Prevalence of asthma, allergic rhinitis, and eczema in 13- to 14-year-old children in Kuwait: an ISAAC study. International Study of Asthma and Allergies in Childhood.

OBJECTIVES: To determine the prevalence of asthma and allergic diseases in 13 to 14 years old children in Kuwait. DESIGN: Supervised self-administered written and video questionnaires of the international study of asthma and allergies in childhood (ISAAC). SUBJECTS: Students at third and fourth years from 40 intermediate level schools chosen randomly from across Kuwait. RESULTS: 3,110 students were surveyed. The prevalence rates (95% CI) in the written questionnaire for wheeze ever, current wheeze (within the last 12 months), and physician diagnosis of asthma are 25.9% (24.5 to 27.4), 16.1% (15.8 to 17.4), and 16.8% (15.5 to 18.1) respectively. The prevalence rates (95% CI) for symptoms of allergic rhinitis (AR) ever, current symptoms of allergic rhinitis (AR), and diagnosis of AR are 43.9% (42.2 to 45.6), 30.7% (29.1 to 32.4) and 17.1% (14.8 to 18.4) respectively. The prevalence rates (95% CI) for itchy rash ever, current itchy rash, and diagnosis of eczema are 17.5% (16.2 to 18.8), 12.6% (11.4 to 13.8), and 11.3% (10.2 to 12.4) respectively. The prevalence of wheeze ever, wheeze during the last year, and physician diagnosis of asthma are higher in males compared with females, P < .01. In multiple logistic regression: male gender (OR 1.6, 95% CI, 1.3 to 2.0) and diagnosis of AR (OR 1.7, 95% CI, 1.4 to 2.2) were associated with the physician diagnosis of asthma even after controlling for symptoms of asthma. CONCLUSION: This is the first study on the prevalence of allergic diseases in Kuwait and it shows that children in Kuwait have a moderate prevalence of asthma, AR, and eczema compared with other countries where the ISAAC study is done. The prevalence of asthma is higher in boys compared with girls.     

Allergic rhinitis and asthma comorbidity in a survey of young adults in Italy

BACKGROUND: Several studies have provided evidence of a strong association between asthma and allergic or nonallergic rhinitis, leading to the hypothesis that allergic rhinitis (AR) and asthma represent a continuum of the same disease. AIM: The aims of our study were: (i) to measure the comorbidity of AR and asthma and asthma-like symptoms and (ii) to assess whether asthma, AR, and their coexistence share a common pattern of individual risk factors. METHODS: The subjects are participants from the Italian multicentre, cross-sectional survey on respiratory symptoms in the young adult general population (Italian Study of Asthma in Young Adults, ISAYA). The relationship between individual risk factors and asthma, AR and their coexistence, was studied by means of a multinomial logistic regression. RESULTS: About 60% of asthmatics reported AR. On the other hand, subjects with AR presented an eightfold risk of having asthma compared to subjects without AR. Age was negatively associated with asthma [OR = 0.89, 95% confidence interval (CI): 0.82-0.96], AR (OR = 0.92, 95% CI: 0.86-0.98), and asthma associated with AR (OR = 0.83, 95% CI: 0.79-0.88). The risk of AR without asthma was significantly higher in the upper social classes (OR = 1.23, 95% CI: 1.08-1.39). Active current smoking exposure was positively associated with asthma alone (OR = 1.24, 95% CI: 1.09-1.41) and negatively associated with AR with (OR = 0.69, 95% CI: 0.54-0.88) or without (OR = 0.76, 95% CI: 0.69-0.84) asthma. CONCLUSIONS: Asthma and AR coexist in a substantial percentage of patients; bronchial asthma and AR, when associated, seem to share the same risk factors as AR alone while asthma without AR seems to be a different condition, at least with respect to some relevant risk factors.     

