Pattern of food-induced anaphylaxis in children of an Asian community

Prevention of Food Allergy: Harmonizing Perspectives from the East and West

BACKGROUND

The global epidemiology of food allergies and anaphylaxis exhibits complex, heterogeneous patterns. While food allergy prevalence has stabilized in Western countries, anaphylaxis incidence continues to rise. In developing regions, data are limited, but urban centers show increasing food allergy prevalence, contrasting with lower rates in rural areas. These disparities likely stem from differences in environmental factors and urbanization levels across the globe. Furthermore, the dominant food allergens vary significantly by regions. Peanuts and tree nuts are the primary triggers in the USA and Europe, whereas eggs, milk, and shellfish are more common in Asia and Latin America.

SUMMARY

In this upcoming review, we will delve into the recommendations for preventing food allergies across Eastern and Western regions. These regional differences in allergen profiles and dietary patterns underscore the need for tailored food allergy prevention strategies. Current prevention guidelines focus on the timing and route of allergen exposure in early life. In high-prevalence regions, early oral exposure is recommended to promote oral tolerance and reduce allergy risk. Conversely, in lower-prevalence areas, non-delayed introduction of allergenic solids is preferred. Moreover, early skin exposure may increase allergy risk, and the role of early, whole-body use of specialized emollients requires further study. Proactive treatment of atopic dermatitis may reduce the incidence of food allergies in infants. Adapting prevention approaches to local contexts and continuously updating guidelines based on emerging evidence is crucial to comprehensively addressing the global burden of food allergies.

Disparities in pediatric anaphylaxis triggers and management across Asia

BACKGROUND

The epidemiology and management of anaphylaxis are not well-reported in Asia.

METHODS

A regional pediatric anaphylaxis registry was established by the Asia-Pacific Research Network for Anaphylaxis (APRA), using standardized protocols for prospective data collection, to evaluate the triggers and management of anaphylaxis in the Asia-Pacific region. Pediatric patients below 18 years presenting with anaphylaxis across four Asian countries/cities (Thailand, Singapore, Hong Kong (HK), and Qingdao) were included. Allergen triggers, symptoms, anaphylaxis severity, and management were compared.

RESULTS

Between 2019 and 2022, 721 anaphylaxis episodes in 689 patients from 16 centers were identified. The mean age at anaphylaxis presentation was 7.0 years (SD = 5.2) and 60% were male. Food was the most common trigger (62%), particularly eggs and cow's milk in children aged 3 years and below. In school-age children, nut anaphylaxis was most common in HK and Singapore, but was rare in the other countries, and wheat was the top allergen in Bangkok. Shellfish anaphylaxis was most common in children aged 7-17. Adrenaline was administered in 60% of cases, with 9% given adrenaline before hospital arrival. Adrenaline devices were prescribed in up to 82% of cases in Thailand but none in Qingdao.

CONCLUSIONS

The APRA identified food as the main trigger of anaphylaxis in children, but causative allergens differed even across Asian countries. Fewer than two-thirds of cases received adrenaline treatment, pre-hospital adrenaline usage was low, and adrenaline device prescription remained suboptimal. The registry recognizes an unmet need to strengthen anaphylaxis care and research in Asia-Pacific.

The future of food allergy: Challenging existing paradigms of clinical practice

The field of food allergy has seen tremendous change over the past 5-10 years with seminal studies redefining our approach to prevention and management and novel testing modalities in the horizon. Early introduction of allergenic foods is now recommended, challenging the previous paradigm of restrictive avoidance. The management of food allergy has shifted from a passive avoidance approach to active interventions that aim to provide protection from accidental exposures, decrease allergic reaction severity and improve the quality of life of food-allergic patients and their families. Additionally, novel diagnostic tools are making their way into clinical practice with the goal to reduce the need for food challenges and assist physicians in the-often complex-diagnostic process. With all the new developments and available choices for diagnosis, prevention and therapy, shared decision-making has become a key part of medical consultation, enabling patients to make the right choice for them, based on their values and preferences. Communication with patients has also become more complex over time, as patients are seeking advice online and through social media, but the information found online may be outdated, incorrect, or lacking in context. The role of the allergist has evolved to embrace all the above exciting developments and provide patients with the optimal care that fits their needs. In this review, we discuss recent developments as well as the evolution of the field of food allergy in the next decade.

Why the importance of geo-origin tracing of edible bird nests is arising?

Edible bird's nest (EBN) swiftlet existed naturally 48,000 years ago in caves as their natural dwellings. Nowadays, edible bird's nest has become a very important industry due to its high nutritional, medicinal and economic value. Additionally, edible bird's nest has a long quality guarantee period. Obviously, the nutritional components and medicinal functions vary depending on geographical origins. Recently, the global demand for edible bird's nest has markedly increased, accompanied by the increasing attention of all key players of the global food trade system, i.e., producers, consumers, traders and the authorities to obtain safe and high-quality edible bird's nest. Hence, this target can be accomplished via the enforcement of an efficient and universal geo-tracing technique. Current methods of the geo-tracking of edible bird's nest, i.e., automation, physical and analytical techniques have several limitations and all of them fail to discriminate different quality grades of edible bird's nest. Meanwhile, in many studies and applications, polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) has proven to be a "cutting edge" technique for greatly enhance food traceability from field to fork through its ability in distinguishing the food products in terms of their quality and safety. This article provides an overview of (1) edible bird's nest as a multiuse strategic food product, (2) quality issues associated with edible bird's nest including implications that the site of acquisition of the edible bird's nest has food safety implications, (3) current regulations and geo-tracking approaches to ensure the safety and quality of edible bird's nest with the special focus on polymerase chain reaction-denaturing gradient gel electrophoresis technique as a vigorous and universal geo-tracing tool to be suggested for edible bird's nest geo-traceability.

