Select Committee on Science and Technology Sixth Report


CHAPTER 4: The Extent and Burden of Allergy in the United Kingdom


4.1.Reports on allergy appear almost weekly in the media and the vast majority of the population either suffer, or know somebody who suffers, from an allergic condition. The true prevalence of allergy is unclear, partly because many reports tend to focus on a particular disease manifestation or population sub-group. Nevertheless, broad conclusions about the recent trends are evident and this chapter examines allergy prevalence within the United Kingdom and the rest of the world, the possible reasons for these trends, and the burden that allergic disorders cause.


Useful sources of data on allergy prevalence
Type of Source  Examples of Source  Data  Advantages and Disadvantages  
Routinely collected clinical data:     
a) Hospital admissions and secondary care data  World Health Organization (WHO) Statistical Information System  Records the prevalence of various diseases and health problems worldwide, using many types of health records including death certificates and hospital records  These data do not provide a reliable assessment of allergic disease prevalence because allergic disorders are normally managed within outpatient departments or in the community. They do however offer an important insight into disease severity and burden  
 Hospital Episode Statistics  A database of hospital admissions in England   
 Scottish Morbidity Record 1  The Information and Statistics Division, Scotland, collects information on in-patient and day-case episodes in Scottish hospitals   
b) Primary care General Practice Research Database (GPRD)  Anonymised longitudinal records from selected general practices in the United Kingdom, collated by the MHRA  The information provided is often restricted due to patient confidentiality. GPRD and DIN are restricted by the cost of obtaining and analysing the data but have extensive detail. RCGP WRS is free but limited in the type of allergic conditions covered  
 Doctors Independent Network (DIN)  Anonymised large United Kingdom GP database   
 Royal College of General Practitioners Weekly Returns Service (RCGP WRS)  Information on general practice consultations across England and Wales   
  Prescribing Analysis and Cost  Details of the number and cost of prescriptions issued   
 Primary Care Clinical Informatics Unit, Aberdeen, Scotland  Information on consultations from a sample of general practices across Scotland   
 Practice Team Information, Scotland  Practice Team Information collects data from a sample of Scottish practices on patients' encounters with members of the practice team, including general practitioners, and practice and community nurses   
 Quality and Outcomes Framework, England and Scotland  These include quality indicators for asthma care. Data from the asthma register used for assessing quality outcomes can be used as a measure of prevalence   
Specifically commissioned by the Department of Health  QRESEARCH project conducted by the University of Nottingham  An analysis of the epidemiology of allergic disorders, based on data collected routinely from general practices   
Population based surveys Health Survey for England  A series of annual surveys since 1991 conducted by the Department of Health on various health aspects. It covers asthma, hayfever and eczema periodically, but has not covered other allergic disorders  Population-based surveys capture a wide range of symptoms and are particularly useful when monitoring disease prevalence over a length of time at repeated intervals  
 Scottish Health Survey  Consists of a series of three national surveys of the Scottish population conducted in 1995, 1998 and 2003 on various health aspects, commissioned by the Scottish Executive Health Department. The only relevant data these surveys provide is on asthma  However, they must include meaningful allergy-related questions which are worded in the same way in each language following translation  
 European Community Respiratory Health Survey (ECRHS)  Data on the prevalence of allergic disease and low lung function in adults from 14 countries (mostly European). After the original ECRHS I survey, a follow-up survey, ECRHS II, began in 1998   
 International Study of Asthma and Allergies in Childhood (ISAAC)  Records the prevalence of asthma, allergic rhinitis and eczema in children worldwide, using questionnaires in three different phases   
Birth cohort Avon Longitudinal Study of Parents And Children (ALSPAC)  Analysis of parents and children in the West of England to examine which biological, environmental and social factors contribute to health or disease. This forms part of the European Longitudinal Study of Pregnancy And Childhood (ELSPAC)   
 British 1958 birth cohort  The National Child Development Study is a longitudinal study which studies all the people born in England, Scotland and Wales in one week in March 1958   
 Isle of Wight Birth Cohort Study  A birth cohort study to examine asthma and allergy within the population of the Isle of Wight   
Mortality National Statistics; General Register Office for Scotland  Routine data on numbers of deaths in the United Kingdom from death certificates. These can be used to calculate population based rates  Only useful for allergies in which there is a relatively high mortality  
 World Health Organization  Collates global mortality data using the International Classification of Diseases   

The prevalence of allergy in the last 50 years

4.2.Data produced by the sources listed in Table 2 show that the prevalence and incidence of allergic disease have markedly increased over the past 50 years. Professor Burney reported that "an increasing prevalence of asthma was first noted in studies of Birmingham school children, starting in the mid 1950s," and since then, the prevalence of asthma and wheezing appears to have doubled "approximately every 14 years" until the mid 1990s (p 37). The trends for other atopic disorders such as hayfever and eczema are similar, although there is less information on these disorders.

4.3.In 2004 the scale of the "allergy epidemic" became apparent: 39 per cent of children and 30 per cent of adults had been diagnosed with one or more of asthma, eczema and hayfever; and 38 per cent of children and 45 per cent of adults had experienced symptoms of these disorders in the preceding 12 months.[20] The rate of change was demonstrated by the QRESEARCH study which showed that at the end of 2005, approximately one in nine people had a recorded diagnosis of "any allergic disease," including any one of asthma, hayfever, eczema, anaphylaxis or peanut allergy. This figure represented a 27.7 per cent increase in prevalence over a four year period.[21]

4.4.However, there is some evidence to suggest that the incidence of certain allergic disorders may have reached a plateau or even declined in particular age groups since the 1990s. Professor Burney told us that the incidence in children appears to be "flattening off … though this is not seen in all countries. In some places the prevalence is still going up, in some places it seems to be going down, so for the first time there is a rather mixed set of evidence" (Q 100). We examine the evidence for each disorder in turn.


