Prevalence of self-reported food allergy in U.S. adults: 2001, 2006, and 2010

Risk Factors for Severe Seafood Allergy Among Adults in an Urban City in Vietnam

Purpose

Increasing seafood consumption is associated with more frequent reports of food allergy. Little is known about seafood allergy (SFA) among adults in Vietnam. We investigated the characteristics of individuals with SFA and the risk factors for severe SFA.

Patients and methods

A cross-sectional, web-based survey was conducted among individuals aged ≥ 18 years from universities in Ho Chi Minh City (Vietnam) between December 2021 and July 2022. The survey was based on a structured, validated questionnaire related to FA. Strict definitions of "convincing allergy" were used. Multivariate analysis was used to estimate the risk factors for severe SFA after adjusting for covariates. Data were analyzed using JASP (v.0.16.3) and SPSS (v.22.0).

Results

Totally, 1038 out of 2137 (48.57%) individuals completed the questionnaire, of whom 285 (27.46%) had reported SFA. Convincing SFA accounted for 20.13% (209/1038) of the cases, with convincing shellfish allergy being more common than fish allergy. Participants with comorbid shellfish and fish allergy had higher prevalence of atopic dermatitis, peanut/nut allergy, other food allergy, and cutaneous and upper airway symptoms compared to participants with shellfish allergy (p < 0.05). The spectrum of reactive seafood was diverse and characterized by local species. The age of symptom onset was most commonly during late childhood and adolescence, with most reactions persisting into adulthood. A history of anaphylaxis, comorbid peanut, and tree nut allergy, and ≥3 allergens were associated with severe SFA.

Conclusion

Features of causative, coexisting seafood allergy, and risk factors for severe SFA were demonstrated, which can provide a reference for future studies.

Revisiting Fruit Allergy: Prevalence across the Globe, Diagnosis, and Current Management

Fruit allergies manifest with a diverse array of clinical presentations, ranging from localized contact allergies and oral allergy syndrome to the potential for severe systemic reactions including anaphylaxis. The scope of population-level prevalence studies remains limited, largely derived from single-center or hospital-based investigations. In this comprehensive review, we conducted a systematic literature search spanning the years 2009 to 2023, with full acknowledgment of potential analytical biases, to provide a global overview of fruit allergy prevalence. The primary mechanistic underpinning of fruit allergies stems from cross-reactivity between aeroallergens and food allergens, a consequence of structurally similar epitopes-a phenomenon recognized as pollen food allergy syndrome (PFAS). In the era of molecular allergology, numerous studies have dissected allergen components with substantial clinical relevance. Within this review, we explore important allergenic molecules found in plant-based foods, scrutinize pertinent cross-reactivity patterns, and offer insights into management recommendations. Additionally, we compare guideline recommendations to enhance clinical understanding and inform decision making.

Understanding food allergy through neuroimmune interactions in the gastrointestinal tract

Food allergies are adverse immune reactions to food proteins in the absence of oral tolerance, and the incidence of allergies to food, including peanut, cow's milk, and shellfish, has been increasing globally. Although advancements have been made toward understanding the contributions of the type 2 immune response to allergic sensitization, crosstalk between these immune cells and neurons of the enteric nervous system is an area of emerging interest in the pathophysiology of food allergy, given the close proximity of neuronal cells of the enteric nervous system and type 2 effector cells, including eosinophils and mast cells. At mucosal sites, such as the gastrointestinal tract, neuroimmune interactions contribute to the sensing and response to danger signals from the epithelial barrier. This communication is bidirectional, as immune cells express receptors for neuropeptides and transmitters, and neurons express cytokine receptors, allowing for the detection of and response to inflammatory insults. In addition, it seems that neuromodulation of immune cells including mast cells, eosinophils, and innate lymphoid cells is critical for amplification of the type 2 allergic immune response. As such, neuroimmune interactions may be critical targets for future food allergy therapies. This review evaluates the contributions of local enteric neuroimmune interactions to the underlying immune response in food allergy and discusses considerations for future investigations into targeting neuroimmune pathways for treatment of food allergies.

Prevalence of self-reported food allergy among adults in Jiangxi, China

Background

Food allergy has become an increasingly important public health problem. However, information regarding epidemiological studies of food allergy among Chinese adults is very limited. This study aims to estimate the prevalence of self-reported food allergy among adults in China.

Method

A population-based cross-sectional study was administered to estimate the prevalence of self-reported food allergy on the basis of a face-to-face questionnaire survey. The participants were recruited by cluster random sampling from three prefectures in Jiangxi Province, China.

Results

A total of 12 082 questionnaires were distributed, and 11 935 (98.8%) of completed ones were collected. The prevalence of self-reported food allergy was 4.0% (3.1% in men and 4.8% in women), self-reported doctor-diagnosed food allergy accounted for 1.4%. The most common allergic symptom was skin reaction showing in 63.9% of the participants with self-reported food allergy. The main allergic foods were shrimp, mollusks, and mango, accounting for the prevalence of 39.8%, 20.8%, and 18.7%, respectively. The self-reported food allergy was significantly linked with gender, age group, body height and other allergic conditions.

Conclusions

The prevalence of self-reported food allergy is about 4.0% among adults in China. The three most common allergenic foods were shrimp, mollusks and mango. Gender, age, and other allergic diseases could be contributing factors associated with food allergy in adults. These findings will provide scientific basis for the further research and prevention of food allergy in adults.

A Meta-Analysis of the Prevalence of Wheat Allergy Worldwide

Wheat allergy is a primary disease of food allergy, and its global prevalence is unclear. This study aimed to characterize the latest worldwide prevalence of wheat allergy based on five different diagnostic methods. Study searches were conducted in Web of Science, PubMed, Ovid LWW, and Cochrane database, with a time limit of 1 January 2007 to 1 September 2022. The review and screening of the articles was undertaken by two independent reviewers. The statistical analysis was conducted by R. A total of 56 articles were finally included. The prevalence of wheat allergy was 0.63% (95% CI: 0.43-0.87%) for self-reported, 0.70% (95% CI: 0.18-1.22%) for self-reported physician-diagnosed, 0.22% (95%CI: 0.07-0.65%) for skin prick test positive, 0.97% (95% CI: 0.43-2.20%) for specific immunoglobulin E positive, and 0.04% (95% CI: 0-0.16%) for food challenge. However, food challenge can be largely subjective, and the results were only based two countries, so the prevalence of wheat allergy confirmed by food challenge may be not entirely trustworthy. In conclusion, investigating the prevalence of wheat allergy in the real world as accurately as possible will contribute to the prevention, management, and risk assessment of wheat allergy.

Intrinsic Allergenicity Potential of Salt-Soluble Protein Extracts from the Diploid, Tetraploid and Hexaploid Wheats: Validation Using an Adjuvant-Free Mouse Model

Wheat allergies are potentially life-threatening and, therefore, have become a major health concern at the global level. It is largely unknown at present whether genetic variation in allergenicity potential exists among hexaploid, tetraploid and diploid wheat species. Such information is critical in establishing a baseline allergenicity map to inform breeding efforts to identify hyper-, hypo- and non-allergenic varieties. We recently reported a novel mouse model of intrinsic allergenicity using the salt-soluble protein extract (SSPE) from durum, a tetraploid wheat (Triticum durum). Here, we validated the model for three other wheat species [hexaploid common wheat (Triticum aestivum), diploid einkorn wheat (Triticum monococcum), and the ancient diploid wheat progenitor, Aegilops tauschii], and then tested the hypothesis that the SSPEs from wheat species will exhibit differences in relative allergenicities. Balb/c mice were repeatedly exposed to SSPEs via the skin. Allergic sensitization potential was assessed by specific (s) IgE antibody responses. Oral anaphylaxis was quantified by the hypothermic shock response (HSR). The mucosal mast cell response (MMCR) was determined by measuring mast cell protease in the blood. While T. monococcum elicited the least, but significant, sensitization, others were comparable. Whereas Ae. taushcii elicited the least HSR, the other three elicited much higher HSRs. Similarly, while Ae. tauschii elicited the least MMCR, the other wheats elicited much higher MMCR as well. In conclusion, this pre-clinical comparative mapping strategy may be used to identify potentially hyper-, hypo- and non-allergenic wheat varieties via crossbreeding and genetic engineering methods.