NAC Manchester Asthma and Allergy Study (NACMAAS): risk factors for asthma and allergic disorders in adults

Asthma and atopic disorders are the most common chronic diseases in the developed countries. Knowledge of the risk factors for these disorders may facilitate the development of preventive strategies aimed at reducing prevalence rates. To investigate the risk factors for asthma and allergic diseases in a large number of adults who are the parents of children in the National Asthma Campaign Manchester Asthma and Allergy Study. All pregnant women and their partners attending "Booking" antenatal clinics were invited to take part in the study. Questionnaire data were collected including the history of asthma and other atopic diseases, pet ownership and smoking habits, and skin prick tests were performed. The prevalence of atopy and the risk factors for asthma and allergic disorders were investigated in all subjects who completed the questionnaire and underwent skin testing. Statistical analysis was carried out using logistic regression. Initially, risk factors were assessed by univariate analysis to see how each potential explanatory variable affected the probability of having allergic disease. Variables were then tested in a forward stepwise multivariate analysis. In 5687 adult subjects there was a very high (48.2%) prevalence of atopy, and 9.7% of subjects had a diagnosis of asthma. In a multivariate regression analysis sensitization to dust mite, cat, dog and mixed grasses were all independently associated with asthma. The odds ratios for current asthma increased with the increasing number of positive skin tests (any two allergens - OR 4.3, 95% CI 3.3-5.5; any three allergens - OR 7.0 95% CI 5.3-9.3; all four allergens - OR 10.4, 95% CI 7.7-14; P < 0.00001). Dog ownership (OR 1.31, 95% CI 1.10-1.57; P = 0.003) and current smoking (OR 1.36, 95% CI 1.15-1.62; P = 0.0004) were significantly and directly associated with "asthma ever". Thirteen per cent of participants reported a history of eczema. In the multivariate analysis the strongest independent associate of eczema was sensitization to dog (OR 1.37, 95% CI 1.14-1.63, P < 0.0001). Apart from dog, the strength of the association between sensitization to common allergens and eczema appeared to be much lower than in the case of asthma. The prevalence of hay fever was high (20.6%), and in the multivariate analysis the association between sensitization to pollen and hay fever was extremely strong (OR 13.6, 95% CI 11.3-16.3; P < 0.0001). The results of the current study emphasize the importance of sensitization to indoor allergens in asthma. However, evidence of a possible direct role of allergen exposure in asthma causation remains unclear.     

Breastfeeding and prevalence of allergic diseases in Japanese university students

BACKGROUND: Although historical support exists for the concept that breastfeeding might be protective against allergic diseases, contradictory findings have been observed recently. OBJECTIVE: To investigate the cumulative prevalence of allergic diseases in Japanese university students and to identify explanatory variables including breastfeeding. METHODS: From March 18, 2003, through March 29, 2005, a total of 9,615 students newly enrolled at the University of Tokyo responded to a written questionnaire on allergic diseases. RESULTS: Cumulative prevalence of allergic rhinitis, atopic dermatitis, and asthma was 47.2%, 17.4%, and 9.3%, respectively. These data were closely correlated, and prevalence of any 1 of the 3 diseases significantly increased the odds for historical prevalence of the other 2 (P < .001). Male sex (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.4-1.7) and maternal (OR, 2.2; 95% CI, 2.0-2.5) or paternal (OR, 1.6; 95% CI, 1.4-1.8) history of allergic rhinitis were significant correlates of increased odds for allergic rhinitis. Maternal (OR, 2.7; 95% CI, 1.6-4.5), paternal (OR, 3.8; 95% CI, 2.2-6.6), or sibling (OR, 1.9; 95% CI, 1.5-2.4) history of atopic dermatitis was a significant correlate of increased odds for atopic dermatitis. As for asthma, maternal (OR, 4.9; 95% CI, 3.0-7.9), paternal (OR, 4.0; 95% CI, 2.3-7.0), or sibling (OR, 3.3; 95% CI, 2.4-4.5) history of asthma was a significant correlate of increased odds. Logistic regression analysis showed no consistent evidence of the effects of breastfeeding on the cumulative prevalence. CONCLUSION: The cumulative prevalence of these diseases among young adults revealed that the effect of breastfeeding is negligible when compared with genetic factors.     

Differences in the prevalence of asthma and current wheeze between Jews and Arabs: results from a national survey of schoolchildren in Israel.

