"There is an epidemic sweeping the western world." "It's an illness that takes many forms." "It can make you sneeze and itch, or it could stop you breathing altogether." "I've seen people who have gone from talking to me to collapse within a matter of minutes." "50 years ago, it barely existed, yet in parts of the Western world it now affects one third of all adults and almost 40% of children." "It is horrible, cos your eyes puff up and you can't see, and you get really panicky, and then you have panic attacks." "This film will take you on a journey to uncover the secrets behind one of the biggest mysteries in modern medicine." "I started to have to go on emergency oxygen because I stopped breathing." "I'm scared for my children and my grandchildren and for everybody's children and grandchildren." "I'm scared for the future of this planet." "From the tropical islands of the Caribbean to the valleys of Wales, from the industrial heartlands of California to the most remote inhabited island in the world," "Horizon attempts to find out why we are becoming allergic to our planet." "We knew it was serious." "I don't think... you appreciate how serious it could be, as you always think of it as a reaction that will cause a swelling or will cause vomiting." "Mike and Sue Obatelli first realised their daughter Kate suffered from allergies when she was two years old." "We were actually shopping in a supermarket and I gave her a taste of a fruit bar that I'd bought, a sticky fruit bar from the health food shop, and then immediately her mouth swelled, and we took her to the hospital because she couldn't even suck her dummy." "Kate was subsequently diagnosed with a severe peanut allergy." "Although Kate and her family were extremely vigilant, it proved impossible to avoid peanuts altogether." "I got a phone call at 11 o'clock saying she was in an ambulance with no pulse, would we go over." "We went to the hospital, they took us through, and there was about eight or nine people round her trying to save her life." "And they just couldn't." "And that's how quick it can happen and how serious it is." "The slightest little bit, if you're so allergic, is a death sentence." "Kate had ordered an Indian takeaway meal." "Although she had specifically asked for no nuts, ground nuts had been added by mistake." "It was enough to send her into an anaphylactic shock, the most severe response a person can have to an allergen." "People always ask how we are, still, nearly five years on, people still ask how you are and it's still very upsetting." "People think that on the outside, cos you're all right, that you are, but you're not." "People say..." "Never will be, no parent would be." "No." "It's not just us, any parent." "There's friends of hers now married, there's friends of hers have got children..." "That's what she should have done." "She already knew what sort of wedding dress she wanted." "She had her life planned out and it was torn away from her." "For the Obatellis, the worry of peanut allergies did not end with Kate." "Their two sons, Steven and Stuart, have a potentially fatal allergy to peanuts, too." "That threat is... is... is hanging over their heads, and not only have they had to deal with Kate's, they've got that to deal with as well." "It makes you neurotic, which the boys get cross at, because they think I'm fussing too much, but you don't want to lose another child." "While fatalities following allergic reactions are rare, the number of children with peanut allergies has more than doubled in the past 15 years." "Throughout the developed world, the number of recorded food allergy sufferers is rising, with admissions to hospitals for anaphylaxis going up by a staggering 700%." "I am allergic to cats." "I'm allergic to penicillin." "Rice." "Household dust." "I have hayfever." "The list of recorded allergies seems endless." "I'm allergic to nuts." "Chocolate." "Engine oil." "I'm allergic to... mostly everything." "But how did allergies become such an important part of our everyday lives?" "Before the Second World War, allergies barely registered on the health agenda, but in the 1950s and 1960s more and more people started sneezing and wheezing and itching and scratching." "Asthma and hayfever rates soared." "But the allergy explosion didn't stop there." "People began to develop new allergies, allergies to nuts, allergies to milk, allergies to washing powder, to fruits, to dust, to latex." "The list goes on." "This patient is allergic to cat fur, fungi and grass pollens." "Whatever the trigger, allergic reactions all have one thing in common." "They happen when our body's immune system overreacts to everyday substances." "Why some people's bodies should react in this way and why allergies are increasing has intrigued scientists for decades." "40 years ago, scientists thought they may have stumbled on the answer." "It lay 1,500 miles off the coast of Africa on the most remote inhabited island on Earth." "Isolated from the outside world for much of its history, it's still only reached by a seven-day boat journey." "Tristan da Cunha has always been a place of great scientific interest." "But there is far more than just its remoteness that makes it so fascinating." "Five-year-old Randall has acute asthma." "His symptoms are so severe that he suffers monthly attacks and is often forced to take medication every few hours." "Some people may have asthma in certain ways, but the way that Randall has it is