Food allergy in Asia

A nomogram for predicting food allergy in infants with feeding problems and malnutrition

BACKGROUND AND OBJECTIVE

As oral food challenge (OFC) cannot be performed routinely in the general outpatient, this study aimed to construct a nomogram to predict the odds of food allergy in infants with idiopathic feeding problems and malnutrition.

METHODS

From August 2018 to December 2021, 289 infants (median age, 6 months; P25-P75, 4-8) with idiopathic feeding problems and malnutrition were enrolled from seven hospitals in Shanghai, China. Food allergy was defined as a positive response to a skin prick test or OFC, with gastrointestinal, dermatologic, or respiratory symptom improvement after 4 weeks of avoidance of the suspected food. Demographic characteristics, Cow's Milk-related Symptom Scores (CoMiSS), and blood eosinophil amounts were evaluated for their associations with food allergy. Multivariable logistic regression analysis was used to identify variables to develop a nomogram model with the bootstrapped-concordance index as an assessment metric.

RESULTS

Totally 249 of 289 infants had food allergy (86.2%). After logistic regression analysis, the feeding pattern (odds ratio [OR] = 5.28, 95% confidence interval [CI]: 2.13-13.09), a family history of allergy (OR = 1.79, 95% CI: 0.71-4.51), CoMiSS (OR = 1.45, 95% CI: 1.19-1.77), and eosinophil percentage (OR = 1.33, 95% CI: 1.11-1.60) were used to develop the model, which had a good performance with an area under the curve of 0.868 (95% CI: 0.792-0.944) and a bootstrapped-concordance index of 0.868.

CONCLUSION

Food allergy is common in infants with idiopathic feeding problems and malnutrition. The developed nomogram may help identify infants with food allergy for further diagnosis.

Are the most common food allergens in an Iranian atopic population compatible with worldwide reports? A systemic review and meta-analysis with molecular classification of frequent allergens

BACKGROUND

Undesirable immunological responses to alimentary allergens are one of the hallmarks of atopic diseases. The prevalence of common food allergens is dissimilar among different communities with distinct nutritional habits and genetic characteristics.

AIM

To assess the prevalence of the most common food allergens in Iran, using different reliable studies.

METHODS

All studies determining sensitization to common food allergens that were indexed in PubMed, Web of Science, Google Scholar, ProQuest, Scopus, Iran Medex, and Magiran were included in this review. To perform a meta-analysis, STATA 14 and metaprop command was applied. A logistic-normal random-effects model with Freeman-Tukey double arcsin transformation was applied to combine the findings of different studies and evaluate their heterogeneity. Random pooled estimate (ES) (pooled prevalence), 95% confidence interval (95% CI) and p-value were determined.

RESULTS

A total of 23 studies with data from a total of 6126 children and adults met the inclusion criteria for entering this meta-analysis. The respective pooled prevalence of a positive family history of allergy and positive specific IgE to at least one food allergen was 72% (95% CI: 66-77%) and 41% (95% CI: 33-49%), respectively. Our results in the total population revealed that allergic sensitization to egg yolk, cow's milk (CM), egg white, and wheat were 25% (95% CI: 16%-35%), 24% (95% CI: 19-29%), 23% (95% CI: 18%-28%), and 9% (95% CI: 6%-14%), respectively. Walnut, peanut, and soybean sensitization was detected in 23% (95% CI: 17%-31%), 23% (95% CI: 13%-33%), and 20% (95% CI: 12%-28%) of patients, respectively. Random pooled ES for sensitization to shrimp and fish was 32% (95% CI: 21-45%) and 12% (95% CI: 6-20%), respectively. The result of analysis in different age groups revealed that allergic sensitization to milk, egg white, and egg yolk declines in higher age groups; while shrimp sensitization increases in older patients. In patients with atopic dermatitis, egg white was the most frequent food allergen 29% (95% CI = 18-42%); while wheat was the least frequent 8% (95% CI = 4-14%).

CONCLUSIONS

Considering the prevalence of different food allergens, the results of the current meta-analysis revealed that egg yolk and cow's milk had the second and third rate after shrimp, respectively. The high prevalence of sensitization to shrimp may be attributed to its high consumption in coastal areas and/or cross-reactivity of shrimp with some aeroallergens such as mites.

Epidemiologic studies about food allergy and food sensitization in tropical countries. Results and limitations

The variety of foods and methods of preparation are part of the cultural identity of each population, and thus the main foods that cause symptoms vary among different regions. Due to their increasing frequency, Adverse Reactions to Food (AFR) have been the subject of extensive study, especially in North America and Europe but few studies have been conducted in other areas, especially in populations located in the tropics and subtropics. In this article, we review available information on the epidemiology of food sensitization and food allergies in tropical regions and explore the different epidemiological data considering the major food involved, the underlying immune mechanism and clinical symptoms partners. In addition, we identify the possible limitations and questions that arise from studies conducted in tropical countries, which helps to generate objectives for future research.

Clinical Features and Culprit Food Allergens of Korean Adult Food Allergy Patients: A Cross-Sectional Single-Institute Study

Purpose

To investigate the causative allergens and clinical characteristics of Korean adult patients with food allergy (FA).

Methods

This retrospective, cross-sectional single-institutional study enrolled Korean adult patients (n = 812) suspected of having FA. For diagnosis, causality assessment history taking, ImmunoCAP specific immunoglobulin E measurement and/or skin prick test were performed.

Results

Among 812 patients, 415 were diagnosed as having FA. The most common causative allergen was fruit, with a diagnosis of pollen food allergy syndrome (PFAS: 155, 37.3%), followed by crustaceans (111, 26.7%), wheat (63, 15.1%), fruits in patients without PFAS(43, 10.3%), buckwheat (31, 7.4%), peanut (31, 7.4%), walnut (25, 6.0%), red meat due to reaction to galactose-α-1,3-galactose (α-Gal) (8, 1.9%), and silkworm pupa (13, 3.1%). Allergy to egg, milk, fish, or shellfish was rare in Korean adults. One-third of patients with FA exhibited multiple FAs (238/415, 57.3%); the average number of causative allergens was 2.39. About 129 patients (31.0%) were diagnosed as having anaphylaxis; in these patients, wheat was the most frequent causative food. Twenty patients were further diagnosed with food-dependent exercise-induced anaphylaxis (FDEIA); all were due to wheat. In particular, crustaceans, wheat, PFAS, buckwheat, and red meat (α-Gal) were also frequent causes of anaphylaxis.

