Confirmed prevalence of food allergy and non-allergic food hypersensitivity in a Mediterranean population

Milk-induced anaphylaxis among children presenting to Canadian emergency departments

BACKGROUND

Cow's milk is one of the most common and burdensome allergens in pediatrics, and it can induce severe anaphylactic reactions in children. However, data on cow's milk-induced anaphylaxis are sparse.

OBJECTIVE

To describe the epidemiology of pediatric cow's milk-induced anaphylaxis and to determine risk factors for repeat emergency department (ED) epinephrine administration.

METHODS

Between April 2011 and May 2023, data were collected on children with anaphylaxis presenting to 10 Canadian EDs. A standardized form documenting symptoms, triggers, treatment, and outcome was used. Multivariate logistic regression was used.

RESULTS

Of 3118 anaphylactic reactions, 319 milk-induced anaphylaxis cases were identified (10%). In the prehospital setting, 54% of patients with milk-induced anaphylaxis received intramuscular epinephrine. In those with milk-induced anaphylaxis, receiving epinephrine before presenting to the ED was associated with a reduced risk of requiring 2 or more epinephrine doses in the ED (adjusted odds ratio, 0.95 [95% CI, 0.90-0.99]). Children younger than 5 years of age were more likely to experience a mild reaction compared with that in older children, who experienced a moderate reaction more often (P < .0001). Compared with other forms of food-induced anaphylaxis, children presenting with milk-induced anaphylaxis were younger; a greater proportion experienced wheezing and vomiting, and less experienced angioedema.

CONCLUSION

Prehospital epinephrine in pediatric milk-induced anaphylaxis is underused; however, it may decrease risk of requiring 2 ED epinephrine doses. Milk-induced anaphylaxis in children younger than 5 years of age may be less severe than in older children. Wheezing and vomiting are more prevalent in milk-induced anaphylaxis compared with that of other foods.

Prevalence of tree nut allergy in Europe: A systematic review and meta-analysis

In 2014, the European Academy of Allergy and Clinical Immunology (EAACI) published the first systematic review that summarized the prevalence of food allergy (FA) and food sensitization in Europe for studies published 2000-2012. However, only summary estimates for tree nut allergy (TNA) were feasible in that work. In the current update of that systematic review, we summarized the prevalence of tree nut allergy/sensitization to individual tree nuts. Six databases were searched for relevant papers published 2012-2021 and 17 eligible studies were added to the 15 studies already identified between 2000 and 2012, giving a total of 32 studies. Of the investigated tree nuts, meta-analysis was possible for hazelnut, walnut, almond, and in few cases, for cashew, and Brazil nut. The lifetime self-reported prevalence was 0.8% (95% CI 0.5-1.1) for hazelnut and 0.4% (0.2-0.9) for walnut. The point self-reported prevalence was 4.0% (2.9-5.2) for hazelnut, 3.4% (2.0-4.9) for Brazil nut, 2.0% (1.1-2.9) for almond, and 1.8% (1.1-2.5) for walnut. Point prevalence of food challenge-confirmed TNA was 0.04% (0.0-0.1) for hazelnut and 0.02% (0.01-0.1) for walnut. Due to paucity of data, we could not identify any meaningful and consistent differences across age groups and European regions.

Oral immunotherapy in alpha-gal red meat allergy: Could specific IgE be a potential biomarker in monitoring management?

BACKGROUND

Oral immunotherapy (OIT) is a promising treatment for food allergies. Our aim was to establish the long-term safety and efficacy of a novel red meat (RM) OIT in galactose-alpha-1,3-galactose (alpha-gal) allergy in adults.

METHODS

Out of 20 patients with confirmed RM allergy, five (41.66%) underwent an early OIT, seven (58.33%) underwent a delayed protocol and eight patients who were not desensitized formed the patient control group. 15 and 27 day RM OIT for early-onset and delayed-onset alpha-gal allergy were administered, respectively. Desensitized patients were recommended to continue eating at least 100 g RM every day for 6 months and every other day in the following 6 months. After a year, the consumption was recommended 2/3 times in a week. Patients were followed up with skin tests with commercial beef and lamb extracts, fresh raw/cooked beef and lamb and cetuximab and also with serum alpha-gal specific Immunoglobulin-E (sIgE) in the first and fifth years.

RESULTS

All patients who underwent OIT became tolerant to RM. During the 5 year follow-up, the median alpha-gal sIgE concentration gradually decreased in nine patients who consumed RM uneventfully while remained unchanged in the control group (p = .016). In two patients, rare tick bites acted as inducers of hypersensitivity reactions with concomitant elevation of alpha-gal sIgE concentrations whereas one patient with low follow-up alpha-gal sIgE concentrations consumed RM uneventfully after frequent tick bites.

CONCLUSIONS

Our study showed the long-term safety and efficacy of alpha-gal OIT. Additionally, alpha-gal sIgE seems to be a potential biomarker to monitor OIT.

