Approach to food avoidance

Once the diagnosis of food allergy or intolerance has been made, avoidance of the offending food (or foods) is the most important treatment.5 The diagnosis of food intolerance is not always easy, as patients often tend to blame foods for Fig. 5.1 Algorithm for the management of food tolerance. Fig. 5.1 Algorithm for the management of food tolerance. many symptoms that are both related and unrelated to food and there is no test which can reliably exclude or confirm the condition. The approach to...

Atopic eczema

A proportion of young children with atopic eczema show an improvement when selected foods are excluded from their diet.16 Common foods implicated in the causation of eczema are egg and milk, and in some cases wheat and peanut. A detailed history and skin prick tests or RAST are sometimes helpful in identifying the food, but a negative test does not exclude the possibility of benefit from a food exclusion diet. If the child is sensitised to one or more foods on skin test or RAST, a trial diet...

Avoidance therapy 521 General principles

The diagnosis of food-related symptoms should not be taken lightly, as food avoidance can be difficult, expensive, disruptive and even harmful to the health of the patient, especially in infants and young children1 (Table 5.1). The increasing complexity of our food intake and a higher proportion of packaged cooked foods in our diet make the avoidance of a particular food difficult (Table 5.2). The food industry has become increasingly important in the lives of patients with food allergy and...

Clinical categorisation of allergic reactions

In a series of 62 adults and children with peanut allergy, Ewan18 divided patients into those whose separate symptoms were symptoms involving skin and airway significant fall in blood pressure or loss of consciousness. Out of the 62 patients, 20 had skin changes only, 33 had evidence of airway involvement with laryngeal oedema or wheezing, and nine had evidence of a significant fall in blood pressure.18 The categorisation of laryngeal oedema is discussed below. Contact symptoms are common in...

Coeliac disease

Coeliac disease deserves a special mention. When discussing this lifelong condition, it is essential that it is not confused with classic food allergy. Allergic reactions usually occur within seconds or minutes of contact with the offending food, or occasionally within hours, whereas coeliac disease rarely causes such an acute, immediate reaction. This is an important distinction, because there is a danger that food companies may place gluten traces in the same danger category as nut traces,...

Common food allergies

Table 10.10 compares clinical reactions to foods, and Table 10.11 compares skinprick specific IgE reactions to foods, between allergy clinic populations from different countries. As such they deal with a selected population and some studies involve small numbers. They show that cows' milk and egg are among the 2-3 commonest foods causing allergy in most countries. Peanut, fish, soy, wheat and shellfish are among the next most common groups of foods causing allergy, although significant...

Commonly reported food allergies 1031 Cows milk

Cows' milk is an important weaning food in many countries. In recent years it has become practically ubiquitous, being found in an increasing range of commercially produced foods (Sampson 1998). There is extensive cross-reactivity between milks of different species (Businco et al. 1995, Carroccio et al. 1999). Cows' milk is one of the first foods to enter an infant's diet and therefore is often the first to cause problems. Adverse reactions to cows' milk can be divided into two main groups,...

Conclusions

The measured incidence and prevalence of adverse food reactions in a population depend largely on the precise definition and diagnostic criteria. The gold standard for diagnosing adverse food reactions is the DBPCFC but this is not suited to large epidemiological studies for practical reasons. In such studies, specific IgE alone will measure allergic sensitisation rather than clinical allergy and overestimate the true incidence and prevalence of food allergy. In such large population studies,...

Diet and behaviour problems

In children, food intolerance has been implicated in hyperactivity or behaviour disorders. It has been claimed by some that children's behaviour improved on a food diet containing few or no additives. Parents often strongly believe that food additives, especially azodyes (e.g. tartrazine), are responsible for the child's behaviour. However, scientific proof is lacking and studies have not been able to prove conclusively the effectiveness of the dietary approach. There are considerable problems...

Evolution of allergic reactions

Two of the most important features that distinguish allergic reactions associated with allergen-specific IgE are the rapid onset of symptoms, usually within 5-10 minutes of exposure to foods, and the gradual resolution in the course of one or two hours. Most mild to moderate reactions occur within this time frame. Mild to moderate reactions are generally defined as reactions confined to the skin or gastrointestinal tract, while severe reactions are those that threaten the airway or cause a fall...

Fish and shellfish

Fish is usually introduced relatively late into the infant diet and is therefore one of the less common infant food allergies. Shellfish usual enter the diet even later and adverse reactions to these are usually not seen until the teenage years or adulthood. Both fish and shell allergy are generally IgE mediated with a rapid onset of symptoms. Both have been implicated in anaphylaxis (Kemp et al. 1995, Yunginger et al. 1988, Bock 1992). There is cross-reactivity between different species of...

Foods commonly associated with allergy Table

Yunginger et al.3 and Sampson et al.4 showed the most common cause of severe food-related allergic reactions in adults and older children to be peanuts, crustaceans, shellfish, tree nuts and fish. In selected American children with atopic dermatitis (eczema), Burks et al.5 showed that skin prick testing with eight foods identified 99 of subjects who reacted to a food in DBPCFC, even if the food causing the reaction in the challenge had not been one of the foods used for skin testing. Or, put...

