Select Committee on Science and Technology Minutes of Evidence

Letter from Professor Chris Corrigan, Professor of Asthma, Allergy & Respiratory Science and Consultant Physician, Guys Hospital

  I am pleased to submit written evidence for this Committee in my capacity as Consultant Allergist and Researcher at Guy's Hospital, London, which is one of the biggest NHS centres for treatment of allergic disease in the UK, as Educational Supervisor to two allergy SpR trainees, as Secretary of the Joint Committee on Higher Medical Training Specialist Advisory Committee on Allergy and as counsel member of the British Society for Allergy and Clinical Immunology, the professional body for clinical and non-clinical doctors and allied health and other scientific professionals working in the field of allergy.


  Allergic diseases represent a particular class of immunological "hypersensitivity" reactions ("hypersensitivity" reactions are immunological responses produced in certain persons which, instead of being advantageous to the person, such as in fighting off infections, are actually harmful by causing tissue damage, disruption of vital organ function and even death). Allergic hypersensitivity reactions occur because certain individuals have a propensity to produce an allergic antibody called IgE, which recognises external foreign proteins which find their way to the mucosal surfaces of the skin, airways or bowels of predisposed patients. The particular proteins which set off these responses are collectively called "allergens". It is not known why some individuals make IgE antibodies to allergens whereas others do not, even though everyone is exposed to a broadly similar range of allergens by breathing them in or swallowing them. Once the allergic IgE antibodies are formed, they coat the surfaces of special inflammatory cells in the tissues or circulating in the blood called mast cells and basophils respectively. Further exposure to allergen then causes these cells to degranulate or burst, releasing a number of toxic inflammatory substances including histamine, leukotrienes and prostaglandins. Allergic reactions are characterised by their immediacy: that is, exposure to allergen causes mast cells and basophils to release their toxic inflammatory substances within seconds of exposure. This is why allergic reactions belong to the class of hypersensitivity reactions called "immediate hypersensitivity". Histamine, prostaglandins and leukotrienes induce generalised effects on the body, particularly lowering of the blood pressure which can lead to fainting, collapse and cardiac arrest, constriction of the bronchi or breathing tubes, causing shortness of breath and wheeze which may be particularly severe in asthmatics, and the swelling of the tissues, which may cause a rash on the skin but also swelling of critical organs such as the larynx which may block the airway and is another potential cause of death in severe allergic reactions.

  As allergists we recognise quite clearly which diseases are caused by, or made worse by allergic "hypersensitivity" reactions. These include asthma, allergic rhinitis (including hay fever), eczema, anaphylactic reactions to bee and wasp stings, reactions to latex proteins and some, but not all reactions to foodstuffs and drugs. In contrast the general public and many medical and allied health professionals, because they have had little training in allergy, tend to classify a much wider range of reactions to external agents as "allergic" inappropriately. This is typified by the situation with food allergy and intolerance. Food allergic reactions are immediate, reproducible and evolve with a very typical pattern in allergic individuals. It is possible to tell whether or not patients have true food allergy with a brief history and relevant simple tests. On the other hand, many patients (and often their doctors) attribute a range of non-specific symptoms to foods which occur much later after they have been eaten and very widely in their clinical manifestations. There is little or no evidence that such late reactions are caused by reactions to foods, and the term "allergy" is in this case not appropriate. If late reactions to foods do occur (and there is no definite evidence that they do except in rare patients with very well defined inborn areas of metabolism which cause biochemical abnormalities after eating certain foods, and with the exception of coeliac disease, a rare non-allergic hypersensitivity reaction to gluten found in various grains), their mechanisms are uncharacterised and consequently there are no suitable diagnostic tests.

  Allergic disease is characterised by the so-called "allergic march" in which infants predisposed to allergy typically developed severe eczema soon after birth. This is followed by manifestations of food allergies, typically to cow's milk, egg, grains, nuts and fish which develop about the time these foods are introduced into the infant's diet, and later allergic rhinitis and asthma. In such patients, allergic reactions to foods and airborne allergens such as pollens and animal danders can be demonstrated by simple tests such as skin prick tests. One of the major mysteries in allergy, however, is the fact that many of these diseases tend to remit clinically as the child gets older, yet this is not usually accompanied by produced production of allergic IgE antibodies. Having an allergic reaction is not, therefore, simply a question of whether or not the body makes IgE antibodies. Clearly, there are whole layers of understanding to be uncovered about what governs the presence and severity of clinical allergic reactions in patients and how this varies with time. It seems very likely that environmental factors, as well as possible genetic predisposition of certain individuals govern these processes, but little or nothing is known about their nature.