Prevalence estimates of eight big food allergies in Europe: Updated systematic review and meta-analysis

In 2014, the European Academy of Allergy and Clinical Immunology published prevalence estimates for food allergy (FA) and food sensitization (FS) to the so-called eight big food allergens (i.e. cow's milk, egg, wheat, soy, peanut, tree nuts, fish and shellfish) in Europe for studies published between 2000 and 2012. The current work provides 10-year updated prevalence estimates for these food allergens. A protocol was registered on PROSPERO before starting the research (reference number CRD42021266657). Six databases were searched for studies published 2012-2021, added to studies published up to 2012, resulting in a total of 93 studies. Most studies were graded as at moderate risk of bias. The overall pooled estimates for all age groups of self-reported lifetime prevalence were as follows: cow's milk (5.7%, 95% confidence interval 4.4-6.9), egg (2.4%, 1.8-3.0), wheat (1.6%, 0.9-2.3), soy (0.5%, 0.3-0.7), peanut (1.5%, 1.0-2.1), tree nuts (0.9%, 0.6-1.2), fish (1.4%, 0.8-2.0) and shellfish (0.4%, 0.3-0.6). The point prevalence of food challenge-verified allergy were as follows: cow's milk (0.3%, 0.1-0.5), egg (0.8%, 0.5-1.2), wheat (0.1%, 0.01-0.2), soy (0.3%, 0.1-0.4), peanut (0.1%, 0.0-0.2), tree nuts (0.04%, 0.02-0.1), fish (0.02%, 0.0-0.1) and shellfish (0.1%, 0.0-0.2). With some exceptions, the prevalence of allergy to common foods did not substantially change during the last decade; variations by European regions were observed.

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.

Frequency of food allergy in Europe: An updated systematic review and meta-analysis

Food allergy (FA) is increasingly reported in Europe, however, the latest prevalence estimates were based on studies published a decade ago. The present work provides the most updated estimates of the prevalence and trends of FA in Europe. Databases were searched for studies published between 2012 and 2021, added to studies published up to 2012. In total, 110 studies were included in this update. Most studies were graded as moderate risk of bias. Pooled lifetime and point prevalence of self-reported FA were 19.9% (95% CI 16.6-23.3) and 13.1% (95% CI 11.3-14.8), respectively. The point prevalence of sensitization based on specific IgE (slgE) was 16.6% (95% CI 12.3-20.8), skin prick test (SPT) 5.7% (95% CI 3.9-7.4), and positive food challenge 0.8% (95% CI 0.5-0.9). While lifetime prevalence of self-reported FA and food challenge positivity only slightly changed, the point prevalence of self-reported FA, sIgE and SPT positivity increased from previous estimates. This may reflect a real increase, increased awareness, increased number of foods assessed, or increased number of studies from countries with less data in the first review. Future studies require rigorous designs and implementation of standardized methodology in diagnosing FA, including use of double-blinded placebo-controlled food challenge to minimize potential biases.

Food intolerances in children and adolescents in Switzerland

Adverse food reactions have become an important health concern in pediatrics. There are discrepancies between diagnosed and self-reported food allergies and intolerances, leading to food avoidance with possible psychological and nutritional implications in the latter. There is no data available so far on the number of children and adolescents, who reduce or completely avoid certain foods in their diet. The aim of this study was to determine the prevalence of children and adolescents in the Northwest of Switzerland, who omit foods from their diet because of a self-reported intolerance, as well as the prevalence of children and adolescents who eliminate well-tolerated foods for presumed health reasons. This is a cross-sectional study conducted in the Children's hospitals of Aarau and Basel (Switzerland) and in 4 pediatric private practices. A total of 2036 children and adolescents (54% male and 46% female) between 1 month and 18 years (mean age: 7.4 years) were included, of which 316 (16%) participants reported to avoid foods due to intolerance. Lactose intolerance is the most frequent one. In 55% of all cases, no medical tests had been performed to confirm such an intolerance. Avoiding tolerated foods for presumed health reasons was stated by 251 (12%) participants.  Conclusions: Clinicians should be aware of the high frequency of food avoidance in the pediatric population due to true intolerance, functional diseases, or due to lifestyle reasons. Milk is the most avoided food and half of the affected patients avoid foods without guidance by professional dieticians, therefore risking possible negative impacts on their physical and mental health. Pediatricians should perform further investigations or advise nutritional guidance if an avoidance of foods or specific diets occurs. What is Known: • The prevalence of food intolerances in children and adolescents is unknown. • Eating behavior in children is influenced by the consumption of social media. What is New: • Based on this large cross-sectional study, it was shown that 16% of children and adolescents avoid foods, half of them without any medical advice. • Food avoidance is common among this Swiss cohort of children because of different reasons: lifestyle habits, functional diseases, true intolerances with possible consequences such as micronutrient deficiencies if not properly monitored.

