Food allergy: temporal trends and determinants

The Relationship Between Dietary Patterns and the Epidemiology of Food Allergy

Food allergies are increasing globally, particularly in Asia; however, the etiologies of allergic diseases remain poorly understood despite comprehensive studies conducted across a variety of populations. Epidemiological research demonstrates that food allergy is more prevalent in Westernized or urbanized societies than in rural or developing ones. As such, comparing the distribution and patterns of food allergies as well as the environmental exposures between regions may provide insight into potential causal and protective factors of food allergy. Diet is an important exposome that has been shown to modulate the immune system both directly and indirectly via pathways involving the microbiota. Changes in dietary patterns, especially the shift to a Westernized diet with reduced dietary fiber and an abundance of processed foods, impact the gut and skin epithelial barrier and contribute to the development of chronic inflammatory diseases, such as food allergy. Although dietary intervention is believed to have tremendous potential as a strategy to promote immunological health, it is essential to recognize that diet is only one of many factors that have changed in urbanized societies. Other factors, such as pollution, microplastics, the use of medications like antibiotics, and exposure to biodiversity and animals, may also play significant roles, and further research is needed to determine which exposures are most critical for the development of food allergies.

Trends of Peanut-Induced Anaphylaxis Rates Before and After the 2017 Early Peanut Introduction Guidelines in Montreal, Canada

BACKGROUND

Food allergies, particularly peanut, represent the predominant cause of anaphylaxis. Whereas early allergen introduction has emerged as a potential preventive strategy, the precise impact of recent guidelines on peanut-induced anaphylaxis rates in Canada remains unclear.

OBJECTIVE

To assess the impact of the 2017 Addendum Guidelines for the Prevention of Peanut Allergy on peanut-induced anaphylaxis rates in Canada.

METHODS

Using a comprehensive longitudinal registry capturing pediatric anaphylaxis presentations to the Montreal's Children's Hospital, we compared children with and without known peanut allergy who presented with peanut-induced anaphylaxis between 2011 and 2019 inclusive, excluding data beyond 2019 owing to the Coronavirus disease 2019 (COVID-19) pandemic. We calculated rates of peanut-induced anaphylaxis presentations per 100,000 age-adjusted all-cause emergency department visits using 4-month intervals. Interrupted time series analysis was used to compare anaphylaxis rate trends before and after 2017 for children ages 0 to 2 and 3 to 17 years.

RESULTS

We examined 2,011 cases of pediatric anaphylaxis, including 429 (21%) triggered by peanuts. Compared with pre-guideline estimates, the yearly rate of change of peanut anaphylaxis rates decreased by 7.96 (95% confidence interval -14.57 to -1.36; P = .018) after 2017 among patients with new-onset anaphylaxis in children 2 years of age or younger (n = 109). No significant changes were identified for older patients ages 3 to 17, or in patients with known peanut allergy.

CONCLUSIONS

Early introduction guidelines in Canada are associated with a reduced risk of new-onset peanut-induced anaphylaxis in young children within a single center in Montreal. Further research is required to assess the impact on a wider population and other food allergens.

Marine Bioactive Compounds with Functional Role in Immunity and Food Allergy

Food allergy, referred to as the atypical physiological overreaction of the immune system after exposure to specific food components, is considered one of the major concerns in food safety. The prevalence of this emerging worldwide problem has been increasing during the last decades, especially in industrialized countries, being estimated to affect 6-8% of young children and about 2-4% of adults. Marine organisms are an important source of bioactive substances with the potential to functionally improve the immune system, reduce food allergy sensitization and development, and even have an anti-allergic action in food allergy. The present investigation aims to be a comprehensive report of marine bioactive compounds with verified actions to improve food allergy and identified mechanisms of actions rather than be an exhaustive compilation of all investigations searching beneficial effects of marine compounds in FA. Particularly, this research highlights the capacity of bioactive components extracted from marine microbial, animal, algae, and microalgae sources, such as n-3 long-chain polyunsaturated fatty acids (LC-PUFA), polysaccharide, oligosaccharide, chondroitin, vitamin D, peptides, pigments, and polyphenols, to regulate the immune system, epigenetic regulation, inflammation, and gut dysbiosis that are essential factors in the sensitization and effector phases of food allergy. In conclusion, the marine ecosystem is an excellent source to provide foods with the capacity to improve the hypersensitivity induced against specific food allergens and also bioactive compounds with a potential pharmacological aptitude to be applied as anti-allergenic in food allergy.

Immunomodulatory effect of marine lipids on food allergy

Seafood is highly enriched in n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFAs), particularly eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3), in contrast to the ultra-processed foods included in the modern Western diet that have high levels of n-6 linoleic acid (LA, 18:2 n-6), precursor for the pro-inflammatory n-6 arachidonic acid (ARA, 20:4 n-6). The capacity of marine lipids to reduce plasmatic triglycerides and blood pressure have been well-described. Moreover, recent studies have also raised evidence of a potential regulatory action of marine lipids on inflammation, the immune system, and food allergy (FA). FA is considered one of the main concerns to become life threatening in food safety. The prevalence of this emerging global problem has been increasing during the last two decades, especially in industrialized countries. About a 6-8% of young children and 2-4% of adults is estimated to be affected by FA. The main objective of the current study is to update the existing knowledge, but also the limitations, on the potential impact of marine lipids and their lipid mediators in regulating immunity, inflammation, and ultimately, food allergies. In particular, the focus is on the effect of marine lipids in modulating the key factors that control the sensitization and effector phases of FA, including gut microbiota (GM), inflammation, and immune system response. Results in animal models highlight the positive effect that consuming marine lipids, whether as a supplement or through seafood consumption, may have a relevant role in improving gut dysbiosis and inflammation, and preventing or reducing the severity of FA. However, more systematic studies in humans are needed to optimize such beneficial actions to each particular FA, age, and medical condition to reach an effective clinical application of marine lipids to improve FAs and their outcomes.

Prevalence of reported food allergies in Brazilian preschoolers living in a small Brazilian city

Introduction

Although the prevalence of allergic diseases, including food allergies, has increased over recent decades, relevant information on this topic is still lacking, particularly in younger children living in small cities.

Objective

To investigate the prevalence of reported food allergies in preschoolers in Limoeiro/Pernambuco, Brazil.

