Select Committee on Science and Technology Sixth Report


1 November 2006

A seminar was organised at the Royal Society of Medicine to give the Committee an opportunity to discuss issues connected to the inquiry with a number of academic and clinical experts, along with representatives from charities and the Department of Health.

Members of the Sub-Committee present were: Lord Broers, Lord Colwyn, Baroness Finlay of Llandaff (Chairman), Baroness Perry of Southwark, Baroness Platt of Writtle, Lord Soulsby of Swaffham Prior, Lord Taverne. In attendance were: Miss Sarah Jones (Clerk), Professor A. B. Kay (Specialist Adviser) and Dr Cathleen Schulte (Committee Specialist).

The participants were: Professor Stephen Holgate (University of Southampton), Professor Peter Burney (Imperial College London), Professor Adnan Custovic (University of Manchester), Professor John Warner (Imperial College London), Dr Pamela Ewan (Co-Chair, National Allergy Strategy Group), Dr Glenis Scadding (Royal National Throat, Nose and Ear Hospital), Dr Clare Mills (Institute of Food Research), Professor Aziz Sheikh (University of Edinburgh), Professor William Cookson (Imperial College London), Professor Anthony Frew (President, EAACI), Professor Tak Lee (Director, MRC-Asthma UK Centre in Allergic Mechanisms of Asthma), Professor Gideon Lack (Guy's and St Thomas' Hospital), Ms Lindsey McManus (Allergy UK), Ms Mandy East (Anaphylaxis Campaign) and Mr Alan Bell (Department of Health).

The Committee was welcomed to the Royal Society of Medicine by Baroness Finlay of Llandaff, President of the Royal Society of Medicine and Chairman of the Sub-Committee. The following presentations were heard:

What is allergy and intolerance? (Professor Kay)

Professor Kay began by introducing the concept of allergy. Since Clemens von Pirquet's original proposal of the word "allergy", the term had been corrupted and often used synonymously but incorrectly with hypersensitivity. The word "allergy" needed redefining but as there was no universally agreed definition there was still confusion.

An allergy was an exaggerated immunological response to a foreign substance which was either inhaled, swallowed, injected, or came into contact with the skin or eye. Therefore allergy was a mechanism, not a disease. In contrast, other disorders such as food intolerances and irritable bowel syndrome were not allergies because they did not involve an alteration to the immune system. The term "multiple chemical hypersensitivity" (MCS) was a misnomer as patients were not sensitised to chemicals in an immunological sense. The term MCS was used largely by lay people and doctors practising complementary medicine to describe a condition which conventional practitioners labelled "idiopathic environmental intolerance."

There were different classifications of allergy. Atopic (IgE-mediated) allergy was the domain of allergy specialists, whereas non-atopic (IgG or T cell-mediated) allergy, which caused conditions such as extrinsic allergic alveolitis and contact dermatitis, was usually managed by the appropriate organ specialists.

The mechanisms of allergy and allergic disease (Professor Holgate)

Professor Holgate discussed the mechanisms of allergic diseases, pointing out that they were often associated with an inflammatory response. For example, when a person suffered from bronchial asthma, the inflamed airways resulted in constriction, and this was often associated with remodelling or repair processes which amplified the symptoms of asthma.

Allergic symptoms were not solely due to a persistence of the allergen, but were also dependent on the genetic composition of the person and a range of environmental factors. For example, the faeces of the housedust mite contained a major allergen but the number of mites which lived in a house was dependent on the age of the house, ventilation, dampness and furnishing.

Professor Holgate explained the role of the IgE antibody in the allergic response, which involved the release of inflammatory mediators from mast cells. The T lymphocyte (T cell) was also important in determining allergic phenotypes in genetically susceptible people. There were still a number of questions to be answered, such as the role that regulatory T cells played in modifying allergic responses in early life, and why allergies were often less severe in later life. Certain types of immunotherapy could reduce allergic symptoms and it was important to find the role that T cells played in this response. The way in which the allergic and inflammatory responses in the airways interacted with structural elements to cause an increase in airway smooth muscle, and other signs of remodelling, was unknown.

Epidemiology and rising trends in allergy and asthma (Professor Burney)

Professor Burney began by describing the general increase in the prevalence of allergic disease in recent years. There had been a general increase in male asthma admissions over the last four decades, but there was a birth cohort effect, and the majority of this increase had been seen in 0-14 year olds. The trends were slightly different for women, amongst whom there was a higher prevalence of asthma at child-bearing age.