Food anaphylaxis in the elderly: Analysis of allergy vigilance network data from 2002 to 2021

BACKGROUND

Few studies have focused on food allergies in the elderly, even though it may persist or appear de novo.

METHODS

We reviewed data for all cases of food-induced anaphylaxis in people age ≥ 60 reported to the French "Allergy Vigilance Network" (RAV) between 2002 and 2021. RAV collates data reported by French-speaking allergists regarding cases of anaphylaxis graded II to IV according to the Ring and Messmer classification.

RESULTS

In total, 191 cases were reported, with an even sex distribution and mean age was 67.4 years (range 60 to 93). The most frequent allergens were mammalian meat and offal (31 cases, 16.2%), often associated with IgE to α-Gal. Legumes were reported in 26 cases (13.6%), fruits and vegetables in 25 cases (13.1%), shellfish 25 cases (13.1%), nuts 20 cases (10.5%), cereals 18 cases (9.4%), seeds 10 cases (5.2%), fish 8 cases (4.2%) and anisakis 8 cases (4.2%). Severity was grade II in 86 cases (45%), grade III in 98 cases (52%) and grade IV in 6 cases (3%) with one death. Most episodes occurred at home or in a restaurant and in most cases adrenaline was not used to treat the acute episode. Potentially relevant cofactors such as beta-blocker, alcohol or non-steroidal anti-inflammatory drug intake were present in 61% of cases. Chronic cardiomyopathy, present in 11.5% of the population, was associated with greater, grade III or IV reaction severity (OR 3.4; 1.24-10.95).

CONCLUSION

Anaphylaxis in the elderly has different causes to younger people and requires detailed diagnostic testing and individualized care plans.

Food allergies and allergens in Lebanon: Characterization and perceptions toward labeling

Background

Food allergy is a life-threatening medical condition of public health concern. The aim of our study was to characterize food allergies, in terms of sources, symptoms, severity, and history, as well as to assess the knowledge, practices, and attitudes towards food allergens and allergies, in addition to food allergen labeling, in Lebanon.

Methods

For this, 1100 participants filled over the phone a comprehensive valid questionnaire composed of 41 questions.

Results

Fruits were reported as top food allergens (29.6%), while itching and rash were the most reported symptoms (9.6% and 8.0%, respectively). In terms of knowledge, participants scored on average 67.9 ± 16.2%. Participants who identified as females, below 35 years, highly educated, and from health backgrounds had a significantly higher score (p < 0.05), while area of residence did not have any significant effect (p > 0.05). Participants who are medically diagnosed with allergies and those with health background were found to check the ingredients list and read nutritional claims significantly more frequently than those from a non-health background and who are non-medically diagnosed, respectively, while females were found to check ingredients list and read nutritional claims significantly more frequently (p < 0.05). The majority reported that ingredients are easy to understand (63.2%) and simple to read (61.3%), while allergic individuals agreed that the font size of the ingredients list is not big enough (56.8%) and that E-code numbers are not understood (68.7%). The majority considered it "important" to have the label writings larger and bolded (85.7%), to use simple language (95.5%), to place allergen warning (82.2%), and to use a striking allergen symbol (93.5%).

Conclusions

Our results emphasize the need for national awareness campaigns to improve knowledge and practices, and to lobby policymakers for appropriate management of food allergies and allergens in Lebanon.

Risk Assessment of Allergic Diseases Among Preschool Children in Guangzhou, China: A Cross-Sectional Study

Purpose

To investigate the lifestyle and stress of mothers during pregnancy to analyze the risk factors for the disease in early childhood.

Patients and Methods

A cross-sectional survey was conducted from January 2022 to June 2022 in a sub-district in Guangzhou, China. A total of 3437 valid questionnaires were eventually collected. The questionnaire consisted of 56 questions in three sections included questions on child's birth conditions and early life environment, questions on mother's lifestyle during pregnancy, and questions about father.

Results

49.75% of the children were likely to have allergic diseases (suspected allergy group). There were more boys in the suspected allergy group (58% vs 50%), and the percentage of children born at first birth was also higher in the suspected allergy group (61% vs 51%). 67% to 69% of children had suspicious allergies when one parent claimed an allergy, and 80.1% when both parents reported an allergy. The results of the multifactorial logistic model showed that male had 1.49 (1.28 to 1.73) times the risk of allergic diseases than female, and preterm births increased the risk of allergic diseases by 1.53 (1.13-2.07) times compared to full-term births. Both unplanned pregnancies and pregnancy complications increased the risk of allergic diseases in children before school age [1.34 (1.15-1.55) and 1.82 (1.46-2.26)]. Among pregnant women who reported regular passive smoking, the risk of the disease was increased 2.43 (1.71 to 3.50) times in preschool children. Reported allergies in all family members were significant risk factors for allergic diseases in children, especially mother [2.88 (2.41~3.46)]. In the prenatal period, maternal negative emotions are more common in children with suspected allergies.

Conclusion

Nearly half of the children in the region suffer from allergic diseases. Sex, birth order and full-term delivery all contributed to early childhood allergy. Family history of allergy, especially maternal, was the most important risk factor, and the number of family members with allergy was significantly associated with the allergy in children. Maternal effects are also reflected in prenatal conditions such as unplanned pregnancy, smoke exposure, pregnancy complications, and prenatal stress.

Multi-Perspective Observation on the Prevalence of Food Allergy in the General Chinese Population: A Meta-Analysis

Reliable estimates of the prevalence of food allergy (FA) among the general Chinese population have remained unclear. This meta-analysis aims to provide an accurate estimate of FA prevalence in China with comprehensive data. A systematic literature search was conducted in eight electronic databases, i.e., China National Knowledge Infrastructure, Wanfang, Weipu, China Biology Medicine, Web of Science, PubMed, Cochrane, and Embase. A random-effects model was used to analyze the pooled prevalence of FA for four different assessment methods. A total of 46 eligible articles were included in the narrative synthesis, and 41 articles were ultimately included in the meta-analysis. Overall, the pooled prevalence of self-reported FA, self-reported physician-diagnosed FA, SPT (specific skin prick test)-positive FA, and OFC (open food challenge)-positive FA were 11.5% (95% CI: 9.8-13.5%), 5.3% (95% CI: 4.2-6.5%), 11.6% (95% CI: 9.6-14.1%), and 6.2% (95% CI: 4.4-8.7%), respectively. Subgroup analyses suggested that the prevalence of FA was affected by age, year of data collection, region, and sample size, but not by gender. This meta-analysis indicated that FA is common among Chinese people, with an increasing trend in prevalence during the past two decades. Given the high heterogenicity between these studies, a national survey with a large sample size based on standardized diagnosis is urgently needed to gain a more scientific understanding of the actual situation of food allergy in China.

White as milk: Biocentric bias in the framing of lactose intolerance and lactase persistence

The majority of the world population is lactose intolerant, as 65%-70% of people lose the enzymes to digest lactose after infancy. Yet, in the United States, where lactose intolerance is predicted to affect only 36% of people, this phenomenon is often framed as a deficiency as opposed to the norm. This is because the United States has a higher prevalence of people who are lactase persistent. Lactase persistence is a genetic trait most common among Europeans and some African, Middle Eastern and southern Asian groups with a history of animal domestication and milk consumption. In this study, we take the case of lactose intolerance to examine how popular media maintains biocentric biases. Analysing relevant articles published in The New York Times and Scientific American between 1971 and 2020, we document how ideas about milk, health and race evolve over time. Over this fifty-year period, writers shifted from framing lactose intolerance as racial difference to lactase persistence as evolutionary genetics. Yet, articles on the osteoporosis 'epidemic' and vitamin D deficiency worked to perpetuate lactose intolerance as a health concern and standardise the dairy-heavy American diet. Studying media portrayals of lactose intolerance and lactase persistence, we argue that popular discourses normalise biocentric biases through messages about eating behaviours and health.