quite... it's like it's really serious." "He's like a ticking time bomb, because it can just pop up any time, and then all of sudden... he may happen to take the wrong move or he caught the wrong thing, whatever, and it's there." "But Randall is not the only asthmatic in the family." "My son's got asthma, my elder sister has asthma, my dad has asthma." "He's got a brother and two sisters that also has asthma." "Also, my mum's dad is also..." "he's also asthmatic as well." "In the late '60s, I had one of my cousins that died of asthma at the age of nine." "Is it in every generation in your family?" "Yeah, like I said, from there up to my sister and to my dad, all falls back to... both sides." "The Repetto family have suffered from asthma for over four generations, but on Tristan Da Cunha they are not alone." "Asthma affects every single family on the island." "Almost half of the 266 inhabitants suffer from asthma." "It has the highest prevalence of the disease anywhere in the world." "When it was first discovered, this mysterious phenomenon baffled scientists." "Why would such a tiny isolated community have such a disproportionate number of people with asthma?" "Was it something peculiar about the people or the environment?" "It's a mystery to which Noe Zamel has dedicated his career to trying to solve." "In the early 1960s, as a young graduate student," "Zamel was involved in conducting a series of examinations on the islanders after they were forced to flee their homes following a volcanic eruption." "There was rumours that... asthma was very prevalent in that community, but it was never tested objectively." "So I got in touch with the Tristanians for the first time by performing pulmonary function tests, and I was amazed that virtually every second one that" "I tested had evidence of airways obstruction caused by asthma." "Never having witnessed anything like it before," "Zamel believed that if he could uncover the cause of asthma on Tristan da Cunha, it could lead to a better understanding of the disease throughout the world." "Zamel never forgot what he'd observed, but it would be another 30 years before he got the opportunity to visit the island for himself and carry out his own comprehensive study." "The excitement was contagious to everyone, the preparation." "There was not a single person that didn't hear about this remote place with this crazy doctor about to do his crazy study, and from laughing it became serious and we did come and got the permission, and we did the study." "In the course of two visits to the island, Zamel has run detailed tests on virtually every islander." "He has also traced the family lineage of every surname on the island, all seven of them." "In this graveyard there's only seven family names." "In fact there is only seven names in the entire island, like Hagan..." "Swain, Lavarello..." "Over here Green, over here Rogers," "Glass, Glass..." "Over there..." "Repetto, Repetto." "Everybody in the island is a cousin of each other several times over, some of them about 50 times over, and it has been like this for many generations, actually from the beginning of the first settlers." "For a long time, scientists have been preoccupied with external irritants for diseases like asthma, but Zamel was convinced that in a community with such a prevalence of one disease and remarkable degree of inter-marriage that at least part of the answer had to lie in the genes." "In an attempt to uncover the source of the disease," "Zamel traced the lineage of every islander back as far as the very first settlers." "In 1816, Tristan da Cunha was occupied by a garrison of British soldiers stationed to guard Napoleon, imprisoned on neighbouring St Helena." "In the years following his death in 1827, five men settled on the island." "As bachelors they sent for five women from St Helena to become their wives." "Even though at the time asthma was an extremely rare condition, bizarrely, three of the five women had the disease." "70 years later, the next people to arrive were two shipwrecked Italian sailors." "Against all odds, both also suffered from asthma." "Three of the matriarchs that came to the island from St Helena in 1827 had asthma and brought a gene of asthma to the island." "Two men brought the gene of asthma to Tristan da Cunha from Italy, two sailors that were shipwrecked in Tristan da Cunha in 1892," "Gaetano Lavarello and Andrea Repetto." "In fact, Andrea Repetto died at age 44 of severe asthma." "Two chance events in the island's early history played a key role in spreading asthma to all subsequent generations." "So no wonder that the original settlers that found all those seven families, more than 50% had asthma, no wonder that the descendants presently have about" "50% of asthma transmitted from the original settlers." "While this tiny community has suffered the consequence of their unique history, their rare genetic homogeneity provided Zamel with a unique opportunity to unlock the secrets of the Tristanians' genes." "Here there was a place to find a gene, was right here." "This was the highest prevalence of asthma in the most homogenous gene pool." "If we couldn't find the gene of asthma here, most likely we aren't going to find it anywhere else." "After several years spent analysing the DNA of the asthmatic and non-asthmatic islanders," "Zamel has eventually been able to identify a series of significant genetic differences." "We found that the asthmatics had a difference in