Food allergy has been recognised as a major paediatric health problem in western countries. Although the true figure is unknown, the prevalence of food allergy in Europe and North America has been reported to range from 6%–8% in children up to the age of 3 years.1
The need for the guideline
In 2006, the Department of Health reviewed allergy services and concluded that there was considerable variation in allergy care, with no agreed treatment pathways, referral criteria, or service models.2 Most NHS allergy care in the UK takes place in primary care and most cases of food allergy present in this setting. In a survey from 2004, GPs expressed concerned about their ability to diagnose and manage children who have allergic problems. They were also unsure about the management of food allergy.3
Few GPs receive formal training in food allergy as part of undergraduate or postgraduate training. It is known that many people with allergies practise self-care, using alternative sources of support (e.g. complementary services with non-validated tests and treatments) rather than NHS services.2
The NICE guideline Diagnosis and assessment of food allergy in children and young people in primary care and community settings aims to provide consistency in the assessment and diagnosis of food allergy in children and young people (from birth up to 19 years of age).1 A correct diagnosis can help reduce the incidence of adverse reactions to food allergens. At present, even without a medically confirmed diagnosis, children may have foods removed from their diet because of a suspicion of food allergy. By empowering primary care clinicians with practical guidance on how to identify signs of a food allergy and subsequently confirm or exclude the diagnosis, it is hoped that children and young people with symptoms suggestive of this condition will be able to get a timely and accurate diagnosis, thereby reducing the number of allergic reactions to foods and avoiding unnecessary dietary restrictions.
Types of food allergy
Food allergy is an adverse immune response to a food. It can be classified as either immunoglobulin E (IgE)-mediated or non-IgE-mediated. Some children show both IgE- and non-IgE-mediated reactions to food and these are referred to as mixed reactions. IgE-mediated reactions are immediate onset type 1 hypersensitivity reactions. The mechanism of non-IgE-mediated reactions is poorly understood but reactions usually occur several hours after allergen exposure and are thought to be T-cell mediated.1 In both IgE- and non-IgE-mediated reactions, the immune system reacts adversely to a protein within a food and elimination of this allergenic food protein is required to prevent symptoms.
The NICE guideline only covers reactions to food where the immune system is involved. Non-immunological reactions to food (often referred to as food intolerances) are not included (e.g. lactose intolerance where the lack of the enzyme lactase prevents the absorption of the sugar, lactose).
Recognition of symptoms
To ensure prompt recognition, it is essential that GPs and other primary healthcare professionals are educated regarding the diverse symptoms that can result from food allergy. Failure to recognise these symptoms can result in unnecessary and costly investigations, medications, and referrals (see Box 1, below).
It is important to consider food allergy in persistent eczema,4 gastro-oesophageal reflux disease (GORD), and chronic gastrointestinal symptoms (including chronic constipation) that has not responded adequately to treatment.1
|Box 1: Signs and symptoms of possible food allergy*1|
|The gastrointestinal system|
|The respiratory system (usually in combination with one or more of the above symptoms and signs)|
* Note: this list is not exhaustive—the absence of these symptoms does not exclude food allergy.
National Institute for Health and Care Excellence (NICE) (2011) CG116. Food allergy in children and young people. London: NICE. Available from www.nice.org.uk/guidance/CG116 Reproduced with permission.
Allergy focused clinical history
Obtaining a clinical history and asking specific allergy focused questions is extremely important during diagnosis. The NICE guideline states that this can be done by GPs or other primary healthcare professionals with the appropriate competencies.1 The questions suggested for an allergy focused clinical history are shown in Box 2.
On examination of the child or young person, the healthcare professional should pay particular attention to growth, physical signs of malnutrition, and any signs indicating allergy related co-morbidities (e.g. atopic eczema, asthma, and allergic rhinitis).1 This may result in findings that indicate atopic conditions, which had not been previously diagnosed and may not have been obvious from the history. Discovery of these makes food allergy a more likely diagnosis. If the child's growth is poor and there are signs of malnutrition, the need for referral is greater regardless of whether food allergy is suspected.
|Box 2: Allergy focused clinical history1|
|National Institute for Health and Care Excellence (NICE) (2011) CG116. Food allergy in children and young people. London: NICE.
Available from www.nice.org.uk/guidance/CG116 Reproduced with permission.
The patient’s clinical history should help determine whether the mechanism of the reaction is likely to be IgE- or non-IgE-mediated.
