid reflux and, more alarmingly, didn’t seem to be putting on weight. She and her husband Ian had been taking him back and forth to the local surgery pretty regularly, for one reason or another. They’d been referred to a paediatrician, and started topping-up his feeds with a bottle. But Will refused, spitting the milk back out. It was driving Sarah crazy.

Recently, Will had developed little white lumps round his mouth. It didn’t look right to Sarah. Maybe it was an allergy. Could babies even be allergic to milk? She wasn’t sure. The health visitor, ever reassuring, said to just keep doing what they were doing. They’d get there in the end. But a week later, after bottle time, she was so alarmed by the growing lumps that she bundled him into his buggy and wheeled him straight to the local clinic. Really? she thought. Can this really be normal?

By the time they arrived, Will was bright red and the lumps—hives, as she knows to call them now—were the size of 50p coins. Within minutes, he was struggling to breathe. 

In the subsequent panic, all a blur to her now, a doctor was summoned, equilibrium recovered, a critical situation averted. Later, in hospital, she was presented with a tin of dairy-free formula, emergency adrenaline EpiPens, and antihistamines. “That,” she tells me, “was the beginning.”

Will is one of an estimated 5 to 8 per cent of children in the UK to suffer from serious food allergies. After undergoing a battery of tests, he was found to be highly sensitive to cow’s milk, eggs, wheat, soya, nuts and a number of other common foods. Although the severity and complexity of Will’s allergies is unusual, food allergies themselves are not—indeed, they have been growing more and more common throughout the world in recent decades. Global rates are thought to have at least doubled since the 1960s; here in the UK, one of the most affected countries, allergies are now so widespread that one might expect perhaps two children to be affected out of a typical school class of 30.

In the UK, an estimated two million people live with a diagnosed food allergy, a huge spike in prevalence that scientists say cannot simply be attributed to hypochondria or increased levels of detection. In the past five years alone, the number of people admitted to hospital suffering from anaphylaxis—an extreme, sometimes fatal, inflammatory response, when a patient’s throat can swell shut—has risen by a third, reaching 2,134 in 2020. (Admissions for less severe reactions have risen by three-quarters over the same period.) Fatalities due to food allergies are rare, but not unknown: in England and Wales, 152 deaths due to allergic anaphylaxis were recorded between 1998 and 2018. 

“For parents of children with severe allergies, the worst-case scenario is a largely rational fear”

Symptoms of food allergies range from vomiting, cramps, eczema and nausea to difficulty breathing. Overall, peanuts cause the most issues, accounting for between a quarter and a third of all diagnosed allergies, but cow’s milk is associated with the largest proportion of deaths. Peanut allergies are so ubiquitous that many schools across the country have adopted a “nut-free” policy, banning the use of nuts in their canteens, and requesting parents refrain from including nuts in packed lunches. 

Allergies should be distinguished from “intolerances,” a vaguer term for a food that might “disagree” with you in a number of ways. A true allergy is a disorder of the immune system, where the body incorrectly identifies a harmless food protein as a threat. Antibodies are released, which in turn flood the body with a chemical called histamine. In normal circumstances, the release of histamine helps your body repair injured tissue and fight off parasites; it is also responsible for the itching, sneezing and swelling associated with allergic reactions. 

These reactions happen very quickly after coming into contact with the troublesome allergen—usually within a matter of minutes. And the effects can be extreme. In October, “Natasha’s Law” will come into force, requiring all premises that package food on site ahead of sale—like freshly-made sandwiches—to carry a full ingredients list. The new rules are the result of tireless campaigning by the parents of Natasha Ednan-Laperouse, a 15-year-old girl who died on a flight to Nice in 2016 after eating a Pret a Manger sandwich that, unknown to her, contained sesame seeds—to which she was allergic. Despite two injections of adrenaline administered by her father and a desperate attempt at resuscitation, Natasha died before the plane had a chance to land. 

While the explosion in food allergies is well documented, there is no agreement on why it’s happened. Theories abound: one of the most enduring has been the so-called “hygiene hypothesis,” put forward by the epidemiologist David Strachan in 1989, which suggested that modern society’s obsession with cleanliness was at the root of the problem. The hypothesis proposed that a lack of exposure to dirt and bugs leads to a badly calibrated immune system prone to misfires. But though the idea feels intuitive, and has thus found a willing public audience, evidence for it has been lacking. Scientists now say that over-enthusiastic hygiene practices are unlikely to be the cause, although exposure to the lungs of particular cleaning products might be. 

More recently, the British researcher Graham Rook has reformulated the hygiene hypothesis to foreground the importance of growing up with what he calls “old friends”—the micro-organisms found in soil, dung and thatch that we co-evolved with. Other factors suspected to play a role include the rise in caesarean sections (babies born this way are exposed to less of their mother’s microbiota); over-bathing of small children, which irritates their skin and provokes an immune response; taking too many folic acid supplements; lack of vitamin D; repeated use of antibiotics; or the use of peanut oil-based emollients on damaged, eczema-prone skin. Generally, public health advice recommends that children avoid common allergens like peanuts completely during early infancy—although some researchers now fear that this advice may have actually contributed to the explosion in allergies. Some scientists believe exclusively breastfeeding helps; others contradict them. For new parents, or soon-to-be parents, the whole debate is a confusing, anxiety-inducing morass. 

