[show abstract][hide abstract] ABSTRACT: Food allergy (FA) is an important atopic disease although its precise burden is unclear. This systematic review aimed to provide recent, up-to-date data on the incidence, prevalence, time trends, and risk and prognostic factors for FA in Europe. We searched four electronic databases, covering studies published from 1 January 2000 to 30 September 2012. Two independent reviewers appraised the studies and qualified the risk of bias using the Critical Appraisal Skills Programme tool. Seventy-five eligible articles (comprising 56 primary studies) were included in a narrative synthesis, and 30 studies in a random-effects meta-analysis. Most of the studies were graded as at moderate risk of bias. The pooled lifetime and point prevalence of self-reported FA were 17.3% (95% CI: 17.0–17.6) and 5.9% (95% CI: 5.7–6.1), respectively. The point prevalence of sensitization to ≥1 food as assessed by specific IgE was 10.1% (95% CI: 9.4–10.8) and skin prick test 2.7% (95% CI: 2.4–3.0), food challenge positivity 0.9% (95% CI: 0.8–1.1). While the incidence of FA appeared stable over time, there was some evidence that the prevalence may be increasing. There were no consistent risk or prognostic factors for the development or resolution of FA identified, but sex, age, country of residence, familial atopic history, and the presence of other allergic diseases seem to be important. Food allergy is a significant clinical problem in Europe. The evidence base in this area would benefit from additional studies using standardized, rigorous methodology; data are particularly required from Eastern and Southern Europe.
[show abstract][hide abstract] ABSTRACT: Anaphylaxis is an acute, potentially fatal, multi-organ system, allergic reaction caused by the release of chemical mediators from mast cells and basophils. Uncertainty exists around epidemiological measures of incidence and prevalence, risk factors, risk of recurrence, and death due to anaphylaxis. This systematic review aimed to (1) understand and describe the epidemiology of anaphylaxis and (2) describe how these characteristics vary by person, place, and time.
Using a highly sensitive search strategy, we identified systematic reviews of epidemiological studies, descriptive and analytical epidemiological investigations, and studies involving analysis of routine data.
Our searches identified a total of 5 843 potentially eligible studies, of which 49 satisfied our inclusion criteria. Of these, three were suitable for pooled estimates of prevalence. The incidence rates for all-cause anaphylaxis ranged from 1.5 to 7.9 per 100 000 person-years. These data indicated that an estimated 0.3% (95% CI 0.1-0.5) of the population experience anaphylaxis at some point in their lives. Food, drugs, stinging insects, and latex were the most commonly identified triggers.
Anaphylaxis is a common problem, affecting an estimated 1 in 300 of the European population at some time in their lives. Future research needs to focus on better understanding of the trends across Europe and identifying those most likely to experience fatal reactions.
[show abstract][hide abstract] ABSTRACT: IgE-mediated food allergy is a common condition in childhood and a recognized public health concern. An accurate diagnosis of food allergy facilitates the avoidance of the allergen – and cross-reactive allergens – and allows for safe dietary expansion. The diagnosis of food allergy relies on a combination of rigorous history, physical examination, allergy tests [skin prick tests (SPT) and/or serum-specific IgE] and oral food challenges. Diagnostic cut-off values for SPT and specific IgE results have improved the diagnosis of food allergy and thereby reduced the need to perform oral food challenges. This clinical case series seeks to highlight a contemporary approach to the diagnosis of food allergy in children strategies.