Foods that commonly cause allergy

Foods that can give rise to allergic reactions in susceptible individuals appear to be diverse in nature. However, although reactions to many different foods have been described in individual case reports, the list of common causal agents is relatively short. This has led researchers to postulate that there may be certain features characteristic of food allergens. Common causes of allergy are milk, egg, peanut, tree nuts, fish, shellfish, soy and citrus fruits for populations in the UK and the...

Genetic factors

If either parent has a history of an allergic disease then siblings are at increased risk of developing allergic disease, which includes eczema, asthma, allergic rhinitis and food allergy (Zeiger and Heller 1995). The risk is greater if either parent is atopic, and increases if both parents are atopic. In children with cows' milk allergy, a family history of atopy in first-degree relatives has been found in 23-80 of cases (Goldman 1963, Ventura 1988, Host 1990). Findings from a Danish study...

Implications of study design

In deciding on which study to use to estimate the prevalence of food allergy statistical, practical and financial constraints must be considered. The ideal sample would include all the individuals in the population but this is clearly impossible and our studies must be conducted on a subset of the total population. It is this down-sizing that leads to important methodological problems due to the selection procedures. The different types of study described below represent different selection...

Interpreting data on the natural history of food allergy

Cohort studies have been very successful in delineating the natural history of allergies to foods such as cows' milk and egg because they are almost completely outgrown within a few years. For longer lived allergies, such as fish, shellfish, peanut and tree nuts, the natural history is less clear because of the difficulties in interpreting the available data. This is illustrated by results from an interview survey investigating the prevalence of peanut allergy (Emmett et al. 1999). The...

Intervention strategies aimed at preventing adverse food reactions

Most of the work in this area has been directed at preventing allergic sensitisation (primary prevention), rather than the prevention or suppression of clinical disease once sensitisation has occurred (secondary and tertiary prevention respectively). Up to now, no therapy has been shown to be of value in secondary or tertiary prevention of adverse food reactions. Furthermore, whilst some studies show that pharmacological intervention may alter the incidence and natural history of asthma, there...

Introduction the law and food intolerance

The results of a food intolerance condition can vary from mild discomfort through severe pain to tragedy. How can the law help to regulate this situation and protect the consumer whilst providing a framework in which business can operate How successful is it in achieving this objective Throughout history laws have existed to protect the consumer against the adulteration of food, whether deliberate or accidental. Watering down of milk and the contamination of food with heavy metals have long...

Maternal intervention

The potential for in utero sensitisation to food allergens via the placenta or swallowing of amniotic fluid has led to a number of investigators restricting possible antigens in the maternal diet during pregnancy. The potential for sensitisation during lactation also exists as small amounts of food allergens have been found in breast milk. Beta-lactoglobulin is found in the breast milk of 95 of mothers consuming cows' milk during lactation (Host et al. 1988). Peanut and other proteins have also...

Measuring the frequency of adverse food reactions and relating this to the natural history

There are a number of ways of measuring the degree to which a population is affected by a disease process such as food allergy. The best approach depends on the question being asked. Investigators usually measure either the incidence or the prevalence. The incidence is the number of new cases of adverse food reactions developing over a specified time. This is a useful measure when studying causality and possible preventative strategies but it gives little idea of the proportion of the...

Nonimmunological mechanisms

Enzymatic food intolerance is due to an enzyme defect which could result from an inborn error of metabolism or could be secondary to a number of disorders. The most common food intolerances in this category are disaccharide deficiencies, galactosemia and phenylketonuria. Amongst disaccharide deficiencies, lactose intolerance is the most common. Lactose deficiency can be congenital, persisting in the neonatal period, or can be acquired where it presents later.19 These deficiencies are...

Novel and uncommon food allergies

There are a number of foods that are eaten in geographically or culturally quite specific populations and adverse food reactions are limited to these groups. However, with diversification of cultures and diets across the globe, particularly in developed countries, adverse reactions to these foods may be seen in many other countries. A good example is sesame seed, to which allergy in Western countries was rarely reported (Rance et al. 1999). However, there are reports of an increasing number of...

Novel treatments

IgE-mediated food allergic reactions depend on the binding of allergen with IgE antibodies bound to the receptors on the mast cells and basophils. This antigen-antibody reaction causes degranulation of mast cells with the release of preformed and newly synthesised mediators initiating a cascade of inflammatory cell influx, and production of cytokines and mediators. The clinical effect of this is an allergic reaction that may be systemic (anaphylactic reaction), or localised to an organ or...

Occupation and smoking

Respiratory diseases have known associations with those working in the food and food-related industries. These include occupational asthma, occupational rhinitis and hypersensitivity pneumonitis. Skin diseases such as contact dermatitis and contact urticaria are also associated with work in these industries. These diseases are not all Type I, IgE-mediated reactions. Some cases of occupational asthma and some of contact dermatitis occur as a result of irritation.12 Hypersensitivity pneumonitis...

Occupational food allergy

There are a number of subjects who are at increased risk of developing food allergy related to occupational exposure, virtually all mediated by an IgE reaction. The most common and best studied foods are listed below. A number of shellfish can cause occupational asthma and rhinoconjunctivitis primarily from inhalation of particles during food processing. The reactions have been demonstrated to occur with shrimp, crab and oyster handlers. Workers affected include those involved in seafood...

