Frequency of food group consumption and risk of allergic disease and sensitization in schoolchildren in urban and rural China

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.

Early Origins of Asthma and Allergies: Clues From Studies in China

Asthma and allergies have emerged as some of the most common chronic diseases, particularly in developed countries. Epidemiological studies have consistently demonstrated that children growing up in farming/rural environments are less likely to develop these conditions. Over the past three decades, China has experienced unprecedented economic development and urbanisation, accompanied by a rapid rise in the prevalence of allergic disorders. Despite the substantial number of affected individuals, allergy management in China remains inconsistent and often inadequate, compounded by variations in diagnostic criteria and limited healthcare access in less developed regions. Furthermore, the vast population, regional disparities, and methodological inconsistencies in data collection have hindered the acquisition of comprehensive, large-scale epidemiological data. This review examines the factors contributing to asthma and allergies from their early origins, focusing on modifiable factors from a specific perspective of China. Factors related to traditional lifestyle, such as early-life exposure to agricultural farming and poultry, diverse dietary patterns, and early introduction of allergenic foods, appear to offer protection against allergies. Conversely, exposure to open-fire cooking, incense burning, tobacco smoke, as well as early-life antibiotic use and perinatal factors like Caesarean section delivery and prematurity may represent potential risks. A clear understanding of the role of these factors would pave the way for developing effective interventions to mitigate the substantial health and socioeconomic burdens associated with asthma and allergies.

Trends in atopic dermatitis prevalence among the Chinese population (1990-2021) with projections for 2022-2030

BACKGROUND

Atopic dermatitis (AD) has the highest disease burden among all skin diseases. However, reports on AD prevalence trends in China are limited. This study aimed to investigate the time trends of AD prevalence in China from 1990 to 2021 and to explore the age and sex differences.

METHODS

Data were obtained from the Global Burden of Disease Study, 2021. We analyzed the annual percentage change in the crude prevalence rate and age-standardized prevalence rate (ASPR) of AD from 1990 to 2021 using the Joinpoint model. We predicted the future prevalence of AD from 2022 to 2030 using the Bayesian age-period-cohort model.

RESULTS

The total ASPR decreased slightly from 1990 (1357.93 per 100,000) to 2021 (1347.11 per 100,000). The ASPR of females (1457.64 per 100,000) was higher than that of males (1247.04 per 100,000) in 2021. The prevalence rate of AD was highest in the under 5 years old age group (3455.56 per 100,000) and the 5-9 years old age group (3360.31 per 100,000). By 2030, the predicted ASPR of AD will be 1394.36 (per 100,000) in males and 1603.69 in females (per 100,000). The predicted prevalence rate in the under 5 years old (3996.14 per 100,000 in males and 3990.68 per 100,000 in females) and 5-9 years old (3714.61 per 100,000 in males and 3963.96 per 100,000 in females) age groups will be higher than those in other age groups.

CONCLUSION

Despite a slight decrease from 1990 to 2021, there has been an increasing trend since 2015 in the total AD burden. Given the increasing burden of AD on Chinese children and females, healthcare practitioners should enhance community education, improve disease management abilities of patients and caregivers, and reduce the burden and healthcare costs of AD.

Dairy intake in association with asthma symptoms among a large sample of children and adolescents: a cross-sectional study

Background and objective

Dairy products may be associated with an increased risk of asthma, although there is little scientific evidence to support this association. The goal of this study was to explore the association between dairy consumption and asthma symptoms.

Materials and methods

This cross-sectional study was conducted on children and adolescents aged 6-8 and 13-14 years living in central Iran. Dietary food consumption was assessed using a multiple-choice questionnaire. Logistic regression was used to obtain odds ratios for the association between milk, other dairy products, and total dairy consumption with the risk of asthma symptoms.

Results

In total, 7,667 participants (3,414 boys and 4,253 girls) were included in the current study. Milk intake and total dairy consumption were not associated with the likelihood of wheezing, asthma confirmed by a doctor, current asthma, and asthma medication use. In addition, there was no association between other dairy product intake and the odds of wheezing in the past 12 months in the crude model. However, after adjusting for several confounders, those in the top category had lower odds of wheezing in the past 12 months than those in the bottom category (OR: 0.58; 95% CI: 0.40-0.85).

Conclusion

The consumption of dairy products other than milk, including cheese and yogurt, might reduce the likelihood of wheezing in children and adolescents.

Consumption of milk and dairy products and risk of asthma in children: a systematic review and Meta-analysis

BACKGROUND

Some reports demonstrate that asthma benefits from milk and dairy products, however, the findings are controversial. We used meta-analysis as a tool to summarize published data on the association between dairy products consumption and asthma.

METHODS

A systematic literature search was conducted to identify studies of dairy products and asthma in children in PubMed, ISI (Web of Science), and EMBASE until 21 July 2022. Random-effect meta-analyses with summarized data were performed for total (high/low) milk and dairy intake. Subgroup analysis was used to identify sources of variation in responses. Publication bias and sensitivity analysis were done to examine the stability of results.

RESULTS

There was no correlation between consumption of dairy products and reduced risk of asthma (OR = 0.82; 95% CI: 0.60-1.05). Our results revealed that elevated consumption of milk and dairy has significant correlation with reduced risk of asthma in Non-Asian population (OR = 0.74; 95% CI = 0.51-0.96) and high quality studies (OR = 0.73; 95% CI = 0.50-0.95). No individual study influence and publication bias was seen in the sensitivity analysis and publication bias assessment.

CONCLUSION

There was no correlation between consumption of dairy products and reduced risk of asthma. However, we observed that elevated consumption of milk and dairy has significant correlation with reduced risk of asthma in Non-Asian population and high quality studies. More high-quality and population-specific studies should be conducted to determine the risk link between milk consumption and asthma in children.

