How a Family History of Allergic Diseases Influences Food Allergy in Children: The Japan Environment and Children's Study

Prevalence and Impact of Food Allergies Among Jordanian Schoolchildren: A Comprehensive Analysis of Parent-Reported Data and Associated Atopic Conditions

Background: Food allergies, characterized by immune reactions to food proteins, have emerged as an increasing global concern, impacting over 10% of the population. This study investigates the prevalence of food allergies among schoolchildren aged 5-14 years in northern and central Jordan. Methods: A randomized cross-sectional online questionnaire was administered to students aged 5-14 years residing in the central and northern regions of Jordan. Parents of these students (n = 1629) completed the questionnaire, which comprised information on demographics, dietary habits, food allergies, and allergy history. Results: The parent-reported food allergies exhibited a prevalence of 11.5% (95% confidence interval = 10-13%). Of these reported allergies, 10.1% (95% CI = 8.6-11.7%) were classified as convincing, while only 5.7% (95% CI = 4.5-6.8%) received a formal diagnosis from a healthcare professional. The most commonly reported allergens included eggs (17.8%), cow's milk (15.8%), peanuts (14.5%), and strawberries (13.8%). The majority of children (67.1%) had a single reported allergen, while 15.8% had two, and 17.2% had more than two allergens identified. Food allergies were significantly more prevalent among children with comorbid atopic conditions and those with a family history of allergies. Additionally, regional variations were observed, with high prevalence rates in metropolitan regions. Conclusion: This study emphasizes the significance of considering persuasive food allergy (FA) data in addition to parent-reported information. The findings highlight the considerable burden of food allergies and their relationship with other atopic disorders. Comprehensive management strategies and further research to elucidate the underlying causes of food allergies are necessary.

Food allergen introduction practices and parent/caregiver attitudes based on family history of food allergy

Background

The National Institute of Allergy and Infectious Disease (NIAID) addendum guidelines for primary prevention of peanut allergy1 provide recommendations regarding peanut introduction, and a recent consensus statement highlighted the importance of timely introduction of other commonly allergenic solids, and the role of family history as a risk factor.2ObjectiveTo determine whether children in households with a food allergic parent/caregiver or sibling have different rates of being fed commonly allergenic solids during the first year of life than children lacking this family history.

Methods

A pretested survey was administered between January-February 2021 to a U.S. sample of 3,062 parents/caregivers of children born since the NIAID Addendum guidelines. Survey-weighted chi-square statistics and logistic regression models tested the independence of key variables across strata of interest before and after covariate adjustment.

Results

Peanut, almond, shellfish, and other tree nuts are more likely to be introduced to children with one or more food-allergic caregivers. Respondents with food-allergic parents (39.3%) and siblings with FA (35.8%) were more familiar with the 2017 NIAID guidelines compared to parents (12.9%) and siblings without FA (12.7%).

Conclusion

Findings suggest that respondents with food-allergic parents and siblings are more likely to have many of the most prevalent allergens introduced at younger ages, which could be due to knowledge related to the NIAID-sponsored guidelines and other national guidance, but that even among these higher-risk families overall rates of "early" introduction during infancy still remain relatively low.

Immune profiling of ART-conceived children in Kazakhstan: a case-control study

Objective

The increasing use of assisted reproductive technologies (ART) has led to a growing interest in the health outcomes of offspring. However, the impact of ART on the immune system of children remains poorly understood. While only two publications were found, their findings contradict each other and did not consider other risk factors in their analysis except for ART use. Therefore, this study aimed to examine the potential impact of ART on the immune system of offspring.

Methods

A case-control study was conducted in Kazakhstan to investigate the immune system of ART-conceived children compared to those conceived naturally (NC). The study included participants who met certain criteria, such as having undergone a successful ART program resulting in the birth of either a single or multiple pregnancies. Patients who used donor oocytes/sperm, intrauterine insemination, or surrogacy were excluded. Anamnesis data were collected from children in both groups, and laboratory measurements were performed and analyzed using IBM SPSS Statistic 26.