Patch testing

Patch testing is a diagnostic tool commonly employed in the diagnosis of contact dermatitis. This may be irritant or allergic in origin. It may be difficult and even artificial to distinguish between these two. Irritants make up about 80 of the problem, and an allergic cause can be attributed to about 20 of patients with contact dermatitis. It is rarely used in the investigation of systemically induced food allergies.12 Patch testing infants suffering from eczema with cow's milk may hold some...

Prevention of allergy

There is general consensus that the prevalence of asthma and other atopic diseases, including food allergies, is increasing. A history of allergic disease in the immediate family (atopic heredity) is the most important risk factor. Recent studies indicate that exposure to allergens in utero and in the first few months of life is critical in the development of allergic disease in children with an atopic heredity. In children at high risk, reduction in exposure to allergen should lead to a...

Prickpuncture tests

Prick-puncture tests are less sensitive and less reproducible, but more specific than intradermal tests.26 The specificity of prick tests and their superior safety profile is the reason why they are recommended by the European Academy of Allergology and Clinical Immunology and the US Joint Council of Allergy, Asthma and Immunology.25 Each antigen is placed upon the skin and introduced into the epidermis. The test is most reliably carried out on the volar aspect of the forearm, though...

References

1 ISOLAURI E and TURJANMAA K, 'Combined skin prick and patch testing enhances identification of food allergy in infants with atopic dermatitis', J Allergy Clin Immunol, 1996 97 (1) 9-15. 2 SACKETT D L, RICHARDSON W S, ROSENBERG W and HAYNES R B, Evidence-based Medicine, Churchill Livingstone, New York, 1997. 3 METCALFE D D, 'Food allergy in adults'. In Metcalfe D D, Sampson H A and Simon R A (eds), Food Allergy Adverse Reactions to Foods and Food Additives, Blackwell Science, USA, 1997. 4...

Research into allergy and intolerance

Much progress has been made in recent years in understanding the mechanisms of allergy, but our knowledge is far from complete. Despite good work done in the UK and the United States and elsewhere, it is still uncertain how and why some people become allergic to certain foods and substances. As far as the allergy sufferer is concerned, all he or she can really do is try to avoid the offending food, scrupulously carry around prescribed medication, devise an action plan for when things go wrong -...

Severe allergic reactions

Following assessment of severity, if the reaction is not thought to be immediately life-threatening, antihistamine and hydrocortisone may be given while the patient is observed in a medical facility. This can be quite dramatic, with erythema and rash all over the body surface, and swelling of the face, lips and tongue. However, if confined to the skin and oral mucosa, it is usually not life-threatening. This reaction responds to oral or parentral antihistamine in addition to corticosteroids....

Sources of further information and advice

Anaphylaxis Campaign PO Box 149, Fleet, Hampshire GU13 0FA Tel. 01252 542029 www.anaphylaxis.org.uk Deepdene House, 30 Bellegrove Road, Welling, Kent DA16 3PY Allergy helpline 020 8303 8583. PO Box 220, High Wycombe, Bucks HP11 2HY Tel. 01494 437278 Food and Chemical Allergy Association 27 Ferringham Lane, Ferring, West Sussex BN12 5NB PO Box 278, Twickenham, Middlesex TW1 4QQ Tel. 020 8892 2711 Ministry of Agriculture, Fisheries and Food Ergon House, London SW1P 3JR Leatherhead Food Research...

Specific immunotherapy

Immunotherapy (desensitisation) has been used in the treatment of allergic diseases since 1911. Extracts of allergen to which the patient is sensitised are given in increasing concentration, starting with a very dilute solution, until tolerance is achieved. Allergen immunotherapy is specific to the allergen being administered. The exact mechanism is unknown but presumably depends on the development of specific IgG antibodies which bind to the IgE receptor on mast cells and basophils, thus...

Support organisations for individuals with food intolerance

Reading, The Anaphylaxis Campaign, Fleet 9.1 Introduction In October 1993, my 17-year-old daughter Sarah died of an overwhelming allergic reaction after going into a restaurant and eating a slice of lemon meringue pie containing crushed peanuts. Sarah had thought she was only mildly allergic to peanuts and had no idea that an allergic reaction could kill. National newspaper and television reports referred to 'a very rare allergy to peanuts'. But its rarity was challenged by letters which...

The Coeliac Society

The Coeliac Society was founded in 1968 as a national support group for people with coeliac disease and dermatitis herpetiformis. Coeliac disease is a lifelong inflammatory condition of the intestinal tract which affects the small intestine in genetically susceptible individuals. This is caused by gluten, a protein in wheat, and similar proteins in rye, barley and oats. Through its national office in High Wycombe, the charity provides advice and support to people who have been, or are in the...

The diagnostic pathway

Diagnostic tests for food allergy, as with all medical tests, cannot be discussed in isolation. They are only one part of the whole diagnostic pathway. When an individual presents a particular problem to a health professional, a diagnostic pathway is embarked upon. This pathway starts with the professional taking the individual's medical history, the story of their particular problem. This is often complemented by an examination. The pathway may or may not conclude with particular tests. All...

The practical application of due diligence to food allergenicity

The key to practical implementation of the 'due diligence' defence is knowing your product. Modern foods are complex and will rarely be manufactured from a handful of fresh ingredients derived from known sources. Frequently, complex flavouring compounds and other bought-in functional ingredients will be used in order to provide the specific manufacturing properties and product attributes which are necessary to make a product successful in today's competitive world. It is therefore important to...