Conclusions

Wheat, fruits with or without PFAS, and crustaceans are important and frequent causative allergens in Korean adult FA; these allergens differ from those found in childhood FA. It is notable that non-classic allergies, such as PFAS, FDEIA, and α-Gal allergy, are the important causes of anaphylaxis in Korean adult FA.

Food Allergy in Children: An Overview

The estimated prevalence of food allergy amongst children in the west is around 6-8% but there is paucity of data in the Indian population. There is a complex interplay of environmental influences and genetic factors in the immuno-pathogenesis and manifestations of food allergy. A reliable thorough clinical history, combined with positive skin prick tests or food-specific IgE, is essential for a more precise diagnosis of food allergy. Currently there is no cure for food allergy. The management of food allergy usually includes strict avoidance, patient education and provision of emergency medication (adrenaline-autoinjectors). Emerging therapies based on evolving research are focused on a more active approach to management which includes early introduction of potentially allergenic foods, anticipatory testing and desensitisation to food allergens. Lack of food labelling policy and non availability of adrenaline auto-injectors is a huge limiting factor for effective management of food allergy among children in India. The present review focuses on IgE mediated food allergy.

Food allergen labelling: "May contain" evidence from Malaysia

Food allergen labelling is mandatory and regulated whilst precautionary allergen labelling (PAL) remains voluntary in most countries. It is the aim of this study to identify the food allergens declared in food products sold in a developing country and to what extent food allergens and PAL are emphasised in the products. A total of 505 food and beverages (snacks, baked goods, confectionary, baby food, condiments & jams, beverages, powder & paste, instant food, chilled & frozen food and canned food) were evaluated in Malaysia. Soybean represents the largest group of food allergen declared in labels, followed by wheat and milk products. Thirteen variations of contains statement were found with "Contains [allergen(s)]" being the most common (55.02%). There were 22 different types of "may contain" statements with 'May contain traces of [allergen(s)]' being the most common advice labelling used (55.41%). Different font type or emphasis such as brackets (51.57%) and bold font (33.86%) were used to inform consumers about presence of allergens. The national regulations on food allergen labelling are then critically contrasted with other Asian countries and the EU Regulation No. 1169/2011, which represents one of the most stringent food regulations in the world. Improving current allergen labelling limitations and practices would be of great benefit to consumers to prevent risk of food hypersensitivity.

Prevalence of food allergies in South Asia

OBJECTIVE

To evaluate the published medical literature on the prevalence and types of food allergies in South Asia.

DATA SOURCES

A PubMed search was performed using the keywords India and food allergy, Asia and food allergy, and South Asia and food allergy for any period. Articles cited in selected studies were reviewed for their appropriateness of inclusion into this review.

STUDY SELECTIONS

Publications were included that were original research and fit the topic of food allergy and South Asia. South Asia is defined as region inclusive of India, Pakistan, Bangladesh, and Sri Lanka.

RESULTS

A total of 169 articles were initially identified, and 47 were reviewed in detail for inclusion in this review. The primary focus was placed on 10 studies that consisted of case reports of newly reported or documented food allergy, survey studies that investigated food allergy prevalence in specific demographics, and prospective and cross-sectional studies with case controls, all of which investigated food allergy prevalence by allergy testing in a selected population.

CONCLUSION

The medical literature on the prevalence and types of food allergy in South Asia indicates that there is a variety of unusual and unique allergens and an overall low incidence of food allergy. There is also an association of increased food allergy prevalence in individuals who live in metropolitan regions or who migrate to communities that have adopted westernization.

Heat processing of peanut seed enhances the sensitization potential of the major peanut allergen Ara h 6

SCOPE

Processing of food has been shown to impact IgE binding and functionality of food allergens. In the present study, we investigated the impact of heat processing on the sensitization capacity of Ara h 6, a major peanut allergen and one of the most potent elicitors of the allergic reaction.

METHODS AND RESULTS

Peanut extracts obtained from raw or heat-processed peanut and some fractions thereof were biochemically and immunochemically characterized. These extracts/fractions, purified Ara h 6, or recombinant Ara h 6 including Ara h 6 mutants lacking disulfide bridges were used in in vitro digestion tests and mouse models of experimental sensitization. Peanut roasting led to the formation of complexes of high molecular weight, notably between Ara h 6 and Ara h 1, which supported the induction of IgE specific to native Ara h 6. On the contrary, a fraction containing free monomeric 2S albumins or purified native Ara h 6 displayed no intrinsic allergenicity. In addition to complex formation, heat denaturation and/or partial destabilization enhanced Ara h 6 immunogenicity and increased its sensitivity to digestion.

CONCLUSION

These results suggest that sensitization potency and IgE binding capacity can be supported by different structures, modified and/or produced during food processing in interaction with other food constituents.

Prevalence of food sensitization and probable food allergy among adults in India: the EuroPrevall INCO study

BACKGROUND

Data are lacking regarding the prevalence of food sensitization and probable food allergy among general population in India. We report the prevalence of sensitization and probable food allergy to 24 common foods among adults from general population in Karnataka, South India.

METHODOLOGY

The study was conducted in two stages: a screening study and a case-control study. A total of 11 791 adults in age group 20-54 were randomly sampled from general population in South India and answered a screening questionnaire. A total of 588 subjects (236 cases and 352 controls) participated in the case-control study involving a detailed questionnaire and specific IgE estimation for 24 common foods.

RESULTS

A high level of sensitization (26.5%) was observed for most of the foods in the general population, higher than that observed among adults in Europe, except for those foods that cross-react with birch pollen. Most of the sensitization was observed in subjects who had total IgE above the median IgE level. A high level of cross-reactivity was observed among different pollens and foods and among foods. The prevalence of probable food allergy (self-reports of adverse symptoms after the consumption of food and specific IgE to the same food) was 1.2%, which was mainly accounted for cow's milk (0.5%) and apple (0.5%).

CONCLUSION

Very high levels of sensitization were observed for most foods, including those not commonly consumed in the general population. For the levels of sensitization, the prevalence of probable food allergy was low. This disassociation needs to be further explored in future studies.