Clinical outcomes of a novel porcine small intestinal submucosa patch for full-thickness hand skin defects: a retrospective investigation

OBJECTIVE

To investigate the clinical outcomes of a novel soft tissue repair patch (porcine small intestinal submucosa patch, SIS patch) in the treatment of full-thickness hand skin defects.

METHODS

From January 2017 to July 2019, 80 patients with hand soft tissue defects, who met the inclusion criteria, were retrospectively reviewed and divided into two groups. After debridement, patients in group A were treated with the novel SIS patch to cover the wound, and patients in group B were treated with autologous skin graft. The dimensions of skin defect area and healing outcome were evaluated and recorded. Scar assessment was carried out using Scar Cosmesis Assessment and Rating Scale (SCAR scale) at the last follow-up postoperation, and the recovery of wound sensation was assessed at the same time using British Medical Research Council (BMRC) grading of sensorimotor recovery. All the data were collected and statistically analyzed.

RESULTS

A total of 80 patients were enrolled in the study with 40 patients in each group. Four patients in group A and 5 patients in group B were excluded due to wound infection and lost to follow-up. There were 36 patients in group A and 35 patients in group B finally got follow-up postoperation with mean interval of 12.75 ± 5.61 months in group A and 14.11 ± 5.42 months in group B. The dimensions of skin defect area in group A ranged from 7.5 to 87.5 cm² (mean 25.97 ± 18.66 cm²) and in group B ranged from 7.5 to 86.25 cm² (mean 33.61 ± 19.27 cm²) which have no significant difference (P > 0.05). SCAR scale results of group A and group B were 10.98 ± 0.33 and 9.49 ± 0.35, respectively, and the difference was statistically significant (P < 0.05). BMRC grading results showed 6 cases of S4, 11 cases of S3+, 5 cases of S3, 6 cases of S2, 6 cases of S1 and 2 cases of S0 in group A, and 8 cases of S4, 10 cases of S3+, 7 cases of S3, 4 cases of S2, 5 cases of S1, and 1 case of S0 in group B, which had no significant difference between them (P > 0.05).

CONCLUSIONS

The novel SIS patch is an applicable biological material in the treatment of hand skin defect, which could achieve a better cosmetic appearance of the newborn skin tissue.

Sensitisation profile of Chinese allergic rhinitis patients and effectiveness of a joint allergy-ENT clinic

Purpose

House dust mite (HDM) is the predominant cause of allergic rhinitis (AR) in Hong Kong but remains under-diagnosed and -treated. The association between patient-reported outcome measures (PROMs) and nasoendoscopy findings for AR have also not been investigated. This study investigated the demographics, sensitisation patterns, quality of life, use of sublingual immunotherapy and the association of PROMs and nasoendoscopy findings in AR patients through the first allergist-otorhinolaryngologists AR joint (ARJ) clinic in Hong Kong.

Methods

This single-centred, retrospective observational study was conducted between January 2021 and December 2021. Clinical data from AR patients attending the ARJ clinic were analysed to identify the prevalence of HDM allergens, change in PROMs and the association of PROMs with nasoendoscopy scores.

Results

The three most common sensitising HDM allergens were Dermatophagoides pterynosinus (94.4%), Dermatophagoides farinae (88.9%) and Euroglyphus maynei (88.9%). At the 13- to 32-week follow-up (median 28 weeks), patients who attended the ARJ clinic had significant improvement in Total Nasal Symptom Score (TNSS; p = 0.038). The visual analogue scale (VAS) was associated with nasoendoscopy score (p = 0.018). Patients using SLIT (sublingual immunotherapy) showed overall improvements in PROMs.

Conclusion

The ARJ clinic significantly improved AR symptoms. SLIT was effective and safe for patients who failed conventional treatments. VAS positively correlated with nasoendoscopy findings. Testing for Dermatophagoides pterynosinus as a single agent during skin testing was sufficient for the diagnosis of HDM AR and should be prioritized when resources are restricted. Further studies should be done to investigate the treatment outcome of AR patients and the effectiveness of SLIT in the Chinese population.

Supplementary Information

The online version of this article (10.1007/s40629-022-00218-5) contains supplementary material, which is available to authorized users.

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.

Allergic disease and sensitization disparity in urban and rural China: A EuroPrevall-INCO study

BACKGROUND

Studies in comparison with allergic diseases and sensitization between rural and urban environments in westernized countries might be biased and not adequately reflect countries undergoing rapid transition.

METHODS

A total of 5542 schoolchildren from urban area and 5139 from rural area were recruited for the EuroPrevall-INCO survey. A subsequent case-control sample with 196 children from urban area and 202 from rural area was recruited for a detailed face-to-face questionnaire and assessment of sensitization. Skin prick tests and serum-specific IgE measurements were used to assess sensitizations against food and aeroallergens. Logistic regression analysis was used to determine associations between risk/protective factors, food adverse reactions (FAR), allergic diseases, and sensitizations.

RESULTS

Prevalence of self-reported allergic diseases, including asthma (6.6% vs.2.5%), rhinitis (23.2% vs.5.3%), and eczema (34.1% vs.25.9%), was higher in urban than in rural children. Urban children had a significantly higher prevalence of FAR and related allergic diseases, and lower food/inhalation allergen sensitization rate, than those of rural children. In urban children, frequent changing places of residency (odds ratio 2.85, 95% confidence interval: 1.45-5.81) and antibiotic usage (3.54, 1.77-7.32) in early life were risk factors for sensitization, while sensitization and family history of allergy were risk factors for allergic diseases. In rural children, exposure to rural environments in early life was protective against both allergen sensitizations (0.46, 0.21-0.96) and allergic diseases (0.03, 0.002-0.19).