The use of disclaimers on food labels

In February 1994, one of the founder members of the Anaphylaxis Campaign gave a shrewd warning about the possible negative effects of any food labelling campaign companies would begin to take the easy way out by printing disclaimer notices. A leading chocolate company had already begun to include a warning under the ingredient list of two of its brands stating 'May on rare occasions contain nut traces.' And dire warnings were given that this might conceivably catch on. The prophecy has come...

Treating the immediate symptoms 551 Acute allergic reactions to foods

Development of symptoms within two hours of ingestion of the suspected food may be reasonably classified as an acute reaction. These reactions are commonly due to milk, egg, fish and nuts (Table 5.6). The person may or may not know the food responsible. In children, allergic reaction may occur to the first known exposure to a food such as cow's milk, egg or peanut. It may also develop in an Table 5.6 Foods commonly implicated in the anaphylactic reactions Tree nuts brazil nut, hazelnut, almond,...

Mechanisms of oral tolerance

Oral tolerance is very much the norm. The reason why we are not all allergic and intolerant when we eat food is due to basic mechanisms that function in the development of our tolerance. Food intolerance and food allergy is in fact a failure of oral tolerance. The existence of oral tolerance has been known for a long time, but its mechanisms are still not fully understood. A number of experimental models have been used to demonstrate this phenomenon. One such example is the oral tolerance to...

Types of foods available

Allergic reactions require large protein molecules (antigens) to stimulate the production of antibodies. To reduce allergenicity, the source protein can be broken down into small peptide molecules and amino acids by enzyme hydrolysis. This process has been used successfully in the production of hydrolysed formulae (HF). These infant formulae are based on animal or vegetable protein (casein, whey, soy and bovine collagen) and are used extensively in children with cow's milk allergy or...

Fruits and vegetables

Vegetables and fruits are staple foods in diets worldwide although the types of vegetables and fruits consumed vary widely. It is therefore not surprising that considerable geographical variations exist in respect of adverse reactions to specific fruits and vegetables. Vegetables, and more particularly fruit, may cause adverse reactions that are either IgE-mediated which most often have their onset after the first few years of life (in contrast to many other foods), or occur via other...

Cromoglycate

Sodium cromoglycate is a sodium salt of chromone-2-carboxylic acid. It inhibits the release of mediators from mast cells and basophils, although this does not fully explain its effectiveness in IgE-mediated allergic diseases. Only 1 of the orally administered dose is absorbed from the gastrointestinal tract. Oral sodium cromoglycate may be useful in some patients with multiple food allergies.12 It is a less effective but safer alternative to steroids in the management of chronic food allergy...

Skin testing

Skin testing is an in vivo method of identifying the presence in an individual of specific IgE to a given allergen.25 It is useful for both clinical practice and research purposes. Clinically it is used to supplement the patient's history and examination. Reactions to specific allergens will guide the clinician as to the specific substance that has caused or is causing the patient's problem. If the patient had a life-threatening reaction and the results of the skin prick test are concordant...

Canteen and restaurant facilities

The control of allergens extends from the production line itself to all areas of food provision within the manufacturing site. This includes canteen and Welcome to our factory.This site uses peanuts and hazelnuts in some products. Peanut or hazelnut dust is present in the air within certain areas of the factory. If you suffer allergic reactions to either peanuts or hazelnuts we recommend that you do not enter these areas of the factory at all. Please speak to your contact at this site for...

Chocolate

A 2.2-6.6 self-reporting of reactions to chocolate are reported in two questionnaire surveys (Niestijl Jansen et al. 1994, Young et al. 1994). In an American population-based birth cohort study of 480 children followed up to three years old, 1.7 complained of adverse reactions to chocolate, but none was confirmed on food challenge (Bock 1987), and chocolate is rarely a cause of positive food challenge in allergy clinics (Bock et al. 1988, Crespo et al. 1995). It is likely that the majority of...

Confirmation of presence of allergens

Once all the above steps have taken place, food manufacturers are able to make a judgement based on all the evidence obtained as to whether a product contains or is free from a particular allergen. Information should be provided to allergy sufferers to enable them to select suitable foods for their diet. The provision of information to consumers on packaged food and food sold loose is discussed later in the chapter. In addition, a number of tests are available that can be used to analyse...

OAS and pollen allergy

The frequency with which OAS occurs in subjects with pollen allergy is notable. Up to 40 of subjects with birch and ragweed allergy suffer OAS.15 Ragweed allergy is particularly associated with reactions to bananas and melons, and birch allergy with celeriac, apple and hazelnut allergens. The basis of the latter is thought to be homology between the relevant allergens, particularly Bet V 2 from birch, Mal d 1 from apple, and Bet v1 and Apig 2 from celeriac.16 Treatment of pollen allergy with...

Toxic food reactions

In principle, these are reactions which could occur in any individuals if the dose is high enough to trigger a reaction. They are usually caused by direct action of food components without involvement of immune mechanisms. Toxic compounds which trigger such reactions can occur naturally, such as from eating a puffer fish complete with its poison sac Or they can be contaminants of food. Although such reactions are fairly distinguishable from non-toxic food reactions in terms of mechanism, one...