Tree Nut-Induced Anaphylaxis in Canadian Emergency Departments: Rate, Clinical Characteristics and Management

BACKGROUND

Data are sparce regarding tree nut-induced anaphylaxis (TNA).

OBJECTIVE

We aimed to characterize rate, clinical characteristics, and management of TNA in children (0-17 years old) across Canada, and assess factors associated with severe reactions and epinephrine use.

METHODS

Between April 2011 and May 2020, data were collected on children presenting to five emergency departments (EDs) in Canada. Multivariate logistic analysis was used to evaluate factors associated with severe reactions (stridor, cyanosis, circulatory collapse, or hypoxia) and epinephrine use.

RESULTS

Among 3096 cases of anaphylaxis, 540 (17%) were induced by tree nut. The median age was 5.2 years [Interquartile range (IQR): 2.5-9.5] and 65.4% were males. Among all reactions, 7.0% were severe. The major tree nuts accounting for anaphylaxis were cashew (32.8%), hazelnut (20.0%) and walnut (11.5%). Cashew-induced anaphylaxis was more common in British Columbia [14.0% difference (95% CI, 1.6%-27.6%)] versus Ontario and Quebec, whereas pistachio-induced anaphylaxis was more common in Ontario and Quebec [6.3% difference (95% CI, 0.5%-12.2%)]. Pre-hospital and ED intramuscular (IM) epinephrine administration was documented in only 35.2% and 52.4% of cases, respectively. Severe reactions were more likely among males [adjusted Odds Ratio (aOR) 1.05 (95% CI, 1.01-1.10)] older children [aOR 1.00 (95% CI, 1.00-1.01)], and in reactions triggered by macadamia [aOR 1.27 (95% CI, 1.03-1.57)].

CONCLUSION

Different TNA patterns in Canada may be due to differences in lifestyle (higher prevalence of Asian ethnicity in British Columbia versus Arabic ethnicity in Ontario and Quebec). IM epinephrine underutilization urges for EAI stocking in schools and restaurants, patient education, and consistent policies across Canada.

Nutrition and urticaria

Urticaria is a distressing dermatologic condition for many. Although the wheals of urticaria are characteristically evanescent, lasting less than 24 hours, patients tend to have recurrent episodes. Hives that last less than 6 weeks are considered acute urticaria. Acute urticaria does not routinely require supplementary work-up because the history often identifies a convincing, inciting allergen. Chronic urticaria is defined as episodes that occur for longer than 6 weeks, and there is often not an easily identifiable trigger. For both acute and chronic urticaria, patients frequently report food as a precipitating cause. For acute urticaria, the foods that are associated with true allergies, such as nuts and shellfish, are the most frequent offenders. The relationship between diet and chronic urticaria is not as firmly defined. Many patients unnecessarily restrict their diets, so it becomes the role of dermatologists to help patients identify if there is a reproducible link between their symptoms and their dietary exposures. The literature suggests that diets free from pseudoallergens and histamine-releasing foods may attenuate urticaria. Supplements such as fats, vitamin D, iron, and flavonoids have also been studied and may diminish symptoms.

Potential Biomarkers, Risk Factors and their Associations with IgE-mediated Food Allergy in Early Life: A Narrative Review

Food allergy affects the quality of life of millions of people worldwide and presents a significant psychological and financial burden for both national and international public health. In the past few decades, the prevalence of allergic disease has been on the rise worldwide. Identified risk factors for food allergy include family history, mode of delivery, variations in infant feeding practices, prior diagnosis of other atopic diseases such as eczema, and social economic status. Identifying reliable biomarkers which predict the risk of developing food allergy in early life would be valuable in both preventing morbidity and mortality and by making current interventions available at the earliest opportunity. There is also the potential to identify new therapeutic targets. This narrative review provides details on the genetic, epigenetic, dietary and microbiome influences upon the development of food allergy and synthesizes the currently available data indicating potential biomarkers. While there is a large body of research evidence available within each field of potential risk factors, there are very limited number of studies which span multiple methodological fields, for example including immunology, microbiome, genetic/epigenetic factors and dietary assessment. We recommend that further collaborative research with detailed cohort phenotyping is required to identify biomarkers, and whether these vary between at-risk populations and the wider population. The low incidence of oral food challenge confirmed food allergy in the general population, and the complexities of designing nutritional intervention studies will provide challenges for researchers to address in generating high quality, reliable and reproducible research findings.

STATEMENT OF SIGNIFICANCE

Food allergy affects the quality of life of millions of people worldwide and presents a significant psychological and financial burden for both national and international public health. Identifying reliable biomarkers which predict the risk of developing food allergy would be valuable in both preventing morbidity and mortality and by making current interventions available at the earliest opportunity. This review provides details on the genetic, epigenetic, dietary and microbiome influences upon the development of food allergy. This helps in identifying reliable biomarkers to predict the risk of developing food allergy, which could be valuable in both preventing morbidity and mortality and by making interventions available at the earliest opportunity.