Edible Bird's Nest: Recent Updates and Industry Insights Based On Laboratory Findings

Edible bird’s nest (EBN) is a traditional Chinese delicacy made of the saliva of swiftlets found in Southeast Asia. With increasing demands for EBN, quality control of EBN products is important for safe consumption. The processing steps are particularly important for efficient extraction of bioactive compounds. Geographical location, collection place, and harvesting season contribute to differences in nutritional contents in EBN. Concerns regarding presence of adulterant, chemical, and microbial contaminants in EBN as well as authentication and chemical composition measuring methods are discussed in this review. Recent discoveries of beneficial health functions of EBN in antimicrobial and antiviral actions, immunomodulation, cancer prevention and treatment, tissue regeneration, cardiometabolic maintenance, antioxidant action and neuroprotection are also reviewed. Our review provides an update on the recent research on EBN.

The global burden of illness of peanut allergy: A comprehensive literature review

Peanut allergy (PA) currently affects approximately 2% of the general population of Western nations and may be increasing in prevalence. Patients with PA and their families/caregivers bear a considerable burden of self‐management to avoid accidental peanut exposure and to administer emergency medication (adrenaline) if needed. Compared with other food allergies, PA is associated with higher rates of accidental exposure, severe reactions and potentially fatal anaphylaxis. Approximately 7%–14% of patients with PA experience accidental peanut exposure annually, and one‐third to one‐half may experience anaphylaxis, although fatalities are rare. These risks impose considerably high healthcare utilization and economic costs for patients with PA and restrictions on daily activities. Measures to accommodate patients with PA are often inadequate, with inconsistent standards for food labelling and inadequate safety policies in public establishments such as restaurants and schools. Children with PA are often bullied, resulting in sadness, humiliation and anxiety. These factors cumulatively contribute to significantly reduced health‐related quality of life for patients with PA and families/caregivers. Such factors also provide essential context for risk/benefit assessments of new PA therapies. This narrative review comprehensively assessed the various factors comprising the burden of PA.

Potential Residual Contaminants in Edible Bird's Nest

Edible bird’s nest (EBN) is recognized as a nourishing food among Chinese people. The efficacy of EBN was stated in the records of traditional Chinese medicine and its activities have been reported in many researches. Malaysia is the second largest exporter of EBNs in the world, after Indonesia. For many years, EBN trade to China was not regulated until August 2011, when a safety alert was triggered for the consumption of EBNs. China banned the import of EBNs from Malaysia and Indonesia due to high level of nitrite. Since then, the Malaysia government has formulated Malaysia Standards for swiftlet farming (MS 2273:2012), edible bird’s nest processing plant design and management (MS 2333:2010), and edible bird’s nest product quality (MS 2334:2011) to enable the industry to meet the specified standards for the export to China. On the other hand, Indonesia's EBN industry formulated a standard operating procedure (SOP) for exportation to China. Both countries can export EBNs to China by complying with the standards and SOPs. EBN contaminants may include but not limited to nitrite, heavy metals, excessive minerals, fungi, bacteria, and mites. The possible source of contaminants may come from the swiftlet farms and the swiftlets or introduced during processing, storage, and transportation of EBNs, or adulterants. Swiftlet house design and management, and EBN processing affect the bird’s nest color. Degradation of its optical quality has an impact on the selling price, and color changes are tied together with nitrite level. In this review, the current and future prospects of EBNs in Malaysia and Indonesia in terms of their quality, and the research on the contaminants and their effects on EBN color changes are discussed.

Anaphylaxis - Lessons learnt when East meets West

The rapidly increasing prevalence of allergic disorders over the past 2 decades highlights the need to understand the epidemiology of anaphylaxis. In Europe, the United States, and Australia, the incidence of anaphylaxis is estimated to be between 60 and 950 cases per 100 000 population, with a lifetime prevalence of anaphylaxis of 0.05%-2%. The incidence appears to be increasing over time. Although the existing Asian literature is heterogeneous and limited by under-reporting, it also suggests a similar increasing trend in anaphylaxis incidence in Asia. Anaphylaxis triggers in Asia, such as the predominance of shellfish and wheat in older children and adolescents, differ from those seen in Western populations. Triggers unique to Asia such as traditional Chinese medications, galacto-oligosaccharides, and food delicacies have also been reported. Low usage of adrenaline as first-line treatment of anaphylaxis is evident across all countries and is particularly concerning. There is a need to establish prospective, standardized protocols for anaphylaxis data collection and reporting, to enhance the collective understanding of anaphylaxis and its burden, gaps in management and to identify areas for future research and intervention in each region. Understanding of the underlying reasons explaining the difference between East and West will facilitate future primary preventive strategies.

Challenges of managing food allergy in the developing world

Food allergy (FA) is currently a significant health care problem in the developing world. Widely varying study populations and methodologies, the use of surrogate markers such as self report or hospitalization rates due to anaphylaxis rather than objective methods, limits robust estimation of FA prevalence in low income settings. Also, allergy is under-recognized as a clinical specialty in the developing world which compromises the chance for accurate diagnosis. In this review, most published data on food allergens from developing or low income countries are displayed. The diagnostic challenges and limitations of treatment options are discussed. It seems that FA is an under-appreciated health care issue in the developing world, and accurate determination of its burden in low-income settings represents an important unmet need. Multicenter surveillance studies, using standardized methodologies, are, therefore, needed to reveal the true extent of the problem and provide epidemiological clues for prevention. Preventive strategies should be tailored to fit local circumstances in different geographic regions. In addition, studying the gene environment interactions and impact of early life microbiota on the expression of FA in developing communities would be worthwhile. Efforts and resources should be directed toward public health education and training of health care providers dealing with food allergic patients.

Hypersensitive adverse drug reactions to glucosamine and chondroitin preparations in Australia between 2000 and 2011

Purpose of the study

This study investigates spontaneous adverse drug reactions (ADRs) to glucosamine and chondroitin in the Australian population between 2000 and 2011, with a primary focus on hypersensitivity reactions.