CONCLUSION

We observed a disparity in rates of allergic diseases and allergen sensitization between rural and urban children. In addition to family history, the development of allergic diseases and allergen sensitization were associated with specific urban/rural environmental exposures in early life.

The Baseline Gut Microbiota Enterotype Directs Lifestyle-Induced Amelioration of Pollen Allergy Severity: A Self Controlled Case-Series Study

Deciphering the key factors underlying individual responses to a habitual diet is important in implementing personalized nutrition strategies to treat allergic diseases. This prospective randomized cohort study aimed to identify key factors determining individual pollen allergy (PA) trajectories in a natural setting. Baseline data on fecal microbiota composition, lifestyle activities, and diet habits of 190 participants with PA and 92 healthy controls were collected, followed by a SOMPO-guided intestinal activity program. Three enterotypes enriched in Bacteroides, Prevotella, and Ruminococcus and four subenterotypes for enterotypes Bacteroides and Prevotella enriched with Faecalibacterium, Megamonas, and Fusobacterium were identified at baseline. PA severity was significantly negatively correlated with the daily intake of fermented plants and no weekly intake of meat, but positively correlated with poor sleep quality. Interactions between enterotype and lifestyle factors affected PA severity, and intestinal activity intervention based on the baseline enterotype reduced the PA severity score. In conclusion, the findings of this study demonstrated that the baseline gut enterotype plays a crucial role in PA. This study suggests combining enterotype data with habitual diet can improve PA severity.

Rural environment reduces allergic inflammation by modulating the gut microbiota

Rural environments and microbiota are linked to a reduction in the prevalence of allergies. However, the mechanism underlying the reduced allergies modulated by rural residency is unclear. Here, we assessed gut bacterial composition and metagenomics in urban and rural children in the EuroPrevall-INCO cohort. Airborne dusts, including mattress and rural henhouse dusts, were profiled for bacterial and fungal composition by amplicon sequencing. Mice were repeatedly exposed to intranasal dust extracts and evaluated for their effects on ovalbumin (OVA)-induced allergic airway inflammation, and gut microbiota restoration was validated by fecal microbiota transplant (FMT) from dust-exposed donor mice. We found that rural children had fewer allergies and unique gut microbiota with fewer Bacteroides and more Prevotella. Indoor dusts in rural environments harbored higher endotoxin level and diversity of bacteria and fungi, whereas indoor urban dusts were enriched with Aspergillus and contained elevated pathogenic bacteria. Intranasal administration of rural dusts before OVA sensitization reduced respiratory eosinophils and blood IgE level in mice and also led to a recovery of gut bacterial diversity and Ruminiclostridium in the mouse model. FMT restored the protective effect by reducing OVA-induced lung eosinophils in recipient mice. Together, these results support a cause-effect relationship between exposure to dust microbiota and allergy susceptibility in children and mice. Specifically, rural environmental exposure modulated the gut microbiota, which was essential in reducing allergy in children from Southern China. Our findings support the notion that the modulation of gut microbiota by exposure to rural indoor dust may improve allergy prevention.

Time-trends for eczema prevalences among children and adults from 1985 to 2015 in China: a systematic review

Background

Several studies have reported that childhood prevalence of eczema has been increasing worldwide. However, none study quantitatively evaluated prevalence trends of eczema among children and adults in the last 30 years in China.

Methods and Findings

Via a systematic review of literature databases in English and Chinese, we summarized all studies reporting eczema prevalences from 1985 to 2015 in China as well as diagramed prevalence and eczematous population trends against year for different age groups. A total of 93 studies and 17 studies (16 for children and one for adults) were selected for qualitative and quantitative synthesis, respectively. Childhood lifetime-ever eczema prevalences ranged from 10.0% to 30.0%. Prevalences among 3-12-year-olds children showed increasing trends in most specific cities, but national lifetime-ever eczema prevalences among 13-14-year-olds children decreased from 10.6% in 2001 to 8.6% in 2009 in mainland China. We estimated that about 1.5 million children aged 13-14-year-olds in 2009 and 15.5 million children aged 3-6-year-olds in 2012 had lifetime-ever eczema in mainland China. Similar studies were too few to ascertain time-trends of eczema prevalence among adults. About 39.4, 20.0, and 11.6 million adults aged 15-86-year-olds in 2010 had contact dermatitis, seborrheic dermatitis, and atopic dermatitis in the mainland China, respectively.

Conclusions

The burden of eczema became heavier in young children, whereas perhaps had been reduced in adolescent in China. More studies for eczema prevalence in adults are warranted.

Prevalence of adult eczema, hay fever, and asthma, and associated risk factors: a population-based study in the northern Grassland of China

Background

There has been research about the prevalence and risk factors of eczema, hay fever, and asthma in children, but little is known about these conditions in adults in China.

Objectives

To explore the prevalence of adult eczema/atopic dermatitis (AD) and its risk factors in northern China.

Methods

A cluster sampling randomized population-based survey was conducted using a face-to-face questionnaire combined with skin prick tests of ten common aeroallergens including nine pollen allergens and Dermatophagoides pteronyssinu (Dp) allergen. The questionnaire was designed by specialists and included questions on the prevalence of eczema, hay fever, and asthma, socioeconomic risk factors, family history of atopy and environmental exposures. The prevalence of eczema with asthma and/or hay fever (EAH) was applied as a proxy of AD in this study.