Immunological markers

The role of cord blood total IgE as a marker for the development of food allergy is not clear. Studies do not consistently show a positive association (Dean 1997, Kjellmann et al. 1988, Kulig et al. 1999). Furthermore, in the recent German multicentre allergy study where an association between cord blood total IgE and sensitisation to foods at one year of age was found, the authors comment on the poor predictive performance of cord blood IgE (Kulig et al. 1999). This study puzzlingly also...

The epidemiology of adverse food intolerance

Lack, St. Mary's Hospital, London 10.3 Commonly reported food allergies 10.5 Cross-reactions between foods 10.7 Risk factors for the development of adverse food reactions 10.8 Intervention strategies aimed at preventing adverse food reactions

Neurological and musculoskeletal disease

Migraine is a very difficult symptom to describe and has many causes. It is familial and many people describe migraine that is related to foods. Whether it is due to direct effects of molecules that are in the food or an immunological reaction to the food is difficult to establish. The same is true for arthralgia. I am not aware of any double-blind studies that have shown an association between arthralgia and food. The association of foods with symptoms such as ME (myalgic encephalomyelitis) is...

The catering industry

So far I have concentrated on food sold in supermarkets, but it has to be accepted that the greater risks for people with severe allergies lie in catering establishments, where the owners are under no legal obligation to label allergenic ingredients. Most of the known deaths from food-related allergies have occurred when the food was eaten away from home. Although information on near-fatalities is largely anecdotal, it is almost certain that most of these incidents happen when food is eaten in...

Abbreviations

Association for Dietitians in South Africa double-blind placebo-controlled food challenge European Academy of Allergology and Clinical Immunology Food Allergy Research and Resource Program Food and Chemical Allergy Association Food and Consumer Products Manufacturers of Canada FEIA fluorescent enzymatic immunoassay FEV1 forced expiratory volume in 1 second FIDB Food Intolerance Databank (South Africa) FLEP Food Law Enforcement Practitioners GMP Good Manufacturing Practice GPSR General Product...

Brand extensions

Many brand names are now used across a wide variety of products for example, a chocolate bar brand may be used for a dessert, ice cream, drink, chocolate spread, Easter egg, and various shapes and sizes of chocolate bars. It is possible that individuals with a specific food allergy and for whom the original chocolate bar is acceptable may assume that the other products sold with the same brand name are also suitable for their diet. However, in most cases different products will contain...

Handling food allergens in retail and manufacturing

Hignett, Nestle UK Ltd, Croydon 8.1 Introduction Food allergies can be uncomfortable, severe or potentially fatal to those who suffer them, depending on the nature of the reaction. The most common advice to sufferers is to avoid consumption of the trigger food in the diet. On the surface this seems a relatively simple and straightforward means of avoiding reactions. However, the fact that some individuals can react to minute amounts of the trigger food combined with the fact that the most...

Diagnosing adverse food reactions

Different studies vary considerably in their working diagnostic criteria for food allergy. This has an important influence on the resultant measurement of prevalence and incidence in a population. In looking at IgE-mediated allergic problems, there are three levels of diagnostic criteria (1) questionnaire-based histories, (2) specific IgE and or skinprick testing and (3) food challenges (see Chapter 3). If, for example, we compare two population studies defining the prevalence of cows' milk...

Control of allergens throughout the supply chain 841 Crosscontamination

Cross-contamination is the risk of small particles of one ingredient being transferred from a product where they are added to another product where that ingredient is not present. Although it is a term that sounds negative, from a food industry point of view it simply represents the risk of small amounts of certain ingredients being present in a product to which they were not initially added. This can occur when two or more slightly different products are manufactured or packed on the same line...

Corticosteroids

Corticosteroids are indicated in severe systemic allergic reactions when intravenous hydrocortisone may be needed followed by a short course of oral steroids. Rarely, in patients with severe atopic allergy to multiple foods or where causative food(s) are not known and symptoms are severe, systemic steroids can be used on a long-term basis. The dose should be kept to a minimum because of the well-known side effects. These side effects can be explained by the mineralocorticoid or glucocorticoid...

Information for industry

Publications, CD-ROMs and training materials There is an increasing number of publications and CD-ROMs that act as reference sources for UK, EC or international food legislation. These include the Leatherhead Food RA publications Guide to Food Regulations in the UK, EC Legislation and International Food Legislation Manual, all available in hard copy or in CD format. Traditionally recognised publications such as Bell and O'Keeffe's Sale of Food and Drugs and Butterworths in the UK are valuable...

May contain statements

The statement 'may contain xxx traces' is used to show where there may be small amounts of the allergen present in the product, most likely as a result of cross-contamination. Currently it is most commonly used for peanuts and nuts. The statement must only be used where there is a real risk of cross-contamination and not as a catch-all to remove any liability. GMP and HACCP studies will identify real areas of risk and the need to use such a statement. Where it is used it needs to be clearly...

Nontoxic food reactions

These reactions are either immune-mediated or non-immune-mediated. When the reaction is immune-mediated the term 'food allergy' is applied, and when non-immune-mediated the term 'food intolerance' is recommended. Both types of reactions are reproducible and depend on an individual's susceptibility. Food allergy itself can be subdivided into two categories, IgE-mediated food allergy and non-IgE-mediated food allergy (Fig. 1.1). Immunoglobulin (Ig) E, or IgE, is the main antibody involved in...