Study design

Case reports of ADR to glucosamine and chondroitin sent to the Therapeutic Goods Administration between 2000 and 2011 were obtained and analysed. The demographic information and severity of the ADR were recorded for individual ADR cases. These reactions were classified according to the Brown et al grading system for generalised hypersensitivity reactions. This included mild hypersensitivity reactions (generalised erythema, urticaria and angioedema) through to moderate hypersensitivity reactions (wheeze, nausea, vomiting, dizziness (presyncope), diaphoresis, chest or throat tightness and abdominal pain), and more severe reactions (hypotension, confusion and collapse).

Results

In this study of 366 ADRs to glucosamine and chondroitin preparations, 71.85% of cases (n=263) were found to have hypersensitivity reactions. Of these 263 cases, 92 cases were classified as mild (eg, pruritus, urticaria and lip oedema), 128 cases classified as moderate (such as dyspnoea, nausea and abdominal pain), and 43 cases classified as severe (including amnesia, gait disturbance, somnolence and hypotension). It is not clear whether the patients involved had a known shellfish allergy or underlying atopy.

Conclusion

Results of this investigation support the need for clear labelling on glucosamine and chondroitin preparations to raise awareness of possible adverse events for those predisposed to allergy or atopy in response to shellfish.

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.

Food allergen extracts to diagnose food-induced allergic diseases: How they are made

OBJECTIVE

To review the manufacturing procedures of food allergen extracts and applicable regulatory requirements from government agencies, potential approaches to standardization, and clinical application of these products. The effects of thermal processing on allergenicity of common food allergens are also considered.

DATA SOURCES

A broad literature review was conducted on the natural history of food allergy, the manufacture of allergen extracts, and the allergenicity of heated food. Regulations, guidance documents, and pharmacopoeias related to food allergen extracts from the United States and Europe were also reviewed.

STUDY SELECTIONS

Authoritative and peer-reviewed research articles relevant to the topic were chosen for review. Selected regulations and guidance documents are current and relevant to food allergen extracts.

RESULTS

Preparation of a food allergen extract may require careful selection and identification of source materials, grinding, defatting, extraction, clarification, sterilization, and product testing. Although extractions for all products licensed in the United States are performed using raw source materials, many foods are not consumed in their raw form. Heating foods may change their allergenicity, and doing so before extraction may change their allergenicity and the composition of the final product.

CONCLUSION

The manufacture of food allergen extracts requires many considerations to achieve the maximal quality of the final product. Allergen extracts for a select number of foods may be inconsistent between manufacturers or unreliable in a clinical setting, indicating a potential area for future improvement.

Anaphylaxis in Children: Experience of 485 Episodes in 1,272,482 Patient Attendances at a Tertiary Paediatric Emergency Department from 2007 to 2014

Introduction: Anaphylaxis is a predominantly childhood disease. Most of the literature on anaphylaxis has emerged from Western countries. This study aimed to describe the incidence, triggers and clinical presentation of anaphylaxis among children in Singapore, look for predictors for anaphylaxis with severe outcomes, and study the incidence of biphasic reactions. Materials and Methods: We retrospectively reviewed records of children presenting with anaphylaxis to our paediatric emergency department from 1 January 2007 to 31 December 2014. Results: We identified 485 cases of anaphylaxis in 445 patients. Cutaneous symptoms (urticarial/angio-oedema) were the most common across all age groups (481 cases, 99%), followed by respiratory (412, 85%), gastrointestinal (118, 24%) and cardiovascular (35, 7.2%) symptoms. Central nervous system symptoms (drowsiness/ irritability) were rare across all age groups (11, 2.2%). Food was identified as the most common trigger across all age groups (45% to 63%). Seafood was the most common food trigger (57, 25%). A total of 420 (86.6%) children were treated with adrenaline, 451 (93%) received steroids and 411 (85%) received antihistamines. Sixty-three (13%) children fulfilled the criteria of severe anaphylaxis. There was no statistically significant association between severe anaphylaxis and the type of trigger (P = 0.851), nor an overall past history of atopy (P = 0.428). The only independent predictor for severe anaphylaxis was a previous drug allergy (P = 0.016). A very low prevalence of biphasic reactions (0.6% of study population) was noted in our study. Conclusion: We described the presentation and management of anaphylaxis in the Singapore population. A history of drug allergy is associated with severe presentation. Biphasic reactions are rare in our population.

Allergens and molecular diagnostics of shellfish allergy: Part 22 of the Series Molecular Allergology

Shellfish belongs to "The Big 8" food groups causing allergy, which often does not outgrow during childhood. Shellfish is one of the main food allergens in adults and constitutes a diverse group of species subdivided into crustaceans and mollusks, which seem to include similar but also different allergens. Several pan-allergens are characterized in detail, including tropomyosin and arginine kinase, responsible for clinical cross-reactivity with other invertebrate allergen sources, embracing mites, insects, and parasites. Currently, at least seven different shellfish allergens have been identified, mostly from crustaceans. However, only three recombinant allergens are available for IgE-based routine diagnostic, including tropomyosin, arginine kinase, and sarcoplasmic Ca²⁺-binding protein. Other allergens include myosin light chain, troponin C, triosephosphate isomerase, and actin. This review summarizes the current advances on the molecular characterization of shellfish allergens, clinical cross-reactivity, and current diagnostic approaches for the management of this life-threatening disease.