[show abstract][hide abstract] ABSTRACT: Anaphylaxis is an increasing emergency in Western countries, especially in children. In the last decade, efforts have been attempted to widely understand anaphylaxis from several angles but at present, there are still numerous issues to be clarified and tackled for its earlier identification. The discrepancies in the operational definitions and diagnostic criteria of anaphylaxis represent one of the most controversial issues in casting light upon its epidemiology. Furthermore, the lack of reliable markers of the disease hampers its diagnosis. Further basic and clinical research is urgently needed to confirm the recent promising results derived from studies on animal models, and to clarify the key role of selected mediators and markers in the different steps of the reaction, in its severity and in the recurrences. The underuse of adrenaline is another important issue, as available data demonstrate physicians' preference for steroids and anti-histamines despite the current lack of evidence of their effectiveness. In the near future, the management of anaphylaxis will be strongly influenced by the development of a stepwise approach, as well as by the creation of a system improving transmission of good quality data between the emergency room, the allergist and the family doctor. This process will certainly be enhanced by the establishment of a network of Centres of Excellence collaborating for high quality research and care and involved in the dissemination of new knowledge at a primary care level. This review will seek to briefly overview our current knowledge and highlight the key questions that need to be addressed in the next decade to improve clinical care to children and will focus on the epidemiology of anaphylaxis, the identification of individuals at risk of anaphylaxis, the special issues related to infants, community management of children at risk of anaphylaxis and school related issues.
[show abstract][hide abstract] ABSTRACT: Anaphylaxis is a growing paediatric clinical emergency that is difficult to diagnose because a consensus definition was lacking until recently. Many European countries have no specific guidelines for anaphylaxis. This position paper prepared by the EAACI Taskforce on Anaphylaxis in Children aims to provide practical guidelines for managing anaphylaxis in childhood based on the limited evidence available. Intramuscular adrenaline is the acknowledged first-line therapy for anaphylaxis, in hospital and in the community, and should be given as soon as the condition is recognized. Additional therapies such as volume support, nebulized bronchodilators, antihistamines or corticosteroids are supplementary to adrenaline. There are no absolute contraindications to administering adrenaline in children. Allergy assessment is mandatory in all children with a history of anaphylaxis because it is essential to identify and avoid the allergen to prevent its recurrence. A tailored anaphylaxis management plan is needed, based on an individual risk assessment, which is influenced by the child's previous allergic reactions, other medical conditions and social circumstances. Collaborative partnerships should be established, involving school staff, healthcare professionals and patients' organizations. Absolute indications for prescribing self-injectable adrenaline are prior cardiorespiratory reactions, exercise-induced anaphylaxis, idiopathic anaphylaxis and persistent asthma with food allergy. Relative indications include peanut or tree nut allergy, reactions to small quantities of a given food, food allergy in teenagers and living far away from a medical facility. The creation of national and European databases is expected to generate better-quality data and help develop a stepwise approach for a better management of paediatric anaphylaxis.
[show abstract][hide abstract] ABSTRACT: Allergic disease has been shown to impair health-related quality of life (HRQL). The relationship between HRQL and either allergen exposure or allergic inflammation has not been previously assessed.
To assess the relationship between HRQL and both grass pollen exposure and airway inflammation using the Paediatric Allergic Disease Quality of Life Questionnaire (PADQLQ). This is a novel questionnaire previously developed to assess the multi-system aspects of allergic disease.
Eighty-four subjects, aged 6-17 years, with seasonal allergic rhinoconjunctivitis, asthma and/or cutaneous manifestations were assessed before and during the grass pollen season. They were assessed with the PADQLQ, a visual analogue scale (VAS) to assess quality of life, symptom diary and exhaled nitric oxide (FENO).
HRQL, as measured by the PADQLQ, significantly correlated with the average pollen count in the previous week (regression coefficient 0.038, 95% confidence interval (CI) 0.027-0.049, P<0.001). The PADQLQ score was also found to be significantly associated with airway inflammation as measured by FENO (regression coefficient 0.410, 95% CI 0.175-0.646, P=0.001). Additionally, PADQLQ showed a high degree of correlation with symptom scores and quality of life as measured by a VAS, good within-subject reliability and a small minimal important difference (0.20, 95% CI -0.09 to 0.49 on a seven-point scale).
HRQL is related to both allergen load and allergic inflammation and the PADQLQ has excellent cross-sectional and longitudinal validity with respect to quality of life and symptoms.
