Prevalence of respiratory and atopic disorders among children in the East and West of Germany five years after unification.

Living conditions in eastern Germany have changed rapidly since unification in 1990 and little is known about how these changes affect the prevalence of atopic diseases. This study describes methods and prevalences of a large epidemiological project investigating determinants of childhood asthma and allergies in eastern (Dresden and Leipzig) and western (Munich) Germany in 1995/1996. Community based random samples of 9-11 yr old children in Dresden (n=3,017) and Munich (n=2,612), and of 5-7 yr old children in Dresden (n=3,300), Leipzig (n=3,167) and Munich (n=2,165) were studied by parental questionnaires, bronchial challenges with hypertonic saline, skin examination, skin-prick tests, and measurements of specific and total serum immunoglobulin (Ig)E using Phase II modules of the International Study of Asthma and Allergies in Childhood (ISAAC). In 9-11 yr old children, the prevalence of physician diagnosed asthma (7.9% versus 10.3%; p<0.01) and bronchial hyperresponsiveness (15.7% versus 19.9%; p<0.05) was lower in Dresden than in Munich. No difference between Munich and Dresden was observed in the prevalence of diagnosed hay fever, skin test reactivity to > or = 1 allergen, and increased levels (>0.35 kU x L(-1)) of specific IgE against inhalant and food allergens. Symptoms and visible signs of atopic eczema tended to be more prevalent in Dresden. Similar East-West differences between the three study areas were seen in the younger age group. These findings are in line with recently observed increases in the prevalence of hay fever and atopic sensitization, but not of asthma and bronchial hyperresponsiveness, among 9-11 yr old children in Leipzig.     

What makes a child allergic? Analysis of risk factors for allergic sensitization in preschool children from East and West Germany.

Earlier epidemiologic studies within Germany found a higher frequency of allergic sensitization in West Germany. The reasons for that and the role of environmental factors in the process of allergic sensitization are not fully understood. This study aimed to determine the prevalence of positive skin-prick test results 5 years after unification and to investigate risk factors for allergic sensitization in preschool children. A total of 1235 children (5-6 years) from two West and five East German locations were skin-prick tested after the compulsory school entrance examination. Six common aero- (birch, grass, mugwort pollen, cat, HDM, alternaria) and two food allergens (egg, milk) were used and additional information was obtained by questionnaire. Of the tested children 23.3% exhibited at least one positive reaction. The prevalence of sensitization to the single allergens was as follows: grass (14.4%), birch (6.6%), mugwort pollen (4.5%), cat (8.5%), HDM (5.5%), alternaria (4.9%), egg (2.8%), and milk (3.9%). In the crude analysis significantly more children were sensitized in the East German city Magdeburg (40.2%) compared to the West German control region Borken (23.5%) (OR 2.20, CI 1.47-3.29). Dampness and visible molds were reported in 8.8% of all households, but significantly more often for East German apartments (10.3% versus West Germany 1.9%, OR 5.85, CI 2.55-16.53). Dampness and molds were associated with a higher frequency of sensitizations (40.6% versus 27.6% in unaffected homes). After controlling for sex, parental atopy, SES, family size, and smoking during pregnancy, this association remained statistically significant (OR 1.93, CI 1.19-3.12). With regard to single allergens, dampness and visible molds were significantly associated with sensitization to HDM (OR 3.37, CI 1.63-6.96), cat (OR 3.19, CI 1.11-5.74), and mugwort pollen (OR 2.86, CI 1.29-6.35). In addition, family size was inversely and linearly associated with the frequency of sensitization (OR for four, three, and two-person households: 1.10 (0.74-1.63), 1.57 (1.06-2.42), 2.70 (1.39-5.24), respectively, when compared to family size of five or more). Neither parental predisposition for atopic diseases nor parental education level influenced the prick test reactivity. We conclude that in addition to genetic predisposition, environmental factors like indoor climate and probably infectious stimuli (family size) play an important role in the process of allergic sensitization in children.     

Lower prevalence of asthma and atopy in Turkish children living in Germany.