BACKGROUND: There is evidence that the prevalence of asthma is higher in Jewish schoolchildren than in Arab schoolchildren. It is not clear to what extent other risk factors explain these differences. OBJECTIVE: To evaluate whether the population group differences in the prevalence of asthma and current wheeze remain after adjustment for several potential risk factors. METHODS: A national survey of 10,057 13- to 14-year-old schoolchildren was carried out in Israel in 1997. There were 7,436 Jewish children and 2,621 Arab children. Differences in the two population groups were examined while controlling for demographic and environmental factors such as: sex, parental education, parental smoking and asthma, crowding, and presence of older siblings. RESULTS: The prevalence of asthma and current wheeze was significantly higher in Jewish children compared with Arab children. The asthma prevalence was 7.8% for Jewish children and 4.9% for Arab children (P = 0.001), and prevalence of current wheeze was 20.7 and 10.1%, respectively (P = 0.001). After adjustment for demographic and environmental factors, the prevalence of asthma and current wheeze was still increased in the Jewish population (odds ratios: 1.51; 95% confidence interval [CI] = 1.06 to 2.15; 2.15 95% CI = 1.70 to 2.73, respectively). History of asthma in parents and residence in a rural area were significant risk factors for asthma and current wheeze. In addition, the presence of less than three older siblings was a significant risk factor for asthma, and female sex, ever having pets, and maternal smoking were significantly associated with current wheeze. CONCLUSIONS: The differences between Jewish and Arab children were not explained by the studied factors. Genetic factors, different environmental exposure, and nutritional habits should be studied to further explain the differences between these populations.     

Farming, rural lifestyle and atopy in adults from southern Germany – results from the MONICA/KORA study Augsburg

BACKGROUND AND OBJECTIVE: The increasing urbanization and the decrease in the numbers of farms in southern Germany might be associated with an increasing prevalence of allergic diseases. We compared the prevalence of allergic diseases in farmers, and rural, suburban and urban residents in the small geographical area of Augsburg in southern Germany. METHODS: In a cross-sectional survey adults, aged 25-75 years selected from the community population register were investigated. Rural, suburban and urban residents were defined by community size and farmers by occupation. Allergic respiratory disorders were assessed by self-administered questionnaires and specific IgE antibodies to five common aeroallergens. RESULTS: In comparison to rural residents the urban population had an increased risk of allergic rhinitis (OR = 1.5; 95% CI: 1.2-1.9), atopic sensitization (OR = 1.2; 95% CI: 1.0-1.4) and sensitization against pollen (OR = 1.5; 95% CI: 1.2-1.9). There was no difference in the risk of asthma (OR = 1.0; 95% CI: 0.6-1.6) and a decreased risk in the sensitization against house dust mite (OR = 0.8; 95% CI: 0.7-1.0). The suburban residents did not differ from urban residents. Farmers had lower risks in allergic rhinitis, atopic sensitization, sensitization against pollen and mites (OR = 0.63; 0.86; 0.51 and 0.80, respectively) than rural non-farming residents, however, these differences were statistically not significant. Reported allergic rhinitis with sensitization to pollen was 2.5 times (95% CI: 1.8-3.6) more prevalent in urban than in rural residents. CONCLUSION: A farming environment and rural lifestyle might be associated with unknown protective factors impacting the prevalence of allergies.     

Risk Factors of Acoustic Neuroma: Systematic Review and Meta-Analysis

PurposeMany epidemiological studies have investigated environmental risk factors for the development of acoustic neuroma. However, these results are controversial. We conducted a meta-analysis of case-control studies to identify any potential relationship between history of noise exposure, smoking, allergic diseases, and risk of acoustic neuroma.ResultsEleven case-control studies were included in our meta-analysis. Acoustic neuroma was found to be associated with leisure noise exposure [odds ratio (OR)=1.33, 95% confidence interval (CI): 1.05–1.68], but not with occupational noise exposure and ever noise exposure (OR=1.20, 95% CI: 0.84–1.72 and OR=1.15, 95% CI: 0.80–1.65). The OR of acoustic neuroma for ever (versus never) smoking was 0.53 (95% CI: 0.30–0.94), while the subgroup analysis indicated ORs of 0.95 (95% CI: 0.81–1.10) and 0.49 (95% CI: 0.41–0.59) for ex-smoker and current smoker respectively. The ORs for asthma, eczema, and seasonal rhinitis were 0.98 (95% CI: 0.80–1.18), 0.91 (95% CI: 0.76–1.09), and 1.52 (95% CI: 0.90–2.54), respectively.ConclusionOur meta-analysis is suggestive of an elevated risk of acoustic neuroma among individuals who were ever exposed to leisure noise, but not to occupational noise. Our study also indicated a lower acoustic neuroma risk among ever and current cigarette smokers than never smokers, while there was no significant relationship for ex-smokers. No significant associations were found between acoustic neuroma and history of any allergic diseases, such as asthma, eczema, and seasonal rhinitis.     