4.5.The QRESEARCH study found that 3.3 million people in England have a recorded diagnosis of allergic rhinitis at some point in their life, and one person in every 135 of the population was diagnosed during 2005.[22] However, increases over the past five years have been relatively small: the ISAAC study found a slight increase in prevalence of rhinoconjunctivitis symptoms amongst the six to seven year old age group, and a decrease in 13-14 year olds over a period of approximately five years.[23]

4.6.Patients with allergic rhinitis may have seasonal and/or perennial symptoms, so distinguishing between the causes in epidemiological surveys is difficult. A recent study found a very high prevalence of seasonal allergic rhinitis (hayfever) across Western Europe, but concluded that it is frequently undiagnosed.[24] The World Health Organisation workgroup, Allergic Rhinitis and its Impact on Asthma (ARIA), has therefore proposed classifying allergic rhinitis by whether symptoms are intermittent or persistent, in an attempt to improve the monitoring of the prevalence of rhinitis.[25]


4.7.According to QRESEARCH, an estimated 5.7 million people in England are affected by asthma, and one person in 192 in the population was newly diagnosed during 2005.[26] In 2006, the ISAAC Phase III study reported that the incidence of asthma symptoms had risen in six to seven year olds in the United Kingdom, from 18.4 per cent to 20.9 per cent over a period of approximately five years. The prevalence of asthma symptoms in 13 to 14 year olds was higher, at 24.7 per cent, but the incidence within this age group had actually decreased from 31 per cent.[27]

4.8.Dr Mark Rosenthal, a consultant respiratory paediatrician from the Royal Brompton Hospital, suggested that the prevalence of asthma had probably reached a plateau or was "possibly even falling" (Q 650). There has been a steady decline in child hospital admissions since 1990, and asthma related deaths in childhood remain uncommon.[28] The newly recorded incidence of asthma within primary care also decreased from 6.9 per 1000 person-years in 2001, to 5.22 per 1000 in 2005,[29] possibly due to a greater awareness of the disease and the availability of more effective treatments. However the allergy burden is unclear: Professor Burney pointed out that "there are a lot of other conditions that are probably not allergic which make people wheeze" (Q 98).


4.9.Hospital admissions due to anaphylactic shock rose seven-fold from 1990/01 to 2003/04.[30] During the 1990s, approximately 20 deaths each year were identified as having been caused by anaphylaxis, although this figure does not include additional undetected fatal reactions such as those to antibiotics, where an autopsy might only identify the infection for which the antibiotic was taken.[31] The Anaphylaxis Campaign also reported that the number of deaths due to food anaphylaxis was often underestimated "because of misdiagnosis or misreporting" (p 172). According to the UK fatal anaphylaxis register, for the period 1992-1998, around half the number of anaphylaxis deaths were due to "medical interventions such as drugs used in anaesthesia or injections for special X-ray investigations," with the rest being caused by stings, foods or rare causes such as latex, hair dye or parasitic worms (p 180). The pattern of fatal anaphylaxis to food during this period was similar to that reported from 1999-2006, when 48 deaths occurred in people ranging from five months to 85 years old, caused by milk (6), peanuts (9), tree nuts (9), fish (1), shellfish (1), snail (1), sesame (1), egg (1), tomatoes (1) and "uncertain" allergen deaths (18).[32] Data on anaphylaxis due to drugs, latex and exercise and other causes are incomplete.


4.10.Specific United Kingdom data are lacking but European studies estimate that about two per cent of the adult population has had a systemic reaction to bee or wasp stings.[33]


4.11.Adverse reactions to drugs can be both allergic and non-allergic. Allergy and anaphylaxis to anaesthetic agents, antibiotics, aspirin and non-steroidal anti-inflammatory drugs are responsible for most drug hypersensitivity cases, but reliable data on the true incidence of these reactions is absent. Many people claim to be allergic to penicillin but only a small proportion will actually have that diagnosis verified by thorough investigation. One study showed that approximately only 14 per cent of patients with a convincing history of penicillin allergy were skin test positive.[34]


4.12.The Institute of Food Research (IFR) told us that the lack of agreement on the diagnosis of food allergy made estimates of the prevalence of food allergy "generally imprecise." The greatest burden of food allergies is in children, with approximately "5-7 per cent of infants" experiencing an allergic reaction, although egg and milk allergies tend to resolve with age. Some food allergies persist and the IFR estimates that around "1-2 per cent of adults" suffer from a food allergy (p 286). Although the persistence of childhood allergy is unusual, once a food allergy is established in an adult it is rarely cured.[35]

4.13.The increase in peanut allergy has been extraordinary. QRESEARCH found a 117.3 per cent increase in the prevalence of peanut allergy from 2001 to 2005, and estimated that 25,700 people in England are affected. One in every 12,420 people was newly diagnosed during 2005.[36]

4.14.New food allergies are regularly being described, for example to fruits, vegetables, soya, sesame, mustard, chick pea and kiwi fruit (Chinese gooseberry), but the reasons for the prevalence and rising trends of these new allergies, including the oral allergy syndrome, are basically unknown. Professor Jonathan Hourihane, Professor of Paediatrics and Child Health, Cork University Hospital, pointed out that many of these new allergies appear to persist into adulthood to a greater extent, so in the future "we may see a hardcore of up to three per cent" of adults with serious allergies (Q 650).