The health effects of soy: A reference guide for health professionals

Soy is a hotly debated and widely discussed topic in the field of nutrition. However, health practitioners may be ill-equipped to counsel clients and patients about the use of soyfoods because of the enormous, and often contradictory, amount of research that has been published over the past 30 years. As interest in plant-based diets increases, there will be increased pressure for practitioners to gain a working knowledge of this area. The purpose of this review is to provide concise literature summaries (400-500 words) along with a short perspective on the current state of knowledge of a wide range of topics related to soy, from the cholesterol-lowering effects of soy protein to the impact of isoflavones on breast cancer risk. In addition to the literature summaries, general background information on soyfoods, soy protein, and isoflavones is provided. This analysis can serve as a tool for health professionals to be used when discussing soyfoods with their clients and patients.

An Adjuvant-Free Mouse Model Using Skin Sensitization Without Tape-Stripping Followed by Oral Elicitation of Anaphylaxis: A Novel Pre-Clinical Tool for Testing Intrinsic Wheat Allergenicity

Wheat is a major food allergen per the regulatory bodies of various nations. Hypersensitivity reactions to wheat have been steadily increasing for reasons that are not completely understood. Wheat-allergy models typically use adjuvants to induce sensitization to wheat proteins followed by an intraperitoneal challenge to elicit anaphylaxis. Although these models are very useful, they lack the ability to reveal the intrinsic allergenicity potential of wheat. To improve the mouse model of wheat allergy, we tested the hypothesis that repeated skin application of salt-soluble protein extract (SSPE) from durum wheat will clinically sensitize the mice to oral anaphylaxis to SSPE. Balb/c mice were bred and maintained on a plant-protein-free diet and used in the experiments. Adult female mice were exposed to SSPE once a week for 9 weeks via a solution on intact skin. Sensitization was measured by SSPE-specific IgE (sIgE) antibody and total IgE (tIgE) levels. Oral anaphylaxis was quantified by hypothermic shock response (HSR), and mucosal mast cell response (MMCR) was quantified by measuring MMCP-1 after oral challenge. Using single mouse data, correlation analyses were performed to determine the relationship among the allergenicity readouts. Spleen cytokines were quantified using a protein microarray method. Our results show that (i) repeated skin exposures to SSPE elicited robust increases in the sIgE and tIgE levels; (ii) skin exposure to SSPE was sufficient to sensitize mice for oral anaphylaxis and MMCR; (iii) both HSR and MMCR showed a strong correlation with each other, as well as with sIgE, and a modest correlation with tIgE levels; (iv) selected Th2/Th17/Th1 cytokines were elevated in skin-sensitized mice; and (v) oral allergen-challenged mice showed selective elevation of IL-6 and a panel of chemokines compared to saline-challenged mice. Together, we report the development and characterization of a novel adjuvant-free wheat-allergy mouse model that uses skin sensitization without tape-stripping followed by oral elicitation of anaphylaxis. Furthermore, validation of quantifiable wheat allergenicity readouts makes this model particularly suitable as a pre-clinical testing tool to assess the intrinsic sensitization/oral-anaphylaxis elicitation potential of novel wheat proteins (e.g., processed wheat) and to develop hypo/non-allergenic wheat products.

A Pilot Study to Evaluate the Dietary Intake of Adults Attending a Food Allergy Clinic, and Compare the Results Against the Final Diagnostic Outcome

Background: The impact of poor diet on growth and development in children with a food allergy is well-recognized and researched. Food allergy is an increasing problem in adults, as are food intolerances. Another issue is the rising number of individuals adopting a vegetarian or vegan lifestyle. Studies evaluating the diet of adolescents and adults with food allergy against controls suggest their dietary intakes are similar. We wished to evaluate all patients attending a food allergy clinic to determine whether there were dietary and nutritional differences between those with a food allergy or a food intolerance. Methods: All adults newly referred to a secondary care food allergy clinic in a UK hospital, in a 1-month period, were included in the study. Prior to their appointment, those who consented to take part had their height and weight documented and an assessment made of their habitual food intake. Their subsequent diagnosis was reviewed, and results for those with a confirmed diagnosis of food allergy were compared to those with a food intolerance or where the cause of symptoms was unknown. Results: Thirty subjects were recruited, with full results available for 29 subjects, 15 of whom (52%) were diagnosed with a new/existing food allergy (FA). For the whole cohort, dietary intake was sufficient for protein, and most vitamins and minerals, whereas energy, carbohydrate, unsaturated fat and fiber intakes were well-below the reference range. Those with a FA had lower intakes of iron, zinc and vitamin B12 compared to those with no FA. In addition, iron and energy intakes were depleted in those avoiding nuts, and wheat avoidance was linked to a lower intake of riboflavin. Conclusion: The results from this small exploratory study suggest that whilst the majority of nutrients in the diet are sufficient in adults presenting to the food allergy clinic, intakes of energy and fiber may be below the reference range. Those with a food allergy are more likely to have a reduced intake of iron, zinc and vitamin B12. As others have demonstrated, the exclusion of specific food groups can also affect nutritional intakes.

Aquatic food animals in the United States: Status quo and challenges

This review summarizes (1) the U.S. status quo for aquatic food animal production and marketing; (2) major food safety and quality issues/concerns for aquatic food animals in the United States, including fish misbranding, finfish/shellfish allergies, pathogens, toxins and harmful residues, microplastics, and genetically engineered salmon; and (3) various U.S. regulations, guidances, and detection methods for the surveillance of fishery products. Overall, fish misbranding is the biggest challenge in the United States due to the relatively low inspection rate. In addition, due to the regulatory differences among countries, illegal animal drugs and/or pesticide residues might also be identified in imported aquatic food animals. Future regulatory and research directions could focus on further strengthening international cooperation, enhancing aquatic food animal inspection, and developing reliable, sensitive, and highly efficient detection methods.

Population-based incidence of food allergies in Olmsted County over 17 years

Background: There is growing concern about the rising incidence and prevalence of food allergy globally. We previously reported the incidence of food allergy in Olmsted County, Minnesota, between 2002 and 2011. We sought to update the incidence and temporal trends of food allergies in our region through 2018. Methods: By using the Rochester Epidemiology Project, all Olmsted County residents, with an incident diagnosis of food allergy between January 2, 2012, and December 31, 2018, were identified and their medical records were reviewed. These cases were combined with the previously collected incidence cases from January 2, 2002, and December 31, 2011, to understand longitudinal trends in food allergy incidence rates. Results: Over the 17-year study period, 1076 patients (58.0% male patients, 72.1% white) were diagnosed with an incident food allergy. The median (interquartile range) age at first diagnosis was 2.0 years (1.1-8.4 years). The overall annual incidence rate for all ages was 3.9 (95% confidence interval [CI], 3.6-4.1) per 10,000 person-years and was significantly higher in male than in female patients (4.4 [95% CI, 4.0-4.7] and 3.3 [95% CI, 3.0-3.6], respectively; p < 0.001). The most common food allergen was egg in infancy (57.7%), peanuts in ages 1-4 years (58.3%), tree nuts in ages 5-18 years (57.4%), and seafood in adults (≥19 years) (45.3%). Conclusion: The incidence of food allergy in Olmsted County steadily increased from 2002 to 2008, then remained relatively stable between the years 2008 and 2013, and again presented a rising trend over the next 5 years until 2018. This warrants further investigations into the effects of changes in guidelines for early introductions of allergenic foods and other factors that affect causality.