Results

Overall, 2096 subjects were enrolled and completed the study. The prevalence of eczema was 15.7% (95% CI 14.3–17.4), while the prevalence of hay fever and asthma were 20.6% (95% CI 18.9–22.4) and 6.5% (95% CI 5.5–7.6), respectively. In particular, the prevalence of EAH was 5.1% (95% CI 4.4–7.0). The prevalence of eczema and EAH was significantly associated with younger age, atopy family history, high education level, urbanization, and antibiotic overuse (P < 0.05, logistic regression). The sensitization rate was higher in EAH compared with eczema (48.2% vs 41.0%, P = 0.018), with weed pollen sensitization being the most common. Subjects with two or more concomitant allergic diseases had increased risk of eczema and EAH (P < 0.001). Allergen sensitization increased the risk of eczema and EAH (P < 0.001, both).

Conclusions

Adult eczema and EAH are prevalent in northern China under high pollen exposure. Socioeconomic and environmental factors affected the prevalence of adult AD in China. Dp had a particular impact on the prevalence of eczema/AD in the grassland region.

High milk consumption is associated with carotid atherosclerosis in middle and old-aged Chinese

Background

Carotid atherosclerosis (CA) can reflect atherosclerotic status of systemic vessels, and is associated with ischemic stroke and cognitive impairment. Milk consumption is growing in China, and data are limited on the association between milk and CA risk.

Methods

Participants aged ≥40 years in China National Stroke Prevention Project were recruited for carotid ultrasound examination, and those with carotid endarterectomy, carotid stenting stroke or coronary heart disease were excluded. Participants were defined as having CA when intima-media thickness (IMT) ≥1 mm or plaques were detected by ultrasonography. For milk consumption, though contents were not analyzed, people were divided into high consumption (≥200 ml/day and ≥5 day/week) and low consumption (occasional or never) groups. Multivariate logistics regression analyses were done in both full and propensity score-matched population to identify the association between milk consumption and CA.

Results

84880 participants were included in the final analysis. After being adjusted by age, gender, living location, smoking habits, drinking habits, physical activity, obesity, hypertension, diabetes, and dyslipidemia, high milk consumption is associated with CA in both full population (odds ratio [OR] = 1.26, 95% confidence interval [CI] 1.19-1.33) and propensity score-matched population (OR = 1.25, 95%CI 1.17-1.34). High milk consumption is also a risk factor for IMT thickening (OR = 1.15, 95%CI 1.08-1.23), carotid plaque formation (OR = 1.17, 95%CI 1.09-1.25) and carotid stenosis over 50% (OR = 1.52, 95%CI 1.10-2.14) in the propensity score-matched population.

Conclusions

High milk consumption is related to CA in middle and old-aged Chinese population. More cautious advice on milk intake should be given in this population for prevention of atherosclerosis.

Adult and Pediatric Food Allergy to Chickpea, Pea, Lentil, and Lupine: A Scoping Review

BACKGROUND

Nonpriority legume allergies, which include chickpea, pea, lentil, and lupine, are frequently implicated in severe allergic reactions. Yet, studies on public health knowledge and educational needs are near-absent.

OBJECTIVE

To summarize what is known from the existing literature about nonpriority legume food allergy.

METHODS

Eligible, original research articles reported on both nonpriority legume food allergy and 1 or more of prevalence, burden, food labeling information, or current education strategies. Screening was performed by 2 independent reviewers. Conflicts were discussed and if consensus could not be reached, a third reviewer was consulted.

RESULTS

Of the 8976 titles identified, 47 were included subsequent to full-text screening. Most studies identified focused on prevalence, and were conducted in Europe, with additional studies from Asia, and North America. Although we defined burden quite broadly, few studies addressed the burden of nonpriority legume food allergens. Moreover, no studies addressed labeling or educational needs for these allergens.

CONCLUSIONS

Our review of the literature found current research focused on the prevalence of nonpriority legume allergy with significant gaps regarding burden, allergen labeling, and education strategies. To this end, further research on these aspects of nonpriority legume allergy is warranted.

Allergic sensitization in patients with rhinitis and bronchial asthma in Ningxia region of China

BACKGROUND

Allergic rhinitis and bronchial asthma are common allergic diseases. The pattern of dominant allergens depends on the degree of urbanization and the geographic region. The present study characterized the allergens of patients with allergic rhinitis and bronchial asthma in Ningxia region of China.

METHODS

A total of 309 patients were enrolled in this study. Western blotting assays were performed of the serum samples to evaluate allergen-specific IgE antibody for inhaled and ingested allergens. Statistical analysis was performed to compare the positive rate among different subgroups.

RESULTS

Among the 309 patients, 221 of them had positive test results. There were 157 positive cases for ingested allergens and 174 positive cases for inhaled allergens. No significant differences in positive rates were found between the ingested and inhaled allergens. Among the inhaled allergens, Artemisia was the most frequent allergen, followed by fungi and dog hair. Cashew was the most common ingested allergen, followed by crab, mango, and beef. Further analysis showed no significant differences in positive rate between males and females. However, significant differences in positive rate of inhaled and ingested allergens were found between children (1-13 years old) and adults (above 18 years old) (P < .05), while no significant differences were found between the children and teenagers (14-18 years old). For the comparison between teenagers and adults, significant difference in positive rate was found only in the ingested allergen.

CONCLUSION

This study provided the characteristics of allergens in Ningxia population, providing clinical and epidemiological data for prevention and treatment of the diseases in the region.

Association of bacterial load in drinking water and allergic diseases in childhood

BACKGROUND

Treatment of drinking water may decrease microbial exposure.

OBJECTIVE

To investigate whether bacterial load in drinking water is associated with altered risk of allergic diseases.

METHODS

We recruited 1,110 schoolchildren aged 6-16 years between 2011 and 2013 in Požega-Slavonia County in Croatia, where we capitalized on a natural experiment whereby individuals receive drinking water through public mains supply or individual wells. We obtained data on microbial content of drinking water for all participants; 585 children were randomly selected for more detailed assessments, including skin prick testing. Since water supply was highly correlated with rural residence, we compared clinical outcomes across four groups (Rural/Individual, Rural/Public, Urban/Individual and Urban/Public). For each child, we derived quantitative index of microbial exposure (bacterial load in the drinking water measured during the child's first year of life).