several regions of the chromosomes and one of them, the linkage in terms of significance was the highest and that was in the chromosome eleven in the short arm, a division called P-13." "By comparing his findings with other asthmatic populations, the team has isolated one particular gene known as ESE-3." "Let's see how you do." "ESE-3 regulates a series of genes responsible for the deposition of collagen in the airways." "If the gene is faulty, collagen is overproduced, constricting the airways and making breathing more difficult." "And again?" "40 years after his first encounter with the Tristanians," "Zamel had finally identified the very first genes involved in allergic asthma." "We have this sense that by doing this study we are doing history." "Scientists are supposed to be cool, detached, objective, but coming this place to obtain the data, it's one emotion after the other." "It's absolutely exhilarating." "Each and every one of us inherit a unique allergic imprint from our parents." "This determines how susceptible we are to developing an allergic disease." "But our genes do not tell the whole story." "The genes play just a partial role in allergen and asthma." "In asthma probably between 30 to 40%, so more than 50% of the causes of asthma are not genetic." "The Tristan da Cunha findings does not explain the whole problem of allergy in asthma, surely not." "It's just a small piece in the jigsaw." "Over 8,000 miles away on the other side of the world, there is a different suspect entirely." "Our genes take thousands of years to change and evolve, yet in certain parts of the world, allergy rates have more than trebled in the past few decades." "Something else about the way in which we live has to be responsible." "When she starts coughing she says," ""Mummy, my throat hurts a lot. "" "When we go to sleep, she usually coughs all night non-stop." "She feels suffocated." "Erica Olvera lives with her two children in Los Angeles." "Her daughter Natalie has severe asthma, a condition that only developed after the family moved from Mexico to California." "Erica is convinced that her daughter's illness is directly related to where they live." "Around all the schools near here there is a refinery on one side." "On the other side there is a freeway." "They are surrounded by contamination everywhere." "Professor Frank Gilliland has been studying the effects of pollution on families like the Olveras." "What he's discovered has revolutionised our understanding of the link between the environment and allergies such as asthma." "We know that traffic is a major issue across the developed world." "In every city there's huge amounts of traffic." "It's worrying because the effects are real, they're large and the levels of exposure especially to traffic, are increasing." "Gilliland fears that until now the most dangerous effects of pollution may have been ignored because they are invisible to the human eye." "The air we breathe is an aerosol which means it has particles in it as well as gases." "These particles can be breathed in and they're small enough that they go into the deepest part of the lungs and are deposited, and they're coated with a bunch of metals and other toxic chemicals that can then reside in the lung and produce adverse effects." "In order to directly assess the impact of this particulate air pollution," "Gilliland and his team conducted a series of clinical trials." "A number of subjects were given a nose spray containing diesel particles equivalent to the levels experienced during 40 hours in southern California." "Others were given a dose of a common ragweed allergen or of diesel particles and allergen combined." "Their allergic responses were then measured." "The most dramatic finding was that allergen alone would have, say, a response of one unit on one of our measures and if you combine diesel exhaust and allergen that would be 20-fold." "Gilliland had shown that for some people, simply living near a major road could dramatically increase the risk of developing an allergic disease." "In the past, it's generally believed that air pollution causes respiratory symptoms and asthma and allergies to get worse, however that air pollution didn't cause asthma or allergies." "The emerging data is that air pollution does indeed cause asthma, cause allergy, as well as exacerbating it once you already have those conditions." "Within the 150 or 300 metres of major roadways or freeways are those who are at risk from this exposure, so it's really in this hot zone around busy freeways that seem to have the potential to induce asthma." "TRANSLATION:" "We would like to go somewhere else but we can't." "Where do we go to?" "We haven't got any money, we have nowhere to go." "Living in a polluted environment can make the difference between developing an allergic disease or not." "But the risk from the air we breathe may be just one of the ways ways our changing lifestyle is making us increasingly vulnerable to allergies." "Sometimes I can stay in the bath up to two hours just to get the skin proper soft, and my legs are terrible." "They've been so bad lately." "It's just sometimes I can't walk with them and it really hurts." "And that's just why, really." "14-year-old Billy Perkins has a rare genetic skin disorder knows as Netherton Syndrome." "His skin sheds on a permanent basis and he's sort of very red in appearance so he has to take several baths a day and apply creams from head to toe