Responses of consumers with food allergy to the new allergen-labelling legislation in Saudi Arabia: a preliminary survey

OBJECTIVE

Preventing a food allergy reaction depends primarily on eliminating allergens from the diet. In October 2019, the Saudi Food and Drug Authority (SFDA) introduced new legislation requiring food establishments providing and selling non-prepacked foods to state the presence of the top fourteen food allergens on their menus. The current study aimed to assess the allergen-labelling knowledge, practices, preferences and perceptions towards the new SFDA allergen-labelling legislation among consumers with food allergy in Saudi Arabia.

DESIGN

Observational cross-sectional study using an online questionnaire.

SETTING

Saudi Arabia; February - March 2020.

PARTICIPANTS

Residents of Saudi Arabia with food allergy (n 427), aged 18-70 years.

RESULTS

Among participants, only 28·1 % knew that there were governmental regulations in Saudi Arabia regarding food-allergen labelling and approximately two-thirds (67 %) check labels on prepacked food products for allergens. The majority of the participants preferred food products carrying safety statements (84·1 %) and symbols (80·1 %). A total of 47·1 % were aware that regulations in Saudi Arabia require allergens to be declared in ingredient lists, while 51·3 % were aware that advisory allergen labelling is not required by law. Only 26·2 % were aware of the new SFDA legislation regarding provision of allergen information by food establishments. However, the majority (94·4 %) were supportive of the new legislation, and most of them were more likely to eat at restaurants that reported allergen information for food items on the menu.

CONCLUSIONS

The new SFDA food allergen-labelling legislation needs to be more widely and effectively disseminated to increase the level of awareness among adults with food allergy in Saudi Arabia.

Time trends of childhood food allergy in China: Three cross-sectional surveys in 1999, 2009, and 2019

BACKGROUND

Many countries have recorded the trends of food allergy (FA) prevalence. Little is known about epidemiologic trends of childhood FA in China.

METHODS

In three cross-sectional surveys conducted in 1999, 2009, and 2019, the prevalence of and characteristic changes in FA in children aged ≤ 2 years were assessed and the outcomes were compared. All the children were recruited during well-baby check-ups at the Children's Hospital of Chongqing Medical University. All participants had a detailed medical history taken and underwent skin prick tests using ten commercial food extracts. Open food challenges were used for confirmation of FA.

RESULTS

The three studies included 1228 children (314 in 1999, 401 in 2009, and 513 in 2019; response rate > 95%). The prevalence of FA in 2009 (7.7%) and 2019 (11.1%) was significantly higher than that in 1999 (3.5%). However, there was no statistically significant difference in prevalence between 2009 and 2019 (P = .086). There was evidence of increased prevalence in CMPA between 1999 and 2019 (1.6% versus 5.7%; P = .004). However, no statistic difference was found in egg allergy (2.9% versus 5.5%; P = .21). The incidence of skin symptoms did not differ significantly over the study period, while the incidence of gastrointestinal symptoms increased significantly (18.2% in 1999, 12.9% in 2009, and 43.9% in 2019; P < .05).

CONCLUSIONS

The prevalence of FA in children rapidly increased after the 1990s and gradually stabilized after 2010. Cow's milk has become the most common food allergen among children in Chongqing. The incidence of gastrointestinal symptoms as a manifestation of FA has increased significantly since 2010.

Effect of Processing on Fish Protein Antigenicity and Allergenicity

Fish allergy is a life-long food allergy whose prevalence is affected by many demographic factors. Currently, there is no cure for fish allergy, which can only be managed by strict avoidance of fish in the diet. According to the WHO/IUIS Allergen Nomenclature Sub-Committee, 12 fish proteins are recognized as allergens. Different processing (thermal and non-thermal) techniques are applied to fish and fishery products to reduce microorganisms, extend shelf life, and alter organoleptic/nutritional properties. In this concise review, the development of a consistent terminology for studying food protein immunogenicity, antigenicity, and allergenicity is proposed. It also summarizes that food processing may lead to a decrease, no change, or even increase in fish antigenicity and allergenicity due to the change of protein solubility, protein denaturation, and the modification of linear or conformational epitopes. Recent studies investigated the effect of processing on fish antigenicity/allergenicity and were mainly conducted on commonly consumed fish species and major fish allergens using in vitro methods. Future research areas such as novel fish species/allergens and ex vivo/in vivo evaluation methods would convey a comprehensive view of the relationship between processing and fish allergy.

IgE-mediated food allergy throughout life

Food allergy (FA) has become an increasing problem throughout the world. Over the last 2 decades, the frequency of FA has increased in both children and adults. The prevalence differs according to the research methodology, age, and geographic regions, ranging between 2.0% and 10.0%. The most common form of FA is immunoglobulin E (IgE)-mediated FA. In this form, patients may present with life-threatening conditions, such as anaphylaxis, or milder conditions, such as urticaria, angioedema, sneezing, and nausea alone. The gold standard in the diagnosis of FA is oral provocation tests. Epidermal skin prick tests and specific IgE measurements, as well as component-resolved diagnostic techniques are helpful in the diagnosis and follow-up of patients. In this review, the epidemiology, diagnosis, follow-up, and prognosis of IgE-mediated FA in children and adults were discussed and some specific forms of FA, such as pollen FA syndrome, alpha-gal allergy, and food-dependent exercise-induced anaphylaxis were explained.

Burden and socioeconomics of asthma, allergic rhinitis, atopic dermatitis and food allergy

INTRODUCTION

Asthma, allergic rhinitis, atopic dermatitis, and food allergy affect approximately 20% of the global population. Few studies describe the burden of the totality of these diseases and only a handful studies provide a comprehensive overview of the socioeconomic impact of these diseases.

AREAS COVERED

For this narrative review, we searched Pubmed using selected keywords and inspected relevant references using a snowballing process. We provide an overview of the socioeconomic burden of allergic diseases (in particular, asthma, allergic rhinitis, atopic dermatitis, and food allergy). The focus of this review is on their epidemiology (incidence, prevalence), burden (disability-adjusted life years, quality of life), and direct and indirect costs (absenteeism and presenteeism). We have put special emphasis on differences between countries.

EXPERT COMMENTARY

Both the prevalence and the burden of allergic diseases are considerable with prevalence varying between 1% and 20%. We identified a plethora of studies on asthma, but studies were generally difficult to compare due to the heterogeneity in measures used. There were only few studies on the burden of food allergy; therefore, more studies on this allergy are required. For future studies, we recommend standardizing epidemiologic, socioeconomic impact, and quality of life measures of allergic diseases.

Current Trends in Proteomic Advances for Food Allergen Analysis

Food allergies are a global food challenge. For correct food labelling, the detection and quantification of allergens are necessary. However, novel product formulations and industrial processes produce new scenarios, which require much more technological developments. For this purpose, OMICS technologies, especially proteomics, seemed to be relevant in this context. This review summarises the current knowledge and studies that used proteomics to study food allergens. In the case of the allergenic proteins, a wide variety of isoforms, post-translational modifications and other structural changes during food processing can increase or decrease the allergenicity. Most of the plant-based food allergens are proteins with biological functions involved in storage, structure, and plant defence. The allergenicity of these proteins could be increased by the presence of heavy metals, air pollution, and pesticides. Targeted proteomics like selected/multiple reaction monitoring (SRM/MRM) have been very useful, especially in the case of gluten from wheat, rye and barley, and allergens from lentil, soy, and fruit. Conventional 1D and 2-DE immunoblotting have been further widely used. For animal-based food allergens, the widely used technologies are 1D and 2-DE immunoblotting followed by MALDI-TOF/TOF, and more recently LC-MS/MS, which is becoming useful to assess egg, fish, or milk allergens. The detection and quantification of allergenic proteins using mass spectrometry-based proteomics are promising and would contribute to greater accuracy, therefore improving consumer information.