Particularities of allergy in the Tropics

Allergic diseases are distributed worldwide and their risk factors and triggers vary according to geographical and socioeconomic conditions. Allergies are frequent in the Tropics but aspects of their prevalence, natural history, risk factors, sensitizers and triggers are not well defined and some are expected to be different from those in temperate zone countries. The aim of this review is to investigate if allergic diseases in the Tropics have particularities that deserve special attention for research and clinical practice. Such information will help to form a better understanding of the pathogenesis, diagnosis and management of allergic diseases in the Tropics. As expected, we found particularities in the Tropics that merit further study because they strongly affect the natural history of common allergic diseases; most of them related to climate conditions that favor permanent exposure to mite allergens, helminth infections and stinging insects. In addition, we detected several unmet needs in important areas which should be investigated and solved by collaborative efforts led by the emergent research groups on allergy from tropical countries.

Characteristics of Anaphylaxis in 907 Chinese Patients Referred to a Tertiary Allergy Center: A Retrospective Study of 1,952 Episodes

Purpose

Comprehensive evaluation of anaphylaxis in China is currently lacking. In this study, we characterized the clinical profiles, anaphylactic triggers, and emergency treatment in pediatric and adult patients.

Methods

Outpatients diagnosed with "anaphylaxis" or "severe allergic reactions" in the Department of Allergy, Peking Union Medical College Hospital from January 1, 2000 to June 30, 2014 were analyzed retrospectively.

Results

A total of 1,952 episodes of anaphylaxis in 907 patients were analyzed (78% were adults and 22% were children). Foods are the most common cause (77%), followed by idiopathic etiologies (15%), medications (7%) and insects (0.6%). In food-induced anaphylaxis, 62% (13/21) of anaphylaxis in infants and young children (0-3 years of age) were triggered by milk, 59% (36/61) of anaphylaxis in children (4-9 years of age) were triggered by fruits/vegetables, while wheat was the cause of anaphylaxis in 20% (56/282) of teenagers (10-17 years of age) and 42% (429/1,016) in adults (18-50 years of age). Mugwort pollen sensitization was common in patients with anaphylaxis induced by spices, fruits/vegetables, legume/peanuts, and tree nuts/seeds, with the prevalence rates of 75%, 67%, 61%, and 51%, respectively. Thirty-six percent of drug-induced anaphylaxis was attributed to traditional Chinese Medicine. For patients receiving emergency care, only 25% of patients received epinephrine.

Conclusions

The present study showed that anaphylaxis appeared to occur more often in adults than in infants and children, which were in contrast to those found in other countries. In particular, wheat allergens played a prominent role in triggering food-induced anaphylaxis, followed by fruits/vegetables. Traditional Chinese medicine was a cause of drug-induced anaphylaxis. Furthermore, exercise was the most common factor aggravating anaphylaxis. Education regarding the more aggressive use of epinephrine in the emergency setting is clearly needed.

Assessment of knowledge, attitude and practice of food allergies among food handlers in the state of Penang, Malaysia

OBJECTIVES

Food handler's knowledge, attitude and practice regarding food allergies are important to prevent debilitating and sometimes fatal reactions. This study aimed to assess their food allergy knowledge, attitude and practice, which could help to maintain the safety and hygiene of food consumed by the public.

STUDY DESIGN

Cross-sectional survey.

METHODS

A cross-sectional survey involving 121 conveniently sampled (81.76% response rate) respondents among the food handlers in the state of Penang, Malaysia, was conducted using a validated self-administered questionnaire. Their knowledge, attitude and work practice were captured using a 37-item questionnaire that elicited their responses using a mixture of closed-ended and Likert scale techniques.

RESULTS

The mean knowledge score for respondents was 50.23 (SD = 14.03), attitude score was 54.26 (SD = 11.67) and practice score was 45.90 (SD = 24.78). Only 1.79% of the respondents were considered to have excellent knowledge, 21.37% had a low risk practice and 4.27% had positive attitudes towards food allergies. Most of the respondents (70%) knew about food allergies and their seriousness. There was a statistically significant correlation between the attitude and practice of respondents (r = 0.51). The type of establishment was the only characteristic significantly associated (P < 0.05) with food handler allergy knowledge, attitude and practice.

CONCLUSIONS

More than half of food handlers in Penang have moderate levels of food allergy knowledge, practice and attitude. Only a small proportion of them have excellent food allergy knowledge, practice and attitude. Integration of food allergy training into compulsory food safety training programmes is needed to reduce food allergy risks and prevent fatal allergic reactions to food among their customers.

Total IgE Distribution in Food Allergy Suspected Patients in Republic of Macedonia (2001-2011)

BACKGROUND: IgE may be considered the hallmark of allergic disorders. It is easily detected in serum and can be measured as total IgE and as allergen-specific IgE. In fact, the serum IgE assay is used to diagnose an allergy.AIM: The aim of this study is to evaluate, investigate and present the distribution of total serum IgE levels, determined with UniCap system, in food-allergy suspected patients in a Republic of Macedonia.MATERIAL AND METHODS: In this study we analyzed retrospectively 8898 consecutive patients that were admitted for allergy testing at the Institute of Immunobiology and Human Genetics during the ten year period between 01.01.2001 and 01.01.2011. Total IgE levels in patient sera were detected with the in vitro system UniCAP100 (Pharmacia, Uppsala, Sweden).RESULTS: When we analyzed the number of patients according to the total IgE groups, we noted that most of the patients have normal levels of total IgE in serum. However, we also discovered a group of patients with elevated levels of total IgE that are greater than 200 kU/L. The average concentration of total serum IgE is higher in women in the age group 6 (6-7 years), followed by a steep decrease in the age group 9 (9-10 years), and after that the average concentrations of total IgE were mostly constant with the exception of a partial increase in the age group 21 (65-69 years). For men, the average serum concentrations of total IgE were highest in the age group of 6 (6-7 years), which was significantly higher than the average concentrations of total IgE in all other age groups.CONCLUSION: The large number of enrolled patients, a particular strength of this study, revealed that average concentrations of total IgE in men are higher than in women and that total IgE did not decrease with age. On the contrary, increased total IgE levels were found in patients aged 65 and 69 of both genders. We continue our work with analyses of the specific IgE antibodies values toward food and the correlation with total IgE values.