4.15.People with oral allergy syndrome typically suffer from at least two allergies: a food allergy to fruits, vegetables and/or certain nuts, as well as hayfever caused by tree or grass pollen allergy. A recent Danish study reported that approximately 30 per cent of pollen allergic adults also suffered from food allergies, particularly involving fruit or nuts. [37]


4.16.Urticaria and angioedema are amongst the commonest problems referred to allergists. Some studies estimate that one in five of the population have urticaria at some point in their lifetime,[38] and hospital admission rates for urticaria more than doubled from 1990 to 2000. However, the rates for angioedema appeared unaltered.[39]


4.17.Eczema has steadily increased since the 1980s, and Professor John Harper, Professor of Paediatric Dermatology at Great Ormond Street Hospital, suggested the prevalence in children was between "10 to 15 per cent" but cited "some studies approaching 20 per cent" (Q 650). QRESEARCH estimated that 5.8 million people in England are affected by eczema and 1 in every 74 people was newly diagnosed in 2005.[40] Six to seven year olds in the United Kingdom have the highest incidence of eczema amongst the Western European countries surveyed in the ISAAC study, with the prevalence increasing from 13 per cent to 16 per cent over a period of approximately five years. However, just as with asthma, eczema saw a decrease from 14.7 per cent to 10.6 per cent in the 13-14 year old age group.[41]

4.18.Professor Gawkrodger estimated that "approximately 50 per cent" outgrew atopic eczema in their teens leaving around "10 per cent of adults" with atopic eczema "to a greater or lesser extent" (Q 612). Professor Harper added that "in a smaller percentage, maybe around one per cent, this is quite severe" (Q 650).


4.19.Asthma, eczema and allergic rhinitis often occur together; Professor Sheikh told us that "multiple allergic disorders also seem to be increasing" (Q 104). This comorbidity, or multiple allergic disease, often requires multiple referrals to different organ specialists. QRESEARCH defined patients with more than one of asthma, hayfever, eczema, anaphylaxis or peanut allergy, as having "multiple allergic disease." It estimated that 2.3 million people in England suffered from multiple allergic disease, and that the prevalence rate had increased by 48.9 per cent between 2001 and 2005. In 2005, patients with multiple allergic disease consulted a GP 4.9 times per year, and a nurse 2.1 times per year on average.[42]


4.20.Allergic sensitisation (atopy) and allergic symptoms are not synonymous. Only a proportion of patients who are skin prick positive to allergens will actually exhibit symptoms. The development of disease symptoms therefore depends on a variety of factors.

4.21.Amongst adults born before 1970, recorded sensitisation rates increase over time, with increasing prevalence rates of allergic disease in each subsequent generation. This increase will probably continue in the future, but Professor Burney told us that "we do not have that information for children yet" as the ISAAC study only measured the prevalence of symptoms potentially attributable to allergy, rather than sensitisation (Q 100). It is likely that sensitisation levels amongst children will continue to rise in the future. As a result, the same will probably also be true of allergic disorders but, due to the lack of data, "there is less evidence" for this (Q 120). Therefore it is important that data on childhood sensitisation is collected, and that sensitised people are monitored to examine what happens in terms of disease in later life.

4.22.Information from children on sensitisation and symptoms is especially important and must be followed up to assess the progression of allergic diseases in order to predict workload. We recommend that future epidemiological studies measure not only the incidence of allergic symptoms, but also record the prevalence of confirmed allergic sensitisation.


4.23.Most of the information comparing asthma and allergy incidence around the world comes from ISAAC studies, a unique project which has attracted worldwide interest and unprecedented large scale participation. The increase in allergy and atopy in the United Kingdom has been mirrored in many other developed countries in Western Europe, the United States, Canada, Australia and New Zealand. However, developing countries in Africa and the Middle East still report a relatively low prevalence of allergy.

4.24.ISAAC Phase One demonstrated large variations worldwide in the prevalence of asthma symptoms in children, with the highest prevalences reported from centres in the United Kingdom, New Zealand, Australia and the Republic of Ireland, followed by most centres in North, Central, and South America. The lowest prevalences were from centres in Eastern Europe, Indonesia, Greece, China, Taiwan, India, and Ethiopia. Both rhinoconjunctivitis and atopic eczema, of which the United Kingdom has the second highest prevalence, were reported from across the globe but for both these disorders, centres reporting low prevalence rates tended to also encounter little asthma.[43]

4.25.ISAAC Phase Two studies focused on smaller projects. Comparisons of the United Kingdom (which exhibited a high rate of asthma) and Albania (with a low rate of asthma) showed that the degree of allergic sensitisation in these two countries was actually similar,[44] highlighting the role that the environment must play in allergy disease development. The ISAAC Phase Three study examined variations over time in asthma, allergic rhinoconjunctivitis and atopic eczema worldwide, and assessed the relationship with environmental data.[45]

4.26.Although allergy in adults is less well documented than in children, Professor Burney told us that the examination of specific IgE from the blood of adults in Europe showed that the United Kingdom had some of the highest prevalences of sensitisation, and "correspondingly higher levels of disease." In addition, the ECRHS revealed that the only countries with similar, or higher, rates of sensitisation to the United Kingdom "were other English speaking places like Australia and New Zealand" (Q 108).