It was important to take age and gender into consideration when studying the prevalence of allergies. In general the prevalence of allergy was on the increase, but there was some ambiguity as to whether it was increasing in all age groups. The conclusion was that the incidence of atopic disease in childhood had probably stopped increasing, but older age groups were more likely to suffer from an epidemic of sensitisation in the decades to come. Entirely new food allergies were also appearing, such as allergy to kiwi fruit, but increases in allergy prevalence did not seem to correlate with increases in obesity. Professor Burney noted that policies in all areas should take account of these recent trends.

Environment and lifestyle (Professor Custovic)

Professor Custovic noted that asthma was a heritable condition, but the results of genetic studies relating to allergy prevalence were inconsistent. The fact that asthma had increased in prevalence over the last five decades was not due to a change in the genetic gene pool, but to environmental factors.

However, there was still uncertainty regarding the role that the environment played. Conflicting studies examining environmental factors such as cat ownership or breastfeeding, had shown to protect against, increase the risk, or even make no difference to the likelihood of developing allergic diseases.

It was not urban life per se that increased the risk of allergy, but affluent life. Some studies had demonstrated that an increased exposure to endotoxins reduced the risk of developing allergies, but exposure levels produced different results in different parts of the world. Professor Custovic believed that this was due to the genotype of the populations studied. Polymorphisms in "risk alleles" meant that endotoxin exposure was protective in some populations but not in others. However, a single genetic polymorphism could increase, decrease or have no effect on the risk of developing an allergic disease, as the environment played a vital role in establishing allergy. This implied that no single drug would be effective at treating allergy in everybody, so tailor-made treatments and prevention measures needed to be developed for each patient or population.

Early life origins of allergy (Professor Warner)

Professor Warner highlighted the need for a new approach to tackle allergies considering their increase in prevalence, impact on quality of life and the lack of any cure. Even in the second trimester of pregnancy, there were factors which could start to influence the risk of a child developing an allergy, such as the nutritional state of the mother. In the past it was thought that avoiding specific allergens during pregnancy reduced the chance of a child developing those particular allergies. But recent evidence had disagreed with this, and had shown that exposure to some allergens in appropriate contexts actually helped to protect children. In addition, it was thought that the genotype of a mother affected the chance of her child developing an allergy, as did environmental considerations such as whether the mother smoked or what medication she took during pregnancy.

Prevention of allergic diseases (Professor Sheikh)

Professor Sheikh noted that there were four different levels of allergy prevention: primary, secondary, tertiary and primordial. Primary prevention described interventions which aimed to reduce the incidence of disease, whilst secondary preventative interventions aimed to reduce the prevalence of disease by shortening its duration. Tertiary preventative measures aimed to reduce the impact of long-term conditions, and primordial prevention described actions that inhibited the emergence and establishment of environmental or behavioural conditions which increased the risk of disease. Immunotherapy was a valuable tertiary preventative measure, but due to the risk of hypersensitivity reactions, was no longer used regularly in the United Kingdom.

Primary preventative strategies focussed on well individuals who were yet to develop the condition, and needed to be developed using a robust evidence base. However, high quality clinical data regarding allergy prevention was limited. Professor Sheikh noted that to establish a good evidence base, future clinical studies were needed with robust methodological approaches and long-term follow-ups. Future research would need to consider genetic and environmental interactions, test multi-faceted interventions and also consider the health services involved. Data collection was hampered by the fact that investigators had difficulty accessing the range of data needed to assess the overall impact of any interventions. Innovative data linkage techniques and a change in the regulatory framework were needed to overcome these barriers.

Genetics of asthma and atopy (Professor Cookson)

Professor Cookson explained that allergic diseases were caused by both genetic and environmental factors, but it was the genetic research that had contributed to the majority of our understanding about allergic mechanisms. The study of allergic disorders was complicated by the fact that various genetic polymorphisms could predispose individuals to allergies, and allergic disorders could exhibit many different phenotypes.

A number of genome screens had been carried out to identify possible genes that may be important in the development of conditions such as asthma and atopic dermatitis. It had been found that the development of allergic conditions might be secondary to epithelial damage. It was possible that a normal bacterial flora helped the epithelial barriers to develop, and that when this barrier was deficient it predisposed the person to conditions such as asthma and atopic dermatitis.

The results of the ISAAC studies suggested that different genes were involved in allergy development in different parts of the world, and that the genetic risk was substantial. They also indicated that the genetic risk was multiplicative as combinations of certain genes could greatly increase the risk of a person developing an allergy. Since the human genome had been sequenced, there were very powerful genomic tools that could be used to measure expression levels across the whole genome, which provided a valuable insight into the function of cells and tissues. However, this technology was very expensive and it would take a long to evaluate the data produced.

