Risk Factor For Allergic Diseases Research Articles

Inflammatory bowel disease and allergic diseases: A Mendelian randomization study.

Inflammatory bowel disease (IBD) and allergic diseases possess similar genetic backgrounds and pathogenesis. Observational studies have shown a correlation, but the exact direction of cause and effect remains unclear. The aim of this Mendelian randomization (MR) study is to assess bidirectional causality between inflammatory bowel disease and allergic diseases. We comprehensively analyzed the causal relationship between inflammatory bowel disease (IBD), Crohn's disease (CD), ulcerative colitis (UC) and allergic disease (asthma, Hay fever, and eczema) as a whole, allergic conjunctivitis (AC), atopic dermatitis (AD), allergic asthma (AAS), and allergic rhinitis (AR) by performing a bidirectional Mendelian randomization study using summary-level data from genome-wide association studies. The analysis results mainly came from the random-effects model of inverse variance weighted (IVW-RE). In addition, multivariate Mendelian randomization (MVMR) analysis was conducted to adjust the effect of body mass index (BMI) on the instrumental variables. The IVW-RE method revealed that IBD genetically increased the risk of allergic disease as a whole (OR = 1.03, 95% CI = 1.01-1.04, fdr.p = .015), AC (OR = 1.04, 95% CI = 1.01-1.06, fdr.p = .011), and AD (OR = 1.06, 95% CI = 1.02-1.09, fdr.p = .004). Subgroup analysis further confirmed that CD increased the risk of allergic disease as a whole (OR = 1.02, 95% CI = 1.00-1.03, fdr.p = .031), AC (OR = 1.03, 95% CI = 1.01-1.05, fdr.p = .012), AD (OR = 1.06, 95% CI = 1.02-1.09, fdr.p = 2E-05), AAS (OR = 1.05, 95% CI = 1.02-1.08, fdr.p = .002) and AR (OR = 1.03, 95% CI = 1.00-1.07, fdr.p = .025), UC increased the risk of AAS (OR = 1.02, 95% CI = 0.98-1.07, fdr.p = .038). MVMR results showed that after taking BMI as secondary exposure, the causal effects of IBD on AC, IBD on AD, CD on allergic disease as a whole, CD on AC, CD on AD, CD on AAS, and CD on AR were still statistically significant. No significant association was observed in the reverse MR analysis. This Mendelian randomized study demonstrated that IBD is a risk factor for allergic diseases, which is largely attributed to its subtype CD increasing the risk of AC, AD, ASS, and AR. Further investigations are needed to explore the causal relationship between allergic diseases and IBD.

Residual profiles and health risk of indoor allergens in China

Exposure to indoor allergens is a principal risk factor for allergic diseases. However, most of the previous studies on indoor allergens focused on very limited kinds of allergens in China. Knowledge of the simultaneous exposure to multiple allergens is still lacking. In this study, the residual profiles of 8 allergens were investigated in 166 dust samples from 11 cities in China. The house dust mite allergens including Der p 1, Der f 1, and Der 2 were detected in the range of <0.02–283.83 μg/g dust. The concentrations of dog allergen Can f 1 and cat allergen Fel d 1 varied widely, from <0.84–22,896.46 μg/g dust for Can f 1 and from <0.02–6298.96 μg/g dust for Fel d 1. Cockroach allergen Bla g 2 was detected in 68% of the samples but at a low level with a maximum of 9.44 μg/g dust. Comparatively low detection frequencies were found for mouse allergen Mus m 1 as 37% and for fungi allergen Asp f 2 as 24%. The frequency of cleaning sheets/bedding was negatively correlated to the levels of house dust mite allergens. The presence of pets indoors was associated with higher levels of pet allergens and lower levels of house dust mite allergens and cockroach allergen. Risk evaluation reveals that at least 4 allergens were found in more than 80% of the rooms and more than 2 allergens with median/high risk were detected in 42% of the rooms, indicating that simultaneous exposure to multiple allergens is prevalent in China.

