There’s ‘an explosion’ of food allergies – but what’s behind the boom? – Telegraph.co.uk

Posted: Published on February 9th, 2020

This post was added by Alex Diaz-Granados

The heart-rending case of Natasha Ednan-Laperouse, the 15-year-old who died in 2016 after buying a baguette containing sesame from Pret a Manger at Heathrow, has perhaps done more than any other in recent years to raise awareness of severe allergic reactions. Her mother wept as an inquest heard how Natasha stopped breathing despite the desperate efforts of her father, who twice injected her with adrenalin; how a junior doctor performed CPR as the aircraft they were on descended into Nice. How their efforts came to nought.

But last year alone two other high-profile inquests heard how teenagers Owen Carey and Karanbir Cheema had died in terrible circumstances. Owen had been celebrating his 18th birthday in a burger joint. Karanbir, known as Karan, had cheese thrown at him at school. Before his heart stopped, he scratched so hard at his neck that he bled. He was 13.

Deaths from anaphylaxis are mercifully rare about 20 in the UK each year but particularly shocking. While those around them watch helplessly on, otherwise perfectly healthy adults and, often, children become sudden victims of a killer they could not have avoided: an invisible fleck of nut, an undocumented trace of dairy. Their bodies turn horribly, fatally, upon them. Hijacked.

While the number of deaths is small, the number of patients admitted to hospital with anaphylaxis is much larger: 5,497 in England alone in 2018/19, of whom 1,746 were children. And those numbers have grown dramatically. Only 1,015 children with anaphylaxis were admitted in 2013/14, a rise of 72 per cent in five years. In London, admissions of children rose by 167 per cent in the same period.

These statistics reflect a much broader trend over the past two decades as, in the words of one expert, parts of the Western world have experienced an explosion of food allergies. In the UK, studies now show that six to eight per cent of children havea food allergy. In Australia, one study recorded the rate of egg allergy in one-year-olds at nine per cent. There are myriad theories as to why: hygiene, breastfeeding habits, pollution and changes in the complex bacterial bed in our guts, known as the microbiome. Exploring those possibilities has led to several promising new avenues of treatment, including tailor-made antibodies that may one day, researchers say, reverse food allergies. But in Britain and beyond, a group of eminent doctors believe they have identified an effective method of preventing food allergies developing in the first place; a simple strategy to ward off the potentially fatal conditions that, in terms of effectiveness, is up there with vaccination. And it can be deployed today. The problem is, they say, that an unquestioned, non-science-based dogma elsewhere in the British medical establishment is preventing it from being rolled out.

Lucy Greenwells first son, Kit, was born in September 2012. Greenwell had no family history of allergies and jokingly describes herself then as very prejudiced. I thought food allergy was about women not eating bread in restaurants, a pathetic Californian fad. When he was about 12 weeks old, Kit started to develop a rash on his scalp. It spread rapidly, a storm converging until it was only the tip of his nose that was clear.

Like approximately three quarters of babies who develop food allergies, Kits eczema developed in the first months of his life. If it starts by three months of age, youre more likely than not to develop a food allergy, says Adam Fox, a professor of paediatric allergy at Kings College London. Whereas if youve got very mild eczema that develops over a year of age, youre very unlikely to have a food allergy. There is a critical period for your immune system during the first year of life.

After visiting eight doctors, Greenwell ended up in Great Ormond Street Hospital, where Kit was seen by consultant paediatric dermatologist Mary Glover. Eczema can be such a horrible disease, Glover tells me. It too has exploded in developed nations in the past 20 years, she says, mirroring the dramatic rise in food allergies. You can literally draw a graph plotting the two like that, says Fox, his hands moving in parallel. Kit was subsequently diagnosed with allergies to wheat, dairy, soy, nuts, eggs, legumes, kiwi, sesame I couldnt think what he was going to eat, says Greenwell. In the end it was meat and sweet potato. Just meat and sweet potato.

The link with eczema might have seemed to offer a vital clue to understanding the otherwise baffling rise in food allergies, but eczema is a conundrum in itself. As with allergies, it has what Glover calls a genetic component. Filaggrin (filament-aggregating protein) is a vital ingredient in helping the skin develop its so-called barrier function, protecting us against microscopic invaders and infections. One common mutation of the FLG gene limits the supply of filaggrin, causing scaly skin.

Even so, genetic predisposition by no means guarantees eczema. Environment is hugely important, says Glover. If the same child was born to the same parents but in the Caribbean not in England, they probably wouldnt have eczema at 12 weeks. Its a combination of moisture in the air, warmth, light, and not very hard water. Children of immigrant families from such benign climates who have never suffered eczema develop it quite quickly here.