Possible explanations for the increase in prevalence

4.27.At our seminar, Professor William Cookson from Imperial College London, explained that the development of an allergic disorder depends on both genetic and environmental factors. Genetic factors are complex: several genetic variations can predispose different individuals to the same disorder, and any one allergy can manifest itself in a variety of ways, which differ from one patient to another.

4.28.But Professor Adnan Custovic, Professor of Allergy at the University of Manchester, noted that the genetic background of the population had not changed significantly enough in the last 50 years to explain the dramatic rise in the prevalence of allergy. The increase in allergic conditions over the second half of the 20th century must therefore be due to environmental factors.[46] Whereas the genetic mechanisms of allergic reactions are relatively well understood, no consensus has yet been reached regarding the degree to which various environmental factors are responsible for the dramatic increase in allergy prevalence.

4.29.Some of the environmental factors which may specifically contribute to the development or exacerbation of allergic disorders include:

  • The "hygiene hypothesis" as supported by the protective effects of early childhood infection, bowel flora, farming and the proximity to animals, and a "traditional" lifestyle
  • Diet
  • Allergen exposure
  • Atmospheric Pollution
  • Tobacco smoke.

We now consider each of these in turn.


4.30.In the 1980s, David Strachan put forward the "hygiene hypothesis" in which he proposed that children exposed to poor hygiene and increased infections in early life had lower levels of IgE sensitisation and allergic disease. Some studies have since suggested that a large number of siblings increases the probability that a child will suffer infections, and that repeated infection during early childhood makes the immune system more robust and less prone to the development of allergies. [47]

4.31.Other studies generally supported this hypothesis. Disorders associated with lack of hygiene, such as enteric infections, appear to protect against allergy.[48] As allergic disorders are relatively rare in Africa, parasitic infections were purported to play a protective role, but studies have been inconclusive and parasites probably, as Professor Burney told us "have a different effect and on a different part" of the allergic mechanism, so do not form part of the "hygiene hypothesis" (Q 112).

4.32.It has also been suggested that particular patterns of bowel flora, observed in people living in underdeveloped or unhygienic conditions, are allergy-protective. For example, marked differences in bowel flora have been found between genetically similar allergic and non-allergic infants living in Sweden (an area with a high prevalence of allergic conditions) and Estonia (an area with a low prevalence).[49] Professor Sheikh told us that giving babies "lactobacillus and bacteria in early life, perhaps in combination with other approaches" might halt the progression of allergic disorders (Q 98) and in one study probiotics have been shown to reduce the development of atopic eczema.[50]

4.33.Population studies have been particularly interesting. Before the unification of Germany, poorer children in the East exhibited lower prevalences of allergic disease than those in the West. But following unification, and the changes in environment that resulted from this, the frequencies of hayfever and atopic sensitisation in these children rose significantly.[51]

4.34.Support for the "hygiene hypothesis" has also been obtained from studies examining the importance of traditional rural lifestyles, particularly where pregnant women and children live in close proximity to animals, as children brought up on farms have been shown to have a lower prevalence of IgE sensitisation, wheeze, asthma and hayfever than those brought up in the countryside but not on farms.[52] Children who regularly drink raw, unpasteurised milk in the first year of life and are exposed to other bacteria seem to be less likely to develop allergies.[53]

4.35.Support for the allergy-protective effect of the traditional lifestyle has also come from studies on Steiner school children who follow an anthroposophic lifestyle. This lifestyle involves the minimal use of medications, delayed vaccinations, a lower use of antibiotics and paracetamol, and a diet consisting of organic or fermenting vegetables. Children following this way of life were shown to have a much lower rate of IgE sensitisation, asthma, hayfever and eczema than children attending non-Steiner schools in the same area.[54]

4.36.The "hygiene hypothesis" has stimulated much debate. However, the interventions designed to reverse the rising trends in allergy have not proved as successful as initially hoped. As Professor Harper told us "if you actually have children who are exposed to infection there is no evidence whatsoever that this reduces … [their] risk of allergy or atopic dermatitis. In fact, there are many papers on infection in early life triggering eczema and asthma" (Q 654). So the hygiene hypothesis is far from the whole story.


4.37.Diet during pregnancy and infancy is likely to play a role in developing allergic disease. Dr Graham Devereux, Consultant at the Department of Environmental and Occupational Medicine, University of Aberdeen, told us that "maternal ingestion of nutrients, particularly vitamin E, possibly vitamin D and even zinc" could confer protection against allergies in the child (Q 99). An increased risk of asthma and atopy also appears to be associated with a low intake of fruit, vegetables, fish, butter, dairy fat, antioxidants, magnesium and n-3 fatty acids, and a high intake of sodium, margarine and n-6 fatty acids.[55]

4.38.It is probable that a true window exists in early life where the role of nutrition in protection against atopic disease is critical. Professor Warner told us "exclusive breastfeeding for at least the first four months of life reduces the rates of early food allergy and eczema." However, a longer-term protective effect on later allergic manifestations is less evident (Q 163).

4.39.The role that food allergen consumption plays during early life is still uncertain, although there has been some suggestion that early exposure to allergens such as peanuts may protect against allergy (a subject which will be explored further in Chapter 6).


4.40.Epidemics of asthma have occurred in response to high levels of allergen in the air, supporting the theory that the rise in allergy is simply due to increased exposure to allergens. Such examples are the asthma epidemics in Barcelona associated with the dust of soybean particles created during unloading of soybean cargo at the docks,[56] and "thunderstorm asthma" which is caused by a massive concentration of pollen during a storm.[57]

4.41.However, allergy prevention is not simply a question of allergen avoidance. Measures which reduce the level of housedust mite, a known potent allergen, do not necessarily lead to a reduction in asthma symptoms.[58] To complicate the situation further, pet ownership might sometimes confer protection against allergies, as Professor Burney and Dr Devereux commented "children brought up with dogs have less sensitisation" and "cats are beneficial" (QQ 115, 117). This is possibly because pet products, including bacteria, may induce some form of immunological tolerance which is allergy-protective. Thus allergen exposure alone does not explain the increase in disease prevalence.