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.

A systematic review of psychological, clinical and psychosocial correlates of perceived food intolerance

OBJECTIVE

Perceived food intolerance (PFI) is a distressing condition reported by 3% - 35% of individuals, whereas prevalence of food allergy is 0.9%-3%. The present paper aims to systematically review the evidence for psychological, clinical and psychosocial factors associated with PFI in order to advance the current understanding.

METHODS

Articles published from 1970 until October 2020 were identified. Case-control, prospective cohort, cross-sectional and retrospective studies published in English that a) included a subject population of adults over 18 with PFI and b) examined psychological, clinical and/or psychosocial factors of PFI were reviewed against inclusion criteria. Methodological quality was assessed, data extracted, and a narrative synthesis conducted.

RESULTS

Of 2864 abstracts identified, thirty-six articles met inclusion criteria. Evidence consistently found PFI is associated with female sex, and individuals with PFI often report physical health complaints including gastrointestinal and extraintestinal symptoms, and gastrointestinal and atopic conditions. Evidence for an association between psychological factors and PFI was inconsistent, although some suggested increased levels of common mental disorders and distress. Findings regarding psychosocial factors were mixed and sociodemographic data were infrequently collected.

CONCLUSIONS

PFI is associated with female sex and gastrointestinal and extraintestinal complaints. Limited high-quality evidence supports the role of psychological factors associated with PFI. High-quality research using prospective and longitudinal designs with multivariate analyses is needed. Future research should explore modifiable psychological factors as potential targets for intervention and identify clinical and psychosocial risk factors of PFI to aid in formulating a biopsychosocial model of PFI.

Diagnosis and management of cow's milk protein allergy in Turkey: Region-specific recommendations by an expert-panel

Cow's milk protein allergy (CMPA) is the most common type of food-allergy in younger children. Prognosis is usually good, with most children developing tolerance before school age. Children may present with a wide spectrum of symptoms that range from mild to severe; skin reactions such as angioedema and urticaria and gastrointestinal symptoms are the most common presentations of CMPA. Approximately one-third of CMPA patients suffer from multiple food-allergies; severe conditions such as anaphylactic shock (9%), eosinophilic esophagitis (4.7%), and food-protein induced enterocolitis (1%) may also develop in some children. Timely and accurate diagnosis and management is essential for proper growth and development of children with CMPA. In this expert consensus report, we aimed to adapt current understandings in the CMPA field to the specific conditions in Turkey and health system to help physicians with their day-to-day decision making.

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.

Epidemiology of Food Allergy

Understanding the epidemiology of food allergy is complicated by the difficulty of identifying it on a large scale. The prevalence of food allergy is higher in younger age groups and decreases with age. Allergy to peanut and egg seems to be more common in Northern Europe, the United States, Canada and Australia compared with Southern Europe, Eastern Europe and Asia, whereas shellfish and fish allergies may be more common in Asia. The rate of transient unrecognized food allergy may be high and variable recognition of food allergy may explain some of the differences seen in food allergy prevalence.

Prevalence of fish and shellfish allergy: A systematic review

BACKGROUND

Accurate information on the prevalence of food allergy facilitates a more evidence-based approach to planning of allergy services and can identify important geographic variations.

OBJECTIVE

To conduct a systematic review to assess the age-specific prevalence of fish and shellfish allergy worldwide.

METHODS

Searches were conducted using Web of Science and PubMed. Population-based cross-sectional studies and cohort studies that examined the prevalence of fish and shellfish allergy (IgE mediated and non-IgE mediated) at an identifiable point in time were eligible for inclusion in the study. Reviewers extracted general study information and study design, type of food allergy considered, food(s) assessed, method of diagnosis, sampling strategy, and sample characteristics. Raw data were extracted and percentage prevalence and 95% confidence intervals calculated.

RESULTS

A total of 7,333 articles were identified of which 61 studies met the inclusion criteria and were included in this review. The prevalence of fish allergy ranged from 0% to 7% and the prevalence of shellfish allergy from 0% to 10.3%, depending on the method of diagnosis. Where food challenges were used, the prevalence for fish allergy was found to be 0% to 0.3% and for shellfish allergy was 0% to 0.9%.

CONCLUSION

Few studies have established the prevalence of fish or shellfish allergy using the gold standard double-blind, placebo-controlled challenge criteria, with most instead relying on self-reported questionnaire-based methods. The limited data available suggest that fish allergy prevalence is similar worldwide; however, shellfish allergy prevalence may be higher in the Southeast Asia region.

The management of lactose intolerance among primary care physicians and its correlation with management by gastroenterologists: the SEPD-SEMG national survey

INTRODUCTION AND AIMS

The understanding of lactose intolerance (LI) is limited in some professional settings. Sociedad Española de Patología Digestiva (SEPD) and Sociedad Española de Medicina General (SEMG) have developed a survey in order to: a) Analyze primary care physicians (PCPs) knowledge and clinical management; and b) to compare results with those of a previous survey of Spanish gastroenterologists (GEs).