constantly, otherwise he dries out and goes quite tight." "It also affects his hair." "It's called bamboo hair, because it looks like a strand of bamboo under a microscope." "It grows but it breaks off very, very easy so his hair is quite sparse." "Nethertons patients all have very similar symptoms - thin, red scaly skin and brittle hair." "But they also have something else in common." "They all suffer from allergies." "No, don't cos I'm not sure if I'm allergic to that." "Netherton Syndrome also means that Billy suffers from multiple allergies." "Billy is allergic to nuts, shellfish, kiwi fruit, latex gloves, bee stings and wasp stings." "It's just something that you learn to live with." ""Ingredients cannot guarantee nut free. "" "Why does it say no nuts then?" "My lips swell and my eyes puff up and then sometimes I might pass out." "And it stops my breathing as well." "I get really scared, cos you don't know what is going to happen next." "Do you wish that you didn't have the allergy?" "Oh, yeah, a lot." "I'd rather them go than anything else." "Cos they're the biggest problem." "Hello." "How are you?" "OK." "Billy's doctor, Professor John Harper, has been treating children with Netherton Syndrome for over 20 years." "The skin seems to be doing reasonably well." "Do you think we could have a little look at you?" "He's long been convinced that the link between" "Netherton syndrome and allergies was significant." "Can I look at your head?" "Having seen more and more children with Netherton syndrome," "I realise they are all at risk of a wide range of allergies, so that's what makes Nethertons although it's a very rare disease, very special." "Together with a team of experts, Harper and immunologist Robin Callard, work to isolate and analyse the genes involved in the condition." "But that's consistent with the..." "What they discovered was that in Nethertons patients, an important gene responsible for making a key protein known as Lekti is defective." "In Netherton syndrome you do not have the production of Lekti." "It's absent." "If it's absent then it disturbs the whole protein biology required to form a normal skin barrier." "This was the first insight that we had that the skin barrier might be linked to allergy in some way." "OK." "Lekti is a protein which makes and maintains the surface layer of the skin." "When it is missing the skin barrier is deficient, like a dam with holes in it." "It was an important clue as to why Netherton patients were so allergic." "They were somehow becoming sensitised to allergens through their damaged skin." "It's a discovery that doesn't only apply to Nethertons patients." "Harper and Callard have linked similar genetic differences to other skin conditions such as eczema." "But it may also apply to us all." "We decided to just remove the skin barrier which is done very simply just with Sellotape, but once that's removed without actually damaging the skin, without actually going into the inner layers, without causing any bleeding," "when you put the antigen on the skin then it elicits this very powerful response." "By simply removing a layer of skin," "Callard had shown it was possible to provoke a strong allergic reaction." "This revolutionary new idea may shed light on why allergies are on the rise in the developed world." "We have gone in Britain alone from a time when perhaps 50 or 60 years ago we had a bath in a tin bath in the kitchen once a week to all sorts of products that we use on our skin." "These very strong detergents, rough exfoliating agents, the loofahs and so on." "So I think our hygiene habits can result in damage to the skin barrier." "If we are self-inflicting injury on our skin barrier, even if it's in a very mild way but on a regular daily basis, perhaps we are uncovering a vulnerability to allergy that wouldn't otherwise have been apparent." "The discovery that we are becoming increasingly exposed to allergens through damaged skin and polluted air has significantly contributed to science's understanding of the global allergy epidemic." "But in order to really understand why allergies have risen so dramatically in recent years, scientists are turning their attention to the parts of the world where the rate of increase is most extreme." "Barbados may be the archetypal tropical island paradise, but it too is being plagued by allergies." "Asthma now affects over 20% of the population." "Having asthma is frightening." "You want to breathe but you can't." "That is... it can't be put into words, it just cannot be." "It is really scary." "Deep breath in." "Out." "Dr Harold Watson has been an AE physician for 20 years." "An asthmatic himself, he runs the AE's dedicated asthma bay." "In the 1990s we started with a thousand visits of asthma, now we are seeing 11,000 people out of 45,000 visits in our department." "Not only have doctors here experienced a tenfold increase in the last 20 years, the cases they are treating are also getting more and more severe." "Asthma frightens people because I've seen people who have gone from talking to me to collapse within a matter of minutes." "I've had to deal with asthmatics who have died in front of me." "Just why Barbados should be so severely affected has mystified scientists from around the world." "We think of asthma these days as an epidemic because it's increasing at such a rapid rate, and a rate by which it's very difficult for scientists and physicians to get a handle on what's causing that increase." "But