VOL: 103, ISSUE: 24, PAGE NO: 44
Dave Burns, MSc, CertEd, RGN, RNT, is senior lecturer, Edge Hill University, Liverpool, and national training manager, Respiratory Education UK, Liverpool
Allergy develops in atopic individuals who make large amounts of the immunoglobulin E (IgE) antibody in response to…
Allergy develops in atopic individuals who make large amounts of the immunoglobulin E (IgE) antibody in response to substances such as flower and grass pollens, animal dander, house dust-mite faeces and fungal spores. Atopy is a precursor for allergy, although not all individuals who are atopic develop allergy. For example, some people may have high IgE levels for grass pollen, but are symptom free when exposed to it.
Allergic disease can vary from mild to severe. The atopic triad refers to three common manifestations: atopic dermatitis, allergic rhinitis and asthma.
Some 50% of people with atopic dermatitis will develop asthma and two-thirds allergic rhinitis (Spergel and Paller, 2003). Food allergy affects a small number of people but this is increasing.
Why is allergy increasing?
There are two to three times more asthma, allergic rhinitis and atopic dermatitis cases now than there were in the 1970s (Royal College of Physicians, 2003) and the increase is most prevalent in developed countries (Strachan et al, 1997). Reasons for the increase are unclear but genetic shifts that make people more susceptible to allergy are unlikely over such a short time span (Nowak et al, 2004) and changes in diagnostic trends - for example, patients with COPD being misdiagnosed as having asthma - cannot account for it.
Although genetic predisposition has been shown to be a significant risk factor for atopy, equally important is the interaction of the individual who is genetically predisposed with their environment. Environmental factors include the level and duration of allergen exposure (for example, exposure to house dust-mite or pet allergen), viral infections, smoking and the role of microbial exposure in protecting against atopy (von Mutius and Schmid, 2006). However, there are difficulties in performing sufficiently robust studies investigating the aetiology, epidemiology and natural history of atopy and allergic disease.
The International Study of Asthma and Allergies in Childhood (ISAAC) (Strachan et al, 1997) showed that the incidence of allergic disease in children rises with age. However, the incidences of allergic disease differed between the countries studied.
Further studies under the ISAAC protocol (Grize et al, 2006) reported a halt in the rise in numbers of Swiss children with hay fever and asthma aged five to seven. Although atopic dermatitis in Switzerland seems to have stabilised in boys, it is still increasing in girls. Verlato et al (2003) found that the prevalence of asthma in Italy had stabilised in the past decade but allergic rhinitis has continued to increase. A contrasting picture is evident in Turkey, where Ones et al (2006) found a significant increase in asthma prevalence over a nine-year period. In the UK there has been a significant decrease in symptoms of allergic rhinitis, asthma and atopic dermatitis in 12-14-year-olds in the period 1995-2002 (Ross-Anderson et al, 2004).
Nowak et al (2004) argued that changes in allergy prevalence may show that a ‘saturation point’ has been reached, as all individuals who are prone to developing allergic disease have been sensitised.
The burden of allergy in the UK
Allergy UK (2003) suggests that over 15 million people in the UK suffer with allergies and, in a survey of over 6,000 people, 75% said their allergy interfered with their lives. However, only 25% said that a nurse or doctor had asked them about the impact their allergy had on their quality of life.
Gupta and Sheikh (2004) carried out a secondary analysis of a large number of epidemiological studies and extracted data for the UK. They found that 39% of children and 30% of adults have been diagnosed with at least one allergic condition. Also, allergic disease accounts for 6% of general practice consultations, 10% of primary care prescribing costs and 0.8% of hospital admissions. Direct costs to the NHS of managing allergic conditions were estimated at over £11bn per year.
Data for asthma morbidity in the UK from a number of sources indicate that asthma treatment goals are not being met in many patients. Jones et al (2002) found that 40% of patients with asthma experience all the major symptoms of asthma every day, despite reporting that their condition was well controlled. Bellamy and Harris (2004) reported that 82% of UK patients with asthma did feel that their symptoms were under control.
A survey of 1,000 people with allergic rhinitis found evidence of significant morbidity. Nearly half reported a moderate or severe impact on work or school life, while almost three-quarters reported sub-optimal control of symptoms for at least 10 years (Allergy UK, 2005).
Allergic rhinitis and asthma frequently coexist. One large-scale survey (Walker and Sheikh, 2005) has demonstrated that 78% of people with asthma reported symptoms of allergic rhinitis. Other evidence suggests that poorly controlled allergic rhinitis can affect asthma control (Price et al, 2006).
Lewis-Jones (2006) found that 16-20% of children in the UK have atopic dermatitis; this has a greater impact on their quality of life than asthma, diabetes mellitus or cystic fibrosis.
The Department of Health (2004) compiled a comprehensive review of the problem of allergy in the UK and noted the rise in deaths from anaphylaxis due to severe allergies. The RCP (2003) claims most deaths from anaphylaxis occur due to food allergy, which in turn is often due specifically to peanut allergy in children. This is prevalent in 1:70 children.
How well is allergy managed in the UK?
It is generally accepted that there are a lack of allergy services in the UK. Allergy UK (2003) found that over half of patients with either suspected or diagnosed allergy were not referred to a specialist. Of the ones who were referred, about a third had to wait up to one year to be seen and a small percentage waited up to two years. The RCP (2003) highlighted a shortage of specialist clinicians and centres in the UK, with most located in the south-east of the country. It also identified that there are limited numbers of training posts for medical staff within the UK and, as a result, some doctors involved in allergy management are not allergists/immunologists but specialists in ‘organs’, such as ear, nose and throat, lungs or skin. A similar picture exists for nurses.
How can allergy be managed more effectively?
The RCP (2003) argues that allergy management services need to be increased and suggests most allergy management should be delivered in primary care. The DH (2004) supports this view and suggests primary care professionals who are adequately trained diagnose and treat milder allergic conditions and refer more complex or severe cases, such as children with multi-organ disease, to specialist centres. It acknowledges that specialist services are scarce but says there is little evidence to estimate the level of service required by patients that will give the NHS value for money (DH, 2004).
It is essential that health professionals working with patients with allergies recognise the impact allergic disease may have on their life. Effective treatment options are available and education - for example, teaching inhaler technique in asthma, or the use of nasal sprays in allergic rhinitis - can substantially improve patients’ lives.
Allergy (notably food allergy and more severe manifestations of atopic dermatitis) can be challenging, and this is reflected in the call by the RCP (2003) for greater education of health professionals and development of a more structured allergy service.
If the number of new cases of allergy is levelling off, there is time to ensure that those presenting with symptoms are treated appropriately. Most patients with allergic conditions can be managed in primary care and it is important that health professionals have the knowledge and expertise to provide this care.
- This series is supported by the Association of Respiratory Nurse Specialists.
- This article has been double-blind peer-reviewed.
- For related articles on this subject and links to relevant websites see www.nursingtimes.net.