4.42.Some witnesses have suggested that the increase and change in pollution over the last 50 years is responsible for the increase in allergy incidence. Air pollution is a general term that covers a wide range of pollutants; whereas the infamous smog of the mid-20th century was largely the product of domestic coal burning, air pollution is now largely caused by vehicle emissions. The impact of such pollution upon allergic diseases will be explored further in Chapter 5.


4.43.Smoking is causally related to chronic bronchitis and can aggravate asthma, but whether smoking in itself causes allergic asthma remains highly controversial. More respiratory illnesses and symptoms occur in children, particularly infants, exposed to their parents' tobacco smoke[59] and workers exposed to second hand tobacco smoke in the workplace.[60] However, a specific link between smoking and allergy development has not yet been demonstrated.

The allergy burden

4.44.During the course of our inquiry we have received a great deal of evidence regarding the detrimental impact that allergic disorders can have upon patients' quality of life. In addition to the obvious health effects, allergic disorders can make social interactions difficult as simple everyday activities such as eating out or going to work can pose a major health risk. On a national scale, the treatment of allergy patients forms a significant part of the work of the National Health Service, and the number of allergy-related work absences represents a large but hitherto unquantified cost to the economy. The social and economic impacts will always be difficult to quantify fully, but it is clear that the burden of allergic disorders in the United Kingdom is substantial.


Quality of life

4.45.Allergies are not a minor inconvenience. Allergy UK surveyed 6,000 allergy sufferers and found that over 62 per cent of them felt their allergy "significantly affected all aspects of their lives" (p 293). The health burden of allergy is obvious. Allergies can cause a broad spectrum of disease with symptoms ranging from mildly irritating to extremely debilitating and even fatal.

4.46.At one end of the spectrum, allergic disorders such as hayfever may produce relatively mild symptoms such as sneezing, itchy eyes and a congested nose. Although unpleasant these symptoms can usually be managed with the appropriate use of antihistamines and topical nasal corticosteroids.[61] Hayfever symptoms disrupt children's sleep and often impair their performance at school. Furthermore, the Royal National Throat, Nose and Ear Hospital added that for some patients, rhinitis can also exacerbate other allergic conditions such as "asthma, sinusitis, otitis media with effusion [inflammation in the ear], pharyngitis [inflammation of the throat], sleep problems, and vocal dysfunction" (p 285).

4.47.The effects of more severe conditions can be extremely debilitating and intense. In severe eczema the inflamed skin and itches can be exacerbated by materials such as wool or nylon, and triggered by vaccinations or stressful situations. Patients suffering from severe asthma feel suffocatingly breathless and their extreme wheeziness is often worsened by factors such as exercise, exposure to fumes or viral infection; sometimes an asthma attack can even lead to death.

4.48.At the extreme end of the allergic spectrum is anaphylaxis, a severe hypersensitive reaction. Although about one person in 1,000 would have a serious allergic reaction such as anaphylaxis, Dr Pumphrey pointed out that it will prove fatal in "fewer than one in a million" (p 180). However, the Royal College of Anaesthetists explained that a lack of oxygen to the brain or heart during an anaphylactic reaction could leave the patient with "permanent disabilities" such as poor memory and spatial awareness, loss of balance and permanent cardiac damage (p 350). For people who are allergic to foods, insect venom or drugs, and for patients at highest risk of anaphylaxis, the constant fear of suffering an extreme reaction can make living a normal life virtually impossible.

4.49.For drug allergic patients, receiving medical treatment can be extremely risky. Dr Pumphrey reported that approximately 10 deaths per year in the United Kingdom were caused by "drug anaphylaxis." Although the least severe type of reaction may involve a rash, this can signify the potential for a more serious reaction, such as anaphylaxis, on future exposure to the drug. Therefore future treatment might require the use of alternative medication which may be more expensive, less effective or less safe (p 188). Surgery holds particular hazards because, as the Royal College of Anaesthetists reported, general anaesthetics involve a range of drugs and synthetic intravenous fluids, administered alongside "antibiotics, radiological contrast agents and drugs which manipulate blood coagulation," all of which may precipitate anaphylaxis (p 350). When a reaction has occurred, identifying the culprit drug can be a complicated and time-consuming task which is not always performed.

4.50.For patients with food allergies to certain foods, the Food Standards Agency (FSA) commented that the ubiquitous use of defensive warnings, such as "may contain nuts", on food labels limits the range of products available, causing shopping to take on average "39 per cent longer" and cost "11 per cent more" for peanut allergic consumers (p 152). Allergens are not listed at all on menus in catering establishments so when eating out, food allergic patients must take extra care to question staff about the ingredients used and the food preparation methods. The difficulties this causes can often make social interactions difficult, especially in teenagers and young adults who may not want to draw attention to their condition.[62] In addition, the IFR commented that a lack of frequent testing for food allergic patients may result in patients living with mitigation strategies such as food avoidance "which are no longer necessary" (p 287).