Shellfish Allergy: a Comprehensive Review

Shellfish allergy is of increasing concern, as its prevalence has risen in recent years. Many advances have been made in allergen characterization. B cell epitopes in the major allergen tropomyosin have been characterized. In addition to tropomyosin, arginine kinase, sarcoplasmic calcium-binding protein, and myosin light chain have recently been reported in shellfish. All are proteins that play a role in muscular contraction. Additional allergens such as hemocyanin have also been described. The effect of processing methods on these allergens has been studied, revealing thermal stability and resistance to peptic digestion in some cases. Modifications after Maillard reactions have also been addressed, although in some cases with conflicting results. In recent years, new hypoallergenic molecules have been developed, which constitute a new therapeutic approach to allergic disorders. A recombinant hypoallergenic tropomyosin has been developed, which opens a new avenue in the treatment of shellfish allergy. Cross-reactivity with species that are not closely related is common in shellfish-allergic patients, as many of shellfish allergens are widely distributed panallergens in invertebrates. Cross-reactivity with house dust mites is well known, but other species can also be involved in this phenomenon.

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.

Food allergy and related risk factors in 2540 preschool children: an epidemiological survey in Guangdong Province, southern China

BACKGROUND

Although the number of studies on allergic diseases in the general population of southern China is increasing, only a few have addressed food allergy (FA) in children in this region. The present study aimed to investigate the prevalence, clinical manifestations, spectrum of allergens, and related risk factors of FA in preschool children in Guangdong Province, southern China.

METHODS

A random cluster-sampling method was used to select 24 kindergartens from 12 cities in Guangdong Province. The parents or guardians of the children were requested to complete a questionnaire on general information and data regarding FA diagnosis and symptoms in the children and their first-degree relatives. Thereafter, the Chi-square test, multivariate regression analysis, and Spearman's rank-order correlation coefficient analysis were performed to identify statistically significant differences.

RESULTS

Analysis of 2540 valid questionnaires revealed an FA prevalence rate of 4%. Adverse food reactions were due to the consumption of shrimp (4.4%), crab (3.2%), mango (2.3%), cow's milk and dairy products (1.9%), and eggs (1.4%). Logistic regression analysis indicated that a history of FA and a history of allergic rhinitis in the first-degree relatives were the major factors leading to FA in children.

CONCLUSIONS

The incidence of FA in children in Guangdong Province is higher than that commonly believed. An individual's genetic background is an important risk factor for FA. Hence, mitigation of the impact of lifestyle and environmental factors should be carefully considered to reduce the incidence of childhood FA.

Food allergy in Singapore: opening a new chapter

With the exception of shellfish, the overall food allergy rates in Singapore have not reached the epidemic proportions of the West. The rates of egg, milk and fish allergies remain low. However, the patterns of some food allergies in Singapore have changed over the last decade. For example, peanut allergy, once rare in Singapore, is now the most common cause of anaphylaxis in children. Studies analysing lifestyle practices, particularly with respect to prevention of food allergy, are necessary in order for practitioners to understand global differences and maintain this low prevalence.

Carbohydrates as food allergens

The literature supports the notion that carbohydrate epitopes, on their own, do not contribute significantly to the induction of allergic reactions. They bind weakly to IgE antibodies and have been termed as cross reactive carbohydrate determinants. These epitopes cause confusion in in vitro IgE testing through nonspecific cross-reactivity. Coincident with the rising trends in food allergy prevalence, there has recently been reports of anaphylaxis induced by carbohydrate epitopes. There are two distinct groups, each with unique characteristics and geographical distribution. Anaphylaxis and acute allergic reactions related to the carbohydrate galactose-α-1,3-galactose (α-Gal) epitope that are present in the monoclonal antibody, cetuximab and red meat have been described in the United States and Europe populations where tick bites have been found to be the primary sensitizer. Another carbohydrate inducing anaphylaxis is galacto-oligosaccharides in commercial milk formula which has been described in the several Asian populations including Singapore. The latter is unique in that the allergen is a pure carbohydrate. We summarize the current literature on carbohydrate-induced food allergy, and evaluate the two new groups of carbohydrate allergy that have defied previous findings on carbohydrates and their role.

Exploring Perceptions and Experiences of Food Allergy among New Canadians from Asia

Introduction. In Canada, perceived prevalence of food allergy surpasses systematic estimates. Canadian immigrants have been found more likely to rate the risk of food allergy as "high" compared to nonimmigrants. Methods. Qualitative interviews were conducted with 3 key informants and 18 allergic individuals of East and Southeast Asian descent in order to capture their lived experience with food allergies. Results. Participants found food allergies to be more common in Canada than in Asia. Participants also agreed that having a food allergy is more manageable in Canada as a result of the policy environment (e.g., food labelling and school policies). In addition, participants had dealt with skepticism and disbelief about their food allergy in Asia, resulting in social exclusion and impacting quality of life. Discussion. Findings demonstrate the need to recognize the varied impacts and experiences of food allergy among new Canadians, given that immigrants represent a large and growing proportion of the Canadian population.

Sesame seed food allergy

The number of reports regarding sesame seed food allergy (SFA) has increased significantly worldwide over the past two decades, either due to a genuine increase in SFA or merely an increase in its awareness. Its prevalence is difficult to estimate due to the lack of well designed prospective population-based studies. Based on the available data, we estimate that SFA affects 0.1-0.2 % of the population, in areas where the food is available. Albeit this prevalence appears to be relatively low, it is approximately one-half of that of persistent cow's milk allergy. While only one fatality has been reported, the significant number of SFA patients presenting as anaphylaxis indicates the potential risk. Many reports based the diagnosis of SFA on sensitization criteria alone, particularly amongst atopic dermatitis patients. Elimination of sesame from the diet of these children utilizing such criteria is not justified, and may even increase the risk for developing SFA.

Paediatric anaphylaxis in a Singaporean children cohort: changing food allergy triggers over time

BACKGROUND

We have noticed changes in paediatric anaphylaxis triggers locally in Singapore.

OBJECTIVE

We aimed to describe the demographic characteristics, clinical features, causative agents and management of children presenting with anaphylaxis.

METHODS

This is a retrospective study of Singaporean children presenting with anaphylaxis between January 2005 and December 2009 to a tertiary paediatric hospital.