RESULTS

Cumulative bacterial load in drinking water was higher (median [IQR]: 6390 [4190-9550] vs 0 [0-0]; P < .0001), and lifetime prevalence of allergic diseases was significantly lower among children with individual supply (5.5% vs 2.3%, P = .01; 14.4% vs 6.7%, P < .001; 25.2% vs 15.1%, P < .001; asthma, atopic dermatitis [AD] and rhinitis, respectively). Compared with the reference group (Urban/Public), there was a significant reduction in the risk of ever asthma, AD and rhinitis amongst rural children with individual supply: OR [95% CI]: 0.14 [0.03,0.67], P = .013; 0.20 [0.09,0.43], P < .001; 0.17 [0.10,0.32], P < .001. Protection was also observed in the Rural/Public group, but the effect was consistently highest among Rural/Individual children. In the quantitative analysis, the risk of allergic diseases decreased significantly with increasing bacterial load in drinking water in the first year of life (0.79 [0.70,0.88], P < .001; 0.90 [0.83,0.99], P = .025; 0.80 [0.74,0.86], P < .001; current wheeze, AD and rhinitis).

CONCLUSIONS AND CLINICAL RELEVANCE

High commensal bacterial content in drinking water may protect against allergic diseases.

[Prevalence of pediatric asthma in the rural areas of China: a Meta analysis]

OBJECTIVE

To systematically review the prevalence of pediatric asthma in the rural areas of China, and to provide data for the prevention and treatment of pediatric asthma.

METHODS

PubMed, Cochrane, China National Knowledge Infrastructure, Wanfang Database, and Embase were searched for cross-sectional studies on the prevalence of pediatric asthma in the rural areas of China published up to August 31, 2019. Two researchers independently conducted preliminary screening and data extraction. Stata 14.0 and R software were used to perform a Meta analysis of prevalence rate. Subgroup analysis was also performed.

RESULTS

A total of 24 articles were reviewed, with a sample size of 212 814 children, among whom there were 3 254 children with asthma, with an overall prevalence rate of 2.02% (95%CI: 1.67%-2.36%). Boys had a significantly higher prevalence rate than girls (3.64% vs 2.03%, P<0.001). The annual prevalence rate increased from 1.21% in 1990-1999 to 3.36% in 2011-2015. The prevalence rate of pediatric asthma was 3.15% in South China, which was higher than that in East China (2.31%), Southwest China (2.15%), North China (1.19%), and Central China (1.12%). Preschool children had the highest prevalence rate of 2.63%, followed by infants and young children (2.48%) and school-age children (1.41%).

CONCLUSIONS

The prevalence rate of pediatric asthma is relatively low but tends to increase in the rural areas of China. Boys have a higher prevalence rate of asthma than girls, and the prevalence rate is higher in South China. Preschool children have the highest prevalence rate.

Distribution characteristics of cow's milk-sIgE components in children with respiratory allergic diseases in southern China

Background

Cow’s milk (CM) is the main food allergen for toddlers and infants. Presently, studies on CM specific immunoglobulin E (sIgE) sensitization and positive distribution of CM components ALA-, CAS-, and BLG-sIgE are lacking in infants with respiratory allergic diseases, especially in southern China. This study therefore aimed to investigate the distribution of CM sensitization and the relation between its components α-lactalbumin (ALA), β-lactoglobulin (BLG) and casein (CAS) sIgE in children with respiratory allergic diseases in southern China.

Methods

A total of 1839 children (≤12 years) with respiratory diseases and detected CM-sIgE levels were included. Serum samples were collected from the Respiratory Diseases Bioresources Center of the National Center for Respiratory Diseases in southern China from August 2012 to July 2017. ALA-, BLG-, and CAS-sIgE were detected and questionnaires were completed in 103 children.

Results

A total of 36.7% children were positive for CM-sIgE. CM-sIgE levels were higher in asthmatic bronchitis (AB) group than in other allergic respiratory disease groups (all P < 0.05). Among the 103 CM-sIgE-sensitized children, 64.08% had a history of family allergies. There were 84.47% of the children who tested positive for two or more sIgE components. The average ALA-, BLG-, and CAS-sIgE levels were 1.91 kU/L, 1.81 kU/L, and 0.62 kU/L, respectively. The CM-sIgE level showed a correlation with BLG-sIgE (r_s = 0.833), ALA-sIgE (r_s = 0.816), and CAS-sIgE (r_s = 0.573) levels (all p < 0.001).

Conclusions

In southern China, CM-sIgE levels were higher in children with AB than in those with other respiratory allergic diseases. ALA and BLG were the main allergenic components detected in CM-sIgE-sensitized children with respiratory allergic diseases.

Allergic children with extremely high total IgE but no allergen identified in the initial screening panel

BACKGROUND

High serum IgE level in atopic children usually implies a highly sensitized condition. However, there is a subgroup of atopic children for whom a specific allergen cannot be identified. In this study, we analyzed follow-up data from these children.

METHODS

From March 2014 to July 2017, we recruited 14 atopic children with serum total IgE level higher than 500 Ku/L, but with no specific allergen identified by repeated MAST tests initially. Follow-up studies of specific IgE were conducted by the OPTIGEN MAST Allergy test and ImmunoCAP assays (Thermo Fisher Scientific/Phadia), while total IgE and specific IgG were measured by ImmunoCAP.