If clinical history suggests an IgE-mediated (or mixed) reaction, the child or young person should be offered a skin-prick test and/or blood tests to look for specific IgE antibodies to the suspected foods and likely co-allergens.1 Atopy patch testing and oral food challenges are not recommended for diagnosis of IgE-mediated disease in primary/community care.1
Studies show that both the skin prick test and specific IgE antibody test are similar in diagnostic performance.1 It was not possible to determine which test was more cost effective. The costing report (available on the NICE website), which accompanies the guideline, has more information and may be a useful tool for those considering the provision of allergy services.
The choice of test should be determined by the competencies of the healthcare professional and by what is suitable, safe for, and acceptable to the child or young person.1 The tests requested should be guided by clinical history and the results need to be interpreted by someone trained to do so. Skin-prick testing should only be performed by those skilled in the procedure and under conditions where an anaphylactic reaction could be managed.1 The Guideline Development Group acknowledged that skin-prick tests could be carried out in community settings where facilities are similar to those used for routine childhood vaccinations.1 As skin-prick testing is currently uncommon practice in primary care, consideration will have to be given as to whether this service is made available. There are likely to be training needs for healthcare professionals involved in ordering and interpreting either form of testing.
When the history suggests a non-IgE mediated reaction, a trial of elimination and then reintroduction of the suspected allergen is recommended.1 The suspected allergen should be removed from the diet and reintroduced after 2–6 weeks.1 The NICE guideline recommends consulting a dietitian with appropriate competencies about nutritional adequacies, timings of elimination and reintroduction, and follow-up.1
Provision of information
Although there was little supporting evidence, it was considered important for the following information to be offered to the child and their parents/carers once the initial history has been taken:1
- Type of allergy suspected
- Risk of severe allergic reaction
- Potential impact of the suspected allergy on other healthcare issues, including vaccination (NB the measles, mumps, and rubella vaccine is not cultured on eggs, and the amount of egg protein is negligible. However, the influenza and yellow fever vaccines contain measurable amounts of egg protein5)
- Diagnostic process, which may include:
- an elimination diet followed by a possible planned re-challenge or initial food reintroduction procedure
- skin-prick tests and specific IgE antibody testing, including the safety and limitations of these tests
- referral to secondary or specialist care.
If a trial food elimination diet is proposed because of suspected non-IgE-mediated food allergy, the child and their parents/carers should be offered the following information on:1
- what foods and drinks to avoid
- how to interpret food labels
- alternative sources of nutrition to ensure adequate nutritional intake
- the duration, safety, and limitations of an elimination diet
- the reintroduction procedure and its safety and limitations.
Additional information should be given to the parents or carers of babies and young children with a suspected allergy to cows' milk protein:1
- Food avoidance advice to breastfeeding mothers
- Information on the appropriate hypoallergenic formula or milk substitute to mothers of formula-fed babies.
Information should also be offered about the support available, including details of how to contact support groups.1 It may be that as part of the implementation process, information sheets could be produced locally to provide this information. In our practice, some of the dietary information is also provided in a written format to be given to patients and carers.
NICE has developed the following tools to support implementation of Clinical Guideline 116 on Food allergy in children and young people: diagnosis and assessment of food allergy in children and young people in primary care and community settings. The tools are now available to download from the NICE website: www.nice.org.uk/CG116
Audit support has been developed to support the implementation of this guideline. The aim is to help NHS organisations with a baseline assessment and to assist with the audit process, thereby helping to ensure that practice is in line with the NICE recommendations. The audit support is based on the key recommendations of the guidance and includes criteria and data collection tools.
Baseline assessment tool
The baseline assessment tool is an Excel spreadsheet that can be used by organisations to identify if they are in line with practice recommended in NICE guidance and to help them plan activity that will help them meet the recommendations.
Costing reports are estimates of the national cost impact arising from implementation based on assumptions about current practice, and predictions of how it might change following implementation of the guideline.
Glossary of terms
The glossary of terms has been designed to help put this NICE clinical guideline into practice by defining the commonly used terms. It may be useful in teaching sessions and when using the NICE slide set.
A podcast is available in which a member of the Guideline Development Group discusses the guidance.
The slides provide a framework for discussing the NICE guideline with a variety of audiences and can assist in local dissemination. This information does not supersede or replace the guidance itself.
Referral to secondary care
After the clinical history has been taken, referral to secondary or specialist care should be considered before investigation if:1
- the child or young person has:
- an acute systemic reaction
- a severe delayed reaction
- faltering growth in combination with one or more of the gastrointestinal symptoms listed in Box 1
- significant atopic eczema, where multiple or cross-reactive food allergies are suspected by the parent or carer
- there is persisting parental suspicion of food allergy (especially in children or young people with difficult or perplexing symptoms) despite a lack of supporting history
- there is clinical suspicion of multiple food allergies.