RESULTS

One hundred and eight cases of anaphylaxis in 98 children were included. Food was the commonest trigger (63%), followed by drugs (30%), whilst 7% were idiopathic. Peanut was the top food trigger (19%), followed by egg (12%), shellfish (10%) and bird's nest (10%). Ibuprofen was the commonest cause of drug induced anaphylaxis (50%), followed by paracetamol (15%) and other nonsteroidal anti-inflammatory drugs (NSAIDs, 12%). The median age of presentation for all anaphylaxis cases was 7.9 years old (interquartile range 3.6 to 10.8 years), but food triggers occurred significantly earlier compared to drugs (median 4.9 years vs. 10.5 years, p < 0.05). Mucocutaneous (91%) and respiratory features (88%) were the principal presenting symptoms. Drug anaphylaxis was more likely to result in hypotension compared to food anaphylaxis (21.9% vs. 2.7%, Fisher's exact probability < 0.01). There were 4 reported cases (3.6%) of biphasic reaction occurring within 24 h of anaphylaxis.

CONCLUSION

Food anaphylaxis patterns have changed over time in our study cohort of Singaporean children. Peanuts allergy, almost absent a decade ago, is currently the top food trigger, whilst seafood and bird's nest continue to be an important cause of food anaphylaxis locally. NSAIDs and paracetamol hypersensitivity are unique causes of drug induced anaphylaxis locally.

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.

The prevalence of food allergy in infants in Chongqing, China

BACKGROUND

Over the past three decades, the prevalence of allergic diseases has markedly increased in developed countries. There has been a paucity of data on food allergy (FA) in developing countries such as China. We aimed to estimate the prevalence and the clinical features of FA in Chinese infants attending a routine well-baby clinic in Chongqing, China.

METHODS

From January 1st to February 28th, 2009, consecutive infants and young children aged 0-12 months attending routine well-baby checks at the Department of Primary Child Care, Children's Hospital of Chongqing Medical University, were invited to participate in the study. Parents completed questionnaires, and children were skin prick tested (SPT) to a panel of 10 foods (egg white, egg yolk, cow's milk, soybean, peanut, wheat, fish, shrimp, orange, and carrot) together of histamine and saline controls. Subjects with either a positive SPT or a positive medical history were invited to undergo an oral food challenge.

RESULTS

Of 497 children who consented to participate, 477 (96%) participated fully in the study. Of these, 56 subjects had a positive SPT (11.3%), with 45 positive to egg, 13 to cow's milk, 2 to peanut, 1 to fish, shrimp, and orange respectively. Eighty subjects (16.1%, 80/497) participated in food challenges.

CONCLUSION

  The overall prevalence of challenge-proven FA in 0- to 1-yr-old children in Chongqing, China, was 3.8% (18/477, 95% CI, 2.5-5.9%) with 2.5% (12/477) egg allergic and 1.3% (6/477) cow's milk allergic.

Seafood allergy in children: a descriptive study

BACKGROUND

Food allergy and seafood (fish, mollusk, and crustacean) consumption have increased considerably over the past 40 years. Seafood allergy is now a leading cause of anaphylaxis in both the United States and Australia. However, there is only limited published data describing the clinical presentation and management of seafood allergy.

OBJECTIVES

To describe the characteristics of a large cohort of children with seafood allergy.

METHODS

Using a retrospective chart review, we collected data on all children presenting to our Tertiary Allergy Service with an allergic reaction to seafood between 2006 and 2009.

RESULTS

167 children had a history of definite clinical reaction to seafood and/or positive food challenge (103 male, 62%). 94% had evidence of co-existent atopic disease. Prawn/shrimp was the most common seafood implicated. One-fifth presented with a history of anaphylaxis to seafood. Over 50% of crustacean-allergic children could tolerate non-crustacean fish. Sensitization to other fish species was very common in fish-allergic children, with one third reporting clinical reactions to at least two species; 16% developed symptoms to fish vapours. In children with allergy to tuna and/or salmon, at least 21% were able to tolerate the fish in a tinned form.

CONCLUSIONS

Seafood is a relatively common and important cause of food allergy in Australian children, presenting with a high rate of anaphylaxis.

Clinical Features of Allergic Rhinitis and Skin Prick Test Analysis Based on the ARIA Classification: A Preliminary Study in Malaysia

Introduction: Allergic rhinitis (AR) is a prevalent disease worldwide but is still underdiagnosed in many parts of Asia. We studied the clinical profiles of AR patients in our community based on the new ARIA classification and investigated the aetiological allergens using a skin prick test. Materials and Methods: In 2008, 142 newly diagnosed patients with AR were seen and underwent skin prick testing with 90 patients completing the study. Results: Intermittent mild and moderate/severe AR were evident in 10% and 21.1% of the patients, while persistent mild and moderate/severe were seen in 20% and 48.9%, respectively. Rhinitis and asthma co-morbidity occurred in 28.8% with asthma incidence significantly higher in persistent AR (P = 0.002). There was no significant association between AR severity, city living and asthma co-morbidity. Nasal itchiness and sneezing were the main presenting complaints and were more common in intermittent AR (P <0.05). Sleep disturbance was associated with moderate-severe AR (P <0.05). Polypoidal mucosa was associated with asthma co-morbidity (P <0.05). Mono sensitivity reaction occurred in 12.2% of patients and was associated with fungi sensitivity (P<0.05). Majority of patients were oligosensitive (52.8%) and polysensitive (34.4%) and were significantly associated with moderate-severe persistent AR (P <0.01). The highest positive skin prick reaction and the largest average wheal diameter were for the house dust mites and cat allergen (P <0.05). Conclusion: Our results reflected the AR profiles in our country, which was comparable with typical profiles of the neighbouring country and other Mediterranean countries with a similar temperate climate. Key words: Allergic rhinitis, ARIA classification, Malaysia, Skin prick test

A population-based questionnaire survey on the prevalence of peanut, tree nut, and shellfish allergy in 2 Asian populations

BACKGROUND

There has been a substantial increase in the prevalence of peanut and tree nut allergy in Western populations in the last 2 decades. However, there is an impression that peanut and tree nut allergy is relatively uncommon in Asia.