Prevalence of IgE-mediated sensitization in patients with suspected food allergic reactions in Jordan

Background

Despite the recognition of food allergies as a significant cause of morbidity and a growing public health burden worldwide, there are no epidemiological studies addressing food sensitization and allergy in Jordan.

Objective

To conduct an epidemiological study that retrospectively analyzes sensitization data from 3463 patients with suspected immunoglobulin E (IgE)‐mediated food allergic reactions who performed specific IgE tests in our laboratories in Jordan.

Methods

Specific IgE (s‐IgE) tests were analyzed for patients who performed enzyme allegro‐sorbent testing based on either self‐reported food allergy or upon physician's request.

Results

2.3% of the analyzed samples were cross‐reactive to carbohydrate determinants. A quarter of the patients were sensitized to one or more food allergens, with males having higher odds of being s‐IgE positive. Furthermore, a higher prevalence of sensitization was seen in infants and children compared with adults. s‐IgE was most frequently found against cow milk (11.2%), pistachio (4.9%), soybean (4.6%), cherry (4.4%), and orange (4.4%). Interestingly, the s‐IgE class distribution profile of pistachio differed from the rest of the top hits being skewed away from the weak class 1 leaning more towards higher IgE classes. Food allergen sensitization was age group‐dependent: milk, tree nuts, and eggs were the main food groups causing sensitization in infants, while it was fruits followed by milk in children and adults.

Conclusions

Our work represents the first epidemiological study addressing food sensitization in Jordan. This study lays a solid foundation for future studies that can help better guide food allergy diagnosis, patient dietary modifications, and food elimination plans, as well as assist decision‐makers in the region to develop national strategies for an efficient and sustainable healthcare system.

Untargeted metabolomic profiling identifies disease-specific signatures in food allergy and asthma

BACKGROUND

Food allergy (FA) affects an increasing proportion of children for reasons that remain obscure. Novel disease biomarkers and curative treatment options are strongly needed.

OBJECTIVE

We sought to apply untargeted metabolomic profiling to identify pathogenic mechanisms and candidate disease biomarkers in patients with FA.

METHODS

Mass spectrometry-based untargeted metabolomic profiling was performed on serum samples of children with either FA alone, asthma alone, or both FA and asthma, as well as healthy pediatric control subjects.

RESULTS

In this pilot study patients with FA exhibited a disease-specific metabolomic signature compared with both control subjects and asthmatic patients. In particular, FA was uniquely associated with a marked decrease in sphingolipid levels, as well as levels of a number of other lipid metabolites, in the face of normal frequencies of circulating natural killer T cells. Specific comparison of patients with FA and asthmatic patients revealed differences in the microbiota-sensitive aromatic amino acid and secondary bile acid metabolism. Children with both FA and asthma exhibited a metabolomic profile that aligned with that of FA alone but not asthma. Among children with FA, the history of severe systemic reactions and the presence of multiple FAs were associated with changes in levels of tryptophan metabolites, eicosanoids, plasmalogens, and fatty acids.

CONCLUSIONS

Children with FA have a disease-specific metabolomic profile that is informative of disease mechanisms and severity and that dominates in the presence of asthma. Lower levels of sphingolipids and ceramides and other metabolomic alterations observed in children with FA might reflect the interplay between an altered microbiota and immune cell subsets in the gut.

Epidemiology and Burden of Food Allergy

PURPOSE OF REVIEW

In recent decades, food allergy has become an increasing concern for families, clinicians, and policymakers. This review aims to summarize what is currently known about the epidemiology and population-level burden of IgE-mediated food allergy, including its effects on quality of life.

RECENT FINDINGS

Prevalence surveys, healthcare utilization data, and findings from longitudinal cohort studies across the globe indicate that food allergy imposes a growing societal burden. Worryingly, recent data indicate that food allergies may be more prevalent among adult populations than previously acknowledged, with many reported cases of adult-onset allergies. While it remains unclear how much of the current population-level burden of disease results from true, IgE-mediated allergy, as much epidemiological data does not incorporate clinical confirmation of disease prevalence-it is clear that affected individuals suffer impairments in their quality of life and incur substantial economic costs-beyond the physical health burden imposed by anaphylaxis.

Food Allergy in Adults: Presentations, Evaluation, and Treatment

Food allergy presents in all ages and has a significant impact on an individual's quality of life. Some of the food allergies that start in childhood remain into adulthood and new-onset allergies can occur at any point of life. Health care providers caring for adult patients should be aware of various food allergy presentations and syndromes. In this article, the authors cover recent literature on food allergies in adults and discuss the epidemiology of adult food allergy as well as common clinical scenarios and presentations of various types of food allergies.

Prevalence and risk factors for food allergy in older people: protocol for a systematic review

INTRODUCTION

Studies suggest that the prevalence of food allergy may be increasing worldwide. Results regarding the prevalence and features of adverse food reactions older people have, however, scarcely been analysed in the literature. Thus, the objective of the present systematic review will be to describe the prevalence of food allergy in older individuals, its risk factors, clinical features, as well as the most frequently and commonly involved foods.

METHODS AND ANALYSIS

We will conduct a systematic review and meta-analysis of the incidence, prevalence and risk factors for food allergy in older individuals. We will search international electronic databases including MEDLINE, EMBASE, Cochrane Library, CINAHL, AMED and ISI Web of Science for published, unpublished and ongoing studies from 1980 toJanuary 2019. There will be no restriction on the language or geography of publication. We will use the critical appraisal skills programme quality assessment tool to appraise the methodological quality of included studies. A descriptive summary with data tables will be elaborated, and if deemed clinically relevant and statistically adequate, meta-analysis using random-effects modelling will be carried out, given the expected clinical, methodological and statistical heterogeneity of studies. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist will guide reporting of the systematic review.

ETHICS AND DISSEMINATION

Since this systematic review will be solely based on published and retrievable literature, no ethics approval will be obtained. This study will allow us to draw up-to-date estimates of the prevalence of adverse food reactions in older individuals, worldwide, besides allowing the identification of its major risk factors, clinical manifestations and predominant foods responsible for such reactions. A multidisciplinary team has been assembled for this systematic review and will participate in relevant dissemination activities, namely reports, publications and presentations.

PROSPERO REGISTRATION NUMBER

CRD42018102140.

Self-reported hypersensitivity and allergy to foods amongst Mexican adolescents: Prevalence and associated factors

BACKGROUND

The prevalence of food allergy is on the rise on a global scale.

OBJECTIVE

To determine the prevalence of food hypersensitivity (FHS) and probable food allergy (PFA), as well as the foods and factors associated with these occurrences.

METHODS

A cross-sectional study was carried out among 1992 adolescents (aged 15-18 years). Each adolescent answered a structured questionnaire. A multivariate analysis was used to identify the association between the variables.

RESULTS

The prevalence of FHS was 10.6% (the most commonly associated foods were shrimp, cow's milk and avocado) and the PFA was 7.8% (shrimp, cow's milk and pecan). The prevalences of oral allergy syndrome, food-associated urticaria and systemic reaction were 4.9%, 3.6% and 1.5%, respectively. The following factors were associated with FHS: personal history of asthma (OR 1.63; 95% CI: 1.11-2.41), allergic rhinitis (OR 2.60; 95% CI: 1.75-3.87), atopic dermatitis (OR 2.07; 95% CI: 1.25-3.43), maternal history of asthma (OR 1.80; 95% CI: 1.02-3.16), atopic dermatitis (OR 6.11; 95% CI: 2.45-15.29), and female sex (OR 1.89; 95% CI: 1.38-2.59). PFA was associated with a personal history of asthma (OR 1.65; 95% CI: 1.06-2.56), allergic rhinitis (OR 2.46; 95% CI: 1.56-3.88), atopic dermatitis (OR 2.02; 95% CI: 1.15-3.54), paternal allergic rhinitis (OR 2.52; 95% CI: 1.15-5.51), maternal atopic dermatitis (OR 7.46; 95% CI: 2.93-19.00), and female sex (OR 1.89; 95% CI: 1.31-2.72).