Prevalence of Allergic Diseases and Risk Factors in Preschool Children

Allergic diseases are very common in children. The aim of this study is to obtain information about the frequency and risk factors of allergic diseases in kindergarten children aged 3-6 years. This study was carried out between 13.02.2018 and 30.12.2018 in kindergartens, in accordance with the ISAAC Phase I protocol for children aged 3-6 years. The study was carried out by distributing 3000 questionnaires in 20 kindergartens. 2001 out of 2040 collected questionnaires were included in the study. Of the participants, 986 (49.3%) were female and 1015 (50.7%) were male. The frequency of asthma symptoms was 30.4% (n=608). The frequency of allergic rhinitis symptoms was found to be 37.1% (743 people). The risk of asthma symptoms was significantly higher in males, those whose mothers smoked during pregnancy, those born preterm, those with a smoker at home and those with mold in the home (p

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

To investigate the lifestyle and stress of mothers during pregnancy to analyze the risk factors for the disease in early childhood. A cross-sectional survey was conducted from January 2022 to June 2022 in a sub-district in Guangzhou, China. A total of 3437 valid questionnaires were eventually collected. The questionnaire consisted of 56 questions in three sections included questions on child's birth conditions and early life environment, questions on mother's lifestyle during pregnancy, and questions about father. 49.75% of the children were likely to have allergic diseases (suspected allergy group). There were more boys in the suspected allergy group (58% vs 50%), and the percentage of children born at first birth was also higher in the suspected allergy group (61% vs 51%). 67% to 69% of children had suspicious allergies when one parent claimed an allergy, and 80.1% when both parents reported an allergy. The results of the multifactorial logistic model showed that male had 1.49 (1.28 to 1.73) times the risk of allergic diseases than female, and preterm births increased the risk of allergic diseases by 1.53 (1.13-2.07) times compared to full-term births. Both unplanned pregnancies and pregnancy complications increased the risk of allergic diseases in children before school age [1.34 (1.15-1.55) and 1.82 (1.46-2.26)]. Among pregnant women who reported regular passive smoking, the risk of the disease was increased 2.43 (1.71 to 3.50) times in preschool children. Reported allergies in all family members were significant risk factors for allergic diseases in children, especially mother [2.88 (2.41~3.46)]. In the prenatal period, maternal negative emotions are more common in children with suspected allergies. Nearly half of the children in the region suffer from allergic diseases. Sex, birth order and full-term delivery all contributed to early childhood allergy. Family history of allergy, especially maternal, was the most important risk factor, and the number of family members with allergy was significantly associated with the allergy in children. Maternal effects are also reflected in prenatal conditions such as unplanned pregnancy, smoke exposure, pregnancy complications, and prenatal stress.

Prevalence and Risk Factors of Allergic Diseases Among School Students in Tabuk: A Cross-Sectional Study.

Allergic diseases such as bronchial asthma, allergic rhinitis, and atopic dermatitis are common health problems among children. The prevalence of different allergic diseases is increasing in the Kingdom of Saudi Arabia. This study aimed to estimate the prevalence and risk factors of allergic diseases among school students in Tabuk, Saudi Arabia. This cross-sectional analytical study was conducted in Tabuk city, Saudi Arabia, between the first of August and the end of September, 2022. Students from primary, intermediate, and secondary schools were included. A predesigned, structured, self-administered questionnaire in the Arabic language was used to collect data. This study included 384 school students from Tabuk, Saudi Arabia. The age of the recruited students ranged from five to 19 years old. The prevalence of clinically diagnosed bronchial asthma that occurred at any time in the past was 31.8%.The prevalence of asthma symptoms was 51.0% for lifetime wheezingand 45.8% for current wheezing (in the past 12 months). The prevalence rates of clinically diagnosed allergic rhinitis and atopic dermatitis were 56.8% and 30.2%, respectively. Further, 68.2% of the school students had one or more of the diagnosed allergic diseases. The second or more childbirth orders were significantly associated with an increased risk of allergic diseases (adjusted odds ratio [AOR] = 3.140, 95% CI: 1.864-5.288). A family history of asthma or atopic conditions showed 3.118 times increased likelihood of allergic conditions (AOR = 3.118, 95% CI: 1.827-5.320). Other significant risk factors were the father's smoking (AOR = 1.698, 95% CI: 1.024-2.817) and having a dog, cat, or bird at home (AOR = 0.493, 95% CI: 0.257-0.946). The prevalence of bronchial asthma and other allergic diseases such as allergic rhinitis and atopic dermatitis among school students in Tabuk city, Saudi Arabia, is alarmingly high. Furthermore, both genetic and environmental components of allergic disease pathogenesis have been identified as risk factors.