4.51.Therefore the risks encountered by allergy patients not only pose a risk to their health, but also make it difficult to live a normal life and place a strain on the general wellbeing of sufferers. This is especially apparent in children, where special care has to be taken whilst engaging in everyday activities such as playing outside or attending parties. The extent to which allergies can impair children's quality of life was highlighted by a study in 2003 which showed that children with peanut allergy had higher anxiety levels and had their quality of life impaired to a greater extent than children suffering from insulin-dependent diabetes mellitus.[63]


Asthma and its impacts

It is estimated that around 5.7 million people in England suffer from asthma,[64] and asthma and allergy are so closely interlinked that the majority of asthma cases are caused by an allergic mechanism. Asthma UK reported that "90 per cent of people with asthma tell us that their symptoms are triggered by dust and 79 per cent say their symptoms are triggered by pollen" (p 289). Other non-allergenic triggers such as tobacco smoke or air pollution can also exacerbate asthma symptoms, so for some patients it is almost impossible to avoid situations which may aggravate their condition. Although some asthma patients may present with an isolated cough, others suffer from wheezy breathlessness which can make even the simplest of everyday tasks impossible, and in some cases, an "asthma attack" can lead to death. Furthermore, people with asthma often also suffer from other allergic disorders such as rhinitis, eczema or food allergies, which produce additional burdensome symptoms, and further restrictions in daily life.

The burden of asthma in the population should not be underestimated. Written evidence from Asthma UK included an account from one asthma sufferer, who reported that: "My quality of life is non-existent. I know this may sound extreme to a lot of people but I would be prepared to lose an arm and a leg if it meant my asthma would go away. I face daily restrictions in every aspect of my life … I find it really difficult to do day-to-day activities on my own—I don't have enough breath to push a trolley around the supermarket … I'm not allowed on an aeroplane and it's impossible for me to get travel insurance. Winter is also a problem for me—I can't go outside because the cold air can set off my asthma" (p 291).

Although allergy is a major trigger of asthma attacks, most asthma hospital admissions and deaths are caused by infection or unknown causes, rather than allergy. The DH reported that there were 924 asthma deaths in England in 2004, with most of these occurring in "older people and may not be directly attributed to uncontrolled allergy."[65] The costs of asthma to the nation are phenomenal, with Asthma UK estimating that "over 12.7 million working days are lost each year as a result of asthma, and that the total annual cost of asthma to the economy is £2.3 billion" (p 289). Despite much research, the exact causes of asthma are still unknown, so it is unlikely that this burden will be reduced any time in the near future.

Allergy at school

4.52.At school, children with allergies face a plethora of risks. When children enter the school environment they face a new range of situations and people whose activities can potentially put them at risk. There may be "casual contact" with allergens such as nut proteins, which are easily transferred between surfaces by little hands. Although any resulting reaction is usually mild to moderate, Ms Mandy East, National Co-ordinator of the Anaphylaxis Campaign, spoke of the high levels of anxiety this can create in children with poor understanding of their allergy, and explained that it "can lead to a different type of reaction like a panic attack" (Q 447). Although minimal, the possibility of anaphylaxis at school therefore not only causes a great deal of worry to children and parents, but also places a burden on the school, as the Department for Education and Skills (DfES) said that it is "a head teacher's responsibility to ask themselves whether the cadre of teachers and support staff they have" is able to deal with such an emergency (Q 74).

4.53.Schoolchildren generally feel the need to conform, but an allergic condition can be stigmatising. For example Ms Sarah Day, from the Royal College of Nursing, spoke of the "image" concerns of children with severe eczema (Q 693), and Mrs Margaret Cox, Chief Executive of the National Eczema Society, noted that management of eczema required "frequent topical treatment" which may be difficult to fit into the school routine (Q 620). The Children's Dermatology Life Quality Index, co-ordinated by the Department of Dermatology at the Wales College of Medicine, calculates the impact of dermatological diseases using questionnaires completed by children themselves. This has shown the devastating impact which severe eczema may have on many domains of a child's life, causing their quality of life to be severely undermined. The questionnaires have shown that severe eczema can produce embarrassment, cause a lack of sleep and impair children's performance at school.[66]

4.54.These children underperform academically for several reasons. They have high rates of absence, as shown by a survey in the late 1990s which showed that 38 per cent of children had missed school in the preceding year due to asthma alone (p 3), impaired concentration due to "poor sleeping patterns" (p 293), and those with hayfever may drop a whole grade in their summer exams compared to their winter mocks.[67] The burden of their conditions can therefore have a long-term impact upon their future educational opportunities and career.

4.55.Dr Paul Harrison, Director at the Institute for Environment and Health at Cranfield University, added that children with asthma or allergic rhinitis are "likely to opt out of sporting activities" so their fitness and wellbeing are also affected (Q 459). In extreme cases, food allergic children may even have to face bullying from their peers: Ms East told us that "children have had nuts put into their blazer pockets and into their lunch boxes to try to contaminate their food" (Q 446).