MATERIAL AND METHODS

An online questionnaire was sent to SEMG members with 27 items on various issues: Demographics, occupational characteristics, outlook on LI, diagnostic tests, treatment, and follow-up. Results were compared to those from a survey of GEs.

RESULTS

A total of 456 PCPs responded, versus 477 GEs. PCPs had an older mean age and longer professional experience. Level of understanding of LI was similar, albeit a higher proportion of PCPs lacked epidemiological awareness (p < 0.01). GEs tended to consider LI a "minor" condition (71.3 vs. 40.1%; p > 0.001), and LI symptoms as overlapping those of irritable bowel syndrome (93.5 vs. 88.2%; p = 0.005), although symptoms perceived as suspicious of LI were similar in both groups. Dietary recommendations were recognized as the primary therapeutic approach.

CONCLUSION

This study reveals the outlook of PCPs on LI, and allows comparison with that of GEs, as a basis for the development of strategies aimed at improving LI understanding, approach and management in our setting.

The prevalence of Hymenoptera venom allergy in adults: the results of a very crowded city in Euroasia

BACKGROUND

There are scarce data about the prevalence of Hymenoptera venom allergy in the general population. The aim of this study was to determine the prevalence of Hymenoptera venom allergy in the general adult population of Istanbul.

METHODS

A total of 17,064 randomly selected telephone numbers were contacted and 11,816 (69.25%) individuals who agreed to participate completed a questionnaire. Those who disclosed hypersensitivity reactions due to Hymenoptera stings in this initial survey were called again and given another questionnaire. Those who were suspected of experiencing hypersensitivity reactions to Hymenoptera stings were invited for a clinical investigation with in vivo and in vitro diagnostic tests.

RESULTS

According to the first questionnaire, a total of 1171 (9.9%; 95% CI: 9.38-10.47%) were suspected of having a hypersensitivity to Hymenoptera stings. 51.75% (n: 606) answered the second questionnaire and 21% (n: 128) of these were still suspected of having a hypersensitivity to Hymenoptera stings (1.1%; 95% CI: 0.9-1.29%). The confirmed prevalence of hypersensitivity to Hymenoptera stings according to skin tests and in vitro sIgE levels was 0.2% (95% CI: 0.14-0.30%). Nearly all of the participants with systemic reactions were admitted to the emergency department, although only one tenth of them received adrenaline in the emergency room. 2.3% carried an adrenaline injector, whereas none of the patients received venom immunotherapy.

CONCLUSIONS

The prevalence of Hymenoptera sting reactions in our geographical region is comparable with other European studies. There is a need to increase the awareness of adrenaline in the emergency management of insect sting anaphylaxis and venom immunotherapy in the prophylaxis.

Prevalence of common food allergies in Europe: a systematic review and meta-analysis

Allergy to cow's milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish constitutes the majority of food allergy reactions, but reliable estimates of their prevalence are lacking. This systematic review aimed to provide up-to-date estimates of their prevalence in Europe.Studies published in Europe from January 1, 2000, to September 30, 2012, were identified from searches of four electronic databases. Two independent reviewers appraised the studies and extracted the estimates of interest. Data were pooled using random-effects meta-analyses. Fifty studies were included in a narrative synthesis and 42 studies in the meta-analyses. Although there were significant heterogeneity between the studies, the overall pooled estimates for all age groups of self-reported lifetime prevalence of allergy to cow's milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish were 6.0% (95% confidence interval: 5.7-6.4), 2.5% (2.3-2.7), 3.6% (3.0-4.2), 0.4% (0.3-0.6), 1.3% (1.2-1.5), 2.2% (1.8-2.5), and 1.3% (0.9-1.7), respectively. The prevalence of food-challenge-defined allergy to cow's milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish was 0.6% (0.5-0.8), 0.2% (0.2-0.3), 0.1% (0.01-0.2), 0.3% (0.1-0.4), 0.2% (0.2-0.3), 0.5% (0.08-0.8), 0.1% (0.02-0.2), and 0.1% (0.06-0.3), respectively. Allergy to cow's milk and egg was more common among younger children, while allergy to peanut, tree nuts, fish, and shellfish was more common among the older ones. There were insufficient data to compare the estimates of soy and wheat allergy between the age groups. Allergy to most foods, except soy and peanut, appeared to be more common in Northern Europe. In summary, the lifetime self-reported prevalence of allergy to common foods in Europe ranged from 0.1 to 6.0%. The heterogeneity between studies was high, and participation rates varied across studies reaching as low as <20% in some studies. Standardizing the methods of assessment of food allergies and initiating strategies to increase participation will advance this evidence base.

Food hypersensitivity in mexican adults at 18 to 50 years of age: a questionnaire survey

PURPOSE

There is limited epidemiological evidence of food hypersensitivity (FH) in the adult population. We aimed to determine the prevalence of FH in Mexican adults, their clinical features and to establish common food involved in its appearance.