Results

A total of 120 children conceived by ART and 132 NC children under the age of five were included in our study. We observed that compared with NC group, ART children had lower IgA and IgG levels (p < 0.001), absolute lymphocytosis, high levels of active T-lymphocytes (p = 0.001), and pathological T-helper levels (p = 0.004). Therefore, the clinical presentation of respiratory diseases was lower in ART group. Children born after frozen embryo transfers showed significantly higher levels of T-cytotoxic and active T-lymphocytes compared to children born after fresh embryo transfers (p = 0.007 and p = 0.020, respectively). We utilized ordinal logistic regression to control for confounding variables such as multiple pregnancy, cesarean section, premature birth, and breastfeeding. Despite this, the significant impact of ART on immunogram parameters persisted, indicating the independent and influential nature of ART or other unaccounted factors.

Analysis of heritability and environmental factors in preschool children with eczema: a case-control study

Eczema is common in children, and its onset is affected by both genetic and environmental factors. We investigated the effects of genetic and environmental factors on the incidence of eczema in preschool children. 515 preschool children with eczema and 515 children participating in the physical examination were enrolled. The study included the incidence of childhood eczema, the child's birth and feeding conditions, the history of eczema in the parents, and relevant environmental risk factors, and to comprehensively analyze the genetic and environmental factors influencing childhood eczema. Among 1030 children, 173 parents (8.4%) had eczema, with a heritability of 73.59% for boys' parents and 58.59% for girls' parents. Multivariate logistic regression results showed that premature infants, low birth weight, children who had used antibiotics before the age of 1 year the living environment between the first year of mother pregnancy and the first year of the child is humid, a father with a history of eczema, a mother with a history of eczema are risk factors for eczema in children. Actively preventing environmental factors related to eczema may be an effective means to reduce the risk of eczema in children.

Skin and oral intervention for food allergy prevention based on dual allergen exposure hypothesis

Early-onset atopic dermatitis increases an individual's risk of food allergies, suggesting that transcutaneous sensitization may occur through inflamed skin. Regarding food allergy causation, the dual allergen exposure hypothesis proposes that oral allergen exposure leads to immune tolerance, whereas allergen exposure via inflamed skin causes food allergies. This hypothesis suggests that it is important to induce oral immune tolerance and prevent allergic food sensitization through the skin. This review focuses on the breakthrough evidence based on the dual allergen exposure hypothesis that involves both skin and oral interventions for food allergy prevention.

Baked Egg Oral Immunotherapy: Current State in Pediatric Age

Hen's egg allergy is one of the most common food allergies in the Western world, with an increase in recent years. It affects about 9.5% of the pediatric population, and the onset most often occurs before the first year of life. The occurrence of spontaneous oral tolerance acquisition varies among studies, but it is generally high by school age. Nowadays, allergen immunotherapy may represent the only therapeutic strategy able to modify the natural history of hen's egg allergy. Specifically, many children with hen's egg allergy may tolerate baked eggs. Food processing, specifically high temperatures, alters the allergenicity of hen's egg proteins by causing conformational changes in allergen epitopes, which makes them less allergenic. This review aims to discuss the scientific evidence in the field of baked egg oral immunotherapy in hen's egg-allergic children, with a meticulous examination of the pertinent literature surrounding the subject matter.

Prevalence of Parent-Reported Food Allergies Among Children in Saudi Arabia

(1) Background: Food allergy (FA) is an immune-mediated hypersensitivity to foods, significantly contributing to childhood morbidity and mortality. This study aimed to assess the prevalence, characteristics, and influencing factors of parent-reported FAs among children in Saudi Arabia. (2) Methods: This cross-sectional study utilized a validated parental questionnaire distributed across all regions of Saudi Arabia. Data from 2130 participants were collected and analyzed using SPSS v. 26 and Prism software v. 10.3.0. (3) Results: Parent-reported FA prevalence was 15.2%. Egg was the most common allergen (6.2%), followed by tree nuts (4.1%), peanuts (4.0%), milk (3.8%), and sesame (3.2%). Significant geographical variations were observed, with the western region having the highest burden (p < 0.001). Older children had higher rates of shellfish and fish allergies. Parental allergies and co-existing asthma/drug allergies were positively associated with childhood FAs. (4) Conclusions: This study highlights a substantial burden of parent-reported FAs in Saudi Arabia, with regional variations in food allergen distribution. Parental allergies and co-existing allergic conditions may influence FA risk.

Maternal asthma during pregnancy and risks of allergy and asthma in progeny: A systematic review and meta-analysis

BACKGROUND

Clinical and preclinical evidence indicate that in utero maternal asthma exposure increases progeny asthma risk. Whether maternal asthma also increases the risks of progeny allergy is unclear.