Methods

This was a cross-sectional study with preschoolers. Parents/guardians of all preschoolers enrolled at municipal schools between March and June 2019 (total of 619) were invited to complete a screening questionnaire (total of 619). Another 151 questionnaires were applied on the streets of the town. For positive responses, a second, more detailed and validated questionnaire was completed.

Results

A total of 412 questionnaires were returned, of which, 47 presented a positive response to food allergies and only 29 (7.04%) identified a particular food. The most frequently reported food items were shrimp, mollusks, pork, fruit and milk. Of the 29 who identified foods, 22 responded to the detailed questionnaire, resulting in only 4 (0.97%) positive responses. Of these, two were later discarded through clinical examinations and an open oral provocation test, resulting in a final prevalence of 0.48% of confirmed food allergies.

Conclusion

The prevalence of reported food allergies was lower than that described in previous studies. The most commonly mentioned foods were shrimp, mollusks and pork, with more reports of multiple food allergies, even in children who had never been previously exposed to these possible allergens, which highlights the relevance of perception in reported food allergy studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13223-022-00710-1.

Proteomics for Development of Food Allergy Vaccines

Food allergy is a hypersensitivity reaction to food products initiated by immunologic mechanisms, which represents one of the major concerns in food safety. New therapies for food allergies including oral and epicutaneous allergen-specific immunotherapy are required, and B cell epitope-based allergy vaccines are a good promise to improve this field. In this chapter, we describe a workflow for the design of food allergy vaccines using proteomic tools. The strategy is defined based on the characterization of B cell epitopes for a particular food allergen. For that, the workflow comprises five consecutive steps: (1) shotgun proteomics analysis of different protein isoforms for a particular food allergen, (2) downloading all protein sequences for the specific allergen included in UniProtKB database, (3) analysis by protein-based bioinformatics of B cell epitopes, (4) synthesizing of the selected B cell peptide epitopes, and (5) performing of immunoassays using sera from healthy and allergic patients. The results from this method provide a rationale repository of B cell epitopes for the design of new specific immunotherapies for a particular food allergen. The strategy was optimized for all the beta-parvalbumins (β-PRVBs), which are considered as the main fish allergens. Using this workflow, a total of 35 peptides were identified as B cell epitopes, among them the top 4 B cell peptide epitopes that may induce protective immune response were selected as potential peptide vaccine candidates for fish allergy.

The prevalence and temporal trends of food allergy among preschool children in Northern Thailand between 2010 and 2019

Background

Although recent studies suggest that the prevalence of food allergy (FA) has not changed, the data from developing countries are limited. This study aimed to investigate time trends in the prevalence of FA among preschool children in 2010 and 2019 in Northern Thailand.

Methods

Two cross-sectional studies were performed, 9 years apart (2010 and 2019), using the same methods, in children aged 3–7 years living in Chiang Mai, Thailand. Parent-reporting questionnaire surveys were conducted. Families with children reporting FA were invited to undergo further investigations with skin prick testing, serum specific IgE, and oral food challenge (OFC). The prevalence of parent-reported FA, food sensitization, and OFC-confirmed FA were compared between the 2 periods.

Results

A total of 1013 out of 1146 questionnaires (452/546 in 2010 and 561/600 in 2019) were returned. The response rate was 88.4%. The prevalence of parent-reported food allergy in 2019 was significantly lower than that in 2010 (5.5% vs 9.3%; p = 0.02). However, there was no significant change in the prevalence of OFC-confirmed FA (0.9% vs 1.1%; p = 0.75). Three leading causative foods of parent-reported FA were cow's milk, shrimp, and eggs. Shrimp was still the most common OFC-confirmed food allergen. Atopic dermatitis was the most significantly parent reported factor associated with FA.

Conclusion

The overall prevalence of FA among preschool children in Northern Thailand had not increased during the past decade. There was no significant difference in the prevalence of OFC-confirmed FA between 2010 and 2019.

Risk of peanut- and tree-nut-induced anaphylaxis during Halloween, Easter and other cultural holidays in Canadian children

BACKGROUND

It is not established whether the risk of anaphylaxis induced by peanuts or tree nuts in children increases at specific times of the year. We aimed to evaluate the risk of peanut-and tree-nut-induced anaphylaxis during certain cultural holidays in Canadian children.

METHODS

We collected data on confirmed pediatric cases of anaphylaxis presenting to emergency departments in 4 Canadian provinces as part of the Cross-Canada Anaphylaxis Registry. We assessed the mean number of cases per day and incidence rate ratio (IRR) of anaphylaxis induced by unknown nuts, peanuts and tree nuts presenting during each of 6 holidays (Halloween, Christmas, Easter, Diwali, Chinese New Year and Eid al-Adha) versus the rest of the year. We estimated IRRs and 95% confidence intervals (CIs) using Poisson regression.

RESULTS

Data were collected for 1390 pediatric cases of anaphylaxis between 2011 and 2020. Their median age was 5.4 years, and 864 (62.2%) of the children were boys. During Halloween and Easter, there were higher rates of anaphylaxis to unknown nuts (IRR 1.66, 95% CI 1.13-2.43 and IRR 1.71, 95% CI 1.21-2.42, respectively) and peanuts (IRR 1.86, 95% CI 1.12-3.11 and IRR 1.57, 95% CI 0.94-2.63, respectively) compared to the rest of the year. No increased risk of peanut- or tree-nut-induced anaphylaxis was observed during Christmas, Diwali, Chinese New Year or Eid al-Adha. Anaphylaxis induced by unknown nuts, peanuts and tree nuts was more likely in children aged 6 years or older than in younger children.

INTERPRETATION

We found an increased risk of anaphylaxis induced by unknown nuts and peanuts during Halloween and Easter among Canadian children. Educational tools are needed to increase awareness and vigilance in order to decrease the risk of anaphylaxis induced by peanuts and tree nuts in children during these holidays.