METHODS

We designed a cross-sectional study using a fixed quota sampling; 1,126 subjects answered a structured survey to gather information related to FH.

RESULTS

The prevalence of FH in adults was 16.7% (95% CI, 14.5% to 18.8%), without statistical significant differences related to gender (women, 17.5% and men, 15.9%) or residential location. The most common clinical manifestations in adults with FH were oral allergy syndrome (70 of 1,126) and urticaria (55 of 1,126). According to category, fruits and vegetables were the most frequent foods to trigger FH (6.12%) and were individually related to shrimp (4.0%), and cow milk (1.5%). Adults under age 25 had a higher frequency of FH (OR, 1.39; 95% CI, 1.01 to 1.91, P <0.001). Personal history of any atopic disease was significantly associated with FH (P <0.0001).

CONCLUSIONS

The prevalence of FH is relatively high in Mexican adults, and FH is significantly associated with atopic diseases.

Lactose malabsorption and intolerance: pathogenesis, diagnosis and treatment

Lactose malabsorption is a common condition caused by reduced expression or activity of lactase in the small intestine. In such patients, lactose intolerance is characterized by abdominal symptoms (e.g. nausea, bloating, and pain) after ingestion of dairy products. The genetic basis of lactose malabsorption is established and several tests for this condition are available, including genetic, endoscopic, and H2-breath tests. In contrast, lactose intolerance is less well understood. Recent studies show that the risk of symptoms after lactose ingestion depends on the dose of lactose, lactase expression, intestinal flora, and sensitivity of the gastrointestinal tract. Lactose intolerance has recently been defined as symptoms developing after ingestion of lactose which do not develop after placebo challenge in a person with lactose maldigestion. Such blinded testing might be especially important in those with functional gastrointestinal diseases in whom self-reported lactose intolerance is common. However, placebo-controlled testing is not part of current clinical practice. Updated protocols and high-quality outcome studies are needed. Treatment options of lactose intolerance include lactose-reduced diet and enzyme replacement. Documenting the response to multiple doses can guide rational dietary management; however, the clinical utility of this strategy has not been tested. This review summarizes the genetic basis, diagnosis, and treatment of lactose malabsorption and intolerance.

The epidemiology of food allergy in Europe: a systematic review and meta-analysis

Food allergy (FA) is an important atopic disease although its precise burden is unclear. This systematic review aimed to provide recent, up-to-date data on the incidence, prevalence, time trends, and risk and prognostic factors for FA in Europe. We searched four electronic databases, covering studies published from 1 January 2000 to 30 September 2012. Two independent reviewers appraised the studies and qualified the risk of bias using the Critical Appraisal Skills Programme tool. Seventy-five eligible articles (comprising 56 primary studies) were included in a narrative synthesis, and 30 studies in a random-effects meta-analysis. Most of the studies were graded as at moderate risk of bias. The pooled lifetime and point prevalence of self-reported FA were 17.3% (95% CI: 17.0-17.6) and 5.9% (95% CI: 5.7-6.1), respectively. The point prevalence of sensitization to ≥1 food as assessed by specific IgE was 10.1% (95% CI: 9.4-10.8) and skin prick test 2.7% (95% CI: 2.4-3.0), food challenge positivity 0.9% (95% CI: 0.8-1.1). While the incidence of FA appeared stable over time, there was some evidence that the prevalence may be increasing. There were no consistent risk or prognostic factors for the development or resolution of FA identified, but sex, age, country of residence, familial atopic history, and the presence of other allergic diseases seem to be important. Food allergy is a significant clinical problem in Europe. The evidence base in this area would benefit from additional studies using standardized, rigorous methodology; data are particularly required from Eastern and Southern Europe.

Similar prevalence, different spectrum: IgE-mediated food allergy among Turkish adolescents

BACKGROUND

Scarcity of reliable data on food allergy prevalence exists in Turkey. We aimed to assess reported and confirmed IgE-mediated food allergy prevalence, and define the spectrum of allergenic food.

METHODS

We prospectively evaluated the ISAAC Phase II study population for food allergy. Participants that reported experiencing food allergy symptom in the last year and/or were skin prick test positive for a predefined list of food allergens, were interviewed via telephone, and those considered as having food allergy were invited to undergo clinical investigation, including challenge tests.

RESULTS

A total of 6963 questionnaires were available. Parental reported food allergy prevalence and skin prick sensitisation rate were 20.2 ± 0.9% and 5.9 ± 0.6%. According to the above-defined criteria, 1162 children (symptom positive n=909, skin prick test positive n=301, both positive n=48) were selected and 813 (70.0%) were interviewed via telephone. Out of 152 adolescents reporting a current complaint, 87 accepted clinical investigation. There were 12 food allergies diagnosed in nine adolescents, with food allergy prevalence of 0.16 ± 0.11%. The most common foods involved in allergic reactions were walnut (n=3) and beef meat (n=2), followed by hen's egg (n=1), peanut (n=1), spinach (n=1), kiwi (n=1), cheese (n=1), hazelnut (n=1) and peach (n=1).