Prevalence of hay fever and allergic sensitization in farmer's children and their peers living in the same rural community

INTRODUCTION: Lower prevalence rates of allergic diseases in rural as compared with urban populations have been interpreted as indicating an effect of air pollution. However, little is known about other factors of the rural environment which may determine the development of atopic sensitization and related diseases. OBJECTIVE: The authors tested the hypothesis that children growing up on a farm were less likely to be sensitized to common aerollergens and to suffer from allergic diseases than children living in the same villages but in nonfarming families. MATERIALS AND METHODS: Three age groups of schoolchildren (6-7 years, 9-11 years, 13-15 years) living in three rural communities were included in the analyses. An exhaustive questionnaire was filled in by 1620 (86.0%) parents. A blood sample was provided by 404 (69.3%) of the 13-15 year olds to determine specific IgE antibodies against six common aeroallergens. RESULTS: Farming as parental occupation was reported for 307 children (19.0%). After adjustment for potential covariates such as family history of asthma and allergies, parental education, number of siblings, maternal smoking, pet ownership, indoor humidity and heating fuels, farming as parental occupation was significantly associated with lower rates of sneezing attacks during pollen season (adjusted OR 0.34, 95% CI 0.12-0.89) and atopic sensitization (adjusted OR 0.31, 95% CI 0.13-0.73) whereas the association with wheeze (adjusted OR 0.77 95% CI 0.38-1.58) and itchy skin rash (adjusted OR 0.86, 95% CI 0.49-1.50) was not statistically significant. The risk of atopic sensitization was lower in children from full-time farmers (adjusted OR 0.24, 95% CI 0.09-0.66) than from part-time farmers (adjusted OR 0.54, 95% CI 0.15-1.96). CONCLUSION: Factors directly or indirectly related to farming as parental occupation decrease the risk of children becoming atopic and developing symptoms of allergic rhinitis.     

Atopic disease and its determinants – a focus on the potential role of childhood infection

BACKGROUND: Atopic diseases develop on a genetic background and are modulated by environmental factors among which some infectious diseases are thought to have a protective influence. OBJECTIVE: The aim of this study was to determine the influence of infectious diseases in younger ages, bacterial and viral, on atopic diseases and sensitization to aero- and food-allergens in adults. METHODS: A population-based sample of 4262 subjects aged 25-74 years were interviewed concerning their history of infectious disease within the first 18 years of life. Information about allergic disease, including atopic eczema, allergic rhinitis (AR), and asthma was obtained. A blood sample was drawn and analysed for allergen-specific IgE antibodies against food- and aero-allergens. RESULTS: Multiple logistic regression analyses identified viral infection to be associated with AR (adjusted odds ratio (OR) = 1.39; 95% confidence interval (95% CI): 1.13-1.72) and sensitization to aeroallergens (OR = 1.21; 95% CI: 1.05-1.41). Bacterial disease was a negative predictor for atopy development in the subgroup of patients sensitized to nutritional allergens with concomitant atopic eczema (OR = 0.34; 95% CI: 0.11-0.99), AR (OR = 0.67; 95% CI: 0.42-1.07), or asthma (OR = 0.41; 95% CI: 0.19-0.87). Influences of viral and bacterial infection on AR differed with regard to family history of atopic disease. CONCLUSION: In our study population, history of viral infection was consistently positively associated with AR. Our data suggests that bacterial infections might be preventive for specific subgroups of atopy.     