Food allergy and asthma

Food allergies (FA) and asthma commonly coexist in patients, with asthma affecting 14% of school-age children and with FA affecting up to 8% of children in the United States. Compared with children without FA, children with FA are two to four times more likely to have asthma. The timings of food sensitization and FA seem to be strong predictors of asthma onset in childhood; results of studies show that food sensitization in the first few years of life is associated with increased odds of developing early wheeze. Having multiple FAs as opposed to a single FA further compounds the risk of asthma. Reciprocally, there is a strong association between the presence of food sensitization and/or FA and poor asthma control, including increased asthma-related healthcare utilization and emergency medication use. Asthma is a risk factor in ~75% of fatal food-related anaphylaxis cases. Therefore, besides FA education and management, patients with FA and with asthma should optimize medical therapy of their asthma and receive asthma education, including identifying possible asthma triggers. Furthermore, allergists should ensure that asthma must be well controlled before conducting oral food challenges. Timely administration of epinephrine is lifesaving and remains the firstline treatment during food-induced anaphylaxis, especially in patients with asthma. Among those biologic therapies that have been highly effective in treating asthma, omalizumab and dupilumab are now also being studied as treatments for FA.

Predictors of Food Sensitization in Children and Adults Across Europe

BACKGROUND

The geographical variation and temporal increase in the prevalence of food sensitization (FS) suggest environmental influences.

OBJECTIVE

To investigate how environment, infant diet, and demographic characteristics, are associated with FS in children and adults, focusing on early-life exposures.

METHODS

Data on childhood and adult environmental exposures (including, among others, sibship size, day care, pets, farm environment, and smoking), infant diet (including breast-feeding and timing of introduction to infant formula and solids), and demographic characteristics were collected from 2196 school-age children and 2185 adults completing an extensive questionnaire and blood sampling in the cross-sectional pan-European EuroPrevall project. Multivariable logistic regression was applied to determine associations between the predictor variables and sensitization to foods commonly implicated in food allergy (specific IgE ≥0.35 kU_A/L). Secondary outcomes were inhalant sensitization and primary (non-cross-reactive) FS.

RESULTS

Dog ownership in early childhood was inversely associated with childhood FS (odds ratio, 0.65; 95% CI, 0.48-0.90), as was higher gestational age at delivery (odds ratio, 0.93 [95% CI, 0.87-0.99] per week increase in age). Lower age and male sex were associated with a higher prevalence of adult FS (odds ratio, 0.97 [95% CI, 0.96-0.98] per year increase in age, and 1.39 [95% CI, 1.12-1.71] for male sex). No statistically significant associations were found between other evaluated environmental determinants and childhood or adult FS, nor between infant diet and childhood FS, although early introduction of solids did show a trend toward prevention of FS.

CONCLUSIONS

Dog ownership seems to protect against childhood FS, but independent effects of other currently conceived environmental and infant dietary determinants on FS in childhood or adulthood could not be confirmed.

Managing Younger Siblings of Food Allergic Children

Current guidelines state that there is insufficient evidence to recommend testing siblings of food allergic children before introduction of potential allergic foods, but the topic continues to remain controversial. Although the proportion of siblings who are sensitized to a food without clinical reactivity is high in comparison to those with a true food allergy, there is still a known increased risk amongst siblings of children with food allergies that has led to much apprehension about management. The appropriateness of testing and further steps for management of sensitization in the absence of history of clinical reactivity should be discussed with parents.

Molecular characterization of B-cell epitopes for the major fish allergen, parvalbumin, by shotgun proteomics, protein-based bioinformatics and IgE-reactive approaches

Parvalbumins beta (β-PRVBs) are the main fish allergens. The only proven and effective treatment for this type of hypersensitivity is to consume a diet free of fish. We present the molecular characterization of B-cell epitopes by shotgun proteomics of different β-PRVBs combined with protein-based bioinformatics and IgE-reactive approaches. The final goal of this work is to identify potential peptide vaccine candidates for fish allergy. Purified β-PRVBs from the main fifteen different fish species that cause allergy were analyzed by shotgun proteomics. Identified β-PRVBs peptide sequences and ninety-eight β-PRVB protein sequences from UniProtKB were combined, aligned and analyzed to determine B-cell epitopes using the Kolaskar and Tongaonkar algorithm. The highest rated predicted B-cell peptide epitopes were evaluated by ELISA using the corresponding synthetic peptides and sera from healthy and fish allergic patients. A total of 35 peptides were identified as B-cell epitopes. The top B-cell peptide epitopes (LKLFLQV, ACAHLCK, FAVLVKQ and LFLQNFV) that may induce protective immune responses were selected as potential peptide vaccine candidates. The 3D model of these peptides were located in the surface of the protein. This study provides the global characterization of B-cell epitopes for all β-PRVBs sequences that will facilitate the design of new potential immunotherapies. SIGNIFICANCE: This work provides the global characterization of B-cell epitopes for all β-PRVBs sequences by Shotgun Proteomics combined with Protein-based Bioinformatics and IgE-reactive approaches. This study will increase our understanding of the molecular mechanisms whereby fish allergens elicit allergic reactions and will facilitate the design of new potential peptide vaccine candidates.

Almond Allergy: An Overview on Prevalence, Thresholds, Regulations and Allergen Detection

Food allergy has been on the increase for many years. The prevalence of allergy to different foods varies widely depending on type of food, frequency of consumption and geographic location. Data from the literature suggests that the prevalence of tree nut allergy is of the order of 1% in the general population. Almond is one such tree nut that is frequently eaten in many parts of the world and represents a potential allergenic hazard. Given the need to label products that contain allergens, a number of different methods of direct and indirect detection have been developed. However, in the absence of population-based threshold data, and given that almond allergy is rare, the sensitivity of the required detection is unknown and thus aims as low as possible. Typically, this is less than 1 ppm, which matches the thresholds that have been shown for other allergens. This review highlights the lack of quantitative data on prevalence and thresholds for almonds, which is limiting progress in consumer protection.

The Epidemiology of Food Allergy in the Global Context

There is a lack of high-quality evidence based on the gold standard of oral food challenges to determine food allergy prevalence. Nevertheless, studies using surrogate measures of food allergy, such as health service utilization and clinical history, together with allergen-specific immunoglobulin E (sIgE), provide compelling data that the prevalence of food allergy is increasing in both Western and developing countries. In Western countries, challenge-diagnosed food allergy has been reported to be as high as 10%, with the greatest prevalence noted among younger children. There is also growing evidence of increasing prevalence in developing countries, with rates of challenge-diagnosed food allergy in China and Africa reported to be similar to that in Western countries. An interesting observation is that children of East Asian or African descent born in a Western environment are at higher risk of food allergy compared to Caucasian children; this intriguing finding emphasizes the importance of genome-environment interactions and forecasts future increases in food allergy in Asia and Africa as economic growth continues in these regions. While cow’s milk and egg allergy are two of the most common food allergies in most countries, diverse patterns of food allergy can be observed in individual geographic regions determined by each country’s feeding patterns. More robust studies investigating food allergy prevalence, particularly in Asia and the developing world, are necessary to understand the extent of the food allergy problem and identify preventive strategies to cope with the potential increase in these regions.