Kathleen Barnes believes that Barbados might offer us our best hope of understanding just what lies behind the global allergy crisis." "One of the reasons that we're so excited about conducting a study on asthma here in Barbados is that it really is a microcosm of what's happening globally." "It's gone through this very rapid period of change over a very short period of time which has been beneficial for us in trying to understand some of the environmental factors involved in asthma that we can't capture in the more developed societies such as the United States or the UK." "In the last two decades Barbados has been radically transformed." "Its people have been rapidly swapping their traditional rural environment for the modern westernised one of the island's towns and cities." "This dramatic transformation has offered Barnes a rare opportunity to witness the effects of these changes as they take place." "The explanation for the increase in asthma here could have something to do with this transition from the traditional chattel homes to the more modern structures because, in fact, that timeframe sort of converged with when they began seeing more asthma," "more severe asthma on the island." "Over the past 20 years, Barnes and her team have analysed the homes on the island in minute detail, collecting dust samples and monitoring allergen levels." "What they discovered surprised them." "We expected to see many many house dust mites in these chattel houses and in fact we did, but what was interesting is that we found higher levels in the better-built concrete structures." "So what we believe is that in the modern home, there are a variety of factors that contribute to this exposure." "Indoor carpeting, better upholstered furniture and so on." "All of these things combined contributed to these higher levels of allergen." "The discovery that the modern home greatly increases exposure to dust mite allergen was significant." "But Barnes believes it is just one of many lifestyle changes that lie behind the allergy crisis here." "It's not the only answer because during this very short period of time there have been a number of other changes that we know to be important including changes in diet, the way people eat, their physical activity," "and probably most importantly the number of cars on the island." "So I suppose the irony here is that we're all striving for living in the most modern fashion as possible." "It is the ultimate dream for everyone and with that no doubt comes certain advantages over a more traditional way of living." "That said, the irony is that, in fact, it's contributing to a microenvironment that might actually not be so good for our health." "But why should modern life have such a dramatic impact on our health?" "Part of the answer came when scientists began to question what possible purpose allergies might serve." "If we look back into our ancient past, perhaps that holds the answer." "In certain parts of rural Africa there was no asthma allergic disease at all and when those same people modernised or moved out of rural Africa into the urban setting, suddenly there was more asthma and allergic disease." "As they began to dig a little deeper, scientists made an important observation." "The antibody known as IGE, which the body uses to fight allergic diseases, also serves another very different purpose." "IGE is that antibody in our immune system that's specifically involved in allergic disease and asthma." "But IGE didn't evolve because of asthma and allergies." "It turns out that it actually evolved as a protective mechanism against the worm, the kinds of parasites that caused diseases like ascaris, schistosomiasis and so on." "So in rural Africa, which was endemic for these parasites, these people produced really high levels of IGE." "If you remove them from that situation, they still are genetically predisposed to produce lots of IGE, but the IGE has nothing to bind to any more." "There's no more worm." "And so oddly enough it binds to these very innocuous proteins such as house dust mite allergens, cockroach and so on." "The same immune mechanism the body uses to fight parasites is also the one it employs to fight harmless allergens." "What evolved to protect us in one type of environment has now become a liability." "So one way we could think of this, and it's potentially controversial, is that we're somewhat out of synch with what we originally evolved for." "So in other words, this protective mechanism called IGE that suited us very well in an environment where we were exposed to lots of parasites, taken from that environment in what is in essence a very short period of time in our human history," "it no longer serves its original purpose and in fact has gone awry, if you will." "From the air we breathe to the way we wash and the homes in which we live, our biology appears to be increasingly out of step with the world we are creating." "But how far will this go?" "Could we eventually become allergic to everything?" "There are already some people who believe themselves to be allergic to modern life itself." "My name is Steven." "I had a law practice." "Every time I went into the office I would just be really sick." "I didn't know what it was..." "I was 33." "I was working as a fire fighter." "The heat from the fire on the side of the building was vaporising all the chemicals, all the plastics, the carpet, rooms were being..." "I kept having these migraine headaches, migraine