RESULTS

The patients were aged from 2 to 17 y/o. The follow-up MAST tests showed significantly positive results in 10 patients. There were no significant differences in any of the clinical characteristics between the MAST-positive and MAST-negative groups. In the MAST-negative group, five allergen-specific IgE antibodies, including those for cockroach, Euroglyphus maynei, Blomia tropicalis, shrimp, and crab, were strongly predictive of negative ImmunoCAP results, according to ROC (Receiver operating characteristic curve) analysis of the AUC (Area under the Curve of ROC) (0.70-0.95), with significance set at p < 0.05.

CONCLUSION

In two thirds of atopic children with a high serum IgE whose specific allergen had yet to be identified, it was possible to identify the specific MAST allergen(s) after an average follow-up of 33.2 months. For patients who still had negative results in follow-up MAST, mite DP, DF, and DM may be suitable choices for further allergen identification by ImmunoCAP.

Soy Preparations Are Potentially Dangerous Factors in the Course of a Food Allergy

The special properties of soy preparations make them common additives for food production and can be dangerous for sensitive individuals. Our aim was to check consumers’ awareness of potential risks of soy preparations added to numerous food products, depending on respondents’ education, and to evaluate immunoreactive properties of chosen soy preparations. A personal questionnaire was used. Respondents (n = 251) were aged 23–28 years old, lived in Poland, and were graduates or students in their last year of food technology, medicine, and university of technology. The slot blot and Western blotting methods were used to mark immunoreactivity of soy preparations. It was shown that most respondents often or usually read labels of food products they buy. The surveyed indicated protein is the allergenic component in soy. Almost half of them were of the opinion that hydrolysis removes the allergenic properties of soy. Most of the medical students surveyed thought that people allergic to soy may consume products that contain soy preparations. The analytical results indicated that soy preparation contained protein fractions that were immunoreactive with sera of allergenic patients. It was proven that preparations, even hydrolysates, contain immunoreactive proteins that may be the source of hidden allergens, even though they are not recognized as dangerous by well-educated respondents.

Urbanisation and asthma in low-income and middle-income countries: a systematic review of the urban-rural differences in asthma prevalence

BACKGROUND

Urbanisation has been associated with temporal and geographical differences in asthma prevalence in low-income and middle-income countries (LMICs). However, little is known of the mechanisms by which urbanisation and asthma are associated, perhaps explained by the methodological approaches used to assess the urbanisation-asthma relationship.

OBJECTIVE

This review evaluated how epidemiological studies have assessed the relationship between asthma and urbanisation in LMICs, and explored urban/rural differences in asthma prevalence.

METHODS

Asthma studies comparing urban/rural areas, comparing cities and examining intraurban variation were assessed for eligibility. Included publications were evaluated for methodological quality and pooled OR were calculated to indicate the risk of asthma in urban over rural areas.

RESULTS

Seventy articles were included in our analysis. Sixty-three compared asthma prevalence between urban and rural areas, five compared asthma prevalence between cities and two examined intraurban variation in asthma prevalence. Urban residence was associated with a higher prevalence of asthma, regardless of asthma definition: current-wheeze OR:1.46 (95% CI:1.22 to 1.74), doctor diagnosis OR:1.89 (95% CI:1.47 to 2.41), wheeze-ever OR:1.44 (95% CI:1.15 to 1.81), self-reported asthma OR:1.77 (95% CI:1.33 to 2.35), asthma questionnaire OR:1.52 (95% CI:1.06 to 2.16) and exercise challenge OR:1.96 (95% CI:1.32 to 2.91).

CONCLUSIONS

Most evidence for the relationship between urbanisation and asthma in LMICs comes from studies comparing urban and rural areas. These studies tend to show a greater prevalence of asthma in urban compared to rural populations. However, these studies have been unable to identify which specific characteristics of the urbanisation process may be responsible. An approach to understand how different dimensions of urbanisation, using contextual household and individual indicators, is needed for a better understanding of how urbanisation affects asthma.

PROSPERO REGISTRATION NUMBER

CRD42017064470.

Increasing Prevalence of Allergic Rhinitis in China

Allergic rhinitis (AR) is a critical public health, medical and economic problem in China. AR is also an important risk factor which will cause many diseases or disorders, especially in children. The trend of AR incidence is still on the rise in recent years and has had a significant effect on the general public. This significant increase is alarming, which highlights an urgent need for better understanding of the prevalence status and characteristics, sensitization patterns, and the associated risk factors of AR in order to improve treatment and develop effective prevention strategies.

Human umbilical cord-derived mesenchymal stem cells ameliorate the enteropathy of food allergies in mice

Food allergy prevalence has steadily increased worldwide over the past decades and immunotherapeutic treatment strategies are gaining attention. Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) exhibit similar immune regulatory properties to bone marrow-derived MSCs. hUC-MCSs can be prepared with fewer ethical constraints and are potential candidates for allergic disorder therapies. The current study aimed to investigate potential antiallergic properties of hUC-MSCs in mice with ovalbumin (OVA)-induced food allergy. Administration of hUC-MSCs cells intraperitoneally combined with oral gavage of the culture medium significantly alleviated OVA-induced diarrhea symptoms. Additionally, this treatment significantly decreased IgE levels and the percentage of T helper 2 cells in the blood, which were increased in mice with OVA-induced food allergy. The mRNA levels of the inflammatory cytokines interleukin-4 and tumor necrosis factor-α, and inflammatory cell infiltration in mouse colons were significantly decreased in hUC-MSCs-treated animals compared with mice with OVA-induced food allergy. Goblet cells were detected in colons of allergy-induced mice and their numbers were reduced following treatment with hUC-MSCs. In addition, treatment with hUC-MSCs reestablished the gut flora. The results revealed that hUC-MSCs may have a potential application in food allergy therapy.