CONCLUSIONS

While parental reported food allergy prevalence was within the range reported previously, confirmed IgE-mediated food allergy prevalence among adolescents was at least 0.16%, and the spectrum of foods involved in allergy differed from Western countries, implying environmental factors may play a role.

Prevalence of confirmed IgE-mediated food allergy among adolescents in Turkey

BACKGROUND

Although food allergy is an important health problem in Western countries, the prevalence varies among geographic regions. There is limited data on the prevalence of food allergy especially for adolescent age group, and the data from Turkey and Mediterranean region are even scarce.

METHODS

The study is a cross-sectional survey including a questionnaire followed by phone survey with families that have reported food allergy and clinical evaluation of children having a history compatible with food allergy after phone survey. The sample number of students has been calculated 9096 of a total of 210.000 students at the second stage (6th, 7th, and 8th grades) of state elementary schools in the metropolitan counties of Ankara province with the assumption of food allergy prevalence (P) = 1% and a δ value = 0.2 (α < 0.05, β = 0.8).

RESULTS

Of 11,233 questionnaires distributed at 34 schools, 10,096 (89.4%) have been returned. The number of reported food allergy was 1139 (11.2%), and it was reduced to 133 (1.3%) after phone survey. After clinical evaluation by skin test, specific IgE and double-blind placebo-controlled food challenge (DBPCFC), proven IgE-mediated food allergy was determined in 15 (0.15%) children. The foods most commonly resulting food allergy were peanut 0.05% and treenuts 0.05%.

CONCLUSION

The prevalence of food allergy among adolescent age group has been confirmed to be comparatively low in Turkey. Peanuts and treenuts were determined to be the most common causes of IgE-mediated food allergy.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Food allergy: temporal trends and determinants

This review summarizes studies discussing temporal trends in the prevalence of food allergy as well as potential factors associated with the development of food allergy. In addition, we will address the potential hypotheses accounting for the apparent increase in food allergy prevalence. Studies suggest increased prevalence of food allergy. However, relatively little is known about its pathogenesis. This review aims to assess temporal trends in the prevalence of food allergy and discuss potential genetic, environmental, and demographic determinants. The search strategy examined the medical literature database MEDLINE (using PubMed) for the time period of January 1, 2002 to January 31, 2012. In recent decades, the prevalence of food allergy in general has increased by 0.60 % [95 % confidence interval (CI), 0.59 %-0.61 %] and the prevalence of peanut allergy by 0.027 % (95 % CI, 0.026 %-0.028 %), but it has now likely stabilized in developed countries. Genes, the environment, and demographic characteristics play a role in the pathogenesis of food allergy. Numerous environmental and demographic factors as well as gene-environment interactions may account for this increase in prevalence, but further studies are required to tease out their relative contribution.

Anaphylaxis in a tertiary adult allergy clinic: a retrospective review of 516 patients

BACKGROUND

Anaphylaxis is a life-threatening acute allergic reaction that can occur at any age.

OBJECTIVE

To determine the frequency, triggering factors, and clinical features of anaphylaxis among adult patients who were referred to a tertiary health care facility.

METHODS

A retrospective medical chart review was performed including all patients referred to the outpatient clinic of the adult allergy department in our university hospital between January 1, 2008 and December 30, 2011 to determine cases involving anaphylaxis.

RESULTS

A total of 516 (2.11%) patients among 24,443 admissions were diagnosed with anaphylaxis. Although the second highest frequency of anaphylaxis cases took place in 2008, a gradual rise in the frequency was determined from 2009 to 2011. Drugs (90.7%) were the most frequent cause, followed by Hymenoptera stings (5.4%), foods (1.6%), latex (0.4%), and exercise (0.2%) respectively. The clinical manifestations during anaphylaxis reported by patients were cutaneous (n = 292, 56.6%), respiratory (n = 253, 49%), cardiovascular (n = 212, 41%), neuropsychiatric (n = 60, 11.6%), and gastrointestinal (n = 52, 10.1%), respectively. Approximately one fifth of the patients received epinephrine, whereas 43% of patients did not receive epinephrine during their treatment in the emergency room. An epinephrine auto-injector was prescribed to 42 patients (8.1%).

CONCLUSION

In this study, the second pattern of National Institute of Allergy and Infectious Disease (NIAID) and the Food Allergy and Anaphylaxis Network (FAAN) diagnostic criteria for anaphylaxis predominated among adult patients. Drugs were the leading triggering factor, followed by Hymenoptera stings, foods, latex, and exercise, respectively. Atopy, asthma, and allergic rhinitis were rarely detected.