All that is certain is that the surest way to avoid a dangerous reaction is to steer well clear of known allergens. For Sarah and Ian, once they had a firm diagnosis, they set to work designing a new, allergen-free lifestyle. Still breastfeeding, she cut dairy from her own diet, and topped-up Will’s feeds with a non-milk formula. They saw an immediate improvement. 

Advised that even tiny traces of the problem foods could cause a reaction, they began purging them from their surroundings. Everyday activities took on layers of complexity. “If we went to a café, we would make sure to wipe down not only the tabletop but under the table too, because children like to put yoghurt-laden sticky fingers under there.” They became, in other words, “that neurotic family”—the type that was scrubbing everything in sight long before Covid-19. Weaning, of course, was a fraught affair that took place in part under medical supervision—certainly not the “liberal, passing-noodles-across-the-table” baby-led weaning that’s in vogue. Sarah had a lot of charts and notebooks. “It wasn’t much fun.”

Allergies are not inherited, exactly, but some have a genetic component and can run in families. After Will’s younger brother Freddie was born, he also had issues with reflux and low weight.

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They took him into hospital for “skin-prick” testing aged five months. In this test, saline solutions containing possible allergens are dripped onto a child’s forearm; a nurse then pierces the skin under each droplet, to allow the allergens to penetrate. If the child is allergic a reaction will usually, within a few minutes, reveal itself via a red, itchy weal. 

“At a café, we would make sure to wipe down not only the tabletop but under the table too, because children like to put yoghurt-laden sticky fingers under there”

Freddie got the all clear: no reaction. Sarah was so relieved that she burst into tears: thank God, she thought, thank God, thank God. But when he began being weaned the following month, he was sick after eating a slice of toast. That was weird. A coincidence, Sarah and Ian told themselves. The test had been negative. Then the next day brought more bread: more vomit, the beginnings of a rash. After scrambled eggs, he suffered from diarrhoea. Something wasn’t right. They tried skin-prick tests again at hospital and Freddie reacted so badly—his arm swelling so suddenly and violently—that the nurse had to run for help. 

Now they had two boys under the age of five, each with multiple, different allergies. The combination made it much harder to cope with. Often “free from,” allergy-friendly products include unusual elements—gluten-free bread might use egg protein for structure, for example, or dairy. The matrix of available foodstuffs, as Sarah was beginning to think of it, was complicated. Life was complicated. It was, in fact, quite overwhelming.

Logistically, there was a lot to think about. Sarah had the normal anxieties of a new mum balancing a return to work with family life. But then there were all the hospital appointments to attend and keep track of, too. And more than that—there was the anxiety that came with knowing that disaster was only one thoughtless move away. “Screw it up once,” she says, “and there will be devastating consequences. Or, not even screw up. Just have something go a bit wrong.”

Most parents reassure themselves that their greatest fears are largely products of their darkest imagination, but for parents of children with severe allergies the worst-case scenario is a largely rational fear. There’s no need for a vivid imagination if scenes from your worst nightmares have already played out in front of your eyes.

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Once, when Will was two and a half, he suffered a major anaphylactic episode in hospital during another food trial. They’d been testing whether he might be able to consume small amounts of baked milk, in the form of a small cupcake. Sarah watched him anxiously as he ate the cake, and then as he became reluctant, then quiet, and then suddenly floppy. “We got the adrenaline pen out,” she remembers, “and I administered it. You’re supposed to recover immediately. But he didn’t.” The nursing staff sprang into action, preparing a second EpiPen, rushing over oxygen. “But it was terrifying. Really terrifying. And that was in hospital, surrounded by doctors and every type of medical care, in a controlled environment. We knew exactly what we were doing. And it was still terrifying.” 

Another time, a confusion over leftovers saw Sarah feed Will a spoonful of food that contained milk, causing another medical emergency. This time the adrenaline worked straight away. But it’s what Sarah means when she talks about major consequences of minor mistakes. 

Every parent of a child with allergies knows about the case of Sussex teenager Owen Carey who, in 2017, celebrated his 18th birthday at the burger chain Byron; despite explaining his allergies to the waiting staff, he was served chicken that had been prepared with buttermilk. On the journey home, Owen collapsed and died in the absence of an EpiPen. (He didn’t carry one because he had never suffered anaphylaxis before.) This is the kind of nightmare scenario parents envisage a thousand times, lying awake in bed in the dark. Tragically, it is teenagers who are most likely to die, as they take on personal responsibility for their eating and EpiPens just as their immune systems are firing up. 