Ethnic origin has been reported to affect the prevalence of atopic diseases in several studies in different parts of the world. However, little is known about the prevalence of asthma and atopy in immigrants living in Europe. The objective of this study was to evaluate the prevalence of asthma and atopy in Turkish children living in Germany and to investigate the role of ethnic origin on the development of asthma and atopy in this population. In a cross-sectional survey the prevalence of physician-diagnosed asthma, atopy, skin-prick tests and bronchial hyperresponsiveness (BHR) to cold dry air challenge was assessed in 7,445 school children aged 9-11 yrs, living in Munich, south Germany. Questionnaires were distributed to the parents for self-completion and children underwent skin prick tests and cold air hyperventilation challenge. The Turkish children showed a significantly lower prevalence of asthma (5.3 versus 9.4%, p<0.05) than their German peers. Furthermore, atopy, as assessed by skin prick tests (24.7 versus 36.7%, p<0.001) and BHR (3.9 versus 7.7%, p<0.001), was less common in Turkish children. In multivariate regression models controlling for potential explanatory factors, Turkish origin still showed a significantly lower risk of developing asthma, atopic sensitization and BHR. The prevalence of childhood asthma was therefore shown to be lower in Turkish children living in Germany than in Turkey. These findings suggest that the lower prevalence of asthma and allergy in Turkish children living in Germany might be attributable to a selection bias affecting the parents of these children, as healthy individuals may have decided to come to Germany for work.     

Increasing prevalence of bronchial hyperresponsiveness in three selected areas in East Germany. Bitterfeld Study Group.

The prevalence of asthma, bronchial hyperresponsiveness (BHR) and allergic rhinitis in children was lower in East Germany compared to West Germany. The reasons for this difference are still not understood. This study tested the hypothesis that prevalence of BHR increased in East German children after reunification. Two consecutive cross-sectional surveys of schoolchildren aged 8-14 yrs from three communities in East Germany were carried out in 1992-1993 and 1995-1996. A subsample of 530 and 790 children with complete lung function and cold air challenge data was analysed. The prevalence of BHR increased from 6.4%, in 1992-1993 to 11.6% in 1995-1996 (odds ratio (OR): 2.0, 95% confidence interval (CI): 1.3-3.0, adjusted for age, sex, season, community and parental education). No changes were found for asthma, allergic rhinitis or allergic sensitization. In contrast, physician diagnosed bronchitis, pneumonia and frequent colds decreased significantly. The observed increase in the prevalence of BHR was reduced (OR: 1.5, 95% CI: 0.95-2.3) after adjustment for several indoor factors. In conclusion, while the prevalence of nonallergic respiratory diseases seems to decrease, the prevalence of bronchial hyperresponsiveness might be a first indicator of the suspected increase of asthma prevalence in East Germany. The present results give indirect evidence, that less respiratory infections may be associated with higher bronchial hyperresponsiveness.     

House dust endotoxin and allergic sensitization in children

A higher exposure to endotoxin was hypothesized to contribute to lower prevalence of allergic sensitization and hay fever in children growing up on a farm. We studied the association between house dust endotoxin and allergic sensitization. We randomly selected 740 children, aged between 5 and 10 years, from a group of children who participated in two cross-sectional surveys performed in Saxony-Anhalt, Germany, from 1992 to 1993 and from 1995 to 1996, such that 50% of the children were atopic or had a diagnosis of asthma. From 1996 to 1998, we collected living-room floor dust in the homes of 454 of these children (61%). The content of endotoxin in house dust was quantified using a chromogenic kinetic limulus amoebocyte lysate test and was related with health outcomes measured in the preceding cross-sectional surveys. Multiple logistic regression analyses adjusted for place of residence, sex, age, parental education, parental atopy, and pet ownership showed a negative association between exposure to endotoxin and sensitization to one or more allergens (aOR [95% CI] 0.95 [0.83; 1.10]) and two or more allergens (aOR [95% CI] 0.80 [0.67; 0.97]) using 0.35 kU/L as the cutoff value for sensitization. The protective effect was strengthened with increasing degree of sensitization. In conclusion, exposure to higher levels of house dust endotoxin is associated with lower prevalence of allergic sensitization in children.     

Similar prevalence of respiratory symptoms and atopy in Estonian schoolchildren with changing lifestyle over 4 yrs.