OBJECTIVES

To synthesise the available evidence on the relationship between in utero exposure to maternal asthma and postnatal asthma, wheezing and allergic diseases (Prospero: CRD42020201538).

SEARCH STRATEGY

We systematically searched MEDLINE [PubMed], Embase [Ovid], Web of Science, Informit Health, the Cochrane Library, CINAHL [EBSCOhost], MedNar [Deep Web Technologies], ProQuest Theses and Dissertations, Scopus [Elsevier] and Trove, to the end of 2023.

SELECTION CRITERIA

Studies reporting asthma, wheeze and/or allergic disease in progeny of women with and without asthma or with asthma classified by control, exacerbation or severity.

DATA COLLECTION AND ANALYSIS

Double screening, selection, data extraction and quality assessment were performed, using Joanna Briggs Institute (JBI) scoring.

MAIN RESULTS

Of 134 non-overlapping studies, 127 were included in ≥1 meta-analysis. Maternal asthma ever was associated with greater risks of asthma (65 studies, risk ratio [95% confidence interval] 1.76 [1.57-1.96]), wheeze (35 studies, 1.59 [1.52-1.66]), food allergy (5 studies, 1.32 [1.23-1.40]), allergic rhinitis (7 studies, 1.18 [1.06-1.31]) and allergic dermatitis (14 studies, 1.17 [1.11-1.23]) ever in progeny. Asthma during the pregnancy, more severe, and uncontrolled maternal asthma were each associated with greater risks of progeny asthma.

CONCLUSIONS

Children of mothers with asthma are at increased risk for the development of allergic diseases. Whether improved maternal asthma control reduces risks of child allergy as well as asthma requires further investigation.

Parental stress and food allergy phenotypes in young children: A National Birth Cohort (JECS)

BACKGROUND

Food allergy children and their families tend to have emotional distress and anxiety. There have been few reports of differences in parenting stress and a child's food allergy phenotypes.

METHODS

We examined the associations between food allergy phenotypes in children and parenting stress assessed by the Parenting Stress Index-Short Form (PSI-SF) from a national birth cohort (Japan Environment and Children's Study).

RESULTS

We included 65,805 children for statistical analysis. Of them, 7.2% of children had a food allergy diagnosis at 2 years old. The means of the total PSI-SF (39.9 ± 10.3, 39.1 ± 9.9), CD-SF (19.5 ± 5.4, 19.1 ± 5.2), and PD-SF (20.5 ± 6.3, 20.0 ± 6.1) scores are similar for caregivers in the with and without food allergy groups. Food allergy diagnosis resulted in significantly higher total PSI scores (coefficient .47, 95% CI 0.19-0.75, p = .001), CD-SF (coefficient .22, 95% CI 0.07-0.38, p = .004), and PD-SF (coefficient .24, 95% CI 0.08-0.41, p = .004). A similar trend was observed for allergy reactions to hen's egg. However, there was no clear relationship between allergic reactions to milk, wheat, nuts, and PSI-SF.

CONCLUSIONS

Parental stress was significantly related to a child's food allergy. Furthermore, hen's egg allergy increased parental stress. Multiple food avoidance might also increase parental stress. Healthcare providers need to be aware of parental stress in our daily clinic.