Fish consumption associated with reduction of fish allergy

Purpose

This paper aims to examine the differences in the self-reported allergies to food, especially fish and shellfish, between children and adults, and to study the association between fish consumption and self-reported fish and shellfish allergy (FSA) according to age.

Design/methodology/approach

This study is based on a survey conducted between April 2014 and December 2016 where children and adults were recruited from the general population of the Fez-Meknes region. The total studied population was 4,046 people.

Findings

The results show that the self-reported food allergy (FA) of the general population was more frequent among children (28.2 per cent) than adults (16.8 per cent), in which eggs, fish/shellfish, milk and cereals were the most common food cited. With regard to the self-reported FSA, the authors found a prevalence of 9.5 per cent in both children and adults, whereas fish species allergies were more frequent among adults than children. The most common clinical manifestations observed in this population were cutaneous reactions. The study of the association between fish consumption and FSA shows that people who consumed fish had a lower rate of FSA, especially in adults (p < 0.001).

Originality/value

The self-reported FA of the general population was more pronounced in children than adults. Regarding the self-reported FSA, the authors have shown a prevalence of 9.5 per cent in both children and adults, indicating an important sensitivity of their population to fish and shellfish. The authors have shown that consumption of fish was associated significantly with a lower rate of FSA, especially in adults.

Food Challenge and Community-Reported Reaction Profiles in Food-Allergic Children Aged 1 and 4 Years: A Population-Based Study

BACKGROUND

Oral food challenge is the main tool for diagnosing food allergy, but there is little data on the reaction profiles of young children undergoing challenges, nor how these reactions compare to reactions on accidental ingestion in the community.

OBJECTIVES

To compare reaction profiles from food challenges and parent-reported reactions on accidental ingestion, and assess predictors of severe reactions.

METHODS

HealthNuts is a longitudinal population-based cohort study of 5276 1-year-old infants. Infants underwent skin prick tests and those with identifiable wheals were offered food challenges. Food challenges were repeated at age 4 years in those with previous food allergy or reporting new food allergies. Community-reported reactions were ascertained from parent questionnaires.

RESULTS

Food challenges were undertaken in 916 children at age 1 year and 357 children at age 4 years (a total of 2047 peanut, egg, or sesame challenges). Urticaria was the most common sign in positive challenges at both ages (age 1 year, 88.7%, and age 4 years, 71.2%) although angioedema was significantly more common at age 4 years (40.1%) than at age 1 year (12.9%). Anaphylaxis was equally uncommon at both ages (2.1% and 2.8% of positive challenges at ages 1 and 4 years, respectively) but more common for peanut than for egg (4.5% and 1.2% of positive challenges at ages 1 and 4 years, respectively). The patterns of presenting signs reported during community reactions were similar to those observed in formal food challenges. Serum food-specific IgE levels of 15 kU/L or more were associated with moderate to severe reactions but skin prick test was not.

CONCLUSIONS

There was a shift from the most common presenting reaction of urticaria during food challenges toward more angioedema in older children. Serum food-specific IgE levels were associated with reaction severity.

The prevalence of food allergy and other allergic diseases in early childhood in a population-based study: HealthNuts age 4-year follow-up

BACKGROUND

The HealthNuts study previously reported interim prevalence data showing the highest prevalence of challenge-confirmed food allergy in infants internationally. However, population-derived prevalence data on challenge-confirmed food allergy and other allergic diseases in preschool-aged children remain sparse.

OBJECTIVE

This study aimed to report the updated prevalence of food allergy at age 1 year from the whole cohort, and to report the prevalence of food allergy, asthma, eczema, and allergic rhinitis at age 4 years.

METHODS

HealthNuts is a population-based cohort study with baseline recruitment of 5276 one-year-old children who underwent skin prick test (SPT) to 4 food allergens and those with detectable SPT results had formal food challenges. At age 4 years, parents completed a questionnaire (81.3% completed) and those who previously attended the HealthNuts clinic at age 1 year or reported symptoms of a new food allergy were invited for an assessment that included SPT and oral food challenges. Data on asthma, eczema, and allergic rhinitis were captured by validated International Study of Asthma and Allergies in Childhood questionnaires.

RESULTS

The prevalence of challenge-confirmed food allergy at age 1 and 4 years was 11.0% and 3.8%, respectively. At age 4 years, peanut allergy prevalence was 1.9% (95% CI, 1.6% to 2.3%), egg allergy was 1.2% (95% CI, 0.9% to 1.6%), and sesame allergy was 0.4% (95% CI, 0.3% to 0.6%). Late-onset peanut allergy at age 4 years was rare (0.2%). The prevalence of current asthma was 10.8% (95% CI, 9.7% to 12.1%), current eczema was 16.0% (95% CI, 14.7% to 17.4%), and current allergic rhinitis was 8.3% (95% CI, 7.2% to 9.4%). Forty percent to 50% of this population-based cohort experienced symptoms of an allergic disease in the first 4 years of their life.

CONCLUSIONS

Although the prevalence of food allergy decreased between age 1 year and age 4 years in this population-based cohort, the prevalence of any allergic disease among 4-year-old children in Melbourne, Australia, is remarkably high.

Food allergy in Catalonia: Clinical manifestations and its association with airborne allergens

BACKGROUND

Food allergy affects around 6% of the European population and its prevalence worldwide has been increasing in the last decades, but studies focused on investigating food allergy epidemiology in Europe are lacking.

OBJECTIVE

The Cibus project was created to register the main culprit foods and their clinical manifestations in food allergic patients in Catalonia.

METHODS

A specific online database was designed. Allergists from eight different Catalan hospitals registered the new diagnoses of food allergy.