Following initial investigations, also consider for referral:1
- those who have not responded to a single-allergen elimination diet
- a child or young person with asthma who has a confirmed IgE-mediated food allergy (even if there was only a mild, localised reaction to food as children with asthma are more at risk of severe reactions)
- where there is a strong clinical suspicion of IgE-mediated food allergy but allergy test results are negative.
Ensuring that local specialist services are available and that healthcare professionals know who to refer to, is an important part of the implementation process.
Due to a lack of evidence, the NICE guideline does not recommend the use of alternative tests such as vega testing, applied kinesiology, hair analysis, and serum-specific IgG testing in the diagnosis of food allergy in children and young people.1
The NICE guideline obviously has many implications for primary care—local protocols, formularies, and pathways of care may need to be developed to aid service delivery. In some areas, changes to service provision will be required at many levels, such as:
- organisation of primary care based clinics with skin-prick testing
- increasing and improving access to dietetic services
- availability of secondary and even tertiary care allergy services.
Implementation of the NICE guideline will have to include the provision of dietitians with appropriate competencies so they can provide support to both the families and the community healthcare professionals. Educational initiatives need to be implemented to make this guideline work in practice and discussions between primary care healthcare professionals, dietitians, paediatricians, and allergists will be imperative.
At present, there is no national guideline for the management of children with food allergies, other than the British Society for Allergy and Clinical Immunology (BSACI) guideline for the management of egg allergy.5 Therefore, the management of children with food allergies following diagnosis will continue to be variable. Development of a management guideline should be considered.
The Royal College of Paediatrics and Child Health was commissioned by the Department of Health to produce a National Clinical Care Pathway for children and young people with allergy (www.rcpch.ac.uk/allergy/foodallergy).6 This care pathway was published in February 2011 and healthcare professionals may find it helpful to refer to this alongside the NICE guideline.
Implementation of the NICE guideline will provide several challenges to primary care. However, if the recommendations are followed:
- Children and young people with food allergy should benefit from a timely and accurate diagnosis
- Primary care and community healthcare professionals should feel empowered and more confident when making the initial assessment and diagnosis in those with symptoms suggestive of food allergy.
Although this article is based on the NICE guideline, some content represents the opinions of the author and are not necessarily those of NICE or the Guideline Development Group.
- Services for allergy are often underdeveloped and commissioners should review commissioned local services based on the NICE guideline
- A local care pathway based on the NICE algorithm would identify referral routes and the need for new commissioned services
- Adoption of such a newly developed care pathway could count towards the QOF quality and productivity indicator, QP8
- Skin-prick testing for IgE-mediated allergy could be commissioned in general practice or the community through a GPwSI or community clinic thereby avoiding expensive tariff charges
- It is likely that education of primary care will increase identification of possible food allergy and therefore result in a rise in referral costs unless these are mitigated as above
- Paediatric clinical immunology and allergy is coded as 255, general paediatric clinics are coded as 420. General paediatric appointments attract a national tariff, while clinics coded 255 are locally negotiated
- Tariff charges for paediatric outpatient = £216 (new), £113 (follow up)a
- National Institute for Health and Care Excellence. Diagnosis and assessment of food allergy in children and young people in primary care and community settings. Clinical Guideline 116. London: NICE, 2011. Available at: www.nice.org.uk/guidance/CG116
- Department of Health. A review of the services for allergy: the epidemiology, demand for and provision of treatment and effectiveness of clinical interventions. London: DH, 2006. Available at: www.dh.gov.uk/en/Publicationsandstatistics/Publications/PublicationsPolicyAndGuidance/DH_4137365
- Levy M, Price D, Zheng X et al. Inadequacies in UK primary care allergy services: national survey of current provisions and perceptions of need. Clin Exp Allergy 2004; 34 (4): 518?519.
- National Institute for Health and Care Excellence. Management of atopic eczema in children from birth up to the age of 12 years. Clinical Guideline 57. London: NICE, 2007. Available at: www.nice.org.uk/guidance/CG57
- Clark A, Skypala I, Leech S et al. British Society for Allergy and Clinical Immunology. Guidelines for the management of egg allergy. Clin Exp Allergy 2010; 40 (8): 1116–1129.
- Royal College of Paediatrics and Child Health. Care pathway for food allergy. www.rcpch.ac.uk/allergy/foodallergy (accessed 30 June 2011).G