OBJECTIVE

To evaluate the prevalence of peanut, tree nut, and shellfish allergy in schoolchildren in 2 Asian countries (Singapore and Philippines).

METHODS

A structured written questionnaire was administered to local and expatriate Singapore (4-6 and 14-16 years old) and Philippine (14-16 years old) schoolchildren.

RESULTS

A total of 25,692 schoolchildren responded to the survey (response rate, 74.2%). Of these, 23,425 responses fell within the study protocol's 4 to 6 and 14 to 16 year age groups and were included in the analysis. The prevalence of convincing peanut and tree nut allergy were similar in both local Singapore (4-6 years, 0.64%, 0.28%; 14-16 years, 0.47%, 0.3%, respectively) and Philippine (14-16, 0.43%, 0.33%, respectively) schoolchildren, but was higher in the Singapore expatriates (4-6 years, 1.29%, 1.12%; 14-16 years, both 1.21%, respectively; 4-6 years, expatriates vs local Singaporeans: peanut, P = .019; tree nut, P = .0017; 14-16 years, P > .05). Conversely, shellfish allergy was more common in the local Singapore (4-6 years, 1.19%; 14-16 years, 5.23%) and Philippine (14-16 years, 5.12%) schoolchildren compared with expatriate children (4-6 years, 0.55%; 14-16 years, 0.96%; P < .001). When data were pooled, respondents born in Western countries were at higher risk of peanut (adjusted odds ratios [95% CIs]: 4-6 years, 3.47 [1.35-8.93]; 14-16 years, 5.56 [1.74-17.76]) and tree nut allergy (adjusted odds ratios [95% CIs]: 4-6 years, 10.40 [1.61-67.36]; 14-16 years, 3.53 [1.00-12.43]) compared with those born in Asia.

CONCLUSION

This study substantiates the notion that peanut and tree nut allergy is relatively low in Asian children, and instead shellfish allergy predominates. Environmental factors that are yet to be defined are likely to contribute to these differences.

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

Shellfish allergy

Seafood plays an important role in human nutrition and health. The growing international trade in seafood species and products has added to the popularity and frequency of consumption of a variety of seafood products across many countries. This increased production and consumption of seafood has been accompanied by more frequent reports of adverse health problems among consumers as well as processors of seafood. Adverse reactions to seafood are often generated by contaminants but can also be mediated by the immune system and cause allergies. These reactions can result from exposure to the seafood itself or various non-seafood components in the product. Non-immunological reactions to seafood can be triggered by contaminants such as parasites, bacteria, viruses, marine toxins and biogenic amines. Ingredients added during processing and canning of seafood can also cause adverse reactions. Importantly all these substances are able to trigger symptoms which are similar to true allergic reactions, which are mediated by antibodies produced by the immune system against specific allergens. Allergic reactions to 'shellfish', which comprises the groups of crustaceans and molluscs, can generate clinical symptoms ranging from mild urticaria and oral allergy syndrome to life-threatening anaphylactic reactions. The prevalence of crustacean allergy seems to vary largely between geographical locations, most probably as a result of the availability of seafood. The major shellfish allergen is tropomyosin, although other allergens may play an important part in allergenicity such as arginine kinase and myosin light chain. Current observations regard tropomyosin to be the major allergen responsible for molecular and clinical cross-reactivity between crustaceans and molluscs, but also to other inhaled invertebrates such as house dust mites and insects. Future research on the molecular structure of tropomyosins with a focus on the immunological and particularly clinical cross-reactivity will improve diagnosis and management of this potentially life-threatening allergy and is essential for future immunotherapy.

Parent-reported adverse food reactions in Hong Kong Chinese pre-schoolers: epidemiology, clinical spectrum and risk factors

The epidemiology of adverse food reactions (AFRs), including the potentially life-threatening food allergy (FA), in Asia is unclear. AFR is believed to be less prevalent than in Caucasians. This study determines the prevalence, clinical features and risk factors for parent-reported AFR in Chinese pre-school children in Hong Kong. Children aged 2-7 yr living in Hong Kong were recruited through local nurseries and kindergartens to ascertain the occurrence and clinical spectrum of AFR and other atopic disorders. Subjects' parents answered a self-administered questionnaire that was modified and validated based on the International Study of Asthma and Allergy in Childhood. A total of 3827 children from 21 nurseries and kindergartens returned the study questionnaires, and information on AFR was analyzable for 3677 (96.1%) children. The prevalence rates of parent-reported AFR and parent-reported, doctor-diagnosed AFR were 8.1% and 4.6%, respectively, whereas 5.0% of pre-schoolers had doctor-diagnosed asthma. The six leading causes of AFR were shellfish (15.8%), egg (9.1%), peanut (8.1%), beef (6.4%), cow's milk (5.7%), and tree nuts (5.0%). When compared with children born and raised in Hong Kong, children born in mainland China (n = 253) had less parent-reported AFR (4.0% vs. 6.7%; p = 0.016). On logistic regression, parent-reported AFR was associated with younger age (p = 0.010), born in mainland China (p = 0.038), and AFR history in father (p = 0.001), mother (p < 0.001), siblings (p = 0.020), and paternal history of rhinitis (p = 0.044). This study shows that AFR is a common atopic disorder in Hong Kong pre-school children, and prevalence rates are comparable to the Caucasians.