RESULTS

618 food allergic patients were included. Egg and milk were the main elicitors in the early ages, while fruits and nuts were the most frequent in patients >14 years old. Fish was more frequent in children, while seafood and Anisakis allergy were more frequent in the >14-year-old group. Overall, peach was the most prevalent food eliciting an allergic reaction (10%). Food allergy diagnosis was reached using compatible clinical history and positive skin prick test to the involved food in 98% of cases. Globally, urticaria was the most frequently reported manifestation in our population (48.2%), followed by oral allergy syndrome (25.6%) and anaphylaxis (24.8%).

CONCLUSIONS

The Cibus project gives a full overview of the profile of food allergic patients in Catalonia and reinforces the predominance of plant food allergies in the Mediterranean area.

The Risk of Recurrent Anaphylaxis

OBJECTIVES

To determine the recurrence rate of anaphylaxis in children medically attended in an emergency department (ED), we performed a prospective cohort study to evaluate prehospital and ED management of children with recurrent anaphylaxis and to assess factors associated with recurrent anaphylaxis.

STUDY DESIGN

As part of the Cross-Canada Anaphylaxis Registry, parents of children with anaphylaxis identified prospectively in 3 EDs and through an emergency medical response service were contacted annually after presentation and queried on subsequent reactions. Cox regression analysis determined factors associated with recurrence.

RESULTS

Among 292 children who were registered as having had medical attended anaphylaxis, 68.5% completed annual follow-up questionnaires. Forty-seven patients experienced 65 episodes of anaphylaxis during 369 patient-years of follow-up. Food was the trigger in 84.6% of cases, and epinephrine was used in 66.2%. In 50.8%, epinephrine was used outside the health care facility, and 81.7% were brought to a health care facility for treatment. Asthma, reaction triggered by food, and use of epinephrine during the index episode increased the odds of recurrent reaction. Patients whose initial reaction was triggered by peanut were less likely to have a recurrent reaction.

CONCLUSIONS

We report a yearly anaphylaxis recurrence rate of 17.6% in children. There is substantial underuse of epinephrine in cases of anaphylaxis. Educational programs that promote effective avoidance strategies and prompt use of epinephrine are required.

Anaphylaxis across two Canadian pediatric centers: evaluating management disparities

BACKGROUND

There are no data on the percentage of visits due to anaphylaxis in the emergency department (ED), triggers, and management of anaphylaxis across different provinces in Canada.

OBJECTIVE

To compare the percentage of anaphylaxis cases among all ED visits, as well as the triggers and management of anaphylaxis between two Canadian pediatric EDs (PEDs).

METHODS

As part of the Cross-Canada Anaphylaxis Registry (C-CARE), children presenting to the British Columbia Children's Hospital (BCCH) and Montreal Children's Hospital (MCH) EDs with anaphylaxis were recruited. Characteristics, triggers, and management of anaphylaxis were documented using a standardized data entry form. Differences in demographics, triggers, and management were determined by comparing the difference of proportions and 95% confidence interval.

RESULTS

Between June 2014 and June 2016, there were 346 visits due to anaphylaxis among 93,730 PED visits at the BCCH ED and 631 anaphylaxis visits among 164,669 pediatric visits at the MCH ED. In both centers, the majority of cases were triggered by food (BCCH 91.3% [88.7, 94.0], MCH 82.4% [79.7, 85.3]), of which peanuts were the most common culprit (24.7% [20.9, 29.9] and 19.0% [15.8, 22.7], respectively). Pre-hospital administration of epinephrine (BCCH 27.7% [23.2, 32.8], MCH 33.1% [29.5, 37.0]) and antihistamines (BCCH 50.6% [45.2, 56.0], MCH 47.1% [43.1, 51.0]) was similar. In-hospital management differed in terms of increased epinephrine, antihistamine, and steroid use at the BCCH (59.2% [53.9, 64.4], 59.8% [54.4, 65.0], and 60.1% [54.7, 65.3], respectively) compared to the MCH (42.2% [38.3, 46.2], 36.2% [32.5, 40.1], and 11.9% [9.5, 14.8], respectively). Despite differences in management, percentage of cases admitted to the intensive care unit was similar between the two centers.

CONCLUSION

Compared to previous European and North American reports, there is a high percentage of anaphylaxis cases in two PEDs across Canada with substantial differences in hospital management practices. It is crucial to develop training programs that aim to increase epinephrine use in anaphylaxis.

Prevalence of food allergy in infants and pre-schoolers in Brazil

BACKGROUND

Food allergy is an increasing problem in public health, especially in childhood. Its incidence has increased in the last decade. Despite this, estimates of the actual incidence and prevalence are uncertain. The aim of this study was to estimate the prevalence of food allergy in infants and pre-schoolers.

METHODS

The parents of 3897 children completed questionnaires on the occurrence of any reaction to food. Children with parentally reported reactions were selected for further examination including a clinical interview, physical examination, allergic tests, and if necessary, oral food challenge to conclude the diagnosis of FA.

RESULTS

The estimated prevalence of allergy in children aged 4-59 months was 0.61%, being, 1.9% in infants and 0.4% in pre-schoolers. Among the 604 patients physicians evaluated with parent-reported FA, 24 (4%) had a confirmed diagnosis of food allergy, and 580 (96%) were excluded in the remaining. Of these, approximately half (51/52.6%) of 97 infants and (128/48%) of 487 pre-schoolers already performed the diet exclusion suspected food for a period of time.

CONCLUSION

This study shows that high overall prevalence of parental belief of current food allergy however the same was not observed in the in physician-diagnosed food allergy. The prevalence of food allergy was lower than that observed in the literature. This study alerts health professionals to the risk entailed by overestimation of cases of food allergy and unnecessary dietary exclusion, which may result in impairment in growth and development of children, especially in their first years of life.