Transgenerational development of food allergies and allergic rhinitis

Both environmental and genetic factors play a role in allergies. Allergies are influenced by genes and how they control immune cell function. Several studies have examined the occurrence of allergic disease in children and its association with other risk factors, including allergic disease in parents. Specific toxins like CO2 and other health conditions can be related to the diagnosis of allergic rhinitis. The response to food allergies was observed in many studies to conclude that heritability from parents to offspring is one of the leading risk factors for allergic diseases. Several studies have found a significant increase in the prevalence of allergic rhinitis in males than in females. Avoidance of a particular food was associated with an increased risk of developing an allergy to that food. At the molecular level, T cells are found to affect allergy outcomes through their part of the immune response. Food proteins such as milk, egg, and peanut - common food allergens - may cause an immune response in allergic individuals. Different therapies include Epicutaneous Immunotherapy (EPIT) and specific infant milk protein formulas. If this formula is taken from infancy, the allergic responses can be prevented/reduced. As with seasonal allergies, prevention can be mediated by avoiding different pollution environments that may cause additional irritation, temperature control in a given atmosphere/humidity, and therapies of Vitamin C for immunity. With many other seasonal allergy triggers, it is ubiquitous among populations and dependent on the area and season.

Protective Role of Vaccination against Tuberculosis and Hepatitis B in Prevention of Atopic Dermatitis: Report on Intermediate Results of Prospective Cohort Study

Background. Studies have shown that vaccination in the first hours/days after birth shifts the immune response from intrauterine Th2 towards Th1-type activation and reduces the risk of atopic conditions. However, we did not find published data from prospective studies on this topic.Objective. The aim of the study is to define the presence of negative correlation between vaccination against tuberculosis and hepatitis B in the first hours/days of life and atopic dermatitis development in infants.Methods. Continuous prospective study of children cohort born from April to June 2021 and observed in one outpatient’s clinic was carried out. Data from 307 infant’s records (F. 112/y), vaccination record cards (F. 063/y), prenatal and delivery records (F. 113/y-20, section № 3), and neonatal discharge summaries were analyzed for the decreed period. The child vaccination status (by the time of vaccination against tuberculosis and hepatitis B), presence of risk factors for allergic disease development, and presence of atopic dermatitis were evaluated.Results. Atopic dermatitis (AD) was significantly less likely to be diagnosed by the age of 1 year in infants from the group of BCG-M vaccinated at maternity hospital than in those vaccinated later or not vaccinated at all (15.2% versus 66% and 35.7%, respectively; p &lt; 0,01). AD was less likely to develop in children with risk factors for allergic disease who were vaccinated against tuberculosis in the maternity hospital than in those vaccinated later or unvaccinated at all (18, 75 and 62.5%, respectively; p &lt; 0.01). The ratio of children with diagnosed AD by the age of 12 months was significantly less in the group of children vaccinated against hepatitis B in the maternity hospital than in those vaccinated later or unvaccinated at all (17.6, 44.9 and 31.8%, respectively; p &lt; 0.01). These ratios for children with risk of allergic disease development were 24%, 50% and 44.4%, respectively (p = 0.043). It has also been shown that timely vaccination with both vaccines in the early neonatal period significantly reduces the risk of AD in general infant population compared to non-vaccinated individuals or those who had only one vaccine (odds ratio [OR] 0.374; 95% confidence interval [CI] 0.253-0.552; p &lt; 0.01). Whereas the disease development in children with allergic risk is less likely with timely vaccination (20.8% versus 53.3%; OR = 0.252; 95% CI 0.145–0.440; OR = 0.374; 95% CI 0,253–0,552; p &lt; 0,01).Conclusion. The obtained results may indicate possible risk reduction for AD development due to timely preventive vaccination against tuberculosis and hepatitis B, especially in children with allergic risk. The study is currently ongoing.

Epidemiology of Allergic Diseases and Risk Factors in Children: A Population based Study in 2022

The International Study of Asthma and Allergies in Childhood (ISAAC) investigated the worldwide prevalence of allergic disease and risk factors. Korea has also participated in several ISAAC surveys: three nationwide surveys in 1995, 2000 and 2010. Research on school aged children will be a helpful to understand the epidemiology of the allergic diseases in the pediatric population. In this perspective, we researched the prevalence and risk factors of allergic diseases in school aged children in Korea.