headaches which were so intense that they'd last for 24 hours with vomiting and diarrhoea and when they started to go away," "I would have suicidal thoughts." "The people in this self-help group all suffer from a highly contentious condition known as Multiple Chemical Sensitivity, or MCS." "They believe they are highly allergic to virtually every modern chemical in the environment." "I counted it up and I had a list of about 40 symptoms and I kept going into different doctors, you know, crying, "What is going on?"" "And I remember one allergy doctor..." "Many of those here feel that they are so sensitive that they fear the slightest contact with us could provoke painful symptoms." "As a result they have requested we only film from a distance and cover our equipment in tin foil to prevent contamination." "I started to have to go on emergency oxygen cos I stopped breathing and I had to..." "Nancy Van Afflen has one of the most severe cases of MCS." "Unable to cope with the modern environment, she has been forced to sell her home and seek refuge in the remote Texas town of Wimberley." "What are the gloves for?" "I'm allergic to vinyl and the polyester." "Why do you have the oxygen in the car?" "So that I won't get sick." "All you're doing is building up... um... toxins in the air all around you, clouds of them." "Even if you can see them that's all you're breathing in." "You can't stop it from coming in." "You can protect yourself from a little bit of it, but that's why" "I use this machine back here with the charcoal filter in it." "I turn that thing on, start cleaning my air, put my oxygen on and give myself a break." "And it's relaxing." "It actually makes you more alert." "You're a better driver." "Convinced that everything around her is a potential danger," "Nancy has spent the past year rebuilding her home in an attempt to protect herself from the thousands of chemicals most of us come into contact with on a daily basis." "You get anxiety attacks, you swell up, your face starts swelling, your eyes swell, you get sick, your pain levels go very high and you've got to be able to get away into some kind of place to run" "that's safe to get better or you're in serious trouble." "It's just downhill all the way." "Till you pass out and you don't live any more cos you get too many things happening and you die." "This is a five inch HEPA down here which is a filter which will take out whatever's in the air." "This is new plywood and it's a plywood made out of soya glue, no particle board, no strand board, no resin, no formaldehyde." "This is putrid." "I had this open almost a year and it still smells." "This smell..." "Come over here." "It's bad, it's very, very bad." "I can't smell anything though." "You can't?" "Get over here." "But it doesn't affect me." "Really?" "Why is that?" "Um, probably cos you're not sick like I am." "You know you still are working at 100% so you're able to de-tox it out." "Despite the heartfelt testimony of Nancy and thousands like her, the medical establishment continues to doubt the bold claims of MCS sufferers and is sceptical about the wide variety and vagueness of symptoms." "As a result, the American Medical Association has not yet granted the condition the status of a genuine medical disorder." "Many doctors believe that MCS sufferers may not be allergic at all but like millions of others might be reacting to something else entirely." "Across the developed world today, almost every other person seems to be allergic to something." "The symptoms are that you just want to scratch when you get into bed." "I would just sneeze and sneeze non-stop." "I end up vomiting like severe vomit for about 24 hours to 48 hours." "But are all these symptoms really allergic reactions?" "I sneeze a lot and I get colds." "I have eczema." "A scratchy throat." "Rashes." "I have to go hospital because I turn red." "While symptoms may sound genuine enough, psychologist Rebecca Knibb believes that not everyone who feels themselves to be allergic actually are." "Up to about 35% of people worldwide, really across most westernised countries, think they react to food whereas bring them into clinic, maybe only one to two percent of the adult population react and maybe five to six percent of children." "The huge discrepancy between what people believe they are allergic to and what they test positive for, may be because some people are confusing allergies with food intolerances." "The general public don't tend to understand the difference between allergy and intolerance." "An allergy is where you have an actual immune mediated reaction and these reactions tend to be quite quick reactions." "They can happen very rapidly once you've eaten a food or even come into contact with a food that you might be allergic to." "Food intolerances are different." "They don't involve the immune system." "There's a much longer time between eating the food and getting a reaction." "It can be six, eight hours before you actually react." "But for others, there may be a completely different reason why they believe themselves to be allergic." "If you actually are extremely worried and anxious that you're going to get a particular type of symptoms, then that fear and that stress may possibly trigger those symptoms." "So, we've seen this in studies where stress has triggered histamine release for example and histamine is one of the things that's released when you have an allergic reaction." "So, again, you are