The prevalence of allergic sensitization and clinical manifestations is low in Eastern Europe, despite a continuous increase in industrialized countries with a market economy. The aim of the present study was to study changes in the prevalence of respiratory symptoms and atopic sensitization over time among schoolchildren in Estonia, in relation to environmental changes as the country transformed into a market economy. A cross-sectional study of 10-yr-old children was carried out between October 1996 and April 1997, employing a questionnaire regarding the prevalence of wheezing, rhinitis and itching rash (n=979) and skin-prick tests with seven inhalant allergens (n=640). The results were compared with those of a similar study performed in 1992-1993. The 12-month prevalence of wheeze was 8.3%, as compared to 9.4% in 1992-1993 (NS) and of asthma was 2.5 versus 3.2% (NS). The prevalence of a positive skin-prick test result was 14.3% in both studies. Furthermore, the prevalence of sensitivity to the individual allergens was similar, except for a significantly higher prevalence of dog sensitivity in 1996-1997 (4.7 versus 2.0%). The prevalence of respiratory and other potentially allergic symptoms, as well as the prevalence of atopic sensitization, remains low in Estonian 10-yr-old children, despite a changing lifestyle over the past 4 yrs. This could indicate that the time period was too short for environmental changes to affect the prevalence of allergy, or alternatively that risk factors associated with a "western lifestyle" are of particular significance earlier in life.     

Fewer allergic respiratory disorders among farmers' children in a closed birth cohort from Sweden.

The aim of this study was to investigate the prevalence of respiratory allergy, eczema and atopic sensitization in a closed birth cohort of Swedish schoolchildren, 7-8 yrs of age (n=707), of farmers and nonfarmers on the island of Gotland, in the Baltic Sea. All children were born and raised on the island. The survey comprised a questionnaire on atopic diseases and lifestyle factors. Atopic sensitization was assessed by the skin-prick test (SPT) with 15 standardized allergens. The risk ratio (RR) for ever having asthma and/or allergic rhinoconjunctivitis was significantly lower among children of farmers compared to children of nonfarmers (RR=0.38, confidence interval (CI) 95% 0.19-0.77). SPTs (test rate 92%) showed that 32% of the children had at least one positive test. Although the number of positive SPTs did not differ between the groups, there was a reduced risk among children of farmers for having both respiratory symptoms and sensitization to any International Study on Asthma and Allergy in Childhood allergen (RR=0.28, CI 95% 0.09-0.88). The present indicate that living in a farming population seems to protect against development of respiratory allergic disorders but not against allergic sensitization.     

Acetaminophen intake and risk of asthma, hay fever and eczema in early adolescence

A positive association between acetaminophen intake and allergic diseases has recently been reported in developed countries with impaired oxidant/antioxidant balance and promotion of atopy as proposed underlying mechanisms. The aim of the study was to explore the relationship between acetaminophen intake and asthma, hay fever, and eczema in The Republic of Macedonia as a country with acetaminophen intake not physician-controlled, high passive smoke exposure and dietary antioxidant intake, and moderately low prevalence of allergic diseases. Self-reported data obtained through the standardized International Study of Asthma and Allergies in Childhood Phase Three written questionnaires of 3026 adolescents aged 13/14 years from randomly selected schools in Skopje, the capital of Macedonia, were used. The frequency of current acetaminophen intake--both unadjusted and adjusted for confounding factors--was correlated to current and ever-diagnosed asthma, hay fever and eczema by odds ratios (OR, 95% CI) in binary logistic regression. Use of acetaminophen at least once monthly increased the risk of current wheeze (adjusted OR 2.04, 1.31-3.20 p = 0.002), asthma 'ever' (adjusted OR 2.77, 1.06-7.26 p=0.039), current allergic rhinoconjunctivitis (adjusted OR 2.95, 1.79-4.88 p=0.000) and hay fever 'ever' (adjusted OR 2.25, 1.36-3.70 p=0.002). A significant association between frequent acetaminophen intake and atopic eczema and also between infrequent acetaminophen intake and investigated allergic diseases was not established. The findings suggest an increased risk of asthma and hay fever, but not atopic eczema associated with frequent acetaminophen use in a developing country.     

Exposure to pets and the risk of allergic symptoms during the first 2 years of life.