  Although there is unequivocal evidence that the prevalence of allergic diseases is rising with epidemic proportions, it is also very clear that the burden of disease is grossly underestimated for all types of allergy. There are several factors operating here. First, because allergy has only recently existed as a separate medical speciality in the UK, specific allergy training never has been, and still is not included in undergraduate and postgraduate medical training curricula, much of it goes unnoticed. For example, many patients with chronic allergic rhinitis are characterised as having a "permanent bad cold" and suffer needlessly for years on end when they could be helped by appropriate allergy diagnosis, identification of causal allergens, appropriate allergen avoidance advice and ancillary medical treatment. Many cases of acute "asthma" presenting to casualty departments are in fact acute anaphylactic reactions (a severe, generalised allergic reaction which may be fatal) caused by oedema of the larynx referred to above, and not asthma at all. Even experienced accident and emergency and general internal medical consultants have had little training in the recognition and subsequent management of allergic diseases. Food allergy reactions in infants often go unnoticed, since the symptoms of anaphylaxis are less dramatic (but still potentially lethal) in infants as compared with adults. Yet food allergy can cause untold suffering in children, with exacerbation of coexisting eczema, asthma and rhinitis. A further gap in recognising the burden of disease is that, because there is not NHS infrastructure for the management of allergic problems, many patients elect to treat themselves, often very unsatisfactorily, and never present to a medical practitioner. In many areas of the UK, there exist no allergy specialists to see these patients even if they do decide to seek help. A clear solution to all of these problems is to establish a network for allergy treatment across the UK, a course of action which was recommended recently by the House of Commons Health Committee but sadly ignored by the Department of Health.

  The socio-economic impact of allergic disease is tremendous and largely unrecognised. Untreated allergic rhinitis, for example, is in the top five causes of lack of sleep in the general population. It is also in the top five causes of loss of time from paid employment. Asthma rates slightly higher in the league table of causes of loss of days at work or school, with enormous socio-economic implications. For example, over 12.7 million working days are lost to asthma each year. Asthma costs the NHS an average of £889 million annually. One child in every year of every school in the UK now has peanut allergy, and in some children this is potentially fatal. Away from impressive statistics, bad hay fever in the summer ruins the social lives, morale and examination performance of millions of young adults every summer.


  Until recently no known treatment was proven to alter the natural history of allergic disease. There are recent exciting suggestions that certain forms of immunotherapy, particularly with modified allergens, may do so. While pharmacological and non-pharmacological therapies (not least sensible and authoritative allergen avoidance advice) have had a major impact on the burden of allergic symptoms, the key to cracking allergy is prevention.

  At present the level of research aimed at understanding the natural history of allergy, the role and scope of primary prevention and altering the natural history of the disease for the better is grossly inadequate. We have been lucky enough to set up, in collaboration with King's and Imperial Colleges, Asthma UK (the country's leading asthma charity) and the Medical Research Council the first MRC Centre for allergic mechanisms of asthma. Apart from this, allergy research is performed in isolated centres of excellence by a small handful of interested individuals. The lack of an organised and structured NHS allergy service has greatly hampered this process, resulting in few young doctor trainees who are interested in doing it, and lack of nationwide access to patients to participate in research projects.

  The most promising areas of research into preventing or treating allergy at present might be summarised as follows:

    (1)  Strategies for prevention: attention to maternal and foetal nutrition, and other early interventions, such as allergen vaccination, which may alter the evolution of allergic disease.

    (2)  Measuring and assessing life-time allergen load and exposure.

    (3)  Drug allergy: organised clinical and epidemiological research, with assessment of outcomes of management by allergists.

    (4)  Further development of allergen immunotherapy (the practise of exposing allergic individuals to progressively large quantities of the allergen at a distinct mucosal surface, such as by injection or under the tongue) is of proven therapeutic benefit. For example, patients with anaphylactic reactions caused by allergy to bee or wasp stings can now be cured of this problem with immunotherapy. With hayfever, immunotherapy can vastly reduce symptoms and transforms sufferers' lives. There is also evidence that immunotherapy reduces the need for conventional medical therapy in asthma. Most interesting of all, however is the evidence that early immunotherapy may reduce the incidence of new allergic sensitisations and the emergence of clinical allergic disease in infants and children. Advances in the formulation and practice of immunotherapy are being made all the time. For example, sublingual immunotherapy for grass pollen allergy has recently become available in the UK. New modifications to allergens to increase their ability to turn off the allergic immunological hypersensitivity response, through better understanding of the immune system and how responses to allergens are regulated, are emerging all the time. There is abundant scope for a nationwide initiative to investigate the efficacy and long-term effects of these interventions. This is likely to save the health service millions of pounds in the medium to long term, not to mention the socio-economic impact of reduced loss of time at work and school.