Legume Protein Consumption and the Prevalence of Legume Sensitization

Sensitization and allergy to legumes can be influenced by different factors, such as exposure, geographical background, and food processing. Sensitization and the allergic response to legumes differs considerably, however, the reason behind this is not yet fully understood. The aim of this study is to investigate if there is a correlation between legume protein consumption and the prevalence of legume sensitization. Furthermore, the association between sensitization to specific peanut allergens and their concentration in peanut is investigated. Legume sensitization data (peanut, soybean, lupin, lentil, and pea) from studies were analyzed in relation to consumption data obtained from national food consumption surveys using the European Food Safety Authority (EFSA), Global Environment Monitoring System (GEMS), and What We Eat in America-Food Commodity Intake Database (WWEIA-FCID) databases. Data were stratified for children <4 years, children 4⁻18 years, and adults. Sufficient data were available for peanut to allow for statistical analysis. Analysis of all age groups together resulted in a low correlation between peanut sensitization and relative peanut consumption (r = 0.407), absolute peanut consumption (r = 0.468), and percentage of peanut consumers (r = 0.243). No correlation was found between relative concentrations of Ara h 1, 2, 3, 6, 7, and 8 in peanut and sensitization to these peanut allergens. The results indicate that the amount of consumption only plays a minor role in the prevalence of sensitization to peanut. Other factors, such as the intrinsic properties of the different proteins, processing, matrix, frequency, timing and route of exposure, and patient factors might play a more substantial role in the prevalence of peanut sensitization.

Cockroach is a major cross-reactive allergen source in shrimp-sensitized rural children in southern China

BACKGROUND

Little is known about the prevalence of food allergy (FA) in China. The aim of this study was to investigate the disparity of FA between urban and rural areas in southern China.

METHODS

EuroPrevall questionnaire responses were obtained from 5542 school-age children in urban Guangzhou and 5319 in rural Shaoguan. A case-control study enrolled 190 children with adverse reactions (ARs) after food intake as cases and 212 controls in Guangzhou, whereas 116 cases and 233 controls in Shaoguan. These subjects underwent skin prick test (SPT) and serum IgE measurements to food and inhalant allergens. Allergen extracts from shrimp, house dust mite (HDM), and cockroach were prepared for IgE cross-reactivity testing in 23 Guangzhou and 20 Shaoguan shrimp-sensitized subjects.

RESULTS

The prevalence of ARs to shrimp was higher in Guangzhou than in Shaoguan children (3.5% vs 1.4%, P < .001). However, sensitization rate to shrimp (SPT: 3.7% vs 11.2%, P = .015; IgE: 12.6% vs 36.2%, P < .001) and cockroach (SPT: 5.3% vs 33.5%; IgE: 2.6% vs 27.6%, P < .001) was lower in Guangzhou. A significant correlation between shrimp and HDM/cockroach IgE was found in Shaoguan children. The proportions of positive IgE to tropomyosin (Pen a 1, Der p 10) were lower than 7.4% in both areas. Cockroach allergen has a significantly higher inhibition rate of binding to IgE to house dust mite allergens in Shaoguan sera.

CONCLUSION

Shrimp is a common allergic food in southern China. Higher proportion of shrimp sensitization in rural subjects could be explained by cross-reactivity to cockroach. Tropomyosin was not a major allergen responding to the cross-reactivity.

Self-reported questionnaire survey on the prevalence and symptoms of adverse food reactions in patients with chronic inhalant diseases in Tangshan city, China

Background

The prevalence of adverse food reactions in patients with chronic inhalant diseases has seldom been studied in China. This study is to investigate the prevalence of adverse food reactions and the symptoms caused in respiratory patients.

Methods

Respiratory patients in allergy clinics were asked to complete a questionnaire. Patients’ information such as age, gender, family history of allergy, and adverse reactions to a list of 48 foods and the symptoms caused, was recorded. Multivariate analyses were performed to determine the prevalence of adverse food reactions and their associated symptoms.

Results

459 subjects, with an average age of 32 years old, completed the questionnaire; 45.3% were male. Among the 459 subjects, 38.1% (175/459) had an adverse reaction to food: 13.6% had an adverse food reaction to crab, 12.4% had an adverse food reaction to shrimp; and 9.9% had an adverse reaction to shellfish. Peach and nectarine were also shown to be common causative foods with 6.8% of the study group showing an adverse reaction to peach and 5.2% to nectarine. Seafood mainly caused skin symptoms and fruits gave rise to more throat, oral, and gastrointestinal problems.

Conclusion

The prevalence of adverse food reactions is high for patients with respiratory diseases. This indicates that adverse food reactions should be considered in the treatment and management of patients with chronic inhalant diseases.

Electronic supplementary material

The online version of this article (10.1186/s13223-017-0228-3) contains supplementary material, which is available to authorized users.

A cross-sectional observational study on allergen-specific IgE positivity in a southeast coastal versus a southwest inland region of China

Few studies addressed trans-regional differences in allergen sensitization between areas within a similar latitudinal range but with distinct geomorphological features. We investigated specific IgE (sIgE) positivity to common allergens in populations from two southern China provinces. Using a uniformed protocol, serum samples were collected from 2778 subjects with suspected atopy in coastal Guangdong and inland Yunnan. The overall prevalence of sIgE positivity were 57.8% (95% CI: 56.0%, 59.6%) from Guangdong vs 60.9% (95% CI: 59.1%, 62.7%) from Yunnan. House dust mite (d1) was the most common allergen in both regions. Among d1-sensitized subjects, only 35.7% (208/583) in Guangdong and 22.9% (147/642) in Yunnan tested positive for d1 alone. Among those poly-sensitized d1-positive subjects, cockroach was the most common co-sensitizing aeroallergen. 41.9% of the d1-sensitized Guangdong subjects showed high-class sIgE reactivity (≥class 4), in contrast to a very low percentage of such reactivity in Yunnan. However, 36.3% of d1-sensitized subjects in Yunnan were concomitantly positive for tree pollen mix. Surprisingly, Yunnan subjects showed high prevalence of sIgE positivity for crabs and shrimps, either by overall or by age-group analysis, compared with their Guangdong counterparts (both P < 0.05). These findings may add to data about local allergies in China and worldwide.