The impact of climate and traffic-related NO2 on the prevalence of asthma and allergic rhinitis in Italy

BACKGROUND: Environmental factors are likely to be involved in explaining the wide geographical variation in asthma and atopic diseases that has been documented in many recent epidemiological studies. AIM: To evaluate to what extent climate and outdoor NO2 pollution can explain the geographical variation in the prevalence of asthma and allergic rhinitis, and to estimate the relative risk for exposure to different levels of these two factors. METHODS: The impact of climate and long-term exposure to nitrogen dioxide (NO2) pollution on asthma and allergic rhinitis was assessed in a cross-sectional study, carried out during 1998 to 2000 on young adults aged 20 to 44 years (n = 18 873), living in 13 areas from two different Italian climatic regions (subcontinental and Mediterranean). RESULTS: Mediterranean areas had a significantly higher prevalence of asthma-like symptoms (P < 0.001), higher annual mean temperature (16.2 degrees C vs. 12.9 degrees C), lower temperature range (16.0 C degrees vs. 22.1 degrees C) and lower NO2 levels (31.46 microg/m3 vs. 57.99 microg/m3) than subcontinental ones. Mediterranean climate was associated with an increased risk of wheeze (OR = 1.23; 95% CI 1.13 to 1.35), tightness in the chest (OR = 1.21; 95% CI 1.11 to 1.33), shortness of breath (OR = 1.21; 95% CI 1.08 to 1.36) and asthma attacks (OR = 1.19; 95% CI 1.07 to 1.31). After adjusting for climate, an increase of 18.3 microg/m3 in NO2 levels moderately increased the risk of asthma attacks (OR = 1.13; 95% CI 0.98 to 1.32), tightness in the chest (OR = 1.11; 95% CI 0.98 to 1.26) and wheeze (OR = 1.11; 95% CI 0.96 to 1.28). When the levels of outdoor NO2 exposure rose, the prevalence of allergic rhinitis increased significantly in the Mediterranean region (OR = 1.38; 95% CI 1.12 to 1.69), but not in the subcontinental one (OR = 1.03; 95% CI 0.83 to 1.28). CONCLUSION: Our results show that the prevalence of asthma increases when annual mean temperature increases and temperature range decreases. Furthermore, climate interacts with NO2 outdoor exposure, increasing the risk for allergic rhinitis in people exposed to high stable temperatures. A long-term role for the effect of traffic pollution on asthma is also suggested.     

Exposure to endotoxin decreases the risk of atopic eczema in infancy: a cohort study.

BACKGROUND: Previous studies have shown a protective effect of early exposure to cats and dogs on the development of atopic eczema, asthma, allergic rhinitis, and atopic sensitization in later life. In particular, a higher microbial exposure to endotoxin in early childhood might contribute to this effect. OBJECTIVE: We examined the associations between bacterial endotoxin in house dust and atopic eczema, infections, and wheezing during the first year of life in an ongoing birth cohort study (LISA). METHODS: Data of 1884 term and normal-weight neonates with complete information on exposure to biocontaminants and confounding variables were analyzed. House dust from the mothers' and the children's mattresses was sampled 3 months after birth. Endotoxin content was quantified by using a chromogenic kinetic limulus amoebocyte lysate test. RESULTS: During the first 6 months of life, the risk of atopic eczema was significantly decreased by endotoxin exposure in dust from mothers' mattresses in the fifth quintile (odds ratio [OR], 0.50; 95% CI, 0.28-0.88), whereas the risk was increased for respiratory infections (OR, 1.69; 95% CI, 1.25-2.28) and cough with respiratory infection, bronchitis, or both (OR, 1.73; 95% CI, 1.28-2.33). The risk of wheezing was also significantly increased during the first 6 months of life (OR, 2.37; 95% CI, 1.40-4.03). For the entire first year of life, these associations attenuated, except for the risk of wheezing, which remained significant (OR, 1.60; 95% CI, 1.10-2.30). CONCLUSION: Our findings support the hygiene hypothesis that exposure to high concentrations of endotoxin very early in life might protect against the development of atopic eczema within the first 6 months of life, along with an increased prevalence of nonspecific respiratory diseases.     