Emergency department visits for food allergy in Taiwan: a retrospective study

BACKGROUND

Little is known about the characteristics of patients who visit the emergency department (ED) due to food allergy in Taiwan. This study aims to assess the triggers, clinical presentations, and management of patients presenting to a tertiary ED for food allergy.

METHODS

This is a retrospective study of 369 visits presenting to the ED of Taipei Veterans General Hospital, Taipei, Taiwan for food allergy over a 2 year period. Patients' demographics, food allergens, presenting features, and management were addressed and analyzed. Adult and pediatric cases were also compared.

RESULTS

The patients had an average age of 32.9 years [standard deviation (SD) ± 20.6]; the cohort was 66.9% adult and 53.7% male. Seafood (67.5%), fish (6.2%), and fruits (4.3%) were the major foods eliciting acute allergic reactions. Overall itchy mucocutaneous lesion was the most common presentation (85.6%), followed by anaphylaxis (12.2%), respiratory distress (1.4%), and anaphylactic shock (0.8%). Mucocutaneous involvement was more common in the pediatric population (92.6% vs. 82.2%, p = 0.007), whereas anaphylaxis was more prevalent in adults (15.4% vs. 5.7%, p = 0.0068). Antihistamines (98.6%) and systemic corticosteroids (63.1%) were commonly used medications. Only 2.2% of patients with anaphylaxis received epinephrine. The average duration in the ED was 1.6 hours (SD ± 1.8). No death was documented in the current study.

CONCLUSION

Seafood, fish, and fruits are common foods which cause acute allergic reactions in Taiwan. Although most food allergies are mild, anaphylactic shock still presents in about 1% of patients. Only a minority of patients with anaphylaxis receive epinephrine. As anaphylaxis may be life-threatening, prompt education and use of an epinephrine auto-injector deserves further concern.

Prevalence of food allergy in Taiwan: a questionnaire-based survey

AIM

Food allergy is common in children and adults, and could be potentially fatal in minor groups. It is important for physicians to identify the prevalence of food allergies and to recognise common food allergens to make precise diagnosis and choose correct therapeutic approaches.

METHODS

We used a nationwide, cross-sectional, random questionnaire-based survey to estimate the self-reported and expert-screened prevalence of food allergies and to identify the common food allergens in Taiwan. In this study, the perceptional diagnosis of food allergies was screened by physicians according to descriptions of convincing symptoms and medical recordings; in the meantime, non-allergic adverse reactions to foods, including food intolerance or food avoidance, were clarified.

RESULTS

A total of 30 018 individuals who met the inclusion criteria was evaluated, and 6.95% of them were diagnosed as victims of food allergies. The prevalence was 3.44% in children under 3 years of age, 7.65% in children aged 4-18 years and 6.40% in adults respectively. About 77.33% of the food allergy population had experienced recurrent allergic attacks. Systemic reactions happened about 4.89% in food allergies group. The most commonly reported food allergen in Taiwan is seafood, including shrimp, crab, fish and mollusc. In addition, mango, milk, peanuts and eggs were also important food allergens in the general population; while milk, shellfish, peanuts and eggs were common in children.

CONCLUSIONS

Less than 10% of the Taiwan population suffers from food allergy with different allergic symptoms to variable food allergens in different age groups.

IgE mediated food allergy in Korean children: focused on plant food allergy

Food allergy (FA) is a worldwide problem, with increasing prevalence in many countries, and it poses a clearly increasing health problem in Korea. In Korea, as a part of International Study of Asthma and Allergy in Childhood (ISAAC), a series of nation-wide population studies for prevalence of allergic disease in children were carried out, with the Korean version of ISAAC in 1995, 2000, and 2010. From the survey, the twelve-month prevalence of FA showed no significant differences from 1995 to 2000 in both age groups (6-12 years-old, 6.5% in 1995 and 5.7% in 2000; 12-15 year-olds, 7.4% in 1995 and 8.6% in 2000). The mean lifetime prevalence of FA which had ever been diagnosed by medical doctor was 4.7% in 6-12 year-olds and 5.1% in 12-15 year-olds respectively in 2000. In Korean children, the major causes of FA are almost same as in other countries, although the order prevalence may vary, a prime example of which being that peanut and tree nut allergies are not prevalent, as in western countries. Both pediatric emergency department (ED) visits and deaths relating to food induced anaphylaxis have also increased in western countries. From a study which based on data from the Korean Health Insurance Review and Assessment Service (KHIRA) from 2001 to 2007, the incidence of anaphylaxis under the age of 19 was 0.7-1 per 100,000 person-year, and foods (24.9%) were the most commonly identified cause of childhood anaphylaxis. In another epidemiologic study, involving 78889 patients aged 0-18 years who visited the EDs of 9 hospitals during June 2008 to Mar 2009, the incidence of food related anaphylaxis was 4.56 per 10,000 pediatric ED visits. From these studies, common causes of food related anaphylaxis were seafood, buckwheat, cow's milk, fruits, peanut and tree nuts. Although systematic epidemiologic studies have not reported on the matter, recently, plant foods related allergy has increased in Korean children. Among 804 children with moderate to severe atopic dermatitis, we reveals that the peanut sensitization rate in Korea reaches 18%, and that, when sensitized to peanut, patients showed a significant tendency to have co-sensitization with house dust mites, egg white, wheat, and soybean. The higher specific IgE to peanut was related to the likelihood of the patient developing severe systemic reactions. In another study, based on the data analysis of 69 patients under 4 years of age who had suspected peanut and tree nut allergy, 22 (31.9%) were sensitized to walnut (>0.35 kU/L, 0.45-27.4 kU/L) and 6 (8.7%) experienced anaphylaxis due to a small amount of walnut exposure. Furthermore, in this review, clinical and immunological studies on plant food allergies, such as buckwheat allergy, rice allergy, barley allergy, and kiwi fruit allergy, in Korean children are discussed.

Food allergy in Asia: how does it compare?