Multi-omics reveals the mechanisms of DEHP driven pulmonary toxicity in ovalbumin-sensitized mice

The plasticizer di- (2-ethylhexyl) phthalate (DEHP) is considered a risk factor for allergic diseases and has attracted public attention for its adverse effects on health. However, respiratory adverse effects after DEHP exposure in food allergies have rarely been reported. MiRNAs are considered to be key regulators in the complex interrelationships between the host and microbiome and may be a potential factor involved in DEHP-induced pulmonary toxicity. To investigate the adverse effects of DEHP on the lung during sensitization, we established an ovalbumin (OVA)-sensitized mouse model exposed to DEHP and performed 16S rDNA gene sequencing, miRNA sequencing, and correlation analysis. Our results showed that DEHP aggravated the immune disorder in OVA-sensitized mice, which was mainly characterized by an increase in the proportion of Th2 lymphocytes, and further enhanced OVA-induced airway inflammation without promoting pulmonary fibrosis. Compared with the OVA group, DEHP interfered with the lung microbial community, making Proteobacteria the dominant phylum, while Bacteroidetes were significantly reduced. Differentially expressed miRNAs were enriched in the PI3K/AKT pathway, which was closely related to immune function and airway inflammation. The expression of miR-146b-5p was elevated in the DEHP group, which was positively correlated with the proportion of Th2 cells and significantly negatively correlated with the abundance of Bacteroidetes. The results indicate that DEHP may interfere with the expression of miR-146b-5p, affect the composition of the lung microbiota, induce an imbalance in T cells, and lead to immune disorders and airway inflammation. The current study uses multi-omics to reveal the potential link between the plasticizer DEHP and allergic diseases and provides new insights into the ecotoxicology of environmental exposures to DEHP.

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

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. 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. 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). 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.

Relationship between Dietary Fiber and Allergy Prevalence in a College Population

ObjectivesTo characterize the relationship between dietary fiber intake and the prevalence of allergic diseases, seasonal allergies and asthma, in a college student population.MethodsData were collected from 2012–2021 through the College Health and Nutrition Assessment Survey, an ongoing cross-sectional study at a midsized, public New England university. Students (18–24 years; n = 4135; 67% female) completed a comprehensive, online demographic and health information survey, a 3-day food record, and an analysis of their average nutrient intake via an online program (Diet and Wellness Plus). After stratifying by sex, students’ fiber intake (g/day) were grouped into quartiles; differences in allergy and asthma prevalence across quartiles were evaluated via chi-square tests. Logistic regression was used to examine differences in allergy and asthma prevalence between low fiber intake and those with higher intakes after controlling for covariates BMI, smoking status, and alcohol consumption.ResultsOf the final sample, 37.6% and 19.2% reported a seasonal allergy and asthma, respectively, after exclusion of participants with missing data (4135 of 5093). Food records indicate only 18.2% of females and 12.2% of males are meeting recommended intakes of dietary fiber. Quartile fiber consumption was associated with seasonal allergy prevalence in males (X2 = 10.657, df = 3, P = 0.014) and females (X2 = 15.526, df = 3, P = 0.001). Females consuming the lowest quartile of fiber intake (<13.62 g/day) experience 1.39 times the odds of seasonal allergies (P < 0.001, 95% CI 1.164–1.651) when controlling for the covariates of BMI, smoking status, and alcohol use. No significant differences in asthma prevalence were identified between fiber intake quartiles.ConclusionsConsistent with previously identified associations, our findings suggest fiber intake is related to seasonal allergies but not asthma, with a stronger relationship among females. This study further emphasizes the need to investigate potential dietary risk factors for allergic diseases and to inform institutions on key dietary priorities for college student health.Funding SourcesNew Hampshire Agriculture Experiment Station and USDA National Institute of Food and Agriculture Hatch Project 1,010,738.

Exploring genetic association of insomnia with allergic disease and asthma: a bidirectional Mendelian randomization study

BackgroundInsomnia is highly prevalent among patients with allergic disease and asthma; however, few studies have investigated their causal relationship. We aim to explore the causal association between insomnia and allergic disease/asthma by performing bidirectional Mendelian randomization (MR) study.MethodsInstrumental variables were constructed using single nucleotide polymorphisms (SNPs). Summary statistics for insomnia, allergic disease, and asthma were obtained from four large-scale genome-wide association studies (GWAS) of European ancestry. The pleiotropy analysis was applied by using the MR-Egger intercept test and the MR pleiotropy residual sum and outlier (MR-PRESSO) test. MR analyses were conducted by using inverse variance weighted (IVW), weighted median, and MR-Egger method.ResultsBased on the multiplicative random effects IVW method, the MR analysis showed that genetically predicted insomnia was causally associated with an increased risk of allergic disease [odds ratio (OR) = 1.054, 95% confidence interval (CI) = 1.031–1.078, P = 3.817 × 10–06], asthma (OR = 1.043, 95% CI = 1.010–1.077, P = 9.811 × 10–03), moderate-severe asthma (OR = 1.168, 95% CI = 1.069–1.277, P = 6.234 × 10–04), and adult-onset asthma (OR = 1.086, 95% CI = 1.037–1.138, P = 4.922 × 10–04). In bidirectional analyses, we did not find evidence supporting the reverse causality relations.ConclusionsOur MR study suggested that genetically predicted insomnia was the risk factor for allergic disease and asthma. Improving sleep quality could be one of the cornerstones in the prevention of allergic disease and asthma.