Allergy at work


Diseases commonly caused by workplace chemical or biological allergens[68]
Disease Common Cause  Workers commonly at risk  
Respiratory conditions (Asthma, Rhinitis, Extrinsic allergic alveolitis)  A wide variety of chemicals  Spray painters

Chemical process workers  

 Flour dust  Bakers 
 Animal waste products  Laboratory and Animal workers  
Allergic contact dermatitis Hair dye, solvents and perfumes  Hairdressers and beauticians  


Chromates and Cobalt  

Die casters (who mould metal)

Fashion industry workers

Cement workers, Leather workers  



Carpet fitters, Car mechanics

Healthcare workers  




Construction workers

Printers, Dental personnel  

 Cutting oils  Machine tool operators  

Glues, Fibreboards

Cleaning products


Embalming fluid  

Construction workers


Dry cleaners


 Plants  Florists and horticulturists  
 Wood  Carpenters 

4.56.Workplace allergens can trigger or exacerbate allergic diseases (Table 3) and the only way to reduce the symptoms of disease is through avoidance. However, even complete avoidance of the allergy aggravating factor may not necessarily result in complete remission of signs and symptoms, as the HSE reported that respiratory allergies may "persist once they have become established" (p 9). Where avoidance is not possible, patients may be advised to give up their job yet Professor Newman Taylor told us that a lack of retraining schemes meant that "between a third and a half of cases of occupational asthma remain unemployed three to five years later" (Q 280).


National Health Service

4.57.The DH estimated that in England approximately 3 million people each year consult their GP with conditions related to allergy, costing £211 to £311 million. In 2004/05 there were also 70,000 admissions to hospitals in England for asthma and over 3,000 patients were admitted to hospital with anaphylaxis. These admissions contribute to a total cost of allergy treatment in secondary care of around £56 to £83 million per annum.[69]

4.58.On top of this are the costs of prescriptions. In 2004, 72.6 million community prescriptions for allergy-related conditions were issued in England. This included 38.9 million prescriptions for asthma, 4.5 million for nasal allergies and 20.4 million prescriptions for eczema. This amounted to a cost of £0.9 billion, which represented 11 per cent of the total drugs budget, compared to 27 per cent spent on cardiovascular diseases and 8 per cent on gastro-intestinal disorders.[70] In addition, there are hidden costs, such as patients with allergies to penicillin being treated with expensive alternative antibiotics; if the drug allergy is wrongly diagnosed, such extra expense is incurred unnecessarily.

Occupational allergic diseases

4.59.The precise burden of occupational allergic disorders is not known, partly because it is impossible to quantify the true cost of absence from work or lowered productivity caused by an illness, and because the data on occupational allergic disease are poor (see Chapter 3).

4.60.What is known is that allergy-related occupational illnesses represent a significant economic burden. A survey of self-reported work-related illness estimated that in the year 2004/05, of all the people that had worked, 137,000 reported breathing or lung problems that were "caused or made worse by work," and 29,000 reported that their work had caused or made their skin conditions worse. For that same year, 791,000 full-time equivalent working days were lost due to breathing or lung problems, out of a total 28.4 million days lost due to all occupational illnesses (pp 9-10). Even if patients remain at work, then the symptoms of their disorders are likely to reduce productivity causing a substantial economic burden. For example, new cases of occupational asthma alone in 2003 were estimated to cost society £71.7 - £100.1 million.[71] However, not all of these disorders have an allergic origin. Dr Orton told us that in fact the majority of dermatitis cases seen were actually "irritant contact dermatitis" rather than "allergic contact dermatitis" (Q267).

4.61.The HSE claims that the best available statistics indicate occupational allergic disease is now declining. According to voluntary reporting by physicians from 2003-2005, "around 570 new cases of occupational asthma" were reported per annum, compared to about 1,000 new cases annually in the mid 1990s. The incidence of occupational contact dermatitis had also decreased from around "3,000-4,000 new cases per year during the late 1990s" to around 2,400 per year (p 9).

4.62.The Industrial Injuries Disablement Benefit (IIDB) provides compensation to those whose occupational allergy causes chronic symptoms and a minimum degree of disability after 90 days, irrespective of whether the individual is working or not (p 12 and Q 69). The Department for Work and Pensions (DWP) could not identify the exact level of benefit paid to allergy patients, but estimated that in March 2003, there were approximately 130 IIDB payments for extrinsic allergic alveolitis, 2,150 claims for allergic rhinitis, 4,230 for asthma and 3,880 for contact dermatitis (p 35).

20  Gupta et al., Clinical and Experimental Allergy 34, 2004, "Burden of allergic disease in the UK: secondary analyses of national databases," pp 520-526. Back

21  QRESEARCH and The Information Centre for health and social care, Primary care epidemiology of allergic disorders: analysis using QRESEARCH database 2001-2006, 2007, pp 69-70. (Hereafter referred to as QRESEARCH report). Back

22  op cit. QRESEARCH report, pp 48-49. Back

23  Asher et al., The Lancet 368, 2006, "Worldwide time trends in the prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and eczema in childhood: ISAAC Phases One and Three repeat multicountry cross-sectional surveys," pp 733-743. (Hereafter referred to as "Worldwide time trends"). Back

24  Bauchau and Durham, European Respiratory Journal 24, 2004, "Prevalence and rate of diagnosis of allergic rhinitis in Europe," pp 758-764. Back

25  See  Back

26  op cit. QRESEARCH report, pp 32-33. Back

27  op cit. "Worldwide time trends." Back

28  Office for National Statistics, The Health of Children and Young People, 2004, Chapter 7. Back

29  op cit. QRESEARCH report, p 33. Back

30  Gupta et al., Thorax 62, 2007, "Time trends in allergic disorders in the UK," pp 91-96. Back

31  Pumphrey, Current Opinion in Allergy and Clinical Immunology 4, 2004, "Anaphylaxis: can we tell who is at risk of a fatal reaction?", pp 285-290. Back

32  Pumphrey and Gowland, Journal of Allergy and Clinical Immunology 119, 2007, "Further fatal allergic reactions to food in the United Kingdom 1999-2006," pp 1018-1019.  Back