Caesarean section delivery and the risk of allergic disorders in childhood

BACKGROUND: The composition of the intestinal flora in young children, if unfavourable, may increase the susceptibility to allergic disorders. Beneficial intestinal microbes originate from the maternal vaginal tract and thus are more likely to be transferred during vaginal births than during Caesarean sections (C-sections). OBJECTIVE: To determine whether children born by C-section have a different risk of allergic disorders compared with those delivered vaginally. We also tested the hypothesis that the risk of allergic disorders is highest for children born after 'repeat C-sections'. METHODS: A retrospective cohort study of 8,953 children aged 3-10 years. Children diagnosed with allergic rhinoconjunctivitis (AR), asthma, atopic dermatitis (AD), or food allergies were identified from the Kaiser Permanente Northwest Region electronic records. The children's sex, birth weight, birth order, postnatal exposure to antibiotics as well as the mothers' age, ethnicity, education, marital status, smoking status during pregnancy, and use of asthma or hayfever medications were identified through the mothers' medical records or through the Oregon Birth Registry. RESULTS: The risk of being diagnosed with AR was significantly higher in the children born by C-section than in those delivered vaginally: adjusted odds ratio (OR)=1.37%, 95% confidence interval (CI)=1.14-1.63. Delivery by C-section was also associated with the subsequent diagnosis of asthma (OR=1.24%, 95% CI=1.01-1.53); this association was gender specific, with a positive association restricted to girls (OR for asthma in girls: OR=1.53%, 95% CI=1.11-2.10; in boys: OR=1.08%, 95% CI=0.81-1.43). There was no significant association between mode of delivery and AD. If children born in a 'repeat C-section' were considered separately the risk of being diagnosed with AR increased further (OR=1.78%, 95% CI=1.34-2.37). The same increase was noted for asthma in girls (OR=1.83%, 95% CI=1.13-2.97) but not in boys. CONCLUSION: Caesarean sections may be associated with an increased risk of developing AR in childhood.     

Pet-keeping in childhood and adult asthma and hay fever: European community respiratory health survey

BACKGROUND: Whether pet-keeping early in life protects against or promotes allergy remains unclear. OBJECTIVE: Our aim was to examine the effects of childhood pet-keeping on adult allergic disease in a large international population-based study, including information on sensitization, adult pet-keeping, and pet prevalence in the populations. METHODS: We used information from structured interviews (n = 18,530) and specific IgE to common aeroallergens in blood samples (n = 13,932) from participants in the European Community Respiratory Health Survey (ECRHS) to analyze the associations between keeping pets and adult asthma and hay fever. RESULTS: Keeping cats in childhood was associated with asthma only among atopic subjects, an association that varied between centers (P =.002) and was stronger where cats where less common (< 40% cats: odds ratio(wheeze) [OR(wheeze)] = 1.84, 95% CI = 1.31-2.57; 40%-60% cats: OR(wheeze) = 1.33, 95% CI = 1.10-1.61; > or =60% cats: OR(wheeze) = 0.98, 95% CI = 0.73-1.33). Dogs owned in childhood or adulthood were associated with asthma among nonatopic subjects (childhood: OR(wheeze) = 1.28, 95% CI = 1.13-1.46; adulthood: OR(wheeze) = 1.31, 95% CI = 1.14-1.51; both: OR(wheeze) = 1.69, 95% CI = 1.40-2.04). In atopic subjects, those who had owned dogs in childhood had less hay fever (OR = 0.85; 95% CI = 0.73-0.98) and no increased risk of asthma (OR(wheeze) = 1.01, 95% CI = 0.87-1.17). Respiratory symptoms were more common in subjects who had owned birds during childhood (OR(wheeze) = 1.12; 95% CI = 1.02-1.23) independent of sensitization. CONCLUSIONS: The effects of pet-keeping in childhood varied according to the type of pet, the allergic sensitization of the individual, and the wider environmental exposure to allergen. Cats owned in childhood were associated with more asthma in sensitized adults who grew up in areas with a low community prevalence of cats. Dogs owned in childhood seemed to protect against adult allergic disease but promote nonallergic asthma.     