CONCLUSION

The adverse reactions associated with foods among late adolescents are a frequent occurrence, and the most commonly associated factor is atopy.

Prevalence of food hypersensitivity in relation to IgE sensitisation to common food allergens among the general adult population in West Sweden

Background

The prevalence of self-experienced adverse reactions to foods seems to have an increasing trend in both adults and children. However, it is unclear if the prevalence of food hypersensitivity in the Swedish adult population is still rising, what symptoms are caused by different foods and which are the most common foods to which adults are more frequently IgE-sensitised.

Methods

In a cross-sectional study based on questionnaire responses, interviews and clinical examinations as part of the West Sweden Asthma Study, 1042 subjects from the general population, 17–78 years of age, living in Västra Götaland, Sweden, were included. The subjects reported symptoms for 56 specified foods and blood samples were taken to examine the IgE-sensitisation pattern for 9 common foods.

Results

Approximately 32% of adults reported food hypersensitivity, affecting mostly women and subjects less than 61 years old. The foods most often reported to cause adverse reactions were hazelnut (8.9%), apple (8.4%), milk (7.4%) and kiwi (7.3%). Less than one percent (0.9%) reported symptoms from ingestion of meat. Symptoms mostly affected the gastrointestinal tract (15%) and the skin (2.7%). Sixteen per cent were IgE-sensitised to common foods, most often to hazelnut (13.3%), peanut (4.9%) and almond (3.0%), while 5.9% reported symptoms and were IgE-sensitised to the same food, mainly to hazelnut (5.3%).

Conclusions

The prevalence of self-reported food hypersensitivity in West Sweden indicates a rising trend. The correspondence between self-reported symptoms and IgE-sensitisation to foods is generally poor, except for hazelnut and almond which exhibit moderate or fair correlation.

Food Allergen Sensitisation Patterns in Omani Patients with Allergic Manifestations

Objectives

This study aimed to evaluate the relationship between food allergen sensitisation patterns and allergic manifestations in Omani patients and highlight the importance of specific immunoglobulin E (IgE) testing.

Methods

This retrospective study included all patients referred due to allergic manifestations to the Sultan Qaboos University Hospital (SQUH), Muscat, Oman, from November 2012 to November 2016. Specific IgE blood testing was performed to determine sensitisation to common foods known to cause allergic reactions.

Results

A total of 164 patients were referred to SQUH over the study period, with 35.4% presenting with one allergic manifestation, 48.8% with 2-3 and 15.9% presenting with more than three manifestations. There was a family history of allergies in 70.7% of patients. Eosinophil counts and total and specific IgE levels were elevated in 18.9%, 54.9% and 73.2% of patients, respectively. Patients demonstrated sensitisation to cow milk (47.6%), wheat (41.5%), chicken eggs (34.8%), mixed tree nuts (34.1%), lentils (33.5%), peanuts (32.9%), soy (32.3%), shrimp (23.2%) and fish (15.2%). Overall, 19.5% were sensitised to a single allergen, 14% were sensitised to 2-3 and 39.6% were sensitised to more than three allergens. Almost one-third (29.3%) of patients suffered from food-induced anaphylaxis, of which 85.4% were prescribed self-injectable adrenaline.

Conclusion

To the best of the authors' knowledge, this study is the first to describe food allergen sensitisation patterns among Omani patients with allergic manifestations. In conjunction with clinical symptoms, the correct interpretation of specific IgE levels is important to diagnose food allergies and make safe decisions about reintroducing foods.

Population based study: atopy and autoimmune diseases are associated with functional dyspepsia and irritable bowel syndrome, independent of psychological distress

BACKGROUND

The pathogenesis of functional GI disorders (FGIDs) is uncertain. However, underlying immune activation and psychological distress has been documented in irritable bowel syndrome (IBS) and functional dyspepsia (FD). Epidemiological data from the UK suggest that FGIDs are linked to atopy and certain autoimmune diseases but this has not been confirmed.

AIM

To test if allergic or autoimmune diseases are independently associated with FGIDs, irrespective of psychological distress in a large population based study.

METHODS

A total of 3542 people (mean age 57.9 years and 52.7% females) randomly selected from the Australian population, returned a mail survey (response rate = 43%). The survey asked about a physician diagnosis of autoimmune disease (scleroderma, psoriasis, rheumatoid arthritis and diabetes mellitus) or allergic conditions (asthma, food, pollen and/or animal allergy). The questionnaire assessed psychological distress and Rome III criteria for FD and IBS.

RESULTS

Asthma, food, pollen and animal allergies, psoriasis and rheumatoid arthritis were univariately significantly associated with IBS and FD. Food allergy (OR = 1.66; 95% CI = 1.15-2.40, P = 0.007), psoriasis (OR = 1.81; 95% CI = 1.19-2.74, P = 0.006) and rheumatoid arthritis (OR = 1.68; 95% CI = 1.15-2.4, P = 0.007) were independent risk factors for IBS, controlling for age, gender and psychological distress. In FD, asthma (OR = 1.32; 95% CI = 1.04-1.68, P = 0.025) and food allergy (OR = 1.78; 95% CI = 1.28-2.49, P = 0.001) were independent predictors, controlling for age, sex and psychological distress.

CONCLUSIONS

There is evidence that both atopic and autoimmune diseases are risk factors for FGIDs, independent of psychological distress, differing in IBS and FD. This provides evidence that different peripheral pathways may be involved in the pathogenesis of certain FGIDs.

Current knowledge and interest of French Canadians regarding nutrigenetics

Objective

The purpose of this study was to draw a global portrait of the current knowledge and interest regarding nutrigenetics in a population of French Canadians from the province of Quebec (Canada).

Methods

A total of 2238 residents from the province of Quebec, Canada, were recruited via social networks and from the Laval University employee/student lists to participate in a 37-question online survey on nutrigenetics.

Results

Most participants were not familiar with the term “nutrigenetics” (82.7%). Participants with good genetic literacy (26.8%) were less interested in nutrigenetic testing (p < 0.0001). The vast majority of participants (90.7%) reported to be willing to follow a personalised diet based on nutrigenetic testing, especially if they came to know themselves as carriers of a polymorphism increasing the risk of certain diseases. Participants had a higher interest in testing related to metabolic response to macronutrients (types of sugars, fats and proteins) than to micronutrients or other nutrients related to food intolerance.

Conclusions

The attitude of French Canadians about nutrigenetics is very consistent with the results from other surveys published in the literature. Although few individuals are familiar with nutrigenetics, the public’s attitude towards nutrigenetics is globally favourable.

Electronic supplementary material

The online version of this article (10.1186/s12263-019-0629-7) contains supplementary material, which is available to authorized users.

Prevalence and Severity of Food Allergies Among US Adults

IMPORTANCE

Food allergy is a costly, potentially life-threatening condition. Although studies have examined the prevalence of childhood food allergy, little is known about prevalence, severity, or health care utilization related to food allergies among US adults.

OBJECTIVE

To provide nationally representative estimates of the distribution, severity, and factors associated with adult food allergies.

DESIGN, SETTING, AND PARTICIPANTS

In this cross-sectional survey study of US adults, surveys were administered via the internet and telephone from October 9, 2015, to September 18, 2016. Participants were first recruited from NORC at the University of Chicago's probability-based AmeriSpeak panel, and additional participants were recruited from the non-probability-based Survey Sampling International (SSI) panel.

EXPOSURES

Demographic and allergic participant characteristics.

MAIN OUTCOMES AND MEASURES

Self-reported food allergies were the main outcome and were considered convincing if reported symptoms to specific allergens were consistent with IgE-mediated reactions. Diagnosis history to specific allergens and food allergy-related health care use were also primary outcomes. Estimates were based on this nationally representative sample using small-area estimation and iterative proportional fitting methods. To increase precision, AmeriSpeak data were augmented by calibration-weighted, non-probability-based responses from SSI.