BACKGROUND: Currently, there is a lack of consensus regarding the influence of household pets on the development of allergic diseases in childhood. OBJECTIVE: The aim of this birth cohort study was to analyze the relationship between pet ownership at time of birth and the prevalence of atopic diseases approximately 2 years later. METHODS: A few days after the delivery of their babies, we asked 3132 mothers of German nationality whether they kept household pets like dogs, cats, or birds. Two years later, we asked whether their children had developed bronchial asthma, eczema, or hay fever. We then used logistic regression models to analyze whether there was an association between the development of allergic reactions among the children and pet ownership at the time of birth. RESULTS: In families without a history of atopic disease, the prevalence of asthma and eczema among 2-year-old children was significantly lower in those families that owned a dog at the time the children were born (odds ratio [OR], 0.52; 95% confidence interval [CI], 0.33-0.83). In contrast, in families with a history of atopic disease, early dog exposure was associated with a higher prevalence of asthma and eczema in 2-year-old children (OR, 1.43; 95% CI, 0.95-2.15). Comparable analyses assessing the influence of cats and birds in the home showed no effect on the development of atopic diseases in early childhood. CONCLUSIONS: This study confirms the findings of several earlier studies suggesting a negative association between dog ownership and the development of atopic diseases in early childhood, although the effect was only observed in families without a history of atopic disorders.     

Consumption of omega-3 and omega-6 fatty acids in former East and West Germany and changes in East Germany after the reunification.

The dietary intake of Omega-3 (omega-3) and Omega-6 (omega-6) fatty acids (FA) may influence the development of atopic diseases. Based on the results of two dietary surveys, the intake of omega-3-FA and omega-6-FA in West Germany in 1985-1989 and in Dresden, East Germany in 1988-1989 and 1990-1991 was estimated. The intake of omega-6-FA but not of omega-3-FA was slightly higher in the West German population before 1990, mainly because of a higher intake of vegetable oil. Immediately after 1990 the omega-6-FA-intake in the observed East German sample increased because of an increase in the consumption of margarine [from a mean of 16 (SD 17) to 38 (24) g day-1]. Additional information indicates that, in contrast, East German infant formulas contained higher amounts of omega-6-FA (linoleic acid) and lower amounts of omega-3-FA (alpha-linolenic acid) than West German formulas. Whether there is a causal relation between the amounts of omega-6-FA and omega-3-FA consumed and the prevalence of atopy in children from East and West Germany remains to be clarified.     

Prevalence of atopy in children with type 1 diabetes mellitus, hepatitis B virus carriers, and healthy children: role of T helper 1 (Th1)-type immune response.

The prevalence of allergic diseases such as asthma, hay fever, and atopic dermatitis has increased over the past few decades, especially in developed countries. They are characterized by a chronic inflammatory reaction mediated by T helper 2 (Th2) cells. Two common chronic diseases of childhood-an autoimmune disease, type 1 diabetes mellitus (DM), and a chronic viral infection, hepatitis B virus (HBV) carriers-are associated with a Th1-dominant and Th1-insufficient cytokine profile, respectively. The purpose of this study was to analyze the frequency of allergic disease in patients with type 1 DM and, in HBV carriers, to evaluate the role of Th1-type immune response in atopy and allergic disease. The study included patients with type 1 DM (group I, n = 52), HBV carriers (group III, n = 47), and a healthy control group (group III, n = 209). Participants were screened for allergic disease and atopic sensitization. Symptoms of asthma, eczema, and atopy were found more commonly in HBV carrier children compared with those with DM and healthy controls. This study supports the Th1/Th2 model. The prevalence of allergic disease and atopy is decreased in Th1-mediated autoimmune disease, type 1 DM, and, conversely, is increased in insufficient Th1 response, chronic HBV carriers. Additional studies are needed to evaluate the effect of atopy and allergic diseases in glycemic control and long-term complications in patients with type 1 DM and the effect of atopy on progression of chronic HBV infection.     