No child is born with eczema, just as no child is born with an allergy. So something happens in the first weeks of life that prompts the conditions to spark into life. Infants are particularly susceptible if they are born in early winter, and their skin is subject in its critical early weeks to central heating. They dry out, says Glover, like a towel on the radiator.

Its not just central heating. Daily washing can take its toll. Quite a lot of things that call themselves baby products are actually quite drying to the skin, she says. One particular culprit is cradle-cap shampoo, specifically designed to remove the top layer of the skin. But anything that creates bubbles should be avoided. So too should wet wipes, which Glover says are fine if youve got to get a load of poo off their bums, but shouldnt be used anywhere else.

It is easy, listening to her, to see how increased hygiene has been fingered for the rise in eczema, and hence allergies. The real culprit may actually be the dryness caused by soaps.

The hygiene hypothesis, muses Professor Fox. Discredited is not quite the right word. But it isnt borne out in the evidence.

It is unusual to have a food allergy without having had eczema. For years at the beginning of this century, the link between eczema and food allergies was clear. But the reasons for it were not and, in consequence, little could be done. We were basically just observing the process then crossing our fingers, says Fox.

The rise of egg and peanut allergies was particularly mystifying. For as dramatic, sometimes tragic tales became widely known, parents delayed or avoided introducing those foods to their babies. Indeed, according to the most recent UK dietary survey of infants, almost half of parents avoid giving nut-containing foods to infants aged seven to nine months, while only 40 per cent of infants between 12 and 18 months are given egg.

That posed a conundrum: the body only develops an allergic reaction after being exposed to something. How then could babies who had never eaten allergenic foods like egg and nuts, turn out to be allergic when tested?

The medical assumption was that these infants were exposed through their mothers, who had eaten nuts, say, in pregnancy or while breastfeeding. The problem was, the evidence did not back this theory up. Then, in 2003, researchers at the University of Bristol published results from a landmark study. It turned out that 84 per cent of the children they looked at with peanut allergy had been given skin creams to soothe their eczema in the first six months of life. And those skin creams contained peanut oil.

Suddenly a new hypothesis emerged. Babies, in the critical early period of immune-system development, were first being exposed to food allergens not through their mother, but through the leaky barrier of their own eczema-ravaged skin.

The lead researcher on the Bristol study was Gideon Lack, also a professor of paediatric allergy at Kings College London. The body thinks that the food molecules entering through the skin are invading parasites and mounts a vigorous allergic response to repel the enemy, Professor Lack tells me. The suggestion was that when babies were eventually weaned, and actually tried eating allergenic foods for the first time, their bodies recognised that enemy, and launched another allergic response.

The study raised another intriguing question: could peanut allergy be prevented by exposing infants with eczema to it in the normal way by eating it before it had a chance to get through the skin?

In 2009, Lack recruited 640 children between four and 11 months of age who had been identified as high risk for peanut allergy, based on an existing egg allergy and/or severe eczema. The results of the LEAP (Learning Early About Peanut) study (and a follow-up, the EAT, or Enquiring About Tolerance, study) were remarkable. We showed that if you introduce peanut early into the diets of infants, theres an 80 to 90 per cent reduction in the number of cases, he says. How early? For children with eczema, four months of age.

There are roughly 20,000 new cases of peanut allergy a year in the UK. We should be able to prevent 16,000 to 18,000, Lack goes on. Thats on the scale of immunisation against polio and other childhood vaccines a very powerful strategy to prevent peanut and egg allergy and probably other food allergies.

Except, he notes with weary frustration, were not employing it at the moment.

Government advice for feeding newborn babies has remained more or less unchanged since 2002, says Professor Ken Ong. In common with the World Health Organizations guidelines, the recommendation is that all babies be exclusively breastfed for the first six months of their lives.

Ong, professor of paediatric epidemiology at the University of Cambridge, is the chair of the Maternal and Child Nutrition subgroup of the Scientific Advisory Committee on Nutrition (SACN), which advises Public Health England (PHE), the government agency responsible for shaping national health guidelines.

In 2018, the SACN confirmed its first- six-months breast milk-only advice in the report Feeding in the First Year of Life. It noted, There is insufficient evidence to demonstrate that the introduction of peanut or hens egg into the infant diet before six months of age reduces the risk of developing a food allergy to any greater extent than introduction from around six months of age.

Gideon Lack fumes, The idea that babies have to be exclusively breastfed for the first six months is damaging, at least as far as allergies are concerned. It is an unquestioned, non-science-based dogma. It is an ingrained cultural prejudice. And it is very troublesome.

Ong is keen to defend the breast is best message. He also says that the Government now advises that parents can feed children potentially allergenic foods from six months, but has only had the confidence to do so in the past year or so. In practice, Lack says, such advice means children are typically breastfed, then given bland pured foods, and the essential food allergens are delayed towards the end of the first year of the babys life. By which time it is too late. Weve missed the boat.