Dietary patterns and the risk of rhinitis in primary school children: a prospective cohort study

This study was to investigate the association between dietary patterns and rhinitis in primary school children. 1,599 students without rhinitis at baseline survey were selected from a primary school children cohort. Information on food consumption, respiratory symptoms, and confounders was collected using questionnaires. Dietary patterns were defined using principal component analysis. Logistic regression was performed to calculate odds ratio (OR) with 95% confidence intervals (95% CI). The incidence of rhinitis during 12 months follow-up was 21.2%. Three patterns were extracted and labeled as pattern I, II and III. Dietary pattern II which had higher factor loadings of legumes, butter, nuts and potatoes was associated with an increased risk of rhinitis (OR: 1.34, 95% CI: 1.01-1.87) when the highest tertile of pattern score was compared to the lowest tertile, after adjusted for confounders. Besides, every 1-unit increase of score of pattern II was also associated with an increased risk of rhinitis (OR: 1.19, 95% CI: 1.05-1.35). Neither pattern I nor Pattern III was observed to be associated with risk of rhinitis. A diet with higher levels of consumption of legumes, butter, nuts and potatoes may increase the risk of allergic rhinitis in primary school children.

IgE-binding potencies of three peach Pru p 1 isoforms

SCOPE

Pru p 1, the Bet v 1 homologue from peach, has been identified as a clinically relevant allergen. Three isoforms have been described, two in peach fruit (Pru p 1.0101 and Pru p 1.0201) and one in pollen (Pru p 1.0301). The present study aimed to compare their IgE-binding potencies.

METHODS AND RESULTS

Three Pru p 1 isoforms were cloned and expressed as soluble proteins with His-tags in Escherichia coli. Protein identity was confirmed by MS, circular dichroism, and RNAse activity. IgE-binding capacity using ELISA and ImmunoCAP was compared. Three Pru p 1 isoforms had quite similar IgE-binding potencies for 60% of the sera, but more than twofold between any two isoforms among 40% of the 47 sera. The mean IgE binding of Pru p 1.0201 was slightly higher than other two isoforms. In a sera pool, homologous ImmunoCAP inhibition was higher than other two heterologous isoforms. Individual serum with diverse IgE values of three isoforms demonstrated the higher IgE inhibition of specific isoform with higher IgE value.

CONCLUSION

A similar and variable pattern of IgE recognition was observed among three Pru p 1 isoforms. The two new isoforms can be used as more accurate diagnostic reagents.

Associations of Early Life Exposures and Environmental Factors With Asthma Among Children in Rural and Urban Areas of Guangdong, China

BACKGROUND

Environmental factors may play important roles in asthma, but findings have been inconsistent.

OBJECTIVE

The goal of this study was to determine the associations between early life exposures, environmental factors, and asthma in urban and rural children in southeast China.

METHODS

A screening questionnaire survey was conducted in 7,164 children from urban Guangzhou and 6,087 from rural Conghua. In the second stage, subsamples of 854 children (419 from Guangzhou, 435 from Conghua) were recruited for a case-control study that included a detailed questionnaire enquiring on family history, early life environmental exposures, dietary habits, and laboratory tests (including histamine airway provocation testing, skin prick tests, and serum antibody analyses). House dust samples from 76 Guangzhou families and 80 Conghua families were obtained to analyze levels of endotoxins, house dust mites, and cockroach allergens.

RESULTS

According to the screening survey, the prevalence of physician-diagnosed asthma was lower in children from Conghua (3.4%) than in those from Guangzhou (6.9%) (P < .001). A lower percentage of asthma was reported in rural subjects compared with urban subjects (2.8% vs. 29.4%; P < .001) in the case-control study. Atopy (OR, 1.91 [95% CI, 1.58-2.29]), parental atopy (OR, 2.49 [95% CI, 1.55-4.01]), hospitalization before 3 years of age (OR, 2.54 [95% CI, 1.37-4.70]), high consumption of milk products (OR, 1.68 [95% CI, 1.03-2.73]), and dust Dermatophagoides farinae group 1 allergen (OR, 1.71 [95% CI, 1.34-2.19]) were positively associated with asthma. Living in a crop-farming family at < 1 year of age (OR, 0.15 [95% CI, 0.08-0.32]) and dust endotoxin levels (OR, 0.69 [95% CI, 0.50-0.95]) were negatively associated with asthma.

CONCLUSIONS

Rural children from an agricultural background exhibited a reduced risk of asthma. Early life exposure to crop farming and high environmental endotoxin levels might protect the children from asthma in southern China.

Environmental protection from allergic diseases: From humans to mice and back

Allergic diseases have a strong environmental component, illustrated by the rapid rise of their prevalence in the Western world. Environmental exposures have been consistently shown to either promote or protect against allergic disease. Here we focus on protective exposures and the pathways they regulate. Traditional farming, natural environments with high biodiversity, and pets in the home (particularly dogs) have the most potent and consistent allergy-protective effects and are actively investigated to identify the environmental and host-based factors that confer allergy protection. Recent work emphasizes the critical protective role of microbial diversity and its interactions with the gut/lung and skin/lung axes-a cross-talk through which microbial exposure in the gut or skin powerfully influences immune responses in the lung.