Asia is a populous and diverse region and potentially an important source of information on food allergy. This review aims to summarize the current literature on food allergy from this region, comparing it with western populations. A PubMed search using strategies "Food allergy AND Asia", "Food anaphylaxis AND Asia", and "Food allergy AND each Asian country" was made. Overall, 53 articles, published between 2005 and 2012, mainly written in English were reviewed. The overall prevalence of food allergy in Asia is somewhat comparable to the West. However, the types of food allergy differ in order of relevance. Shellfish is the most common food allergen from Asia, in part due to the abundance of seafood in this region. It is unique as symptoms vary widely from oral symptoms to anaphylaxis for the same individual. Data suggest that house dust mite tropomysin may be a primary sensitizer. In contrast, peanut prevalence in Asia is extremely low compared to the West for reasons not yet understood. Among young children and infants, egg and cow's milk allergy are the two most common food allergies, with prevalence data comparable to western populations. Differences also exist within Asia. Wheat allergy, though uncommon in most Asian countries, is the most common cause of anaphylaxis in Japan and Korea, and is increasing in Thailand. Current food allergy data from Asia highlights important differences between East and West, and within the Asian region. Further work is needed to provide insight on the environmental risk factors accounting for these differences.

Food allergies in developing and emerging economies: need for comprehensive data on prevalence rates

Although much is known today about the prevalence of food allergy in the developed world, there are serious knowledge gaps about the prevalence rates of food allergy in developing countries. Food allergy affects up to 6% of children and 4% of adults. Symptoms include urticaria, gastrointestinal distress, failure to thrive, anaphylaxis and even death. There are over 170 foods known to provoke allergic reactions. Of these, the most common foods responsible for inducing 90% of reported allergic reactions are peanuts, milk, eggs, wheat, nuts (e.g., hazelnuts, walnuts, almonds, cashews, pecans, etc.), soybeans, fish, crustaceans and shellfish. Current assumptions are that prevalence rates are lower in developing countries and emerging economies such as China, Brazil and India which raises questions about potential health impacts should the assumptions not be supported by evidence. As the health and social burden of food allergy can be significant, national and international efforts focusing on food security, food safety, food quality and dietary diversity need to pay special attention to the role of food allergy in order to avoid marginalization of sub-populations in the community. More importantly, as the major food sources used in international food aid programs are frequently priority allergens (e.g., peanut, milk, eggs, soybean, fish, wheat), and due to the similarities between food allergy and some malnutrition symptoms, it will be increasingly important to understand and assess the interplay between food allergy and nutrition in order to protect and identify appropriate sources of foods for sensitized sub-populations especially in economically disadvantaged countries and communities.

Current status of managing food allergies in schools in Seoul, Korea

Recently the need to manage food allergies in schools has been growing. This study aimed to examine the current status of managing food allergies in schools in Seoul, Korea. A questionnaire survey was conducted in cooperation with the School Dietician Association during April 2009. Among the participating 154 schools, a total of 109 (71%) were determining students' food allergy status through parental surveys based on self-reported food allergies. A total of 72 (47%) had experienced student visits to a school health room due to food allergies within one year before the survey. Over 80 percent of the schools relied on self-care only without any school-wide measures for food allergies in place. Among the 890 menu items most frequently served in school lunch programs, a total of 664 (75%) were found to contain more than one food allergen. It is highly suggested that preventive plans and treatment measures should be established to manage food allergies in schools.

Prevalence of food allergy among preschool children in northern Thailand

BACKGROUND

The epidemiology and clinical spectrum of food allergies (FA) confirmed by oral food challenge tests (OFC) in the Southeast Asian countries are limited. The aim of the present study was to examine the prevalence and characteristics of FA among preschool children in northern Thailand.

METHODS

Five hundred and forty-six children aged 3-7 years living in Chiang Mai, Thailand participated in this study. A cross-sectional parent questionnaire survey was conducted. Families with children reporting FA were invited to undergo further investigations with skin prick testing, serum specific IgE, and OFC.

RESULTS

A total of 452 out of 546 questionnaires (82.8%) were returned. Forty-two children (9.3%) were reported to have FA. The five leading allergic foods reported were shrimp, cow's milk, fish, chicken eggs, and ant eggs. The most commonly reported symptom was a skin rash (78.0%), followed by abdominal pain and vomiting (31.1%). Anaphylaxis was found in two children (3.4%), from ant eggs allergy. Eighteen children underwent OFC; five of them were positive to shrimp, fish, and crab. Either skin prick test or serum-specific IgE was positive in these children. Factors associated with parent-reported FA included personal and family history of atopic dermatitis.

CONCLUSIONS

The prevalence of IgE-mediated FA confirmed on OFC was ≥ 1.11% (95% confidence interval: 0.41-2.98%). The most common causative food was shrimp. Ant eggs were a unique food allergen causing severe reactions in preschool children in northern Thailand.

In silico assessment of the potential allergenicity of transgenes used for the development of GM food crops

Genetically modified (GM) crops require allergenicity and toxicity assessment of the novel protein(s) to ensure complete safety to the consumers. These assessments are performed in accordance with the guidelines proposed by Codex (2003) and ICMR (2008). The guidelines recommend sequence homology analysis as a preliminary step towards allergenicity prediction, later in vitro experiments may be performed to confirm allergenicity. In the present study, an in silico approach is employed to evaluate the allergenic potential of six transgenes routinely used for the development of GM food crops. Among the genes studied, manganese superoxide dismutase (MnSOD) and osmotin shares greater than 90% identity with Hev b 10 and Cap a 1w, respectively. Chitinase shares greater than 70% identity with allergens namely Pers a 1 and Hev b 11, and fungal chitinase showed significant IgE binding with 7 of 75 patients' sera positive to different food extracts. Glucanases (alfalfa, wheat) and glycine betaine aldehyde dehydrogenase gene share 50% homology with allergens like - Ole e 9, Cla h 10 and Alt a 10. The results demonstrate the allergenic potential of six genes and can serve as a guide for selection of transgenes to develop GM crops.

Viewpoint: the future of research in pediatric allergy: what should the focus be?

Allergic diseases have been increasing during the last three decades, and exact reasons for this are still debated. Despite intense ongoing research, a lot of aspects of allergic diseases are still poorly understood, resulting in limitations in current therapeutic approach to allergies. In this viewpoint, important unanswered research questions are raised mainly on novel therapeutic approaches to allergic children, and suggestions for future research are raised. Three aspects of pediatric allergy are distinguished: the prevention, control, and cure.