Prenatal Factors in the Development of Allergic Diseases

Allergic diseases are showing increasing prevalence in Western societies. They are characterized by a heightened reactivity towards otherwise harmless environmental stimuli. Allergic diseases showing a wide range of severity of symptoms have a significant impact on the quality of life of affected individuals. This study aims to highlight the mechanisms that induce these reactions, how they progress, and which prenatal factors influence their development. Most frequently, the reaction is mediated by immunoglobulin E (IgE) produced by B cells, which binds to the surface of mast cells and basophils and triggers an inflammatory response. The antibody response is triggered by a shift in T-cell immune response. The symptoms often start in early childhood with eczema or atopic dermatitis and progress to allergic asthma in adolescence. An important determinant of allergic diseases seems to be parental, especially maternal history of allergy. Around 30% of children of allergic mothers develop allergic sensitization in childhood. Genes involved in the regulation of the epithelial barrier function and the T-cell response were found to affect the predisposition to developing allergic disorders. Cord blood IgE was found to be a promising predictor of allergic disease development. Fetal B cells produce IgE starting at the 20th gestation week. These fetal B cells could be sensitized together with mast cells by maternal IgE and IgE-allergen complexes crossing the placental barrier via the low-affinity IgE receptor. Various factors were found to facilitate these sensitizations, including pesticides, drugs, exposure to cigarette smoke and maternal uncontrolled asthma. Prenatal exposure to microbial infections and maternal IgG appeared to play a role in the regulation of T-cell response, indicating a protective effect against allergy development. Additional preventive factors were dietary intake of vitamin D and omega 3 fatty acids as well as decreased maternal IgE levels. The effect of exposure to food allergens during pregnancy was inconclusive, with studies having found both sensitizing and protective effects. In conclusion, prenatal factors including genetics, epigenetics and fetal environmental factors have an important role in the development of allergic disorders in later life. Children with a genetic predisposition are at risk when exposed to cigarette smoke as well as increased maternal IgE in the prenatal period. Maternal diet during pregnancy and immunization against certain allergens could help in the prevention of allergy in predisposed children.

Feasibility and Safety of the Early Introduction of Allergenic Foods in Asian Infants with Eczema

BACKGROUND

There is a lack of data regarding the early introduction of the consumption of allergenic food among Asian infants.

METHODS

We examined infants who had early-onset eczema before 6 months of age and received instructions from certified allergists for the early introduction of hen's eggs, milk, wheat, peanuts, and tree nuts.

RESULTS

The consumption rates of hen's eggs were 100% at 24 months. For peanuts and walnuts, the consumption rate was moderate at 12 months (48.5% and 30.3%, respectively), but by 24 months, it had progressed to 78.8% and 81.3%, respectively. In contrast, cashews remained at lower levels than other allergens at 20.7% at 12 months and 41.4% at 24 months. No adverse events related to early introductions occurred.

CONCLUSIONS

In infants with eczema, allergenic foods could be introduced early and well tolerated in Asian infants. However, having eczema may indicate a predisposition to food allergies, so caution is necessary when introducing allergenic foods. The early introduction of peanuts and tree nuts was still more challenging in real-world practice in Asia as well as in Western countries.

Infant Formulas With Partially or Extensively Hydrolyzed Milk Proteins for the Prevention of Allergic Diseases: A Systematic Review and Meta-Analysis of Clinical Trials

Despite the widely recommended usage of partially hydrolyzed formula (PHF) or extensively hydrolyzed formula (EHF) of milk protein for preventing allergic diseases (ADs), clinical studies have been inconclusive regarding their efficacy compared with that of cow's milk formula (CMF) or breast milk (BM). We aimed to systematically evaluate the effects of PHF or EHF compared with those of CMF or BM on risk of ADs (cow's milk allergy, allergic rhinitis, eczema, asthma, wheeze, food allergy, and sensitization) in children. We searched PubMed, Embase, Cochrane Library, and Web of Science for clinical trials published from inception to 21 October, 2022. We used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to grade the strength of evidence. Overall, 24 trials (10,950 infants) were included, 17 of which specifically included high-risk infants. GRADE was low for the evidence that, compared with CMF, infants early fed with EHF had lower risk of cow's milk allergy at age 0-2 y [relative risk (RR): 0.62; 95% CI: 0.39, 0.99]. Moderate evidence supported that PHF and EHF reduced risk of eczema in children aged younger or older than 2 y, respectively (RR: 0.71; 95% CI: 0.52, 0.96; and RR: 0.79; 95% CI: 0.67, 0.94, respectively). We also identified moderate systematic evidence indicating that PHF reduced risk of wheeze at age 0-2 y compared with CMF (RR: 0.50; 95% CI: 0.29, 0.85), but PHF and EHF increased the risk compared with BM (RR: 1.61; 95% CI: 1.11, 2.31; and RR: 1.64; 95% CI: 1.26, 2.14). Neither PHF nor EHF had significant effects on other ADs in children of any age. In conclusion, compared with CMF, PHF, or EHF had different preventive effect on cow's milk allergy, eczema, and wheeze. Compared with BM, both PHF and EHF may increase risk of wheeze but not other ADs. Given that most trials included only high-risk infants, more research on non-high-risk infants is warranted before any generalization is attempted. This protocol was registered at PROSPERO as CRD42022320787.