营养素与特应性疾病

特应性疾病又称IgE介导的变态反应性疾病，如花粉症、哮喘和湿疹。近年来特应性疾病的患病率呈明显增加趋势，许多学者认为在过去的20—40年里导致特应性疾病增加的原因之一是饮食结构的改变。流行病学和免疫学研究发现，在胎儿和生命早期，通过调控饮食或补充某种营养素可能降低特应性疾病的发生。本文就近年来国内外有关营养素对特应性疾病影响的研究进展做一综述，重点介绍维生素、矿物质、类脂类等营养素对特应性疾病影响的流行病学证据及其作用机制。     

Prevalence of Asthma among German Adults: Analysis of the German National Telephone Survey

Objective. The purpose of this study was to estimate the prevalence of asthma in German adults. Methods. This analysis used data of 8,318 German adults 18 years of age and older who had participated in the German National Telephone Survey, a nationally representative cross-sectional study. Results. The overall lifetime prevalence of asthma in German adults was 5.7%. It ranges between 4.3% in East and 6.0% in West Germany. Logistic regression analysis showed that asthma was associated with unemployment, younger age, and living in West Germany. Conclusion. This study provides further evidence that differences exist in the prevalence of asthma between East and West Germany.     

Individual allergens as risk factors for asthma and bronchial hyperresponsiveness in Chinese children.

The role of allergen sensitization in the development of asthma in the Chinese is not clear. This study aims to determine the relationship of sensitization to individual allergens, and the development of asthma and bronchial hyperresponsiveness (BHR) in schoolchildren from three Chinese cities: Hong Kong, Beijing and Guangzhou. Community-based random samples of 10-yr-old schoolchildren from three Chinese cities were recruited for study using the International Study of Asthma and Allergies in Childhood (ISAAC) Phase II protocol. Subjects were studied by parental questionnaires (n=10,902), skin-prick tests (n=3,479), and methacholine challenge tests (n=608). The prevalence rates of wheeze in the past 12 months (Hong Kong, 5.8%; Beijing, 3.8%; Guangzhou, 3.4%) and atopy (Hong Kong, 41.2%; Beijing, 23.9%; Guangzhou, 30.8%) were highest in schoolchildren from Hong Kong. Multivariate logistic regression analyses revealed that sensitization to Dermatophagoides pteronyssinus (odds ratio (OR)=4.48; 95% confidence interval (CI): 3.02-6.66), cat (2.59; 1.67-4.03), Dermatophagoides farinae (2.41; 1.65-3.51) and mixed grass pollen (2.85; 1.24-6.50) were significantly associated with current wheeze. Atopy, defined as having > or = 1 positive skin-prick tests, was not an independent risk factor for current wheeze in children from any of the three cities. Furthermore, atopy (OR=2.53; 95% CI: 1.07-5.97), sensitization to cat (3.01; 1.39-6.52) and D. farinae (3.67; 1.93-6.97) were significantly associated with BHR. The authors confirmed that sensitization to house dust mite and cat was significantly associated with current wheeze and bronchial hyperresponsiveness in Chinese schoolchildren. However, the difference in the prevalence rate of atopic sensitization cannot explain the higher prevalence of childhood asthma in Hong Kong, when compared with those children from Beijing and Guangzhou.     