Anaphylaxis and biphasic phase in Thailand: 4-year observation

BACKGROUND

Anaphylaxis, a severe systemic allergic reaction, can be fatal. However, its prevalence has been underestimated especially in biphasic phase, due to a lack of case awareness. This study aimed to determine the rate of anaphylaxis, describe clinical manifestations and management, and identify the causative agents and risk factors of biphasic anaphylactic reaction.

METHODS

An observational study was conducted at the Emergency Department of Thammasat University Hospital, Thailand, during the period 2004-2008.

RESULTS

Of total 208 cases of anaphylaxis identified, the median age was 20.67 years; 52.9% were male. The anaphylaxis rate was 49 per 100,000 patient-years. No fatal case was found; 58.7% had a history of atopy, and 38.5% had experienced a previous allergic reaction, of whom 8.8% had had a previous anaphylactic reaction. The causative allergens were identified in 82.2% of cases; food allergy was most common. Urticaria was the most common presentation (87%). Among 6.3% of the patients who developed biphasic reaction, a significantly longer time from onset of symptoms to administration of epinephrine was detected, with a median of 240 minutes for those with biphasic anaphylaxis, versus 70 minutes for those without (p = 0.002). The median times from onset to hospital arrival and the arrival to administration of epinephrine were also significantly longer in the biphasic group than the non-biphasic patients (p = 0.002 and p = 0.001, respectively). In multivariable regression models, the time intervals from onset and hospital arrival to administration of epinephrine continued to predict biphasic phase occurrence (p < 0.01).

CONCLUSIONS

Anaphylaxis predominantly occurs among children and young adults. Delayed administration of epinephrine was associated with the occurrence of biphasic anaphylaxis.

World allergy organization guidelines for the assessment and management of anaphylaxis

The illustrated World Allergy Organization (WAO) Anaphylaxis Guidelines were created in response to absence of global guidelines for anaphylaxis. Uniquely, before they were developed, lack of worldwide availability of essentials for the diagnosis and treatment of anaphylaxis was documented. They incorporate contributions from more than 100 allergy/immunology specialists on 6 continents. Recommendations are based on the best evidence available, supported by references published to the end of December 2010. The Guidelines review patient risk factors for severe or fatal anaphylaxis, co-factors that amplify anaphylaxis, and anaphylaxis in vulnerable patients, including pregnant women, infants, the elderly, and those with cardiovascular disease. They focus on the supreme importance of making a prompt clinical diagnosis and on the basic initial treatment that is urgently needed and should be possible even in a low resource environment. This involves having a written emergency protocol and rehearsing it regularly; then, as soon as anaphylaxis is diagnosed, promptly and simultaneously calling for help, injecting epinephrine (adrenaline) intramuscularly, and placing the patient on the back or in a position of comfort with the lower extremities elevated. When indicated, additional critically important steps include administering supplemental oxygen and maintaining the airway, establishing intravenous access and giving fluid resuscitation, and initiating cardiopulmonary resuscitation with continuous chest compressions. Vital signs and cardiorespiratory status should be monitored frequently and regularly (preferably, continuously). The Guidelines briefly review management of anaphylaxis refractory to basic initial treatment. They also emphasize preparation of the patient for self-treatment of anaphylaxis recurrences in the community, confirmation of anaphylaxis triggers, and prevention of recurrences through trigger avoidance and immunomodulation. Novel strategies for dissemination and implementation are summarized. A global agenda for anaphylaxis research is proposed.

Comparison of food allergy prevalence among Chinese infants in Chongqing, 2009 versus 1999

BACKGROUND

Food allergy prevalence is increasing in developed countries, but these results have not yet been verified in developing countries, especially in China. Our aim was to determine whether the prevalence and characteristics of food allergy have changed over the last 10 years in Chongqing, China.

METHODS

Two cross-sectional studies were performed, 10 years apart (1999 and 2009) using the same diagnostic methods in the same age group (0-24 months) of the same clinic in Chongqing, China. A total of 401 infants were randomly selected for the present study. Food allergy was confirmed by food challenge. spss 15.0 was used to analyze the difference in prevalence.

RESULTS

Food allergy prevalence increased significantly from 3.5% in 1999 to 7.7% in 2009 (P= 0.017). The prevalence of a positive skin-prick-test response was also increased (from 9.9% to 18%; P= 0.002). Egg and cow's milk were still the most common food allergens, which cause skin and gastrointestinal symptoms in most infants.

CONCLUSION

This is the first study in China to indicate time trends in food allergy prevalence and characteristics. Our data show that in the 10-year period from 1999 to 2009, the prevalence of food allergy seems to have increased in China.

The effects of probiotics supplementation timing on an ovalbumin-sensitized rat model

The aim of the present study was to investigate the effect of oral probiotic bacteria administration at different times on ovalbumin-sensitized rats. Brown-Norway (BN) rats were orally sensitized with ovalbumin for 6 weeks. Probiotics were administered before the initial sensitization (prevention group) or at the end of sensitization period (treatment group). In whole-course intervention group, probiotics were administered 2 weeks before the initial sensitization until 1 week after the end of sensitization period. Ovalbumin-immunoglobulin E (IgE) level, intestinal barrier function and immune responses were analyzed. The positive control group had a significantly increased ovalbumin-IgE level (P<0.05), impaired intestinal barrier function and skewed T-helper 1 (Th1)/Th2 cytokine balance compared with the negative control group. In probiotics prevention and whole-course intervention groups, the infiltration of inflammatory cells (eosinophil and mast cells) in small intestinal mucosa was significantly lower (P<0.05), and the ratio of cytokine interferon-γ/interleukin-4 produced by spleen and mesenteric lymph nodes significantly higher (P<0.05) than in the positive control group, which suggested a cytokine profile inclined to Th1. Both probiotics prevention and prebiotics treatment could attenuate food allergic response. Probiotics prevention tends to modulate the immune response, whereas probiotics treatment has a more obvious effect in enhancing intestinal integrity.

Are peanut allergies a concern for using peanut-based formulated foods in developing countries?

BACKGROUND

Peanut allergy is relatively common among children in developed countries and may have severe outcomes, including anaphylaxis. However, few data about peanut allergy in developing countries are available. Meanwhile, formulated foods with peanuts as a major ingredient are being promoted to prevent and control malnutrition in developing countries.