A comparison of risk factors of allergic diseases between island and inland town in Incheon

A comparison of risk factors of allergic diseases between island and inland town in Incheon

Research on allergen detection technology and allergic disease diagnosis strategy in China

In China, the prevalence of allergic diseases is increasing, but allergy research and allergy diagnosis technologies are still in their infancy, posing certain hurdles to clinical diagnosis and treatment. The detection of allergen is essential for the prevention and treatment of allergic diseases. Clarifying the aetiology and risk factors of allergic diseases is critical in order to provide targeted environmental control and therapy for allergic diseases, as well as reduce patient pain and financial burden. In this study, allergen detection technologies and diagnosis strategies are described in order to provide direction for clinicians and laboratory technicians, improve allergic diseases diagnosis, and guide allergic disease therapy.

Risk factors for allergic diseases: a cross-sectional survey of 9,501 Chinese preschool-aged children

BackgroundChildhood allergic diseases are increasing worldwide with unprecedented complexity and severity, and they cause a major burden on health and healthcare costs. We aimed to identify potential factors, both in isolation and in combination, associated with allergic diseases among preschool-aged children, and to construct a nomogram prediction model based on significant factors.MethodsWe cross-sectionally recruited 9,501 preschool-aged children from 30 kindergartens in Beijing and Tangshan. Allergic diseases were ascertained according to the “International Study of Asthma and Allergies in Childhood” questionnaire. Risk for allergic diseases is quantified by odds ratio (OR) with 95% confidence interval (CI).ResultsFour factors were identified to be independently, consistently, and significantly associated with the risk for allergic diseases overall and by four clinical manifestations separately, including bedtime (per 1 hour late) (taking asthma/wheezing as an example, OR, 95% CI, P: 1.21, 1.08 to 1.35, 0.001), outdoor activities ≤1.5 h per day (1.45, 1.26 to 1.68, 3.77E-07), family history of allergic diseases (2.23, 1.92 to 2.60, 0.00E+00), and antibiotic use during childhood (3.64, 2.44 to 5.42, 1.66E-10). Further analyses revealed that family history of allergic diseases acted with antibiotic use during childhood in an additive manner. For practical reasons, risk prediction nomogram models were constructed for allergic diseases respectively in Beijing and Tangshan based on significant and conventional factors, and the prediction accuracy was good, with the C-index 69% in Tangshan and 68% in Beijing (both P=0.00E+00).ConclusionsOur findings identified four factors in significant association with the risk for allergic diseases, and in particular family history of allergic diseases and antibiotic use during childhood acted additively.

Prevalence of allergen-specific IgE in southern China: a multicenter research.

Identifying allergen distribution is meaningful and significant for effective diagnosis and treatment of allergic diseases. This study compared the allergen sensitivity in four southern China cities. We enrolled 55,432 participants (27,408 male, 28,024 female) between 2007 and 2019. The allergen-specific IgE levels were compared by the χ2 test. The five prevalent sensitivities were for mite mix (10,985, 19.82%), cockroach (4,860, 8.77%), crab (4,450, 8.03%), fish mix (3,874, 6.99%), and house dust (3,486, 6.29%). Almost all allergen sensitivities decreased with age, particularly from infant to middle aged participants (p < 0.05). An exception was Shenzhen, where food allergen positive rates remained constant in all age groups studied. The proportion of male sensitive to at least one food allergen (OR 1.130; 95% CI 1.088–1.174, p < 0.0025) or aeroallergen (OR, 1.117; 95% CI, 1.078–1.158, p < 0.0025) was higher than female in all four cities. Except for dog dander and tree mix, all aeroallergens differed significantly between seasons (p < 0.05). Liuzhou had the highest rates of food allergen- and aeroallergen-positive participants. The allergen-specific IgE distribution differed among the studied cities, with significant seasonal differences. Young age, male sex, and aeroallergens were risk factors for allergic disease.