The 25 rule

This rule is contained in European Food Labelling Legislation. It states that compound ingredients (i.e. those that themselves contain a number of ingredients, e.g. toffee, biscuits, chocolate chips) that comprise less than 25 of the finished weight of the product need only be declared as the compound ingredient and not as the constituent ingredients that make up the product. Manufacturers recognise the importance of providing information on the ingredients list to help sufferers of food...

Past medical and drug history

The patient's full past medical history, including drug history, should be documented, including other allergic and all non-allergic illnesses. The possibility of a psychiatric history should be considered. Some clusters of symptoms at presentation are more likely to be linked with psychiatric diagnoses. People presenting with multiple symptoms, and concerns over many foods and other environmental problems, have been shown to be more at risk of symptoms of depression or anxiety.10 Parents may...

Identification of allergens

The main challenge to the food industry is to provide accurate and up-to-date information at all times so that sufferers of allergies can select foods with confidence. The first step in identifying a strategy for managing allergens in the food industry is to highlight the key allergens to be controlled. These do vary from country to country, but certain allergens are seen as important in most countries. Other key allergens may vary and can be added to the list to suit the specific country for...

Key aspects of legislation from a manufacturing view

Food legislation plays an important role in the development of a policy for the handling of allergens in food manufacturing. Manufacturers have a responsibility to provide safe food for consumers, and this includes safety from an allergy sufferer's view. The obvious legislation is that which directly relates to food, such as Food Labelling Regulations. However, in addition other areas of the law need to be considered and these include relevant consumer protection legislation and requirements...

Food labelling in Europe an outline

The emphasis of European law at European Commission (EC) level is on product and consumer safety, together with ensuring the smooth operation of the internal market. The provision of consumer information, enabling consumers to make an informed choice concerning the foods they buy, is also one of the fundamental concepts of current EC law. Such horizontal provisions have generally replaced the concept of harmonisation by control of specific product standards. Labelling requirements are detailed...

Canada

The Canadian Food and Drug Regulations require the specific declaration of peanut oil, hydrogenated or partially hydrogenated peanut oil and modified peanut oil, wherever they are present, whether they are added as such or are components of ingredients. In 1998, the labelling of foodstuffs that cause severe reactions in certain individuals was the subject of a review by a joint committee from the Canadian Food Inspection Agency and Health Canada. The Canadian authorities have recognised the...

Summary

In this chapter we have seen something of the difficulties which face customers who may have an allergic reaction to a particular food ingredient. We have also seen something of the difficulties faced by food manufacturers in meeting the growing clamour for a greater variety of prepared foods at lower cost whilst trying to safeguard the interests of allergy sufferers. It would be impractical to eliminate from the diet food ingredients which are perfectly harmless to the vast majority of the...

Introduction

Whilst food labelling on manufactured foods appears detailed, it still does not identify every allergenic component within the product. This is because current labelling regulations in some countries permit the manufacturer to use class or generic ingredient names, such as vegetable oil, and not always to have to list the individual components of compound ingredients if they are present in small quantities. The increased awareness of food allergy and intolerance in recent years has led to...

Techniques for identifying allergens and quantifying allergenicity

A number of techniques have been used to identify allergenic proteins, most being based on the principle of Solubilising extracting proteins Isolation of protein fractions Determining IgE binding ability of each fraction Characterisation of the protein glycoprotein and larger-scale purification. The techniques most often used in the current literature for allergen identification are Separation on a gel such as SDS PAGE followed by Western blotting and immuno-labelling Separation by...

Person Responsible Mixer operator

Action Required Disposeof all nutpackaging materials once used Corrective Action If nut packaging materials are observed in use for other purposes report to LINE MANAGER immediately background to the HACCP studies and the actions that must be taken. Briefing about allergies should be included in all induction sessions and regular updates will ensure that staff continue to be well informed. It is particularly important that information is given to all those who work in an area that handles nuts...

Summary trends in treatment

Despite recent advances in our knowledge of immune processes involved in food allergy and intolerance, there have been few major developments in the treatment of this common condition. Avoidance of the offending food remains the mainstay of treatment. Pharmacological therapy is useful in acute reaction due to inadvertent exposure but generally disappointing in the treatment of chronic food intolerance. The importance of a detailed history cannot be overstated. The diagnosis can often be made on...

Predisposing factors for anaphylaxis

It is clearly established now that pre-existing asthma may exacerbate or predispose to anaphylaxis. This is clearly in keeping with the concept of the target organ of the reaction being important. Sampson's group of fatal and nonfatal reactors were clearly distinguished by the presence of a diagnosis of asthma, particularly if the asthma was poorly controlled. Our study in Southampton has supported this finding (Table 4.4).10,21 Other factors that may predispose to severe disease are the use of...

Examination

A general examination of all the major systems of a patient normally supplements the clinician's history taking. In the case of paediatric examination, in particular, it should include the measurement of parameters of growth -height, weight and head circumference - which should be recorded on an appropriate centile chart. Chronic illnesses such as coeliac disease and poorly controlled asthma may result in a thin, short child, as do the use of long-term high-dose steroids. The examination of the...