Quality of life in patients with food allergy

Food allergy has increased in developed countries and can have a dramatic effect on quality of life, so as to provoke fatal reactions. We aimed to outline the socioeconomic impact that food allergy exerts in this kind of patients by performing a complete review of the literature and also describing the factors that may influence, to a greater extent, the quality of life of patients with food allergy and analyzing the different questionnaires available. Hitherto, strict avoidance of the culprit food(s) and use of emergency medications are the pillars to manage this condition. Promising approaches such as specific oral or epicutaneous immunotherapy and the use of monoclonal antibodies are progressively being investigated worldwide. However, even that an increasing number of centers fulfill those approaches, they are not fully implemented enough in clinical practice. The mean annual cost of health care has been estimated in international dollars (I$) 2016 for food-allergic adults and I$1089 for controls, a difference of I$927 (95 % confidence interval I$324–I$1530). A similar result was found for adults in each country, and for children, and interestingly, it was not sensitive to baseline demographic differences. Cost was significantly related to severity of illness in cases in nine countries. The constant threat of exposure, need for vigilance and expectation of outcome can have a tremendous impact on quality of life. Several studies have analyzed the impact of food allergy on health-related quality of life (HRQL) in adults and children in different countries. There have been described different factors that could modify HRQL in food allergic patients, the most important of them are perceived disease severity, age of the patient, peanut or soy allergy, country of origin and having allergy to two or more foods. Over the last few years, several different specific Quality of Life questionnaires for food allergic patients have been developed and translated to different languages and cultures. It is important to perform lingual and cultural translations of existent questionnaires in order to ensure its suitability in a specific region or country with its own socioeconomic reality and culture. Tools aimed at assessing the impact of food allergy on HRQL should be always part of the diagnostic work up, in order to provide a complete basal assessment, to highlight target of intervention as well as to evaluate the effectiveness of interventions designed to cure food allergy. HRQL may be the only meaningful outcome measure available for food allergy measuring this continuous burden.

Eczema in early childhood, sociodemographic factors and lifestyle habits are associated with food allergy: a nested case-control study

BACKGROUND

Studies suggest an increase in food allergy prevalence over the last decade, but the contributing factors remain unknown. The aim of this study was to evaluate the association between the most common food allergies and atopic history, sociodemographic characteristics and lifestyle habits.

METHODS

We conducted a case-control study nested within the SPAACE study (Surveying Prevalence of Food Allergy in All Canadian Environments) – a cross-Canada, random telephone survey. Cases consisted of individuals with probable food allergy (self-report of convincing symptoms and/or physician diagnosis) to milk, egg, peanut, tree nut, shellfish, fish, wheat, soy, or sesame. Controls consisted of nonallergic individuals, matched for age. Cases and controls were queried on personal and family history of atopy, sociodemographic characteristics and lifestyle habits. Multivariate logistic regression was used to evaluate the association between atopy, sociodemographic characteristics and lifestyle habits with probable food allergy.

RESULTS

Between September 2010 and September 2011, 480 cases and 4,950 controls completed the questionnaire. For all 9 allergens, factors associated with a higher risk of probable allergy were as follows: (1) personal history of eczema (in the first 2 years of life), asthma or hay fever (odds ratio, OR 2.3, 95% CI 1.6-3.5; OR 2.8, 95% CI 2.2-3.6, and OR 2.3, 95% CI 1.8-3.0, respectively), (2) maternal, paternal or sibling's food allergy (OR 3.7, 95% CI 2.5-5.6; OR 3.0, 95% CI 1.8-5.1, and OR 3.1, 95% CI 2.2-4.2), (3) high household income (top 20%; OR 1.5, 95% CI 1.2-2.0). Males and older individuals were less likely to have food allergy (OR 0.7, 95% CI 0.6-0.9, and OR 0.99, 95% CI 0.99-1.00). Eczema in the first 2 years of life was the strongest risk factor for egg, peanut, tree nut and fish allergy.

CONCLUSIONS

This is the largest population-based nested case-control study exploring factors associated with food allergies. Our results reveal that, in addition to previously reported factors, eczema in the first 2 years of life is consistently associated with food allergies.

Allergy to sunflower seed and sunflower butter as proposed vehicle for sensitization

BACKGROUND

It is hypothesized that household exposure to allergenic proteins via an impaired skin barrier, such as atopic dermatitis, may contribute to the development of IgE sensitization. Household presence of peanut is a risk factor for the development of peanut allergy in children. Sunflower seed butter is a peanut-free alternative to peanut butter, and sunflower seed allergy is an uncommon but reported entity.

CASE PRESENTATION

A 3 year old boy presented with oral discomfort that developed almost immediately after he ate sunflower seeds for the first time. He was given a dose of diphenhydramine. Subsequently he vomited, and his symptoms gradually resolved. A similar episode occurred to a commercial snack made with sunflower seed butter. Skin prick testing demonstrated a large positive (10 mm wheal) wheal-and-flare response to a slurry of fresh sunflower seed within 3-4 minutes associated with severe pruritus. This child has an older sibling with confirmed peanut allergy (PNA). After the PNA diagnosis was made, the family home became peanut-free. In lieu of peanut butter, sunflower butter was purchased and eaten frequently by family members, but not by the child reported herein. Subsequent to the episodes above, the child ate a bread roll with visible poppy seeds and developed itchy throat, dyspnea, and urticaria. Epicutaneous skin testing elicited a >10 mm wheal size within 3-4 minutes in response to a slurry of whole poppy seeds and 8 mm to fresh pumpkin seed, which had never been consumed.

CONCLUSIONS

A case of sunflower allergy in the context of household consumption of sunflower butter has not yet been reported. We suggest that homes which are intentionally peanut-safe may provide an environment whereby infants with impaired skin barrier are at increased risk of allergy to alternative "butter" products being used, via cutaneous exposure to these products preceding oral introduction to the child.

A survey of plants responsible for causing irritant contact dermatitis in the Amathole district, Eastern Cape, South Africa

ETHNOPHARMACOLOGICAL RELEVANCE

Potentially harmful plants grow almost everywhere, hence, it is not practical to eradicate them all. However, a basic understanding of adverse cutaneous reactions and the common plants that cause each type can enable vulnerable individuals to discover the source of their dermatitis and thus prevent re-exposure. The aim of this study therefore, was to document the plants responsible for irritant contact dermatitis (ICD) in the Eastern Cape, along with their respective irritants and clinical presentations.

MATERIALS AND METHODS

Study participants (161) in 12 locations were selected by convenient sampling with particular focus on local people who regularly interact with plants or plant products. Interview questions were focused on the local names of plants that contain irritating chemicals and physical characteristics that cause ICD.