Association analysis of food allergens

Food allergy patients are known to present with allergic reactions to multiple allergens, but extrapolating these associations is difficult. Data mining, a procedure that analyzes characteristic combinations among large amounts of information, is often used to analyze and predict consumer purchasing behaviour. We applied this technique to the extrapolation of food allergen associations in allergy patients. We sent 1510 families our 'Questionnaire survey for the prevention of food allergies'. Responses noting 6549 allergens came from 878 families with 1383 patients, including 402 with anaphylaxis. Some results of the survey have already been published and here we presented the results of our association analysis of combinations of food allergens. Egg, milk, wheat, peanuts, and buckwheat are the most common food allergens. The most common simultaneous combinations of these allergens were 'egg-milk', 'egg-wheat', and 'milk-wheat'. The occurrence probability of a combination (i.e. one person suffering from a certain allergen also suffers from another) is called 'confidence'. Confidence was higher for 'chicken-egg', 'abalone-salmon eggs', and 'matsutake mushroom-milk'. As well, the combinations of 'crab-shrimp', 'squid-shrimp', and 'squid-crab' also indicated higher values in a statistical examination of the occurrence probabilities of these allergen combinations (Z-score). From the results of the association analysis, we speculated that some food allergens, such as abalone, orange, salmon, chicken, pork, matsutake mushroom, peach and apple did not independently induce food allergies. We also found that combinations, such as 'crab-shrimp', 'squid-shrimp', 'squid-crab', 'chicken-beef', and 'salmon-mackerel' had strong associations.

Ingestion--associated adverse events necessitating pediatric ICU admissions

OBJECTIVE

To review the pattern of food-associated pediatric intensive care unit (PICU) admissions.

METHODS

A retrospective chart review was conducted to analyse the pattern of food-associated PICU admissions at a teaching hospital between January 2004 and May 2007.

RESULTS

Ten cases (7 boys and 3 girls, aged 9 month to 11.7 year) were identified. One girl developed progressive generalized urticarial rash and anaphylactic shock following consumption of bird nest drink. A boy presented with the classic triads of acute onset altered mental state, respiratory depression and small pupils following consumption of a bottle of presumed "green tea", which was subsequently found to contain methadone. In the remaining 8 cases, dried mango, peanut, peanut-shell, fishmeat ball, pork chop, bread and bone were the culprits, impacting in the airway or oesophagus. All but one patient had short ICU stay (<or=3 days). Ingestion-associated adverse events can be protean and may necessitate PICU admissions. All age groups can be affected. Solids are usually associated with symptoms from local obstruction or suffocation, while fluids may be associated with systemic manifestations.

CONCLUSION

Presentations were generally acute, dramatic and unmistaken. The majority of patients made prompt and uneventful recovery and had short PICU stay.

Parvalbumin--the major tropical fish allergen

Fish allergy is common in countries where consumption is high. Asian nations are amongst the world's largest consumers of fish but the allergen profiles of tropical fish are unknown. This study sought to evaluate the allergenicity of four commonly consumed tropical fish, the threadfin (Polynemus indicus), Indian anchovy (Stolephorus indicus), pomfret (Pampus chinensis) and tengirri (Scomberomorus guttatus). Immunoglobulin E (IgE) cross-reactivity with parvalbumin of cod fish (Gad c 1), the major fish allergen, was also studied. Detection of tropical fish and cod specific-IgE was performed by UniCap assay, and skin prick tests were also carried out. The IgE-binding components of tropical fish were identified using IgE immunoblot techniques, and cross-reactivity with Gad c 1 was assessed by ELISA inhibition and IgE immunoblot inhibition. Clinically, nine of 10 patients studied were allergic to multiple fish. All patients exhibited detectable specific-IgE to cod fish (10 of 10 skin prick test positive, eight of 10 UniCap assay positive) despite lack of previous exposure. The major allergen of the four tropical fish was the 12-kDa parvalbumin. IgE cross-reactivity of these allergens to Gad c 1 was observed to be moderate to high in the tropical fish studied. Parvalbumins are the major allergens in commonly consumed tropical fish. They are cross-reactive with each other as well as with Gad c 1. Commercial tests for cod fish appear to be sufficient for the detection of tropical fish specific-IgE.

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.

Clinical characteristics of peanut-allergic children: recent changes

OBJECTIVE

The goal was to determine whether patients seen in a referral clinic are experiencing initial allergic reactions to peanuts earlier, compared with a similar population profiled at a different medical center 10 years ago, and to investigate other changes in clinical characteristics of the patients between the 2 groups.

METHODS

We reviewed the medical charts of peanut-allergic patients seen in the Duke University pediatric allergy and immunology clinic between July 2000 and April 2006.

RESULTS

The median ages of first peanut exposure and reaction were 14 and 18 months, respectively; the respective ages in a similar population profiled between 1995 and 1997 were 22 and 24 months. Within our patient group, those born before 2000 were first exposed to peanuts at a median age of 19 months and reacted at a median age of 21 months, compared with first exposure at 12 months and first reaction at 14 months for those born in or after 2000. Most patients (68%) demonstrated sensitization or clinical allergy to other foods (53% to eggs, 26% to cow's milk, 20% to tree nuts, 11% to fish, 9% to shellfish, 7% to soy, 6% to wheat, and 6% to sesame seeds).

CONCLUSIONS

In the past decade, the ages of first peanut exposure and reaction have declined among peanut-allergic children seen in a referral clinic. Egg allergy is very common in peanut-allergic patients, and sesame seeds should perhaps be considered one of the major food allergens. The decline in the age of first peanut reaction seems to be attributable to earlier exposure.

Features of patients with anaphylaxis admitted to a university hospital

BACKGROUND

Anaphylaxis in hospitalized patients has been infrequently reviewed. There are few studies of anaphylaxis from Asian countries.

OBJECTIVE

To describe the clinical characteristics of patients with anaphylaxis admitted to Siriraj Hospital.

METHODS

The medical records of 101 patients admitted with clinical anaphylaxis between January 1, 1999, and December 31, 2004, were reviewed. Data were analyzed using the chi2 test.