Management of allergic diseases (Professor Frew)

Professor Frew emphasised that allergy prevention should be attempted where possible, but when this failed to halt an allergic disorder there were four areas of allergy management:

Diagnosis: it was vital that doctors correctly identified whether a patient actually had an allergic disorder and what triggered the attacks or episodes.

Allergen avoidance: once an allergic disorder had developed, the chances of further attacks could be minimised by avoiding the allergen or other environmental conditions which aggravated the condition. However, the question of whether the avoidance of factors such as housedust mite resulted in substantial clinical improvement, whether these approaches were cost-effective, and who should pay for such measures, was controversial.

Appropriate use of drugs: a number of drugs, such as antihistamines and corticosteroids, were used to relieve the symptoms of allergic diseases and prevent their progression. However, many allergy sufferers were not prescribed appropriate treatments because they chose to self-care rather than visit their GP. Of those who did visit their GP, a substantial proportion did not achieve full control of their disease and were not referred to specialists. It was important to empower patients who suffered from conditions such as asthma. This could be achieved by providing sufficient education and medication to allow patients to treat themselves, and by carrying out regular reviews of their management plan.

Specific immunotherapy: this involved the administration of increasing doses of allergen extract to desensitise allergy sufferers. Specific immunotherapy was particularly useful in patients at risk of anaphylactic shock following wasp or bee stings, for whom the effects of desensitisation treatment could last around 10 years. Specific immunotherapy was also useful for patients who suffered from allergic rhinitis whose symptoms could not be controlled using standard drug therapy, and for cases where allergen avoidance was difficult to achieve, such as patients who suffered from cat allergy. However, immunotherapy was still relatively expensive and there had been concerns regarding its safety.

Research funding: present and future (Professor Lee)

Professor Lee drew attention to the recent analysis of health research funding, produced by the UK Clinical Research Collaboration, which had shown that the amount of funding for research into different health categories was not proportionate to their disability adjusted life years. Research into allergic diseases crossed several health categories, and research into areas such as immunology and asthma was only partly allergy-related, so it was difficult to identify allergy funding per se.

Funding for allergy came from a variety of sources including the BBSRC, MRC, Wellcome Trust, Asthma UK and the Department of Health, but was insufficient for the level of research required. Compared to other countries, the United Kingdom was not distributing funding for allergy research in a sufficiently co-ordinated manner. Funding bodies needed to recognise that immunology, microbiology, genetics and epidemiology were all complementary when researching allergic diseases. Longitudinal interventional studies were needed to pursue long term research goals, but these required funding which could be guaranteed for a number of years. Multidisciplinary projects were important for fostering translational research.

Food allergies and intolerance (Professor Lack)

Professor Lack explained that there was a wide range of adverse reactions to food, and only some of these were allergic. An allergic reaction had to involve an alteration within the immune system directed against the specific food protein. Food allergies could have a significant impact upon patients' quality of life, and caused symptoms ranging from skin rashes and swelling of the mouth, to anaphylaxis and death. Food allergies were particularly difficult to control in children, whose diets had to be constantly monitored by their parents.

The prevalence of food allergy in children was on the increase, but there were only eight paediatric allergists within the United Kingdom, a relatively small number compared to other European countries. This meant that parents often turned to complementary procedures such as Vega testing. However, Professor Lack felt that many complementary approaches were not clinically proven and could be dangerous. In addition, unnecessary food exclusion could lead to malnutrition and the development of conditions such as rickets or iron deficiency anaemia.

Professor Lack felt that current Government advice regarding food allergies was not sufficiently evidence-based. For example, studies had previously suggested that food allergen avoidance in infancy might prevent the development of food allergies, but more recent observations had suggested the opposite. Therefore the recommendation that pregnant women and infants should not be exposed to peanuts needed re-appraising. To investigate this further, Professor Lack had been granted funding from the Immune Tolerance Network for the LEAP study. The LEAP study would investigate whether the consumption or avoidance of peanuts in infancy could affect the development of peanut allergy.

Professor Lack thought that an evaluation was also needed of DH breastfeeding guidance, which recommended exclusive breastfeeding for the first six months to protect against atopic disease. In summary, public health policies to prevent food allergies had not only been failing, but might have contributed to the problem. More funding was therefore needed to research these issues and formulate reliable public advice.