RESULTS

Forty four plant species distributed in 24 families and 34 genera were reported as causative agents of irritant contact dermatitis. Herbs constituted 67.35%, trees 24.49% and shrubs 8.16%. Mechanical ICD was reported to be caused by 23 species, closely followed by chemical ICD (20 species) and mechanico-chemical ICD (6 species). Species with the highest frequency of citations were Allium cepa, Acacia karroo, Capsicum annuum, Citrus limon and Zea mays. The most representative families were Euphorbiaceae (for chemical ICD), Urticaceae (for mechanico-chemical ICD), Fabaceae and Rutaceae for mechanical ICD. Most of the classes of chemical compounds identified as being responsible for chemical ICD were restricted to plants of specific genera such as the diterpenes in Euphorbia spp., disulphides in Allium spp., terpenes in Citrus spp. and isothiocyanates in Brassica spp. Thorns and hairs were reported for causing Mechanical ICD in 6 plant species each, including widely cultivated plants such as Acacia karoo and Citrus reticulata.

CONCLUSION

Irritant contact dermatitis is a common cutaneous disorder in individuals exposed to plants in the Eastern Cape, especially among workers of the food and flower industries. Health practitioners should therefore consider the possible work-related causes of dermatitis, especially in cases associated with a clear history of symptoms.

Diagnosis and management of food allergies: new and emerging options: a systematic review

It is reported that 6% of children and 3% of adults have food allergies, with studies suggesting increased prevalence worldwide over the last few decades. Despite this, our diagnostic capabilities and techniques for managing patients with food allergies remain limited. We have conducted a systematic review of literature published within the last 5 years on the diagnosis and management of food allergies. While the gold standard for diagnosis remains the double-blind, placebo-controlled food challenge, this assessment is resource intensive and impractical in most clinical situations. In an effort to reduce the need for the double-blind, placebo-controlled food challenge, several risk-stratifying tests are employed, namely skin prick testing, measurement of serum-specific immunoglobulin E levels, component testing, and open food challenges. Management of food allergies typically involves allergen avoidance and carrying an epinephrine autoinjector. Clinical research trials of oral immunotherapy for some foods, including peanut, milk, egg, and peach, are under way. While oral immunotherapy is promising, its readiness for clinical application is controversial. In this review, we assess the latest studies published on the above diagnostic and management modalities, as well as novel strategies in the diagnosis and management of food allergy.

Temporal trends and racial/ethnic disparity in self-reported pediatric food allergy in the United States

BACKGROUND

The prevalence of food allergy is thought to be increasing, but data from the United States have not been systematically synthesized.

OBJECTIVE

To summarize the data on prevalence of food allergy in the US pediatric population and to estimate the effects of time, race/ethnicity, and method of assessing food allergy on the estimated prevalence.

METHODS

Embase, MEDLINE, bibliographies of identified reports, and data from publically available data sets were searched. Studies were limited to those in English with data from the general pediatric US population. Study synthesis was performed by meta-analysis and meta-regression to estimate the effect of study- and participant-level covariates. Meta-regression was limited to nationally representative surveys conducted by the Centers for Disease Control and Prevention.

RESULTS

A total of 10,090 publications were identified, from which 27 different survey administrations, representing 452,237 children, were identified, covering the period of 1988 to 2011. Because of heterogeneity among surveys in the estimated food allergy prevalence, a summary estimate of food allergy prevalence was not possible. Meta-regression was performed using 20 of these surveys. Temporal trends were pronounced, with an estimated increased prevalence of self-reported food allergy of 1.2 percentage points per decade (95% confidence interval [CI], 0.7-1.6). The increase per decade varied by race/ethnicity: 2.1% among non-Hispanic blacks (95% CI, 1.5%-2.7%), 1.2% among Hispanics (95% CI, 0.7%-1.7%), and 1.0% among non-Hispanic whites (95% CI, 0.4%-1.6%).

CONCLUSION

Self-report of food allergy among US children has sharply increased in the past 2 decades. The increase has been greatest among non-Hispanic black children, a disparity that needs to be investigated.

A 4-month-old baby boy presenting with anaphylaxis to a banana: a case report

Introduction

Food allergy is the most common cause of anaphylaxis in children and recent studies suggest increased prevalence of both food allergy and anaphylaxis. Among foods, fruits are rarely implicated as the cause of anaphylaxis. Furthermore, anaphylaxis to fruit in the first months of life is rare. Although banana allergy has been well described in adults, there are only two case reports of anaphylaxis to banana in children.

Case presentation

A 4-month-old Hispanic baby boy with a history of eczema presented to our emergency room with vomiting, urticaria and cyanosis following first exposure to a banana. He improved with administration of intramuscular epinephrine. Skin prick tests showed positive results for both fresh banana (4mm wheal/15mm erythema) and banana extract (8mm wheal/20mm erythema).

Conclusions

Banana is not considered a highly allergenic food. However, as food allergy becomes more common and solid foods are being introduced earlier in babies, banana may become an important allergen to consider in cases of babies presenting with anaphylaxis.

Exploring low-income families' financial barriers to food allergy management and treatment

Objectives. Low-income families may face financial barriers to management and treatment of chronic illnesses. No studies have explored how low-income individuals and families with anaphylactic food allergies cope with financial barriers to anaphylaxis management and/or treatment. This study explores qualitatively assessed direct, indirect, and intangible costs of anaphylaxis management and treatment faced by low-income families. Methods. In-depth, semistructured interviews with 23 participants were conducted to gain insight into income-related barriers to managing and treating anaphylactic food allergies. Results. Perceived direct costs included the cost of allergen-free foods and allergy medication and costs incurred as a result of misinformation about social support programs. Perceived indirect costs included those associated with lack of continuity of health care. Perceived intangible costs included the stress related to the difficulty of obtaining allergen-free foods at the food bank and feeling unsafe at discount grocery stores. These perceived costs represented barriers that were perceived as especially salient for the working poor, immigrants, youth living in poverty, and food bank users. Discussion. Low-income families report significant financial barriers to food allergy management and anaphylaxis preparedness. Clinicians, advocacy groups, and EAI manufacturers all have a role to play in ensuring equitable access to medication for low-income individuals with allergies.