OBJECTIVE

The objectives of the paper are to review the existing epidemiologic data about peanut allergy, to determine whether the prevalence of peanut allergy is lower in developing countries, and to explore the possible reasons for onset of peanut allergy.

METHODS

Publications relevant to peanut allergy were searched via Pubmed, and prevalence and etiological factors of peanut allergy were reviewed.

RESULTS

Data about peanut allergy were scarce in most developing countries. The existing data support the conclusion that peanut allergy is not as common in developing countries as in developed countries and may not be a major concern for programs promoting formulated food containing peanuts for control of malnutrition. However, plans for treatment of individuals with peanut allergy could be incorporated into these formulated food supplementation programs. A few risk factors (late introduction of peanuts to children, peanut processing technology, non-oral peanut exposure, and maternal peanut exposure during pregnancy and lactation) have been hypothesized to be associated with peanut allergy. However, more conclusive data are needed to verify or disprove these hypotheses.

CONCLUSIONS

Peanut allergy is not as common in developing countries as in developed countries and may not be a major concern for programs promoting formulated food containing peanuts for control of malnutrition. However, more research about prevalence of peanut allergy is warranted in developing countries.

Allergies in Asia: differences in prevalence and management compared with western populations

There is wide variability in the epidemiology and management of childhood asthma and related atopic diseases globally. Urbanized, affluent Western countries tend to have a higher prevalence of these diseases compared with Asian nations. However, recent studies have shown that the prevalence in Asia is increasing, although the rate of increase has slowed in the more developed Asian cities. Some possible causes for these differences are socioeconomic status, degree of urbanization, rates of infection, healthcare practices and genetic factors. Importantly, there are significant differences in the way asthma and allergic diseases are managed within Asia. This is of great concern because of the health implications, as these diseases are some of the most common chronic conditions that affect both adults and children. This review compares the differences in prevalence and management between Asia and the West, and discusses some of the possible reasons behind these variations.

Childhood Food Allergy: A Singaporean Perspective

Food allergy is defined as reaction to a food which has an immunologic mechanism. Its prevalence is increasing in children globally and is therefore of increasing clinical importance. A useful clinical approach is to distinguish food allergic reactions by the timing of clinical reaction in relation to food exposure and classified as immediate (generally IgE-mediated) and delayed (generally non-IgE-mediated), with the exception of eczema and eosinophilic gastrointestinal disease, which, when associated with food allergy may be associated with either mechanism. This review is aimed at providing the clinician with a Singaporean perspective on the clinical approach and management of these disorders. Key words: Asia, Children, Food allergy

Serological and clinical characteristics of children with peanut sensitization in an Asian community

In the past two decades, peanut allergy prevalence has increased in the West but has been perceived as having remained low in Asia. To review the clinical presentation of Asian children with peanut hypersensitivity and measure their IgE responses to major peanut allergens. We enrolled 31 children presenting with various allergies and a positive skin prick test to peanut from the Children's hospital outpatient allergy clinic in Singapore. A detailed questionnaire was completed by parents. The children's serum IgE specific to native Ara h 1, native Ara h 2, and recombinant Ara h 3 were detected using ELISA. Of the 31 patients, 19 had previously documented reactions to peanuts, while 12 had no previous clinical reaction. Most, 89.5% (17/19) of first reactions featured skin changes (urticaria, erythema, angioedema), but only 36.8% (7/19) involved skin symptoms alone. Respiratory symptoms and GI symptoms occurred in 42.1% and 26.3% of patients respectively and did not occur as the sole manifestation of reaction. The most common GI manifestation was emesis, present in 26.3% (5/19) of subjects. Two children experienced impaired consciousness with systemic, anaphylactic events. Although most sought treatment for their first peanut reaction only one patient received epinephrine. Half of our patients reported a subsequent accidental ingestion after the diagnosis of peanut allergy, with a median time from diagnosis to first accidental ingestion of 4 months and a reported increased severity of reaction in approximately half of the repeat exposures. Eighty-seven percent of children had specific IgE directed against at least one of the major peanut allergens. Among all patients, 87.1% had IgE specific to both Ara h 1 and Ara h 2 and 54.8% to rAra h 3. Asian children with peanut sensitization have clinically similar presentations and respond to the same major allergenic proteins as their Western counterparts. The perceived differences between the populations in this context do not stem from divergent clinical or immunological responses.

Allergic status of schoolchildren with food allergy to eggs, milk or wheat in infancy

Although children allergic to eggs, milk or wheat in infancy tend to become tolerant by school age, the allergic status of these children at school age has not been well evaluated. To investigate the allergic status of schoolchildren who avoided eggs, milk or wheat because of an immediate-type allergic reaction at <1-yr-old (food avoiders in infancy), we conducted a large-scale questionnaire-based survey of schoolchildren. A questionnaire on allergic diseases was distributed to the parents of 14,669 schoolchildren aged 7 to 15 yr in 30 schools in Kyoto, Japan. Of these, 13,215 responded (response rate, 90.1%). The rate of 7-yr-old children who were food avoiders in infancy was 5.4%. This rate decreased as the current age of the children increased, down to 3% in 15-yr-old children, indicating that food allergy in infancy tended to become more prevalent over the past 8 yr. Although more than 80% became tolerant to these foods by school age, the prevalence of bronchial asthma, atopic dermatitis, allergic rhinitis and allergic conjunctivitis were significantly higher in this group. Moreover, avoidance of other foods (buckwheat, shellfish, fruits and others) at school age was seen at much higher frequencies than in non-food avoiders in infancy (adjusted odds ratio, 7.7; confidence interval, 5.9-10.2). This risk did not differ significantly between those who did and did not develop tolerance to eggs, milk and wheat by 3 yr old. In conclusion, food avoiders in infancy appear to have a higher risk of not only other allergic diseases ('atopic march') but also allergy to other foods ('food allergen march') at school age, indicating the need for continuous attention to food allergy.