Discussion and closing remarks (under Chatham House rules)

Discussion was prompted by short presentations from Dr Ewan, Dr Scadding, Dr Mills, Ms McManus and Ms East. Discussion focussed on the following areas:

Service provision

Allergy patients often felt let down by NHS services, and parents did not know where to go for advice. Many doctors, nurses and dieticians did not recognise or understand allergy symptoms so could not appropriately treat them or refer patients to specialists. This was not only a waste of time and resources, but could prolong patients' discomfort or frustration, and could be dangerous if potentially fatal allergies were left undiagnosed. A general improvement in allergy training for GPs was therefore required.

To correctly diagnose and treat an allergic condition, diagnostic allergy tests had to be interpreted in the context of a patient's history, which required the skills of a specialist allergist. Allergy specialists were often needed to determine the cause of a patient's allergic reaction, to discover whether they suffered from multiple allergies, and to prescribe the appropriate treatment. However, many people who suffered from severe allergic reactions were not referred to allergy specialists because there was only a very small specialist workforce in comparison to the large clinical need.

Although the Department of Health had conceded the problem, its solution that PCTs should develop allergy services was not practical. In 2003, the Royal College of Physicians had recommended that one allergy centre should be established in each of the eight former NHS regions, which had been estimated to cost around £5.6 million per annum. Due to a lack of economists in clinics it was hard to estimate the financial impact of misdiagnosing and mistreating allergy. But in the long-term, it was felt that the indirect costs of undiagnosed allergies (such as the treatment of serious anaphylactic shocks and allergic complications following earlier misdiagnoses), would outweigh the initial costs of establishing allergy centres. The NHS therefore needed to develop better ways to analyse the cost-effectiveness of specialist allergy centres.

The provision of allergy services within the United Kingdom was very different to other European countries. In the United Kingdom, allergy treatment was split between many organ-based specialities, such as ENT, gastroenterology and dermatology; whereas Germany, for example, had a more cross-cutting multidisciplinary approach to allergy treatment. However, it was difficult to draw comparisons between countries because their medical systems had evolved in different ways.

Allergy research

Prevention was preferable to treatment so it was vital to prevent the "allergic march" and halt the increase in the prevalence of allergic conditions. Funding was needed for long-term research projects to investigate interventions that could reduce the risk of children developing allergies. As a large proportion of the population already suffered from some form of allergic disease, it was also important to find general principles that could be implemented to prevent their conditions worsening.

Without a clinical infrastructure to inform a national database of allergy cases, it was hard to co-ordinate clinical research appropriately. Allergy research was complicated as the development of allergic conditions depended on a number of factors including a person's genotype, exposure to environmental substances, diet and immune reactions experienced in early life. Allergy research therefore had to be co-ordinated to cover all these aspects in an integrated manner, and needed to incorporate quantitative research, social science and clinical studies. However, funding for each of these fields came from different bodies, so a co-ordinated national strategy was needed. Asthma was the only allergic condition with a research council, so there was a need for a national research strategy for anaphylaxis, food allergies, allergic dermatitis and other allergic conditions.

Further research was needed into the role that early infections played in the development of food allergies. This would require the use of well defined animal models and model systems in vitro, complemented by focussed studies in humans.

Burden of allergic diseases

It was felt that the DfES did not adequately recognise the effect of conditions such as hayfever on children's academic performance. Conditions such as atopic dermatitis could cause major problems for many people at work, leading to temporary or permanent unemployment and financial difficulties. It was therefore important to consider the socio-economic burden of allergic diseases in addition to their health impact.


There was a spectrum of allergic diseases that ranged from the mild, such as hayfever, to the severe, such as anaphylaxis. Even at the mild end of the allergic spectrum, diseases such as hayfever could have a significant social impact on sufferers. Furthermore, a large proportion of asthmatic people also had rhinitis, and research had shown that the early treatment of rhinitis could prevent the development of asthma in later life. The use of immunotherapy to treat rhinitis was therefore crucial in halting the increase of asthma and other allergic diseases. A long-term cohort study was needed to compare the effectiveness of sublingual immunotherapy and pharmacotherapy in the treatment of allergic conditions.

Complementary medicine and self-testing kits

Some private practitioners offered non-conventional procedures to diagnose and treat allergic conditions, such as kinesiology, Vega testing and the "freedom technique." There was concern that practitioners who offered these treatments exploited vulnerable patients and did not provide a reliable diagnosis or treatment. This was not only expensive for patients, but could also be dangerous if they were incorrectly informed about their risk of reaction.

It was also felt that many self-testing allergy kits, and accompanying diagnostic services, did not provide a reliable diagnosis as they did not take into account the patient's symptoms or history. Stronger regulation of these services was therefore required.

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