Role of aeroallergens in the etiopathogenesis of atopic dermatitis

Atopic dermatitis is a chronic relapsing inflammatory skin disease. It is most frequent in childhood and its clinical manifestations vary with age. The etiopathogenic mechanisms that explain this process are still poorly understood; several studies performed in adults speculate on the possible role of aeroallergens through direct contact with the skin but, because the etiology of this disease varies with age, studies in children of different ages are required.Aims: (i) To determine whether children with atopic dermatitis are sensitized to inhalant allergens. (ii) To determine whether these inhalant allergens cause dermatitis or whether they provoke allergic respiratory disease (asthma, rhinitis) concomitant with atopic dermatitis. (iii) To evaluate whether sensitization to a particular allergen takes place at any age or whether there are differences according to age.Material and methods: This study was performed in the following groups: (i) 64 children with atopic dermatitis, divided into two subgroups, one consisting of 37 children who also presented allergic respiratory disease (asthma, rhinitis) (AR) and another subgroup of 27 patients who presented atopic dermatitis only. (ii) Control group: eight children who presented AR only, to determine whether this group reacted to patch testing with inhalant allergens. (iii) Control group: seven healthy children to rule out non-specific positive tests in the non-atopic population. All groups were divided by age according to the phases of atopic dermatitis: early childhood phase (< 2 years): 21, childhood phase (2-10 years): 37, adolescent phase (> 10 years): 21. In all children total serum IgE determination (RIA), allergen-specific IgE determination (RAST), prick- and patch test were performed. In the three tests the same allergens were used, consisting of the usual components of standardized inhalant and food allergens. When the results of patch testing were positive, biopsy and histopathological analysis were performed and monoclonal antibodies were used to determine reproducibility of the eczematous lesion.Results: Sensitization was found to differ among patients with atopic dermatitis according to whether they presented respiratory symptoms and according to age with a clear predominance of food sensitization in the group aged less than 2 years. In the group aged 2-10 years, mixed sensitization predominated, mainly because of simultaneous respiratory involvement, but it is highly probably that inhalant allergens participate in the etiopathogenesis of atopic dermatitis. In children aged more than 10 years sensitization to inhalant allergens predominated as most presented respiratory symptoms. Patch testing was positive in 34.3 % of patients with atopic dermatitis and approximately half were positive to dust mites. The patch test is of great diagnostic value in atopic dermatitis and none of the tests were positive in the control group. All the biopsies of patch tests with inhalant allergens reproduced the lesions typical of eczema, demonstrating their involvement in the etiopathogenesis of dermatitis.     

Inner city air pollution and respiratory health and atopy in children.

The impact of inner city air pollution on the development of respiratory and atopic diseases in childhood is still unclear. In a cross sectional study in Dresden, Germany, 5,421 children in two age groups (5-7 yrs and 9-11 yrs) were studied according to the International Study of Asthma and Allergies in Childhood (ISAAC) phase II protocol. The prevalences of wheezing and cough as well as doctor diagnosed asthma and bronchitis were assessed by parental questionnaires. Children also underwent skin-prick testing, venipuncture for the measurement of serum immunoglobulin (Ig)E, lung function testing and a bronchial challenge test (4.5% saline) to assess airway hyperresponsiveness. Exposure was assessed on an individual basis by relating mean annual air pollution levels (SO2, NO2, CO, benzene, and O3) which had been measured on a 1 km2 grid, to the home and school address of each study subject. After adjusting for potential confounding factors an increase in the exposure to benzene of 1 microg x m3 air was associated with an increased prevalence of morning cough (adjusted odds ratio (aOR)): 1.15; 1.04-1.27) and bronchitis (aOR: 1.11; 1.03-1.19). Similar associations were observed for NO2 and CO. In turn, the prevalences of atopic sensitization, symptoms of atopic diseases and bronchial hyperresponsiveness were not positively associated with exposure to any of these pollutants. It is concluded that in this study a moderate increase in exposure to traffic-related air pollution was associated with an increased prevalence of cough and bronchitis, but not with atopic conditions in children.     

Decreased prevalence of atopy in paediatric patients with familial Mediterranean fever

BACKGROUND: A number of inflammatory diseases, including familial Mediterranean fever (FMF), have been shown to be driven by a strongly dominated Th1 response, whereas the pathogenesis of atopic diseases is associated with a Th2 response. OBJECTIVE: Because dominance of interferon gamma has the potential of inhibiting Th2 type responses-that is, development of allergic disorders, to investigate whether FMF, or mutations of the MEFV gene, have an effect on allergic diseases and atopy that are associated with an increased Th2 activity. METHOD: Sixty children with FMF were questioned about allergic diseases such as asthma, allergic rhinitis, and atopic dermatitis, as were first degree relatives, using the ISAAC Study phase II questionnaire. The ISAAC Study phase II was performed in a similar ethnic group recruited from central Anatolia among 3041 children. The same skin prick test panel used for the ISAAC Study was used to investigate the presence of atopy in patients with FMF and included common allergens. RESULTS: The prevalences of doctor diagnosed asthma, allergic rhinitis, and eczema were 3.3, 1.7, and 3.3%, respectively, in children with FMF, whereas the corresponding prevalences in the ISAAC study were 6.9, 8.2, and 2.2%, respectively. Only the prevalence of allergic rhinitis was significantly different between the two groups (p<0.001). The prevalence of atopy in these patients with FMF (4/60 (7%)) was significantly lower than in the children of the population based study (20.6%) (p<0.001). CONCLUSION: Family Mediterranean fever seems to be protective against development of atopic sensitisation and allergic rhinitis.     