[show abstract][hide abstract] ABSTRACT: Previous studies measuring the prevalence of allergen sensitization have been relatively small and used small numbers of allergens. To effectively evaluate children with atopic disease, we need an accurate knowledge of which allergens are important.
To measure the prevalence of sensitization within a large unselected birth cohort, to examine the associations between sensitization to different allergens and determine whether atopy can be defined by a small panel of allergens.
The Avon Longitudinal Study of Parents and Children is a population-based birth cohort of 13,638 singletons surviving to 4 weeks of age. The cohort was skin tested at 7 years of age to house dust mite (Dermatophagoides pteronyssinus), grass pollens, cat, peanuts, mixed tree nuts and egg and one of three other panels: animal danders, foods or aeroallergens. Sensitization was defined as a weal diameter of > or =3 mm. The strength of associations between sensitization to different allergens was tested by calculating the odds ratio adjusted for sensitization to D. pteronyssinus and grass pollen and gender.
Valid data were obtained from 6412 singletons. Sensitization was most common to aeroallergens: grass pollens (8.5%), D. pteronyssinus (7.8%), cat (4.9%), D. farinae (3.6%), dog (2.7%), horse (1.4%), rabbit (1.4%). Of the foods tested, the most common sensitization was to peanut (1.4%) and mixed tree nuts (1.0%). More than 95% of subjects with sensitization to any of the 29 allergens tested were sensitized to one of grass, D. pteronyssinus or cat allergen. There were strong associations of multiple sensitizations both within and between different allergen classes (pollens, animals, foods, peanut and tree nuts).
Seven-year-old children in the UK are primarily sensitized to aeroallergens, but also to peanuts and tree nuts. There are strong associations between sensitization within allergen groups as well as between allergen groups. Further studies are required to observe whether similar associations are seen with clinical allergy to these allergens.
[show abstract][hide abstract] ABSTRACT: Latex allergy has been highlighted as a problem in children during the last decade based on a number of case series of children with particular problems such as spina bifida. The actual prevalence of latex allergy in the general United Kingdom population is unclear.
To estimate the prevalence of childhood latex allergy in the general population.
The Avon Longitudinal Study of Parents and Children is a geographically based cohort that has been prospectively followed since birth. The children were invited for skin prick testing at 7 years of age.
Four subjects out of 1877 tested were sensitized to latex. None had a history of clinical reactions to latex.
This study suggests that the prevalence of latex sensitization and clinical latex allergy in the general childhood population are very low, 0.2% (95% confidence interval 0.1-0.6%) and 0.0% (0-0.2%), respectively.
[show abstract][hide abstract] ABSTRACT: Exhaled nitric oxide (NO) has been proposed as a marker of airway eosinophilic inflammation in asthma. There is currently a paucity of longitudinal data relating it to allergen exposure and asthma symptoms.
Forty four children (6-16 years) with seasonal allergic asthma were sequentially followed before and during the grass pollen season. Asthma symptoms, lung function, NO levels, and pollen counts were recorded. The relationship between exhaled NO and both the pollen levels and asthma control were assessed longitudinally, comparing a subject's measurements with their previous ones.
The median exhaled NO concentration was significantly increased during the pollen season (6.2 v 9.2 parts per billion (ppb), p<0.002; median change 2.9 ppb, 95% confidence interval 1.5 to 5.4). Exhaled NO was best associated with the mean pollen count in the week before measurement. It was also significantly associated with asthma control.
The results suggest that, within a longitudinal model, the exhaled NO concentration is related to preceding allergen exposure and asthma control. It may be clinically more useful to compare exhaled NO values with a subject's previous values than to compare them with a population based normal range.
[show abstract][hide abstract] ABSTRACT: Studies have demonstrated that families of children with food allergy have significant deficiencies in their knowledge of how to avoid allergen exposure and how to manage allergic reactions. This study aims to assess the impact of a multidisciplinary paediatric allergy clinic consultation on parental knowledge of food allergy and to determine the rate of subsequent allergic reactions.