RESULTS

Surveys were completed by 40 443 adults (mean [SD] age, 46.6 [20.2] years), with a survey completion rate of 51.2% observed among AmeriSpeak panelists (n = 7210) and 5.5% among SSI panelists (n = 33 233). Estimated convincing food allergy prevalence among US adults was 10.8% (95% CI, 10.4%-11.1%), although 19.0% (95% CI, 18.5%-19.5%) of adults self-reported a food allergy. The most common allergies were shellfish (2.9%; 95% CI, 2.7%-3.1%), milk (1.9%; 95% CI, 1.8%-2.1%), peanut (1.8%; 95% CI, 1.7%-1.9%), tree nut (1.2%; 95% CI, 1.1%-1.3%), and fin fish (0.9%; 95% CI, 0.8%-1.0%). Among food-allergic adults, 51.1% (95% CI, 49.3%-52.9%) experienced a severe food allergy reaction, 45.3% (95% CI, 43.6%-47.1%) were allergic to multiple foods, and 48.0% (95% CI, 46.2%-49.7%) developed food allergies as an adult. Regarding health care utilization, 24.0% (95% CI, 22.6%-25.4%) reported a current epinephrine prescription, and 38.3% (95% CI, 36.7%-40.0%) reported at least 1 food allergy-related lifetime emergency department visit.

CONCLUSIONS AND RELEVANCE

These data suggest that at least 10.8% (>26 million) of US adults are food allergic, whereas nearly 19% of adults believe that they have a food allergy. Consequently, these findings suggest that it is crucial that adults with suspected food allergy receive appropriate confirmatory testing and counseling to ensure food is not unnecessarily avoided and quality of life is not unduly impaired.

Impact of Food Immunoglobulin G-Based Elimination Diet on Subsequent Food Immunoglobulin G and Quality of Life in Overweight/Obese Adults

OBJECTIVES

The goal of this study was to assess changes in serum immunoglobulin G (IgG) food antibody titers and quality-of-life measurements following a targeted elimination diet in overweight/obese adults.

METHODS

We performed a randomized control trial. Participants were randomized in a 2:1 ratio to either an intervention group or waitlist group for 3 months. Food IgG testing was performed on all participants. The intervention group was instructed to eliminate up to 10 foods, for which they had high titers of IgG and communicated with health coaches for nutritional counseling for meal planning and adherence. The waitlist group did not receive their IgG testing results or health coaching. Primary outcome was serum IgG titers for foods eliminated during the trial, compared with baseline concentrations. Secondary outcomes were health-related quality of life measured by Patient-Reported Outcomes Measurement Information System (PROMIS-29) and change in participant-identified symptom severity measured by Measure Yourself Medical Outcome Profile. Exploratory outcomes were changes in body weight and waist circumference.

RESULTS

IgG antibody concentrations decreased in 83% of the targeted foods in the treatment group and in 60% of the foods in the waitlist group, but this was not found to be a statistically significant difference. The intervention group reported improvement in sleep during the trial compared with waitlist, which was the only statistically significant finding in the study.

CONCLUSIONS

The findings are consistent with changes in IgG titer measurements following an elimination diet based on IgG testing. Future larger clinical trials are necessary to determine the degree to which these findings are generalizable.

Regional and National Variations in Reasons for Gluten Avoidance

BACKGROUND

Although studies have assessed the prevalence of celiac disease (CD), less is known about the prevalence of gluten avoidance because of nonceliac gluten sensitivity (GS). The avoidance of foods other than gluten is also understudied in these 2 groups.

METHODS

Participants visiting a web site for information about a newly developed portable gluten detection device (Nima) were instructed to complete questions about food and gluten avoidance patterns. We assessed the relative proportion of CD and GS across world regions and United States (US) regions and determined the distribution of food avoidance patterns.

RESULTS

CD was reported in 6474 respondents and GS in 2597 respondents. Within the United States, the majority of avoiders of gluten reported having CD (69.8%), with the highest ratio of CD to GS in the Northeast (CD: 74.3%; GS: 25.7%) and the lowest in the West (CD: 67.1%; GS: 32.9%) (P<0.0001). Compared with the United States, all other countries had lower proportions of GS, with the lowest in Argentina (CD: 94.7%; GS: 5.3%; P<0.0001). Food avoidances other than gluten were reported by 25% of respondents, with avoidance in all categories more common in GS than CD (P<0.0001).

CONCLUSION

There is a significant difference in the relative rates of CD and GS within the United States and worldwide. Food avoidance other than gluten seems to be a more common component of GS than CD. Future research should focus on the causes of these international and US regional differences and the significance of other food avoidances.

Prevalence of food allergy in Vietnam: comparison of web-based with traditional paper-based survey

Background

Web-based surveys (WBS) are increasingly applied in epidemiological studies as an appealing alternative to traditional survey methods. Rapid data collection, reduced expenditure and ease of access to large populations are some of the clear advantages of online surveys. However, WBS are still subject to limitations in terms of sample size, response rate and other additional biases compared to traditional survey methods. In the present study, we seek to validate data on food allergy (FA) in two independent sample populations collected from a WBS, and compare it to a paper-based survey (PBS).

Methods

Data collected from two survey modes were compared by hypothesis testing for independent sample population. The WBS included 1185 respondents, while the PBS included 9039 respondents.

Results

Overall, the data from the WBS were comparable to the PBS conducted over the same period of time in Vietnamese adults. There were no effects of different survey modes on the lifetime prevalence of doctor-diagnosed FA (5.7%; P = 0.7795, β = 0.05) and IgE-mediated FA (5.8%; P = 0.9590, β = 0.05). Both surveys showed the dominance of seafood allergy in this population (up to 2.6%), followed by beef allergy. Close correlation was seen in the patterns of FAs and different clinical symptoms. The contribution of family history of allergic diseases and place of residence to FA were confirmed in both surveys.

Conclusions

The consistency of the WBS results with the PBS indicates a promising application of online surveys as an economic and validated model for future epidemiological studies, specifically in developing countries.

Electronic supplementary material

The online version of this article (10.1186/s40413-018-0195-2) contains supplementary material, which is available to authorized users.

Barriers to self-management behaviors in college students with food allergies

OBJECTIVE

This study examined barriers to engagement in self-management behaviors among food-allergic college students (1) within the frameworks of the health belief model (HBM) and common sense self-regulation model (CS-SRM) and (2) in the context of overall risky behaviors.

PARTICIPANTS

Undergraduate college students who reported having a physician-diagnosed food allergy (N = 141). Research was conducted from February 2015 through May 2016.

METHODS

Participants were recruited from college campuses through email and social media. The frequency of adherence to self-management behaviors was measured along with HBM, CS-SRM, and risk-taking behaviors through a self-report survey.

RESULTS

Among all participants, HBM and CS-SRM constructs and Tobacco Use explained 30.6% of the variance in adherence. CS-SRM constructs and Tobacco Use explained 44.8% of the variance for participants with self-injectable epinephrine (SIE).

CONCLUSIONS

Food-allergic college students demonstrate inconsistent adherence, and interventions designed to improve adherence should take both SIE prescription status and contextual factors into consideration.

Epinephrine auto-injector carriage and use practices among US children, adolescents, and adults

BACKGROUND

Previous studies have suggested that epinephrine auto-injector (EAI) carriage and emergency use practices could be suboptimal for patients prescribed these devices for anaphylaxis management.

OBJECTIVE

To characterize EAI prescription fill rates, carriage, and use practices and associated factors and perceived barriers to recommended anaphylaxis management behaviors in US children, adolescents, and adults.