中国儿童呼吸道及特应性疾病患病情况调查

目的 由于支气管哮喘(简称哮喘)是一种特应性疾病，且世界各地患病率差异很大，我们对北京、广州、香港三地儿童的呼吸道疾病及特应性疾病进行了比较，以确定特应性在哮喘发生中的作用。方法在北京、广州、香港三城市的9～11岁儿童中随机抽样，应用国际儿童哮喘和过敏性疾病研究(ISAAC)第二阶段问卷，由10902名儿童的父母回答问卷并对3479名儿童进行皮肤检查及皮肤变应原点刺检查。结果近年喘息、重度喘息(说话受限)、鼻(眼)结膜炎及肢体弯曲处皮炎的患病率，香港显高于北京及广州。特应性发生率香港地区(41．2％)也高于北京(23．9％)和广州(30．8％)。表明特应性与近年喘息高度相关(0R=7．74，95％CI=5．70～10．51)。对香港地区人群进一步分析发现，由内地移居香港的儿童，其过敏症状及特应性发生率显低于香港地区出生儿童。结论香港地区学龄儿童哮喘、变态反应性疾病患病率、特应性发生率最高。特应性是中国儿童哮喘发病的重要因素。     

Nonatopic asthma is associated with helminth infections and bronchiolitis in poor children.

Asthma is common in urban centres in Latin America, but atopic asthma may not be the main phenotype among children. Helminth infections are highly prevalent in poor populations, and it was hypothesised that they attenuate allergic asthma, whereas other factors are related to the expression of a nonatopic wheeze/asthma phenotype. A total of 1,982 children from Southern Brazil with a mean+/-sd age of 10.1+/-0.76 yrs completed asthma questionnaires, and 1,011 were evaluated for intestinal parasites and atopy using skin-prick tests (SPTs). Wheeze in the previous 12 months was reported by 25.6%, and 9.3% showed current asthma; 13% were SPT-positive and 19.1% were positive for any helminths. Most children with either wheeze or asthma were SPT-negative; however, severe wheeze was more prevalent among the atopic minority. Helminth infections were inversely associated with positive SPT results. Bronchiolitis before the age of 2 yrs was the major independent risk factor for asthma at age 10 yrs; high-load Ascaris infection, a family history of asthma and positive SPT results were also asthma risk factors. Most asthma and wheeze are of the nonatopic phenotype, suggesting that some helminths may exert an attenuating effect on the expression of the atopic portion of the disease, whereas viral bronchiolitis predisposes more specifically to recurrent airway symptoms.     

Wood stove heating, asthma and allergies.

In two German studies household wood or coal stove use was negatively associated with atopic sensitization and allergic rhinitis in childhood. Wood stove heating is strongly related to 'traditional lifestyle and therefore subjected to confounding factors possibly yet not known. The study was conducted to study these factors and the independent impact of early exposure to wood stove heating on subsequent asthma and atopic disease. In a questionnaire survey among 10667 Finnish university students aged 18-25 years, we investigated the association between wood stove heating at age 0-6 years and asthma and allergies up to young adulthood. Adjustment was made for factors related to the heating system and atopic disorders by using multivariate regression. Unadjusted lifetime prevalence rates for physician-diagnosed asthma, allergic rhinoconjunctivitis, atopic dermatitis and self-reported wheezing were lower among subjects with wood stove heating compared to other heating systems. There was a significant negative association between childhood wood stove heating and allergic rhinitis or conjunctivitis in the univariate model (OR 0.61, 95% CI 0.61-0.91), but not for the other diseases. The significant association disappeared in the multivariate analysis after adjusting for various family indoor and outdoor (adjusted OR 0.96, 95% CI 0.77-1.20) factors. The association between wood stove heating and allergic rhinoconjunctivitis was mainly confounded by childhood residential environment, especially the farm environment. Farm environment was found to be the main confounding factor related to association between wood stove heating and asthma, and atopic diseases.