33  Fernandez et al., Clinical Experimental Allergy 29, 1999, "Epidemiological study of the prevalence of allergic reactions to Hymenoptera in a rural population in the Mediterranean area," pp 1069-1074. Back

34  Stember, Allergy and Asthma Proceedings 26, 2005, "Prevalence of skin test reactivity in patients with convincing, vague, and unacceptable histories of penicillin allergy," pp 59-64. Back

35  Moneret-Vautrin and Morisset, Current Allergy and Asthma Reports 5, 2005, "Adult Food Allergy," pp 80-85. Back

36  op cit. QRESEARCH report, pp 63-64. Back

37  Osterballe et al., Allergy 60, 2005, "The clinical relevance of sensitization to pollen-related fruits and vegetables in unselected pollen-sensitized adults," pp 218-225. Back

38  Nettis et al., British Journal of Dermatology 148, 2003, "Clinical and aetiological aspects in urticaria and angio-oedema," pp 501-506. Back

39  op cit. Office for National Statistics, The Health of Children and Young People, 2004, Chapter 7. Back

40  op cit. QRESEARCH report, pp 40-41. Back

41  op cit. "Worldwide time trends."  Back

42  op cit. QRESEARCH report, pp 78-80. Back

43  Beasley et al., The Lancet 351, 1998, "Worldwide variation in prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and atopic eczema: ISAAC," pp 1225-1232. Back

44  Priftanji et al., The Lancet 358, 2001, "Asthma and allergy in Albania and the UK," pp 1426-1427.  Back

45  op cit. "Worldwide time trends." Back

46  Note of the seminar, Appendix 4. Back

47  Strachan, British Medical Journal 299, 1989, "Hay fever, hygiene and household size," pp1259-1260. Back

48  Matricardi et al., British Medical Journal 314, 1997, "Cross sectional retrospective study of prevalence of atopy among Italian military students with antibodies against hepatitis A virus," pp 999-1003 and Matricardi et al., British Medical Journal 320, 2000, "Exposure to foodborne and orofecal microbes versus airborne viruses in relation to atopy and allergic asthma: epidemiological study," pp 412-417. Back

49  Björkstén et al., Clinical and Experimental Allergy 29, 1999, "The intestinal microflora in allergic Estonian and Swedish 2-year-old children," pp 342-346. Back

50  Kalliomäki et al., The Lancet 357, 2001, "Probiotics in primary prevention of atopic disease: a randomised placebo-controlled trial," pp 1076-1079. Back

51  von Mutius et al., The Lancet 351, 1998, "Increasing prevalence of hay fever and atopy among children in Leipzig, East Germany," pp 862-866. Back

52  Braun-Fahrländer et al., The New England Journal of Medicine 347, 2002, "Environmental exposure to endotoxin and its relation to asthma in school-age children," pp 869-877 and Riedler et al., The Lancet 358, 2001, "Exposure to farming in early life and development of asthma and allergy: a cross-sectional survey," pp 1129-1133. Back

53  Schaub et al., Journal of Allergy and Clinical Immunology 117, 2006, "The many faces of the hygiene hypothesis," pp 969-977. Back

54  Flöistrup et al., Journal of Allergy and Clinical Immunology 117, 2006, "Allergic disease and sensitization in Steiner school children," pp 59-66. Back

55  Devereux, Nature reviews: Immunology 6, 2006, "The increase in the prevalence of asthma and allergy: food for thought," pp 869-874. Back

56  Sunyer et al., The Lancet 28, 1989, "Case-control study of serum immunoglobulin-E antibodies reactive with soybean in epidemic asthma," pp 179-182. Back

57  Marks et al., Thorax 56, 2001, "Thunderstorm outflows preceding epidemics of asthma during spring and summer," pp 468-471. Back

58  Gøtzsche et al., Cochrane Review, 2007, "House dust mite control measures for asthma." Back

59  Cook and Strachan, Thorax 54, 1999, "Summary of health effects of parental smoking on the respiratory health of children and implications for research," pp 357-366. Back

60  Janson et al., The Lancet 358, 2001, "Effect of passive smoking on respiratory symptoms, bronchial responsiveness, lung function, and total serum IgE in the European Community Respiratory Health Survey: a cross-sectional study," pp 2103-2109. Back

61  op cit. Royal College of Physicians, Allergy: the unmet need, 2003, pp 45-46. Back

62  Food Standards Agency, Qualitative Research into the Information Needs of Teenagers with Food Allergy and Intolerance, 2005, p.14. Back

63  Avery et al., Pediatric Allergy and Immunology 14, 2003, "Assessment of quality of life in children with peanut allergy," pp 378-382. Back

64  op cit. QRESEARCH report, p 32. Back

65  op cit. DH A Review of services for allergy, p 17. Back

66  Fivenson et al., Journal of Managed Care Pharmacy 8, 2002, "The Effect of Atopic Dermatitis on Total Burden of Illness and Quality of Life on Adults and Children in a Large Managed Care Organization," pp 333-342. Back

67  Walker et al., Clinical and Experimental Allergy 36, 2006, "Hayfever is associated with a significant detrimental impact on exam performance in UK teenagers: case-control study," p 1209. Back

68  Information from QQ 264-265 and Rook's Textbook of Dermatology, 7th Edition, edited by Burns, Breathnach, Cox and Griffiths, Blackwell, 2004. Back

69  op cit. DH A review of services for allergy, pp. 28, 31. Back

70  op cit. DH A review of services for allergy, p.28. Back

71  Health and Safety Executive, The true cost of occupational asthma in Great Britain, 2006, p.iii. Back


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