METHODS

Survey data were collected for adults (n = 450) and parents of children (n = 255) and adolescents (n = 212) who had been prescribed an EAI. Of eligible participants, survey completion rates were higher than 90%. A multiple-group structural equation model was fit to test adjusted associations.

RESULTS

Most patients (89%) filled their EAI prescriptions; however, of those who did not, the most commonly cited barriers to filling prescriptions were no history of reactions (26%) and EAI cost (25%). Forty-four percent carried at least 1 EAI "all the time" and 24% carried multiple EAIs. Sixty-five percent of respondents reported a personal history of EAI use. Most adults (52%) reported that an EAI was not used, although it would have been beneficial during their most severe allergic reaction. The most frequently given reasons for not using an EAI among respondents owning one were that an EAI was not available (45%) followed by their allergy was undiagnosed at the time (35%). To improve clinical anaphylaxis management, 61% of patients desired more effective patient education and 47% desired more time dedicated to patient education during the physician visit.

CONCLUSION

These data suggest that current anaphylaxis management practices are suboptimal but could be facilitated through lowering EAI-related out-of-pocket costs and improving patient education efforts.

Prevalence of Self-Reported Food Allergy in Six Regions of Inner Mongolia, Northern China: A Population-Based Survey

Background

The aim of this study was to determine the prevalence of self-reported food allergy in 6 regions of Inner Mongolia, northern China.

Material/Methods

A random cluster sampling population study using a field questionnaire was distributed to 4714 individuals in 6 regions within Inner Mongolia, northern China; the study included ethnic Mongol minorities and Chinese Han populations. The questionnaire obtained data on ethnicity, age, sex, level of education, income, socioeconomic status, rural versus urban location, medical and family history, and food allergy.

Results

There were 4441 (73.5%) completed questionnaires. The prevalence of self-reported food allergy was 18.0% (15.2% men; 20.6% women) and was age-related, being significantly greater in children compared with adults (38.7% vs. 11.9%) (P<0.001). There was a significant difference in self-reported food allergy between rural and urban populations (14.6% vs. 21.4%) (P<0.001) and between Mongolian and Han populations (20.8% vs. 15.8%) (P<0.001). Socioeconomic status, higher education level, and increased family income were significantly correlated with the prevalence of food allergy (P<0.001). Participants with allergic diseases and atopic family history were at increased risk (OR>1, P<0.001). There were no significant associations between the prevalence of food allergy and birth history, infant feeding, and duration of breastfeeding.

Conclusions

An increase in the prevalence of self-reported food allergy was found in the Inner Mongolia region of northern China, which was greater in urban areas compared with rural areas.

Genome-wide association study of self-reported food reactions in Japanese identifies shrimp and peach specific loci in the HLA-DR/DQ gene region

Food allergy is an increasingly important health problem in the world. Several genome-wide association studies (GWAS) focused on European ancestry samples have identified food allergy-specific loci in the HLA class II region. We conducted GWAS of self-reported reactivity with common foods using the data from 11011 Japanese women and identified shrimp and peach allergy-specific loci in the HLA-DR/DQ gene region tagged by rs74995702 (P = 6.30 × 10⁻¹⁷, OR = 1.91) and rs28359884 (P = 2.3 × 10⁻¹², OR = 1.80), respectively. After HLA imputation using a Japanese population-specific reference, the most strongly associated haplotype was HLA-DRB1*04:05-HLA-DQB1*04:01 for shrimp allergy (P = 3.92 × 10⁻¹⁹, OR = 1.99) and HLA-DRB1*09:01-HLA-DQB1*03:03 for peach allergy (P = 1.15 × 10⁻⁷, OR = 1.68). Additionally, both allergies’ associated variants were eQTLs for several HLA genes, with HLA-DQA2 the single eQTL gene shared between the two traits. Our study suggests that allergy to certain foods may be related to genetic differences that tag both HLA alleles having particular epitope binding specificities as well as variants modulating expression of particular HLA genes. Investigating this further could increase our understanding of food allergy aetiology and potentially lead to better therapeutic strategies for allergen immunotherapies.

Self-reported prevalence of clinical features of allergy to nuts and seeds, and seafood in university students

Background

In developing countries, there is a lack of epidemiological information related to food hypersensitivity, including nuts and seafood.

Objective

The aim was to determine the prevalence of allergic reactions and clinical manifestations associated with the consumption of nuts and seeds or seafood in university students.

Methods

We designed an observational cross-sectional study. A structured questionnaire was applied to Mexican university students to identify allergic reactions associated with the consumption of nuts and seeds, and seafood.

Results

A sample of 1,200 students was included; mean age of 19.7 ± 1.7 years. Prevalence of symptoms associated with the consumption of nuts and seeds, and seafood were 2.8% (33 of 1,200) and 3.5% (42 of 1,200) respectively. The main clinical manifestations were abdominal pain (63.6% in nuts and seeds), flushing (50% in seafood), and pharyngeal oppression (19% in seafood). Prevalence of perceived, probable and systemic allergy to nuts and seeds was 2.8% (95% confidence interval [CI], 2.5%–3.0%), 0.8% (95% CI, 0.3%–1.3%) and 0.2% (95% CI, 0%–0.4%) respectively. On the other hand, the prevalence (perceived, probable, and systemic) associated with seafood consumption was 3.5% (95% CI, 2.5%–4.5%), 1.8% (95% CI, 1.0%–2.5%), and 0.5% (95% CI, 0.1%–0.9%). Walnut and shrimp were the most frequently reported foods.

Conclusion

For every 100 Mexican university students, approximately 3 or 4 perceived to have allergy attributed to the consumption of some nuts and seeds or seafood, while 1 or 2 students would have a probable reaction to this same type of food. Walnut and shrimp would be causing the higher quantity of food allergic reactions.

Food allergy: is prevalence increasing?

It is generally accepted that the prevalence of food allergy has been increasing in recent decades, particularly in westernised countries, yet high-quality evidence that is based on challenge confirmed diagnosis of food allergy to support this assumption is lacking because of the high cost and potential risks associated with conducting food challenges in large populations. Accepting this caveat, the use of surrogate markers for diagnosis of food allergy (such as nationwide data on hospital admissions for food anaphylaxis or clinical history in combination with allergen-specific IgE (sIgE) measurement in population-based cohorts) has provided consistent evidence for increasing prevalence of food allergy at least in western countries, such as the UK, United States and Australia. Recent reports that children of East Asian or African ethnicity who are raised in a western environment (Australia and United States respectively) have an increased risk of developing food allergy compared with resident Caucasian children suggest that food allergy might also increase across Asian and African countries as their economies grow and populations adopt a more westernised lifestyle. Given that many cases of food allergy persist, mathematical principles would predict a continued increase in food allergy prevalence in the short to medium term until such time as an effective treatment is identified to allow the rate of disease resolution to be equal to or greater than the rate of new cases.

Comparing immediate-type food allergy in humans and companion animals-revealing unmet needs

Adverse food reactions occur in human as well as veterinary patients. Systematic comparison may lead to improved recommendations for prevention and treatment in both. In this position paper, we summarize the current knowledge on immediate-type food allergy vs other food adverse reactions in companion animals, and compare this to the human situation. While the prevalence of food allergy in humans has been well studied for some allergens, this remains to be investigated for animal patients, where owner-reported as well as veterinarian-diagnosed food adverse reactions are on the increase. The characteristics of the disease in humans vs dogs, cats, and horses are most often caused by similar, but sometimes species-dependent different pathophysiological mechanisms, prompting the specific clinical symptoms, diagnoses, and treatments. Furthermore, little is known about the allergen molecules causative for type I food allergy in animals, which, like in human patients, could represent predictive biomarkers for risk evaluation. The definite diagnosis of food allergy relies-as in humans-on elimination diet and provocation tests. Besides allergen avoidance in daily practice, novel treatment options and tolerization strategies are underway. Taken together, numerous knowledge gaps were identified in veterinary food allergy, which need to be filled by systematic comparative studies.