For the parents of small children with allergies like Will’s or Freddie’s, the situation requires constant vigilance, relentless scrutiny—never just taking a waiter’s or teacher’s or babysitter’s word for it, but always checking and double checking the label, speaking to the chef, hovering over the barbecue, rifling through the party bags, wiping the underside of the table. It’s a heavy load to bear. In a 2019 paper, researchers at the University of East Anglia found that more than two-fifths of parents of children with severe food allergies met the clinical criteria for post-traumatic stress. 

Time passes, and bodies change. Out of 10 pre-school children with severe food allergies, perhaps two will grow out of them by the time they go to school. Six others might go on to outgrow them by the end of secondary school. Allergies to milk, eggs, wheat and soy are among those most frequently outgrown, as the body’s immune responses change over time. For the rest, there are a number of promising new treatments. 

One of the benefits of the explosion in allergies—if you can call it a benefit—is that there is now a boom in allergy research. Food desensitisation—wherein tiny but slowly increasing amounts of the allergen are fed to the child daily—has had impressive results, ultimately preventing allergic reactions in upwards of 80 per cent of participants. This form of oral immunotherapy is still in the research phase and in the UK is only presently available from a small number of experimental clinics. In the US and France it is more mainstream, and many British parents make the trip for the expensive treatment.

The aim is not to cure the allergy, but to moderate it: peanut-allergic patients, for example, will not be able to happily tuck into a bowl of roasted peanuts by the end of it, but they might be able to cope with the equivalent of three or four nuts, say—enough to make all the difference should they mistakenly eat contaminated food. Studies have documented 25-fold increases in children’s reaction thresholds, and the majority of peanut-allergic participants being able to consume around 10 nuts without serious reaction. But it is not without risks: participants in the studies may suffer from hives, nausea, cramps or even anaphalaxis. It is not, warn the clinics, for everyone. 

“More than two-fifths of parents of children with severe food allergies met the clinical criteria for post-traumatic stress”

Nevertheless, the success of studies by researchers like Andrew Clark, a paediatric allergy consultant allied with Cambridge University, and professor Adam Fox, president of the British Society of Allergy & Clinical Immunology, has convinced many parents to fork out for treatment—or to wangle a place on an experimental course. It’s “massively reassuring” to know your child is better able to withstand accidental exposure, according to Anna Ford, environmental campaigner and parent of a child undergoing immunotherapy treatment under Fox’s supervision.

The pharmaceutical industry is also hard at work. Nestlé has invested hundreds of millions of dollars in its health-science arm, Aimmune, which has been developing the treatment Palforzia which in 2019 won regulatory approval in the US and Europe. Palforzia takes the form of small caplets containing exact portions of peanut proteins that can be broken open and dusted over food so the patient can remain desensitised. Initially predicted to hit sales of £1.24bn by 2024, rollout has been stymied by Covid-19-related shutdowns—but should proceed this year.

Similar products are following close behind. The French company DBV Technologies has developed a stick-on patch that delivers controlled quantities of allergens through the skin, a little like a nicotine patch, called Viaskin. New York-based Intrommune Therapeutics has developed a toothpaste containing traces of peanuts, so patients will naturally take their daily dose. And a Worthing-based biotech company, Allergy Therapeutics, is reportedly closing in on the “holy grail” of allergy research: a vaccine, which uses a genetically engineered plant virus to train the patient’s immune system to damp down its response to allergens over a course of shots.

In the meantime, however, Sarah, Ian, Anna, and all the other parents of children with serious food allergies must keep up their vigilance. They police the fridge, eat only at trusted restaurants, take only self-catered holidays. They keep their children safe. It can be lonely, and hard work. That’s why Sarah has set up The Allergy Team, a digital community aimed at bringing parents and healthcare professionals together to answer the questions parents have when children are first diagnosed. She also works with Jen Meakin, a chef, to publish allergy-friendly recipes online.”

Over time, says Sarah, the anxiety has become more manageable. And she concentrates on ensuring that the boys are not defined by their allergies. They are children who are thriving at school, and love football, and cooking. They are normal boys, with an unusual relationship with some foods. That’s all. As she has amassed expertise in living with allergies, she has also come across inspiring stories. She finds hope in the Italian fencer Aldo Montano, an Olympic-level athlete with food allergies who spends his life on the road. 

In an interview online, Montano explained how he will spend between 150 and 200 nights a year away from home, in competition. That means 150-200 breakfasts, 150-200 lunches and 150-200 dinners eaten out. He needs to be both careful and lucky, and 99.9 per cent of the time he is both; for that other 0.1 per cent of the time, he is close to a hospital—that’s how he selects his hotels. To me, that sounds anxiety-inducing. But to a mother who has to live with anxiety every day, it sounds like freedom. “My secret is the same as Superman’s,” says Montano. “Stay away from Kryptonite. If I stay away from dairy, I am super strong.”

At least for Will and for Freddie, Kryptonite comes clearly labelled on the packet.  

Parents of food-allergic children and businesses wanting allergy management support can find advice and training at

Illustration by Dave Bain