The Natural History and Risk Factors for the Development of Food Allergies in Children and Adults

PURPOSE OF REVIEW

This narrative review explores food allergy prevalence and natural history stratified by life stages, especially in context of evolving knowledge over the last few decades.

RECENT FINDINGS

The prevalence of food allergy remains highest in early childhood with common food triggers being cow's milk, soy, hen's egg, wheat, peanut, tree nuts, sesame, fish, and shellfish. This correlates with certain risk factors especially pertinent in the postnatal period which appear to predispose an individual to developing a food allergy. Some allergies (such as milk and egg) were previously thought to be easily outgrown in early life; however, recent studies suggest increasing rates of persistence of these allergies into young adulthood; the reason behind this is unknown. Despite this, there is also evidence demonstrating that food allergies can be outgrown in adolescents and adults. An understanding of the paradigm shifts in the natural history of food allergy allows clinicians to provide updated, age-appropriate, and tailored advice for patients on the management and prognosis of food allergy.

A survey on prevalence and parents' perceptions of food allergy in 3- to 16-year-old children in Wuhan, China

Background

The prevalence of food allergy (FA) has risen in recent decades, yet there is limited data on the cognition and beliefs of FA among the parents of FA children.

Objective

To investigate the prevalence of FA and assess the knowledge and perception of FA among parents of FA children in Wuhan, China.

Methods

Online questionnaires were conducted for the parents of 3- to 16-year-old children. They reported symptoms of suspected FA in the screening questionnaire were interviewed for further diagnostic evaluation. All the parents of the suspected FA children completed the subsequent assessments of the knowledge and perception on FA as well as their attitude towards the current online platforms.

Results

A total of 1963 children were recruited. The prevalence of self-reported FA was 10.2% (95% CI: 8.1-12.4%) and the physician-diagnosed FA was 6.2% (95% CI: 5.1-7.2%) in 3- to 16-year-olds in Wuhan. And the children with family history (57.9%) were predisposed to developing FA (P＜0.001). The total Brief Illness Perception Questionnaire (B-IPQ) score was 41.3 ± 10.0 among the parents. The B-IPQ scores correlated with symptom onset, but not with family history or other atopic comorbidities. The parents who never sought treatments obtained lower B-IPQ scores on most items compared to those who received treatments. The accuracy rate of the FA knowledge questionnaire was 56.7%. 11.6% of participants reported that children's FA had an impact on their lives. 67.2% of participants had searched information of FA online, among whom 80% expected to obtain professional suggestions on management and prevention strategies of FA from online platform.

Conclusion

In 3- to 16-year-old children in Wuhan, the prevalence of self-reported and physician-diagnosed FA was 10.2% and 6.2% respectively. Parents' knowledge of FA was insufficient and only a small proportion of parents perceived that their lives and careers have been affected considerably by FA of their children. Patient education and current online platforms should be improved among parents of FA children.

Prevalence of Parent-Reported Food Allergy in a Mexican Pre-School Population

The magnitude and relevance of food allergies in the preschool population remain unknown in most regions of Mexico and Latin America. Thus, our aim was to estimate the parent-reported prevalence of food allergies in a Mexican preschool population and to characterize their clinical diagnosis and presentation. A cross-sectional survey was conducted in Culiacán City. A validated questionnaire was utilized. A total of 810 parents responded to the questionnaire (valid response rate, 40.7%). The estimated prevalence rates (95% CI) were: "physician-diagnosed Food Allergy (FA), ever" 5.30% (3.86-7.08); "immediate-type FA, ever" 2.96% (1.91-4.38); "immediate-type FA, current" 1.60% (0.86-2.73); and food-dependent anaphylaxis 1.11% (0.51-2.01). The main food allergens were milk (0.49%), strawberries (0.37%), egg, and soy (0.25% each). Atopic diseases and a family history of allergies were significantly associated with immediate-type FA. Among "immediate-type FA, current" cases, 76.9% required emergency room visits, but the prescription of epinephrine autoinjectors was reported in one case only. The food reactions occurred at home (92.35%), in a relative's house (38.5), and at restaurants (23%). Immediate-type FA reactions requiring emergency room visits are not uncommon among the studied population. Actions like proper anaphylaxis management and the prevention of cross-contamination of foods should be encouraged.