Prevalence and clinical features of adverse food reactions in Portuguese children

Feast for thought: A comprehensive review of food allergy 2021-2023

A review of the latest publications in food allergy over the past couple of years confirmed that food allergy is a major public health concern, affecting about 8% of children and 10% of adults in developed countries. The prevalence of food allergy varies around the world, with the increase being driven mainly by environmental factors, possibly together with genetic susceptibility to environmental changes. A precise diagnosis of food allergy is extremely important. Both new tests (eg, the basophil activation test) and improved optimization of information provided by existing tests (eg, the skin prick test and measurement of specific IgE level) can contribute to improving the accuracy and patients' comfort of food allergy diagnosis. Understanding the underlying immune mechanisms is fundamental to designing allergen-specific treatments that can be safe and effective in the long term. New discoveries of the immune response to food allergens, including T-cell and B-cell responses, have emerged. Novel therapeutic approaches are being trialed at various stages of development as attempts to allow for more active intervention to treat food allergy. Prevention is key to reducing the increase in prevalence. Early introduction of allergenic foods seems to be the most effective intervention, but others are being studied, and will, it is hoped, lead to modification of the epidemiologic trajectory of food allergy over time.

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.

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.

The reported prevalence of food allergy among school-aged children in Bahrain

Allergic diseases have been continuously studied and monitored, while the topic of food allergy (FA) lags with only a few prevalence studies conducted in certain countries. The main aim of this study was to estimate the prevalence of FA in school-aged children in the Kingdom of Bahrain. A cross-sectional design was used on a randomized sample of school-aged children in Bahrain. An electronic questionnaire inquiring about demographic data and history of FA and its details was administered through school administrations between October and December 2020. Data was obtained from 1370 participants, comprising 822 males and 548 females. The prevalence of a reported history of FA in school-aged children in Bahrain was calculated as 15.5%. Furthermore, 9.9% of children reported a current FA. The most common experienced symptoms were skin symptoms followed by gastrointestinal symptoms. Moreover, 7% of children reported experiencing anaphylaxis, low blood pressure, or shock. This research concluded that the reported prevalence of FA history among school-aged children in Bahrain was higher than that observed in other studies estimating at 15.5%, with 9.9% persisting up to the time of the study. The most common single food allergen was found to be egg. The findings of this study provide a baseline for future larger studies to obtain more in-depth results.

Sensitizations to wheat and strawberry: are they a tangible threat to atopic Egyptian

BACKGROUND

definite figures of allergy to wheat and strawberries in Egypt are lacking. We investigated IgE-mediated sensitization to wheat and strawberry among a group of allergic children, and the relation between wheat and strawberry sensitization.

PATIENTS AND METHODS

This study comprised 256 children, with physician-diagnosed allergy: bronchial asthma (98 patients), allergic rhinitis (28 patients), atopic dermatitis (53 patients) and food allergy (10 patients). Sensitization to wheat and strawberry was assessed using prick testing, followed by oral challenge test to prove allergy.

RESULTS

Wheat sensitization was observed in 9.4% of the studied children with confirmed allergy in 0.4%. Strawberry sensitization was observed in 7.8% of patients, with 2% confirmed allergy. Either sensitization did not influence response of allergy to treatment. Wheat and strawberry sensitizations were positively correlated.

CONCLUSION

Wheat and strawberry allergies are not common among Egyptian children with allergic disorders; and did not impact the response to allergy treatment.

Prevalence and clinical features of adverse food reactions in Portuguese adolescents

Background & aims

The objective of the present study was to determine, for the first time, the prevalence and clinical features of food allergy in Portuguese adolescents.

Methods

Cross-sectional study performed in various secondary schools in central Portugal. Randomly selected adolescents replied to a validated food allergy questionnaire. Those who reported an adverse food reaction were seen at participating hospitals, where clinical history was taken, skin prick (SPT) and prick-prick skin (SPPT) tests were performed, and food allergen-specific IgE levels (sIgE) were determined. An open oral challenge was performed in selected cases. Cases of positive clinical history of immediate (up to 2 h after ingestion) reaction in association with positive food sIgE levels and/or SPT were classified as IgE-associated probable food allergy and as confirmed IgE-mediated food allergy if food challenges were positive. Cases of positive clinical history of delayed (more than 2 h after ingestion) and negative food sIgE levels independently of positive SPT or SPPT results, were classified as non-IgE associated probable food allergy.

Results

The prevalence of probable food allergy in Portuguese adolescents was 1.41% (95% CI: 0.90–2.03%), with fresh fruits, shellfish, nuts, and peanut as the most frequently implicated foods. IgE-mediated probable food allergy occurred in 1.23% (95% CI: 0.67–1.72%) of cases, with fresh fruits, shellfish, and nuts mainly involved. Cutaneous symptoms were most frequently reported.

Conclusions

The prevalence of probable food allergies in Portuguese adolescents is low, is mostly related to fresh fruits, shellfish, nuts, and peanut, and most frequently involves cutaneous symptoms.

An assessment of the risk of allergenicity associated with selected strawberry cultivars on a guinea pig model*

Aim of the study was to assess the risk of any allergic reaction or food hypersensitivity resulting from topical application and chronic oral administration of the fruit of selected strawberry cultivars (‘Elsanta’ and ‘Honeoye’) from farms managed organically. Materials and methods. The plantations were managed according to organic (OFP) as compared to integrated production (IFP) systems. The experiments were performed on outbred young, adult, white albinotic guinea pigs (Dunkin Hartley). Fruit characteristics included total soluble solid content, titratable acidity, sugar, polyphenol content and macro- and micronutrients. Results. The most pronounced changes in guinea pig skin followed topical exposure to ‘Elsanta’ strawberries from plantations managed organically showed discrete, moderate or intense erythema and swelling. Chronic oral administration of selected fruit extracts did not cause any skin reactions in groups receiving ‘Elsanta’ or ‘Honeoye’ from organic or integrated productions. The skin prick test did not show any immediate skin reactions compared to exposure to 1% histamine hydrochloride solution. Conclusion. Organic method of strawberry production cannot be concerned as more allergenic one as compared to integrated system. Any strict relationship between type of cultivar and selected macro-, micronutrients contents or fruit characteristics on the possible increase in allergenicity risk, was not found, either.