RESULTS

The annual occurrence of anaphylaxis increased from 9.16 per 100,000 admitted persons in 1999 to 55.45 per 100,000 admitted persons in 2004. The case fatality rate was 0.19 per 100,000 admitted persons. The mean +/- SD age was 23.73 +/- 21.84 years. Males experienced more anaphylaxis than females in pediatric patients and vice versa in adult patients. Biphasic anaphylaxis was found in 7% of pediatric and 2% of adult patients. Anaphylaxis occurred in the hospital in 37% of patients. Involved systems were cutaneous (86%), respiratory (80%), cardiovascular (52%), and oral and gastrointestinal (36%). Identifiable causes were drugs (50%), foods (24%), idiopathic (15%), and insect stings/bites (11%). Epinephrine was given to 77% of the patients.

CONCLUSIONS

We report the clinical characteristics of patients with anaphylaxis admitted to a university hospital. Knowing the clinical features will raise physician awareness of this condition.

Food allergies: prevalence, molecular characterization, and treatment/prevention strategies

A significant proportion of the population is either affected by or concerned about food allergy. Our knowledge about food allergens and how they stimulate the immune system has increased dramatically over the past decade. However, reasons for the increased prevalence of food allergy are not clear. The diagnosis of food allergy requires that the patient and caregivers examine all foods for the presence of potential allergens in order to prevent inadvertent ingestion and further reactions. Fortunately, many children develop tolerance to allergenic foods after a period of dietary elimination. Various immunotherapy approaches are under investigation to alleviate or prevent food-induced reactions in those who have persistent food allergies.

Dietary restriction and supplementation in children with atopic eczema

Issues on empirical dietary restriction or supplementation are important but inadequately studied in children with atopic eczema (AE). The dietary habits of children with AE followed at a paediatric dermatology clinic (n = 179) were compared with those without eczema (n = 78). The mothers of 53% of the patients with or without eczema did not breastfeed their children. Common food items avoided by parents whose children have moderate-to-severe AE included fish or seafood [64% vs. 32% of controls, odds ratio (OR) 3.84, 95% CI 2.12-6.95], beef (42% vs. 17%; OR = 3.57, 95% CI 1.79-7.11), eggs (34% vs. 14%; OR = 3.05, 95% CI 1.46-6.34) and cows' milk (18% vs. 4%; OR = 5.56, 95% CI 1.61-19.12); whereas their avoidance was less frequent in children with noneczematous diseases. The avoidance of these foods were often based on belief, but 66% of all AE patients who had avoided any of the above foods reported previous experience of eczema exacerbation by these items. Patients with moderate-to-severe AE were more likely to have consumed 'bird's nest' soup and traditional Chinese medicines. It is important to evaluate whether the AE patients are genuinely 'allergic' to some of these food items. Management is suboptimal if children with food allergy and severe disease continue to consume the culprit food. Conversely, avoidance of common foods in children without food allergy could result in food faddism or malnutrition.

Food allergy in Asia

PURPOSE OF REVIEW

Food allergy is increasing in prevalence in Western populations, but little is known about it in Asia. The perception is that the prevalence in this region is low, but is likely to increase with the global increase in allergy. Asia is unique because of the many different cultures and eating habits, with the resulting occurrence of unique food allergens. This review describes the epidemiology and clinical features of food allergy, and introduces some of the unusual food allergens in Asia.

RECENT FINDINGS

Recent studies describing the pattern of anaphylaxis and the role of food triggers show that food is an important cause of severe allergic reactions in Asia. Progress has been made on the characterization of unique food allergens from the region. Peanut and tree nuts are rarely the cause of allergic reactions in Asia. The lack of availability of epinephrine auto-injectors in many countries is an important issue that needs to be addressed.

SUMMARY

The pattern of food allergy in Asia is unique. Unfortunately, data from many parts of Asia are still lacking. Large, well-designed epidemiological studies are needed so that the scale of the problem can be understood, public awareness can be increased and important food allergens in the region can be identified.

Differences in race, ethnicity, and socioeconomic status in schoolchildren dispensed injectable epinephrine in 3 Massachusetts school districts

BACKGROUND

Published surveys depicting the increase in the incidence of food allergy, especially peanut or tree nut allergy, in children have not reported any differences in race, ethnicity, or socioeconomic status.

OBJECTIVE

To analyze the demographics of schoolchildren with diverse racial, ethnic, and socioeconomic characteristics dispensed injectable epinephrine.

METHODS

School nurses in 44 schools enrolling 21,875 students recorded the characteristics of students dispensed injectable epinephrine in the 2003-2004 school year. Surveyed school districts included 2 affluent suburban districts enrolling 5,855 students (> 92% white) and 1 urban district enrolling 16,020 students (60% nonwhite).

RESULTS

A total of 181 students in all 3 districts were dispensed injectable epinephrine; 118 of these children had peanut or tree nut allergy. Males were more likely to be dispensed injectable epinephrine than females (odds ratio [OR], 1.44; P < .02). Whites were more likely to have been dispensed injectable epinephrine than nonwhites (OR, 4.76; P < .001). Whites were nearly 5 times more likely to be dispensed injectable epinephrine for peanut or tree nut allergy than nonwhites (OR, 4.5; P < .001). Most students (75%) dispensed injectable epinephrine for peanut or tree nut allergy were enrolled in prekindergarten through grade 5 (P < .001). Whites were more likely than nonwhites to be dispensed injectable epinephrine for stinging insect allergy (OR, 8.7; P < .001).

CONCLUSIONS

This study found significant racial, ethnic, and socioeconomic differences in the prevalence of childhood allergic disorders, especially peanut or tree nut allergy, requiring prescribed injectable epinephrine in a school setting. Additional studies are needed to determine whether minority children are being underdiagnosed or undertreated for allergic disorders requiring injectable epinephrine or whether they truly have a lower incidence of such allergic disorders.