Effects of food processing on food allergens

Food allergies are on the rise in Western countries. With the food allergen labeling requirements in the US and EU, there is an interest in learning how food processing affects food allergens. Numerous foods are processed in different ways at home, in institutional settings, and in industry. Depending on the processing method and the food, partial or complete removal of the offending allergen may be possible as illustrated by reduction of peanut allergen in vitro IgE immunoreactivity upon soaking and blanching treatments. When the allergen is discretely located in a food, one may physically separate and remove it from the food. For example, lye peeling has been reported to produce hypoallergenic peach nectar. Protein denaturation and/or hydrolysis during food processing can be used to produce hypoallergenic products. This paper provides a short overview of basic principles of food processing followed by examples of their effects on food allergen stability. Reviewed literature suggests assessment of processing effects on clinically relevant reactivity of food allergens is warranted.

When should self-injectible epinephrine be prescribed for food allergy and when should it be used?

PURPOSE OF REVIEW

To explore why epinephrine autoinjectors have failed to prevent fatal food anaphylaxis and how this problem might be solved.

RECENT FINDINGS

Autoinjectors cannot save lives when they are used too late, misused, not carried, or when an inadequate dose is absorbed; food allergy-induced asthma may not respond when asthma management is suboptimal. New markers for severe reactions have been published.

SUMMARY

The fallibility of autoinjectors means that in the management of food allergy, their provision must take second place to accurate identification of the trigger foods, optimal avoidance, and optimal treatment of other medical conditions that make reactions more dangerous.

Food allergy-lessons from Asia

OBJECTIVE

: This is a review on published data available on food allergy in East Asia and a discussion on the insights that it offers.

METHODS

: PubMed searches were made for terms food allergy and anaphylaxis, in combination with Asia.

RESULTS

: There is a paucity of population-based prevalence studies on food allergy in Asia. Certain unique food allergens, such as buckwheat, chestnuts, chickpeas, bird's nest, and royal jelly, which are consumed extensively by certain Asian populations have resulted in clinical food allergy of little importance in other populations. Crustacean shellfish is of importance in this region relative to other common food allergens. The high consumption of these foods and possibly coupled with cross-reactive tropomyosins from dominant inhalant dust mite and cockroach allergens in this region may explain this phenomenon. In contrast, the prevalence of peanut allergy is relatively low in this region. The reasons for this difference are not apparent. However, this may be a reflection of the general reduced propensity in this region to allergic diseases as seen with asthma.

CONCLUSIONS

: Further research on food allergy in Asia is warranted because it offers unique opportunities to further our understanding on the influence of population and environment.

The changing face of food hypersensitivity in an Asian community

BACKGROUND

Food allergy seems to be increasing in Asia as well as world-wide. Our aim was to characterize food protein sensitization patterns in a population of Asian children with possible food allergy.

METHODS

Children presenting to our allergy clinic over 3 years with symptomatic allergic disease and at least one specific food allergen sensitization documented on skin prick testing were included in the analysis.

RESULTS

Two hundred and twenty-seven patients fulfilled inclusion criteria. Ninety (40%) of the positive skin tests were positive to egg, 87 (39%) to shellfish, 62 (27.3%) to peanut, 30 (13.2%) to fish, 27 (11.8%) to cow's milk, 21 (9.3%) to sesame, 13 (3.7%) to wheat and eight (3.2%) to soy. Peanut sensitization was the third most common sensitizing allergen, and seen mostly in young atopic children with multiple food hypersensitivities and a family history of atopic dermatitis. The median reported age of first exposure to fish and shellfish was 6 and 12 months, respectively. The mean age at presentation of children with shellfish hypersensitivity was at 6.7 years of age. The likelihood of shellfish sensitization was increased in children with concomitant sensitization to cockroaches.

CONCLUSIONS

In contrast to previously reported low peanut allergy rates in Asia, in our review, peanut sensitization is present in 27% (62/227) of food-allergic children, mostly in patients with multiple food protein sensitizations. Temporal patterns of first exposure of infants to fish and shellfish are unique to the Asian diet. Shellfish are a major sensitizing food source in Asian children, especially in allergic rhinitis patients sensitized to cockroaches.

Peanut allergy: Emerging concepts and approaches for an apparent epidemic

Peanut allergy is typically lifelong, often severe, and potentially fatal. Because reactions can occur from small amounts, the allergy presents patients with significant obstacles to avoid allergic reactions. In North America and the United Kingdom, prevalence rates among schoolchildren are now in excess of 1%, framing an increasing public health concern and raising research questions about environmental, immunologic, and genetic factors that may influence outcomes of peanut allergy. This review focuses on recent observations that continue to question the influences of maternal and infant diet on outcomes of peanut allergy, and explore how peanut may be uniquely suited to induce an allergic response. We highlight studies that affect current diagnosis, management, and the nature of advice that can be provided to patients, including the utility of diagnostic tests, doses that elicit reactions, characteristics of reactions from exposure, issues of cross-reactivity, concerns about peanut contamination of manufactured goods, and the natural course of the allergy. Clinical, molecular, and immunologic advances are reviewed, highlighting research discoveries that influence strategies for improved diagnosis, prevention, and treatment. Among the therapeutic strategies reviewed are sublingual and oral immunotherapy, anti-IgE, Chinese herbal medicine, and vaccine strategies.

Food allergy in gastroenterologic diseases: Review of literature

Food allergy is a common and increasing problem worldwide. The newly-found knowledge might provide novel experimental strategies, especially for laboratory diagnosis. Approximately 20% of the population alters their diet for a perceived adverse reaction to food, but the application of double-blind placebo-controlled oral food challenge, the “gold standard” for diagnosis of food allergy, shows that questionnaire-based studies overestimate the prevalence of food allergies. The clinical disorders determined by adverse reactions to food can be classified on the basis of immunologic or nonimmunologic mechanisms and the organ system or systems affected. Diagnosis of food allergy is based on clinical history, skin prick tests, and laboratory tests to detect serum-food specific IgE, elimination diets and challenges. The primary therapy for food allergy is to avoid the responsible food. Antihistamines might partially relieve oral allergy syndrome and IgE-mediated skin symptoms, but they do not block systemic reactions. Systemic corticosteroids are generally effective in treating chronic IgE-mediated disorders. Epinephrine is the mainstay of treatment for anaphylaxis. Experimental therapies for IgE-mediated food allergy have been evaluated, such as humanized IgG anti-IgE antibodies and allergen specific immunotherapy.