Sensitivity-related illness: the escalating pandemic of allergy, food intolerance and chemical sensitivity

The prevalence of allergic-related diseases, food intolerance, and chemical sensitivities in both the pediatric and adult population has increased dramatically over the last two decades, with escalating rates of associated morbidity. Conditions of acquired allergy, food intolerance and chemical hypersensitivity are frequently the direct sequelae of a toxicant induced loss of tolerance (TILT) in response to a significant initiating toxic exposure. Following the primary toxicant insult, the individuals become sensitive to low levels of diverse and unrelated triggers in their environment such as commonly encountered chemical, inhalant or food antigens. Among sensitized individuals, exposure to assorted inciting stimuli may precipitate diverse clinical and/or immune sequelae as may be evidenced by clinical symptoms as well as varied lymphocyte, antibody, or cytokine responses in some cases. Recently recognized as a mechanism of disease development, TILT and resultant sensitivity-related illness (SRI) may involve various organ systems and evoke wide-ranging physical or neuropsychological manifestations. With escalating rates of toxicant exposure and bioaccumulation in the population-at-large, an increasing proportion of contemporary illness is the direct result of TILT and ensuing SRI. Avoidance of triggers will preclude symptoms, and desensitization immunotherapy or immune suppression may ameliorate symptomatology in some cases. Resolution of SRI generally occurs on a gradual basis following the elimination of bioaccumulated toxicity and avoidance of further initiating adverse environmental exposures. As has usually been the case throughout medical history whenever new evidence regarding disease mechanisms emerges, resistance to the translation of knowledge abounds.

The role of diet in symptoms of irritable bowel syndrome in adults: a narrative review

This review summarizes what is known about the effect of diet on irritable bowel syndrome (IBS) symptoms emphasizing data from randomized, controlled clinical trials. Studies suggest that IBS symptoms in one quarter of patients may be caused or exacerbated by one or more dietary components. Recent studies indicate that a diet restricted in fermentable, poorly absorbed carbohydrates, including fructose, fructans (present in wheat and onions), sorbitol, and other sugar alcohols is beneficial, but confirmatory studies are needed. Despite a long history of enthusiastic use, fiber is marginally beneficial. Insoluble fiber may worsen symptoms. Some patients with IBS, especially those with constipation, will improve with increased intake of soluble fiber. Prebiotic fibers have not been adequately tested. Daily use of peppermint oil is effective in relieving IBS symptoms. The usefulness of probiotics in the form of foods such as live-culture yogurt and buttermilk for IBS symptoms is not established. In clinical practice, it is very difficult to establish that a patient's symptoms result from an adverse reaction to food. A double blind placebo-controlled food challenge is the most reliable method, but it is not suitable for routine clinical use. A modified exclusion diet and stepwise reintroduction of foods or trials of eliminating classes of food may be useful.

Prevalence of immunoglobulin E-mediated food allergy in 6-9-year-old urban schoolchildren in the eastern Black Sea region of Turkey

BACKGROUND

The prevalence of adverse reactions to food in childhood in Turkey is not known.

OBJECTIVE

We aimed to investigate the prevalence and characteristics of IgE-mediated food allergies (FAs) in 6-9-year-old urban schoolchildren.

METHODS

This cross-sectional study recruited 3500 of the randomly selected 6-9-year-old urban schoolchildren from the eastern Black Sea region of Turkey during 2006. Following a self-administered questionnaire completed by the parents and the child, consenting children were invited for skin prick tests (SPTs) and oral food challenges. Children with suspected IgE-mediated FA were skin prick tested with a predefined panel of food allergens (milk, hen's egg, soy, wheat, peanut, fish, and hazelnut), aeroallergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, cat, dog, Alternaria, grass pollen mix, weed pollen mix, and tree pollen mix), and food allergens reported in the questionnaire. All children with a positive SPT to any food were invited for a double-blind, placebo-controlled food challenge (DBPCFC). The prevalence of IgE-mediated FA was established using DBPCFCs.

RESULTS

The response rate to the questionnaire was 78.2% (2739/3500). The estimated prevalence of parental-reported IgE-mediated FA was 5.7% (156/2739) [95% confidence interval (CI), 4.83-6.57%]. The rate of sensitization to the food allergens was 33.1% (48/145) in the parental-reported group. The confirmed prevalence of IgE-mediated FA by means of DBPCFC in 6-9-year-old urban schoolchildren living in the eastern Black Sea region of Turkey was 0.80% (22/2739) (95% CI, 0.47-1.13%). The most common allergenic foods were beef (31.8%), cow's milk (18.1%), cocoa (18.1%), hen's egg (13.6%), and kiwi (13.6%).

CONCLUSIONS

The rate of reported IgE-mediated FA was significantly higher than clinically confirmed FA by means of DBPCFC (odds ratio, 7.46; 95% CI, 4.67-12.01; P<0.0001). The order of allergenic foods was different and somewhat unique to the eastern Black Sea region of Turkey when compared with western countries.