Sixty-two subjects (<17 years) referred with food allergy were prospectively enrolled. Parental knowledge was assessed by questionnaire and EpiPen trainer. Families saw a paediatric allergist, clinical nurse specialist and dietician. Knowledge was reassessed after 3 months and rate of allergic reactions after 1 year.
After one visit to the paediatric allergy clinic, there was a significant improvement in parental knowledge of allergen avoidance (26.9%, P < 0.001), managing allergic reactions (185.4%, P < 0.0001) and EpiPen usage (83.3%, P < 0.001). Additionally, there was a significant reduction in allergic reactions (P < 0.001). Children with egg, milk or multiple food allergies were more likely to suffer subsequent reactions.
A single visit to a multidisciplinary allergy clinic considerably improves families' abilities to manage allergic reactions to foods with an accompanying reduction in allergic reactions. Young children with egg, milk or multiple food allergies were at greatest risk of further reactions.
[show abstract][hide abstract] ABSTRACT: Allergic asthma is usually considered to be provoked by aeroallergens. However, we have recently recognized a group of children with food allergies who also develop asthma when exposed to the aerosolized form of the food.
Between 1997 and 1999 we prospectively identified children with an immunoglobulin (Ig)E-mediated food allergy who develop asthma on inhalational exposure to the relevant food allergen while it is being cooked. Subjects were exposed for 20 min to the aerosolized form of the allergen and the symptoms and the lung function were monitored. Aerosolization was achieved by cooking the food in a small room. Where possible challenges were double-blinded.
We identified 12 children with an IgE-mediated food allergy who developed asthma on inhalational exposure to food. The implicated foods were fish, chickpea, milk, egg or buckwheat. Nine out of the 12 children consented to undergo a bronchial food challenge. Five challenges were positive with objective clinical features of asthma. Additionally, two children developed late-phase symptoms with a decrease in lung function. Positive reactions were seen with fish, chickpea and buckwheat. There were no reactions to the seven placebo challenges.
We have presented a prospective series of children with food allergy who developed symptoms of asthma with exposure to aerosolized food allergens. Our data demonstrates that, as in the case of other aeroallergens, inhaled food allergens can produce both early- and late-phase asthmatic responses. This highlights the importance of considering foods as aeroallergens in children with coexistent food allergy and allergic asthma. For these children, dietary avoidance alone may not be sufficient and further environmental measures may be required to limit exposure to aerosolized food.
[show abstract][hide abstract] ABSTRACT: Anaphylaxis is a growing paediatric clinical emergency that is difficult to diag- nose because a consensus definition was lacking until recently. Many European countries have no specific guidelines for anaphylaxis. This position paper pre- pared by the EAACI Taskforce on Anaphylaxis in Children aims to provide practical guidelines for managing anaphylaxis in childhood based on the limited evidence available. Intramuscular adrenaline is the acknowledged first-line therapy for anaphylaxis, in hospital and in the community, and should be given as soon as the condition is recognized. Additional therapies such as volume support, nebulized bronchodilators, antihistamines or corticosteroids are sup- plementary to adrenaline. There are no absolute contraindications to adminis- tering adrenaline in children. Allergy assessment is mandatory in all children with a history of anaphylaxis because it is essential to identify and avoid the allergen to prevent its recurrence. A tailored anaphylaxis management plan is needed, based on an individual risk assessment, which is influenced by the childs previous allergic reactions, other medical conditions and social circumstances. Collaborative partnerships should be established, involving school staff, healthcare professionals and patients organizations. Absolute indications for prescribing self-injectable adrenaline are prior cardiorespiratory reactions, exercise-induced anaphylaxis, idiopathic anaphylaxis and persistent asthma with food allergy. Relative indications include peanut or tree nut allergy, reactions to small quantities of a given food, food allergy in teenagers and living far away from a medical facility. The creation of national and European databases is expected to generate better-quality data and help develop a stepwise approach for a better management of paediatric anaphylaxis.