A global survey of changing patterns of food allergy burden in children

While food allergies and eczema are among the most common chronic non-communicable diseases in children in many countries worldwide, quality data on the burden of these diseases is lacking, particularly in developing countries. This 2012 survey was performed to collect information on existing data on the global patterns and prevalence of food allergy by surveying all the national member societies of the World Allergy Organization, and some of their neighbouring countries. Data were collected from 89 countries, including published data, and changes in the health care burden of food allergy. More than half of the countries surveyed (52/89) did not have any data on food allergy prevalence. Only 10% (9/89) of countries had accurate food allergy prevalence data, based on oral food challenges (OFC). The remaining countries (23/89) had data largely based on parent-reporting of a food allergy diagnosis or symptoms, which is recognised to overestimate the prevalence of food allergy. Based on more accurate measures, the prevalence of clinical (OFC proven) food allergy in preschool children in developed countries is now as high as 10%. In large and rapidly emerging societies of Asia, such as China, where there are documented increases in food allergy, the prevalence of OFC-proven food allergy is now around 7% in pre-schoolers, comparable to the reported prevalence in European regions. While food allergy appears to be increasing in both developed and developing countries in the last 10-15 years, there is a lack of quality comparative data. This survey also highlights inequities in paediatric allergy services, availability of adrenaline auto-injectors and standardised National Anaphylaxis Action plans. In conclusion, there remains a need to gather more accurate data on the prevalence of food allergy in many developed and developing countries to better anticipate and address the rising community and health service burden of food allergy.

Effectiveness and safety of orally administered immunotherapy for food allergies: a systematic review and meta-analysis

The aim of using oral and sublingual immunotherapy with food allergies is to enable the safe consumption of foods containing these allergens in patients with food allergies. In the present study, a systematic review of intervention studies was undertaken; this involved the searching of eleven international databases for controlled clinical trials. We identified 1152 potentially relevant papers, from which we selected twenty-two reports of twenty-one eligible trials (i.e. eighteen randomised controlled trials and three controlled clinical trials). The meta-analysis revealed a substantially lower risk of reactions to the relevant food allergen in those receiving orally administered immunotherapy (risk ratios (RR) 0·21, 95 % CI 0·12, 0·38). The meta-analysis of immunological data demonstrated that skin prick test responses to the relevant food allergen significantly decreased with immunotherapy (mean difference - 2·96 mm, 95 % CI - 4·48, - 1·45), while allergen-specific IgG4 levels increased by an average of 19·9 (95 % CI 17·1, 22·6) μg/ml. Sensitivity analyses excluding studies at the highest risk of bias and subgroup analyses in relation to specific food allergens and treatment approaches generated comparable summary estimates of effectiveness and immunological changes. Pooling of the safety data revealed an increased risk of local (i.e. minor oropharyngeal/gastrointestinal) adverse reactions with immunotherapy (RR 1·47, 95 % CI 1·11, 1·95); there was a non-significant increased average risk of systemic adverse reactions with immunotherapy (RR 1·08, 95 % CI 0·97, 1·19). There is strong evidence that orally administered immunotherapy can induce immunomodulatory changes and thereby promote desensitisation to a range of foods. However, given the paucity of evidence on longer-term safety, effectiveness and cost-effectiveness, orally administered immunotherapy should not be used outside experimental conditions presently.

Peanut-specific IgE antibodies in asymptomatic Ghanaian children possibly caused by carbohydrate determinant cross-reactivity

Background

The prevalence of peanut allergy has increased in developed countries, but little is known about developing countries with high peanut consumption and widespread parasitic infections.

Objective

We sought to investigate peanut allergy in Ghana.

Methods

In a cross-sectional survey among Ghanaian schoolchildren (n = 1604), data were collected on reported adverse reactions to peanut, peanut sensitization (serum specific IgE and skin reactivity), consumption patterns, and parasitic infections. In a subset (n = 43) IgE against Ara h 1, 2, 3, and 9 as well as cross-reactive carbohydrate determinants (CCDs) was measured by using ImmunoCAP. Cross-reactivity and biological activity were investigated by means of ImmunoCAP inhibition and basophil histamine release, respectively.

Results

Adverse reactions to peanut were reported in 1.5%, skin prick test reactivity in 2.0%, and IgE sensitization (≥0.35 kU/L) in 17.5% of participants. Moreover, 92.4% of those IgE sensitized to peanut (≥0.35 kU/L) had negative peanut skin prick test responses. Schistosoma haematobium infection was positively associated with IgE sensitization (adjusted odds ratio, 2.29; 95% CI, 1.37-3.86). In the subset IgE titers to Ara h 1, 2, 3, and 9 were low (<1.3 kU/L), except for 6 moderately strong reactions to Ara h 9. IgE against peanut was strongly correlated with IgE against CCDs (r = 0.89, P < .0001) and could be almost completely inhibited by CCDs, as well as S haematobium soluble egg antigen. Moreover, IgE to peanut showed poor biological activity.

Conclusions

Parasite-induced IgE against CCDs might account largely for high IgE levels to peanut in our study population of Ghanaian schoolchildren. No evidence of IgE-mediated peanut allergy was found.

Role of viruses in the development of atopic disease in pediatric patients

The prevalence of atopic diseases continues to rise in modernized countries, without a clear explanation for this increase. One potential cause identified from epidemiologic studies of children is respiratory RNA viral infections leading to development of recurrent wheezing, asthma, and allergic sensitization. We review human epidemiologic data that both support and refute the role of viruses in this process. Exploring recent murine models, we document possible immunologic mechanisms that could translate a viral infection into atopic disease. We further discuss evidence for a post-viral "atopic cycle" that could explain the development of multiple allergen sensitization, and we explore available data to suggest a connection between viral infections of the gastrointestinal tract with the development of food allergy. Taken together, this review documents evidence to support the "viral hypothesis", and, in particular, the role of RNA viruses in the development of atopic disease.

IgE-mediated cow milk allergy and infantile colic: diagnostic and management challenges

Cow milk allergy (CMA) is a common problem affecting 2-3% of children and is the most prevalent food allergy in infancy. Infantile colic is also a common problem in the first year of life. A frequent practice among physicians is to recommend a dairy-free diet to breast-feeding mothers and infants in cases of infantile colic. However, recent studies suggest that late introduction of potentially allergenic foods may increase the risk of developing a life-threatening food allergy. We describe two infants managed with dairy-free diet to control symptoms of colic in whom CMA developed. It is possible that unnecessary cow milk restriction may have contributed to the development of food allergy in these infants.