Introduction the range of treatments

Treatment of food intolerance is primarily by elimination of the food from the diet. This may be a difficult task for a number of reasons. It may not always be possible to identify the foods responsible for the symptoms. Some foods are consumed so frequently that simple elimination without adequate replacement may lead to nutritional deficiencies. Other foods, such as egg and nuts, may be hidden in prepared foods such as cakes and biscuits, and occasional inadvertent exposure may occur.

The Food and Chemical Allergy Association

The Food and Chemical Allergy Association, based at 27 Ferringham Lane, Ferring, West Sussex BN12 5NB, came into being as a result of a letter sent to a daily newspaper in 1976 by its founder, Ellen Rothera. She had been ill for eight years and came to believe that food allergies due to a malfunctioning immune system were the root cause. She managed to stabilise her condition and make a recovery. Ellen's letter to the Daily Express was not only published, but given a leading position. As a...

Labelling and promotion

The majority of manufactured and packaged food products have to carry a full list of the ingredients they contain by law. The list shows the ingredients in descending order of weight in the finished product. There are currently no provisions made under either UK or EU food legislation which require potential allergens to be labelled. Whilst there is a general requirement that all ingredients added to a food must be declared on the ingredients list, in accordance with the Food Labelling...

Food Labelling Agenda

FLAG (Food Labelling Agenda) is a national consumer pressure organisation launched in June 1997 by a group of concerned food and health writers. The organisation campaigns for 'clear, comprehensive and meaningful labelling on all food and food products' and its first task in March 1998 was to deliver a petition calling for improved food labelling to Downing Street. It won support from a huge number of individuals and organisations, including those with interests in allergy, genetic engineering,...

Contributors

The David Hyde Asthma & Allergy Research Centre St Mary's Hospital Newport Tel +44 (0)1983 534187 Fax +44 (0)1983 534907 E-mail dean port.ac.uk tara.dean iowht.swest.nhs.uk Tel +44 (0)1983 534187 Fax +44 (0)1983 534907 Dr Jonathan Hourihane Institute of Child Health 30 Guildford Street London WC1N 1EH Tel +44 (0)20 7242 9789 Fax +44 (0)20 7813 8494 E-mail J.Hourihane ich.ucl.ac.uk The David Hyde Asthma & Allergy Research Centre St Mary's Hospital Newport Tel +44 (0)1983 534373 Fax +44...

Sources of further information and advice 691 Consumers

'Free-from' lists from supermarkets and companies 'Free-from' lists covering own-label products are available from Waitrose, Sainsbury, Tesco and Safeway. These lists cover the standard ingredients covered by the UK Food Intolerance Databank, plus peanut and nuts. Asda contributes data on its own-label products to the UK Food Intolerance Databank. Some of the major food companies also provide 'free-from' information on their products direct to customers. Most of the major food companies will...

Hypoallergenic milk formulae7

CMA in the first year of life is one of the most common problems faced by paediatricians. It is mediated by an immune mechanism, whereas cow's milk intolerance is due to non-immunological causes such as lactase deficiency. CMA may affect the gastrointestinal tract, respiratory tract, skin or blood, and systemic reactions, including anaphylaxis, may occur. Avoidance is the mainstay of treatment, and breast-feeding should be actively encouraged. Since intact cow's milk protein can pass into the...

Geographical variations

Data concerning the incidence of adverse food reactions from different countries may shed some light on factors that might be important in the development of adverse food reactions. These factors include genetic, cultural, dietary and other environmental differences. Unfortunately all the cohort studies are from Europe, Australia and the USA, with no comparable data from other countries. However, there are case series from these other countries that allow comparisons to be made between foods...

Websites and addresses

American Academy of Allergy, Asthma and Immunology www.aaaai.org Anaphylaxis Campaign PO Box 149, Fleet, Hampshire GU13 0FA Tel. 01252 542029 www.anaphylaxis.org.uk Deepdene House, 30 Bellegrove Road, Welling, Kent DA16 3PY Tel. 020 8303 8525 Fax. 020 8303 8792 www.allergyfoundation.com Food Allergy Network www.foodallergy.org Ministry of Agriculture, Fisheries and Food www.maff.gov.uk Ortolani C, Bruinzeel-koomen C, Bengtsson C et al. 'Controversial aspects of adverse reactions to food',...

Gastrointestinal symptoms

Diarrhoea, vomiting and abdominal colic are common manifestations of food intolerance but may also be due to infective or other causes. The cause should be established by appropriate investigations. Food intolerance causing gastrointestinal symptoms could be due to enzyme deficiency and immunological and non-immunological reactions to foods. Cow's milk intolerance is a common problem during infancy that can be treated by excluding cow's milk from the diet. Replacement with soya milk or...

Careful history

History gathering, as discussed earlier, should concentrate on the most likely foods and symptoms. Clearly some patients will not be suitable for a food challenge. Some patients will not be prepared to have what may be strongly held beliefs investigated, and the history should include some assessment of the suitability of the patient for the procedure. Other pieces of additional information essential for the design of the challenge include the timing between the ingestion of the food and the...

Collaboration with the food industry retail and manufacturing

Soames's statement that any change in labelling legislation is a European matter is quite true. That prospect was an alarming one for campaigners who were concerned about food-induced anaphylaxis and the risks of allergy sufferers inadvertently coming into contact with lethal ingredients. Soames seemed to be implying that it would be several years before all prepacked food would be adequately labelled and therefore safe. A major point for discussion was the 25 rule governing compound...