getting actual symptoms, it's not all in the mind but it might be that it's more psychological factors that are causing those symptoms rather than physiological factors." "Records of the global increase in allergies are based on confirmed results but when it comes to allergies, it's crucial not to underestimate the power of psychology." "Around the globe, scientists have been gradually uncovering the complex web of causes of the allergy epidemic." "But to date, all these incremental advances offer little hope to the millions of sufferers affected, sufferers who are holding out hope for an effective cure." "I can't remember exactly what happened because I was quite young but I remember bits of what happened." "When the dog touched me I felt very sleepy, just wanted to sleep." "Within seconds, Danny was crying, saying he felt strange and his face swelled." "There was like this white jelly inside his eyes and he was totally unresponsive." "Eight year old Danny Pearse has one of the most severe dog allergies in Britain." "In the past, he's been hospitalised with anaphylactic shock - the most extreme form of allergic reaction." "When a dog comes along he will just run across the road to the other side of the road to avoid the dog." "He doesn't see danger - when he just sees the dog." "He just goes to pieces, he grabs your hand and he is frightened to death." "They worry about me when I go out to play because they dunno what might be happening and what I might be up to outside." "Danny and his family are hoping that soon their fears may become a thing of the past." "They have agreed to try an experimental new treatment, that, if successful, may cure Danny of his potentially fatal allergy." "Every day for the last year, Danny has received tiny but gradually increasing doses of dog allergen under his tongue." "In Danny's case, we started with a really miniscule amount of dog allergen, yet still he had a very clear reaction the first time he was exposed to it." "So we had to build him up extremely slowly, allowing his body to let us know when it was tolerating it, when we were pushing too far." "Today, Danny will be exposed to the same species of dog that he first reacted to." "I'm obviously feeling a little apprehensive." "This is breaking new ground for us." "It's the first real test of the treatment that we've never used in this way before." "It is very scary, because potentially any time things can change, but we've just gotta do it, we got to go with it now." "At every stage of the test, Danny's blood pressure, temperature, heart rate and oxygen levels will be monitored." "Blood will also be taken to check for any sign of an allergic reaction." "Since Danny has had such severe reactions in the past, he will be exposed gradually." "After firstly being exposed to the room where the dog has been," "Danny must then sit next to the dog without touching it." "Feeling OK?" "Yeah, feel fine." "Good OK, fine." "Having suffered no reaction," "Danny will now have full exposure to the dog." "The last time this happened, he fell unconscious." "Yeah, I just want him to get him on the floor." "I'm a bit worried he's going to bite me." "He definitely won't bite you, he's really soft, look." "He is nervous because, are you feeling a bit nervous?" "HE LAUGHS" "Ready, steady, go." "That's it, that's it!" "Well done!" "Yes yes yes!" "Fantastic, you got it right to the top." "Well done." "I'm just glad that today's over and done with." "I think the kind of stress levels can go down a bit now because... it feels it's almost surreal as well, isn't it?" "It feels surreal in this room with this dog." "We've had no reaction whatsoever." "It just demonstrates how effective the treatment's been, I think, doesn't it?" "OK?" "You all right?" "You are quiet, it's not like you." "30 minutes after touching the dog, Danny starts to feel unwell." "Minutes afterwards, Danny is violently ill." "Doctor Fox and his team cannot take any chances." "It's not completely clear whether this is an allergic reaction or not." "His heart rate actually went down which was something we wouldn't expect if he's having an allergic reaction - it would go up." "To get a better understanding of that, we've done some blood tests." "The blood tests will take two or three days before we get the results back." "Immuno-therapy is certainly tried and tested in pollen allergies but we have far less experience at using it in these sorts of reactions to animals." "Rather embarrassingly for a treatment that's been around in active use for over a hundred years, we have a very poor understanding really of exactly how it works." "For those doctors on the front line of treating allergies, these gaps in their knowledge are taking them back to basics." "They're having to search for answers through trial and error." "Dr Gideon Lack is an allergy specialist, looking at the moment that allergies begin." "Allergies tend to develop sometime during the first year of life." "Babies are not born allergic, they're born with a clean slate as far as the immune system goes, and their immune system has to become educated and has to develop over time." "Sometimes the learning goes wrong and they become allergic to the food." "Traditional medical thinking has been that because of this, avoidance is the best strategy." "For instance women with a history of allergies have been advised to avoid eating peanuts while pregnant and to avoid feeding them to their young children in case