    (5)  Investigation of what factors determine an individual's susceptibility to allergic disease. As mentioned above, this is not simply a question of whether or not they make allergic IgE antibodies to a particular allergen. Virtually nothing is known about this field, yet it promises such scope for understanding the role of heritable and environmental factors in turning clinical allergic reactions on and off.

    (6)  The impact of early intervention in food allergy, in terms of manipulation of maternal diet and the introduction of possible ancillary substances which will head off the development of an allergic response. Despite increasing interest in the role of a foetal and maternal environment in governing the evolution of allergic disease in susceptible patients, few concrete recommendations have so far been possible, and this reflects lack of appropriate and directed research.


  To my knowledge, apart from the publication of pollen counts which are generally measured by private organisations, no government policy has directly addressed the epidemic of allergic disease or produced sufficient public information to aid sufferers with self treatment or by providing the impetus to seek specialist allergist advice. Housing policy and regulations pay little or no attention to allergy, even though the environment likely plays a major role in the epidemic rise in allergic disease. Factors such as nitrogen dioxide emissions from gas burners, the emission of volatile organic compounds from mass produced furniture and the growth of moulds and other allergens in damp or ill ventilated homes may all play a very important role in the epidemic of allergy. Simple design of homes to minimise the accumulation of allergens such as dust mites, or more research into effective means of ventilation and control of humidity might revolutionise suffering from allergic disease. Food policy and labelling regulations have gone some way to help food allergy sufferers, but on the other hand, largely to protect themselves from legislation, many companies have overstated the likelihood of their products containing particular allergens (a typical example is the label that a food "may contain nuts"). Such practices are not helpful to the sufferer who may die from anaphylaxis from accidental nut exposure, and the situation may require expert dietetic input which is really only available at dedicated allergy centres.


  Even notwithstanding the impact of allergies on the quality of life of sufferers and their families, the figures, only a few of which I have quoted above, really speak for themselves. It is absolutely inconceivable to allergists how these issues are ignored when allergic disease is one of the leading causes of morbidity, suffering, NHS expenditure and socio-economic loss in the UK. It is widely perceived that this outrageous anomaly arises simply because allergic diseases are not political "hot potatoes" like cancer and heart disease. Certainly, government spending, health priorities and public education are certainly not the slightest bit attuned to the prevalence and impact of allergic disease.

  Finally, may I say a final word about "over the counter" allergy tests. Many so called "allergy" tests performed, for example, in health food stores or alternative medicine emporia are of no diagnostic value whatsoever. Furthermore, they are misleading in the sense that the patients are often given a completely erroneous and ad hoc list of foods or other substances they should apparently avoid, which not only does not treat the allergic disease but also leads to inappropriate dietary restriction, sometimes to the point of starvation, particularly in children with anxious parents. Even "over the counter" tests of accredited diagnostic worth, such as RAST (a blood test for allergic IgE antibodies), are effectively useless unless interpreted in the light of the patient's history, which can only be done by an experienced allergist. It is a constant source of dismay to allergists that practitioners offering so called "allergy tests" of no diagnostic value are allowed to set up shop and dupe the public in such an outrageous manner, seemingly with no legislative control at all. The fact that these services are used so widely is on the other hand no doubt a reflection of the desperation of allergy sufferers in obtaining access to any form of help at all.

  In conclusion, allergy could effectively be managed in the long term if the Department of Health was to allocate adequate resources and "kick start" the service across the country. This would lead not only to a structured system of management of patients with allergic diseases across the UK, but would also form an invaluable platform for research.

  At present, after rising from the ashes about six years ago, the speciality of allergy is once again struggling at the brink of death in the UK. Despite recognition of the speciality and a clear, full and exciting training programme, there are currently just eight young trainees in allergy across the entire UK. They are increasingly disillusioned about their future careers and see no growth of specialist centres where they can practise their art. The situation is something of a vicious circle since there are correspondingly few centres at which allergists can be fully trained. A career in allergy is exciting and offers a real opportunity significantly to improve the lives of a vast range of people, young and old. It is imperative that the Department of Health facilitates a career pathway for these young people by undertaking the clear recommendations of The Royal College of Physicians and of the House of Commons Select Committee. I therefore implore the honourable members of the Committee to consider this dilemma gravely and beg them to take the appropriate action.

6 October 2006

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