Additional communication initiatives

The ingredients list on the label of a product is the most accurate way of assessing the suitability of a product for a sufferer of allergies. However, reading labels is a laborious and time-consuming process and makes shopping a lengthy ordeal. Most companies and retailers now produce lists of products free from key allergens which make food selection much quicker and easier. The lists are available from the companies directly and are often on the Internet. Once again peanut and nut allergies...

Food additives

The commonest food additives thought to cause adverse reactions are tartrazine (E102), sunset yellow (E110), annatto, aspartame, benzoic acid and sulphites (Fuglsang et al. 1993). Key epidemiological studies are shown in Table 10.9. Adverse reactions to food additives can occur at any age. A UK study showed a higher reporting of adverse reactions to food additives in the first ten years of life, and more often occurring in females (Young et al. 1987). The mechanism of the reaction is often...

The Anaphylaxis Campaign

The Anaphylaxis Campaign, of which I am director, was set up early in 1994 following five well-publicised deaths caused by allergic reactions to peanuts or tree nuts. Those who died included my teenage daughter Sarah, whose death was particularly shocking because her previous allergic reactions to nuts had been mild. As a journalist, I had some expertise in gathering information and there were indications early on that, far from being rare, nut allergy was really quite common. Supported by my...

Immunological mechanisms

These reactions are the most frequent, the best known and the easiest to diagnose. They occur when an individual is already sensitised. In susceptible individuals, when a food allergen is encountered for the first time, the adaptive response initiates production of IgE antibodies. IgE antibody production itself is regulated and depends upon compounds known as cytokines. Once IgE antibodies are produced, they will bind to mast cells. This process, known as sensitisation, precedes symptoms of...

Sources of information and labelling

Smith, Leatherhead Food Research Association 6.2 The UK Food Intolerance Databank 6.3 The Dutch Food Intolerance Databank (ALBA) 6.4 European food intolerance databanks 6.5 Other international databanks 6.6 Food labelling in Europe an outline 6.7 Current and proposed labelling requirements for ingredients causing hypersensitivity 6.9 Sources of further information and advice

Interpretation of skin tests

The size of the weal-and-flare should be read at the peak of its reaction, after approximately 10-20 minutes. A copy of the weal-and-flare reaction should be transferred using pen and clear tape, to ensure a permanent record is kept. The mean of the longest and midpoint orthogonal diameter of the weal has been shown to correlate well with more precise planimetry methods, despite the weal often having a rather irregular shape. The 'cutoff' at which one declares a test positive will influence the...

Australia

Under the Australian Food Standards Code, Standard A1, compound ingredient provisions are detailed whereby, in common with the EC, if an ingredient contributes less than 250 g kg (25 ) of a food, food additives are the only components that must be declared. In contrast to EC law, unless specifically required, if an ingredient contributes less than 100 g kg (10 ) of a food, the components of the food need not be declared. However, the Standard does require that the presence of peanuts must...

Purchasing raw materials

All raw ingredients such as flour, milk, nuts and fruit, and compound ingredients such as processed cereals, chocolate, biscuits or toffee must be purchased against a detailed specification. This must include the nature of the product, the ingredients included in a compound ingredient, and any risks of cross-contamination that may occur in the production or packing of the ingredient that is purchased. Supplier Quality Assurance is a system whereby suppliers are audited to ensure that they meet...

The accuracy of diagnostic tests

Every disease has a rate of prevalence and incidence within both the general population and specific populations. The term 'prevalence' is a statistic based upon a particular point in time. It refers to the number of cases of a particular disease divided by the total number of people within the population and is usually represented as a percentage. 'Lifetime prevalence' is the number of people within a population who may have a particular disease at some time in their life, expressed as a...

Crossreactions between foods

Cross-reactivity is due to a reaction to identical or similar protein allergens that occur in more than one food, or in a food and an inhalant pollen. This is different from associated reactivity where two or more food allergens may be seen to be associated epidemiologically. A good example of the latter is the high rate of association between egg and peanut allergy although the allergens are not related. Establishing a cross-reaction requires the demonstration of at least a positive...

The Dutch Food Intolerance Databank ALBA

ALBA is perhaps the most influential of the food intolerance databanks worldwide. It was established in 1982 by the Agricultural University of Wageningen and became operational in 1984. Since 1988, the databank has been hosted by a division of the government research organisation Netherlands Organisation for Applied Scientific Research (TNO), located in Zeist. ALBA currently holds data on around 500 brands and 11 000 products from 150 manufacturers and retail organisations, representing...

The EC situation

Currently, under EC labelling legislation, there is no need to make a specific declaration in respect of the presence of potential allergens, although product liability laws might influence a decision to make such a declaration. However, the need for such information to be covered by food labelling legislation, in line with current Commission intention, is now widely recognised. A further amendment to Directive 79 112 EEC is already under discussion, which would concern the labelling of...

Open patch test and the diagnosis of contact urticaria

Some food substances can induce an immediate urticarial-type reaction at the point of contact. No standardised test exists for investigating such contact urticaria, but one can demonstrate such a reaction by an open test. The substance is placed on the skin of the flexor surface of the forearm for 30-45 minutes in an attempt to replicate the urticaria. It may be necessary to use non-intact, eczematous skin. This contact urticaria may be secondary to an allergic or non-allergic reaction. In the...