they too develop an allergy, but even the evidence for this is shaky." "What is interesting is there are many countries where peanuts appear to be eaten at a much earlier age and children nevertheless don't have peanut allergy." "I used to sit in clinic a bit like an idiot because mothers, fathers would ask me, "What should I do?" ""I'm pregnant, should I give peanuts to my baby or not?"" "And I would tell them, "Look, we really don't have a clue. "" "It's a simple question - there's a simple answer." "We just don't know it and we decided that it was really right to try and do something about it and find out." "In a groundbreaking study, hundreds of babies are being fed peanuts to see if they really are more likely to develop an allergy compared to those who avoid." "Im quite nervous, I am quite nervous." "Why is that?" "I don't know, really." "I think it's just the hype of the reaction that could go with it." "The theory for introducing peanuts really is for the body's immune system to become tolerant of foods." "It has to be exposed to the foods and recognise the foods as a friend rather than a foe." "Is that a new taste?" "Is that something a bit different?" "It will take another four years for Professor Lack and his team to establish the answer to his simple question." "But at least the immuno-therapy for Danny's dog allergy has had concrete results." "His blood tests and a further dog challenge have confirmed that Danny's episode was not an allergic reaction." "It was most probably brought on by the stress of the situation." "Is he your new friend then?" "Pardon?" "Is he your new friend?" "Yeah." "I think so, new best friend." "Fortunately, together with further tests we were able to do, it was very clear that that reaction wasn't an allergic reaction of any sorts, but to be absolutely sure we brought" "Danny back a couple of weeks later, and repeated the entire exercise." "The only difference we made is that we made the whole thing much lower key." "We didn't have any television cameras there and the whole thing went off extremely well." "At the end of the day, just over a year ago, he wouldn't have been able to go in the room with a dog, let alone do what he's doing today." "We never dreamt for a minute that it'd be as successful as it been within the first 12 months." "It's been amazing - absolutely amazing." "I think he's going to appreciate over the years how hard it's been, and stressful and what you've been through, whereas now you can sort of relax more, a lot more." "It's been life-changing for the family and for Danny." "I didn't think it would ever be like that, the dog on the swing." "When I went to Cardiff Bay with the school and there was this tree that you can make a wish on and I wished that one day I'd be able to stroke dogs and it's come true." "While immuno-therapy has the potential to transform lives of patients like Danny, with little real scientific understanding of how the treatment works, it is not appropriate for everyone." "An effective mass treatment for allergies is still a long way off." "In spite of decades of research and many breakthroughs, the allergy epidemic is not showing any signs of slowing down." "Even as science uncovers more about the causes, across the globe, more and more people are succumbing to allergies." "What is clear is that the solution to the crisis does not lie in one place alone." "From the Caribbean to California, Texas to Tristan da Cunha," "LA to London, there is no one answer to the allergy puzzle." "The most important factor may well lie in how all the different pieces fit together." "Both allergy and asthma are not caused by a single factor." "In fact, so for many factors, we don't even know what they are and how many they are." "It's absolutely frightening." "If this progresses, without any stop... just a question of time." "Virtually everybody's going to be asthmatic." "Over the past 50 years, rapid technological advance and rising standards of living have transformed our lives beyond all recognition." "But this frenetic pace of change is exposing more and more genetic vulnerabilities, hidden in the past." "Clearly we are exposed to toxins and a level of toxins that we've never been exposed to before, at least in evolutionary time." "So in some ways we are very genetically and evolutionarily mismatched to this environment." "We have changed the world around us, the food we eat, the air we breathe." "We have successfully eradicated the infections and diseases that plagued previous generations." "But in the process of modernising our world, we may have created a different plague altogether." "Our immune system, our genetics, our make-up has actually evolved over hundreds of thousands and millions of years, whereas the changes in lifestyle are very sudden." "So a 100,000 years ago, our ancestors would have been walking around in fields naked." "They would be infested with parasites, their food would be often raw or uncooked." "Today, everything has changed." "This convergence, if you will, of our genes, various environmental factors, rapid changes in the domestic environment, changes in lifestyle due to rapid modernisation, all of the cars on the streets and the pollution that comes from these cars," "it's sort of this perfect storm, if you will." "All of these parts coming together to create the situation where there's seemingly no end to how far this will go." "Subtitles by Red Bee Media Ltd" "E- mail subtitling@bbc. co. uk"