Imagine being the parents of a baby who has had eczema since three months. You havent been told about this early feeding. And lo and behold the child has a test for peanut allergy at nine months and its too late. Youre distraught, especially when you learn there is something you could have done about it.

Today Mary Glover recommends that parents dont delay, but treat eczema vigorously when it appears reluctant though they may be to use steroid cream on their infant so the skin barrier is restored and allergies are prevented. She describes the current nutrition guidelines as plucked from the air.

Official response to the LEAP and EAT studies has, Lack says, been very poor, very poor indeed. Theres now incontrovertible evidence that the delayed introduction of solids into infants diets which we asa medical community have [supported], and indeed unfortunately continue to support to a large part is directly responsible for the rise of food allergies.

On the third floor of St Thomas Hospital, near Westminster Bridge, a nine-bed ward serves as a vivid reminder of the impact of food allergies. The walls are covered in soothing images of seals carving through water, as though the room is a liquid realm, safe, calm, a return to the womb.

But it isnt safe. This is a research lab, run by Professor George du Toit, where parents bring their children to feed them tiny, incremental amounts of food they know causes an allergic reaction, under medical supervision, in order to increase their tolerance.

Its a terrible emotional load on families, as is food allergy in general, says du Toit. If I diagnose a child with peanut allergy, every single meal from then on, for the rest of the childs life, they have to be suspicious. It creates a huge burden for families. And indeed for healthcare systems. Care is expensive.

Like Lack, du Toit calls for Government advice on feeding to be changed. But he knows why it is such a sensitive topic. They [PHE] dont want to compromise the breastfeeding message. Also in common with Lack, he insists that introducing allergenic foods from four months should happen alongside, not instead of, breastfeeding. Ong protests that there is good evidence that introducing solids displaces breast milk. Lack shoots back, Thats a myth. A total myth.

The argument rages, but not everywhere. America, du Toit says, has changed its guidelines. The UK is lagging behind. Americas National Institute of Allergy and Infectious Diseases does indeed now suggest that babies with severe eczema and/or egg allergy are given an allergy test, and if that is negative, fed peanut from as early as four months.

In his lab, du Toit is also conducting trials for a company developing a peanut patch applied to the skin to increase tolerance. The company, Aimmune, is American. But it is the development not of patches but of bespoke biologic molecules, which mimic antibodies in the immune system, that is prompting the most excitement. Such drugs are already making an enormous impact in cancer, notably in the treatment of melanoma. Certain biologics, Lack says, can also knock out the mechanistic, molecular pathway that leads to allergies, eczema, asthma, hay fever. The potential, according to du Toit, is staggering.

For Margaret James*, a school nurse of 20 years experience, a breakthrough cannot come soon enough. She has seen, she says, a significant rise in allergies in those two decades, radically changing school life. Procedures, which she suggests are now widespread among educational institutions, include banning nuts, sesame and coconut. Children do not share food on-site, ever, she says. All staff are trained to use adrenalin pens. Children with allergies are served meals at a special canteen counter. A local bakery serving nut croissants means that even classroom door handles have to be wiped down frequently to prevent potential trace contamination. Its a very big responsibility, James says. When children want to bring in biscuits or cakes to celebrate a milestone, they have to sign off an ingredient list. Allergic children are provided substitute treats from an approved list. Its a minefield.

One upside, James tells me, is that the 560 children she looks after are of primary age. Many parents find that it is when children become teenagers, and begin to take greater responsibility for themselves, that the greatest stress arrives.

Gabriella Colquhoun*s daughter, Mariella, was nine months old when she first had a severe allergic reaction to egg. Now Mariella is 13 and Colquhoun, who lives near Stirling, is beginning to worry. Weve trained her to be very vigilant but I worry about teenage peer pressure, someone saying, It cant be that bad? Give it a go. I just hope shell be a strong enough character to say, No. You cant have 100 per cent control as they grow up. Unfortunately. Thats just how it is.

For Lucy Greenwell, the passage of time has brought other challenges. Kit is now seven and, she says, super on it when it comes to his allergies. But a new baby, Mary, is now at 12 weeks what Greenwell calls the big moment that caused such trauma with Kit. It was then that his terrible eczema appeared, soon to be followed by the extensive food allergies that left Greenwell wondering what he was going to eat.

Some memories still haunt her. Once I gave him Weetabix instead of Oatibix. In bed that night he was sick, and where the sick had soaked through his pyjamas, his arm was covered in welts.

She too went to St Thomas Hospital to try to increase his tolerance under medical supervision. The whole experience, she says, was like being in a pitch-black room where you have to blunder around with your arms out trying to find the walls. When you touch them, you usually get a shock. I left in tears.

So far, though, Marys skin is clear.

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There's 'an explosion' of food allergies - but what's behind the boom? - Telegraph.co.uk

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