Research progress on sleep and allergic diseases in children and adolescents

In recent years, the incidence of allergic diseases in children and adolescents has been on the rise globally, which has become an important public health problem. It is important to identify modifiable risk factors for allergic diseases in this group. In this paper, through research review on the association between sleep behavior and allergic diseases in children and adolescents, it is suggested that sleep deficiency, sleep disorder and sleep rhythm disturbance are closely related to children’s allergic diseases, which provides a new concept for prevention of allergic diseases through sleep behavioral improvement. 【摘要】 近年来全球儿童青少年过敏性疾病发病率呈上升趋势, 已成为一项重要的公共卫生问题。识别儿童青少年过敏 性疾病的可改变危险因素具有重要意义。本文通过综述儿童青少年睡眠行为与过敏性疾病的相关研究进展, 认为睡眠不 足、睡眠障碍和睡眠节律紊乱与儿童过敏性疾病联系密切, 通过改善以上睡眠行为对于预防过敏性疾病具有重要意义。

Evaluation of Allergic Disease Prevalence and Related Risk Factors in Children with Autoimmune Thyroiditis

Background: Allergic and autoimmune diseases are caused by an impaired immunological response resulting from different types of T-helper (Th) cells. Since the Th cell production is in a certain balance, an inverse relationship between the 2 disease groups may exist. In this study, we aimed to investigate the frequency of allergic diseases in children with autoimmune thyroiditis (AT). Methods: Symptoms of allergic diseases were investigated by the (International Study of Asthma and Allergies in Childhood) ISAAC questionnaire. The questionnaire was administered to a group of 300 children with AT and a control group of 300 children with no known autoimmune disease. The risk factors for allergic diseases and sociodemographic characteristics were investigated. A multivariable logistic regression analysis was performed with the risk factors of allergic diseases. Results: Asthma, wheezing during the last year, wheezing with exercise, disease-free night cough, and night cough were significantly less common in patients with AT. Allergic rhinitis symptoms, except physician-diagnosed allergic rhinitis, are found significantly less frequently in patients with AT. It was found that the presence of AT and an increase in the number of children in the family reduce the risk of allergic diseases; cat-dog contact before 1 year of age and the presence of asthma, eczema, or allergic rhinitis in the mother increase the risk of allergic diseases. Conclusions: Asthma and allergic rhinitis symptoms were significantly less common in children with AT. AT reduces the risk of allergic diseases.

Epidemiology of Allergy: Natural Course and Risk Factors of Allergic Diseases.

The prevalences of allergic diseases, asthma, atopic dermatitis, allergic rhinitis and lately food allergy have been increasing over the last decades. It has been suggested that the prevalence of allergic diseases has reached a plateau in high income countries, while it is still on the rise in low and middle income countries. Generally, allergic diseases more often set on in childhood than in adulthood and affected children contribute more to the rise in allergic disease prevalence than affected adults. Epidemiological evidence suggests that not all atopic dermatitis and asthma cases are attributable to atopic sensitization. Indeed, mainly genetic association studies have prompted the unravelling of barrier dysfunction as a mainstay in the patho-mechanisms leading to atopic dermatitis and to asthma with atopic sensitization secondary to this dysfunction. Epidemiological research on risk and protective factors for allergic disease, acting against the background of genetic susceptibility, has produced an enormous body of evidence. Prominent observations are the 'sibling effect' and the 'farm effect' which gave rise to the 'hygiene hypothesis' and later the 'biodiversity hypothesis'. Future epidemiological research is required to evaluate and refine these hypotheses in light of the paradigm shift from atopic sensitization to barrier dysfunction with ever increasing options for environmental characterization, currently, e.g., 'omics'-techniques in microbiology and metabolism, and with ever increasing options for phenotyping of allergic techniques, including, e.g., high-resolution time series of symptoms using, e.g., sensing technologies.

Indoor and Outdoor Pollution as Risk Factor for Allergic Diseases of the Skin and Lungs.

Air pollution is worldwide a major public health problem and affects large part of the population. Air pollution does not only harm the respiratory tract system but also the other organs of the body. The damage may result directly from the pollutants toxicity, because the pollutant enters into the organs through a direct route or indirectly through systemic inflammation. There is accumulating evidence suggesting that ambient air pollution not only affects the human lung and the cardiovascular system, but also has negative effects on allergic diseases. In this regard, it has been shown that exposure increases the risk of allergies and eczema in children and adults. However, the mechanism how ambient air pollution affects the skin is not well investigated up to now and needs further research.