Allergic diseases and atopic sensitization in children related to farming and anthroposophic lifestyle--the PARSIFAL study

BACKGROUND: The prevalence of allergic diseases has increased rapidly in recent decades, particularly in children. For adequate prevention it is important not only to identify risk factors, but also possible protective factors. The aim of this study was to compare the prevalence of allergic diseases and sensitization between farm children, children in anthroposophic families, and reference children, with the aim to identify factors that may protect against allergic disease. METHODS: The study was of cross-sectional design and included 14,893 children, aged 5-13 years, from farm families, anthroposophic families (recruited from Steiner schools) and reference children in Austria, Germany, The Netherlands, Sweden and Switzerland. A detailed questionnaire was completed and allergen-specific IgE was measured in blood. RESULTS: Growing up on a farm was found to have a protective effect against all outcomes studied, both self-reported, such as rhinoconjunctivitis, wheezing, atopic eczema and asthma and sensitization (allergen specific IgE > or = 0.35 kU/l). The adjusted odds ratio (OR) for current rhinoconjunctivitis symptoms was 0.50 (95% confidence interval (CI) 0.38-0.65) and for atopic sensitization 0.53 (95% CI 0.42-0.67) for the farm children compared to their references. The prevalence of allergic symptoms and sensitization was also lower among Steiner school children compared to reference children, but the difference was less pronounced and not as consistent between countries, adjusted OR for current rhinoconjunctivitis symptoms was 0.69 (95% CI 0.56-0.86) and for atopic sensitization 0.73 (95% CI 0.58-0.92). CONCLUSIONS: This study indicates that growing up on a farm, and to a lesser extent leading an anthroposophic life style may confer protection from both sensitization and allergic diseases in childhood.     

Association of active and passive smoking with allergic disorders in pregnant Japanese women: baseline data from the Osaka Maternal and Child Health Study.

BACKGROUND: Evidence remains inconclusive as to whether smoking is a risk factor for allergic disorders in adults. OBJECTIVE: To investigate the relationship between active and passive smoking exposure and allergic disorders in pregnant Japanese women. METHODS: This cross-sectional study included 1,002 pregnant women. Participants were classified as having asthma after the age of 18 years if they had used an asthma medication at any time after reaching the age of 18 years. Current atopic eczema and allergic rhinitis (including cedar pollinosis) were defined as being present if participants had received any drug treatment during the previous 12 months. Adjustment was made for age; gestation; parity; family history of asthma, atopic eczema, and allergic rhinitis; indoor domestic pets; family income; education; and the mite antigen level in house dust. RESULTS: Current smoking, but not environmental tobacco smoke exposure, was independently related to an increased prevalence of asthma after the age of 18 years (adjusted odds ratio [OR], 2.66; 95% confidence interval [CI], 1.30-5.38). A significant positive association of current passive smoking exposure at home (adjusted OR, 1.89; 95% CI, 1.10-3.30) and at work (adjusted OR, 2.50; 95% CI, 1.29-4.76) with the prevalence of current allergic rhinitis was observed, whereas no measurable association with active smoking exposure was found. Neither active nor passive smoking was statistically significantly related to the prevalence of current atopic eczema. CONCLUSIONS: These findings suggest that active smoking and environmental tobacco smoke exposure may increase the likelihood of asthma and allergic rhinitis, respectively, in pregnant Japanese women.     

Clinical atopy and associated factors in primary-school pupils

To investigate potential risk factors for clinical atopy in childhood, we obtained cross-sectional data from a cohort of 1376 8-year-old pupils. Parental atopy (hay fever, asthma, eczema), gestational age, maternal smoking habits, and the child's history of asthma, hay fever, and eczema were ascertained by questionnaire. Combining the history and the result of a skin prick test using seven aeroallergens, we defined the child's atopic diseases. Of the population evaluated, 25.4% were categorized as atopic (10.2% allergic asthma, 17.3% eczema, 6.9% hay fever). As compared with the clear nonatopics (40.2%), parental atopic diseases were more prevalent in each of the atopic groups. Significant associations of the parents' and child's disease were obvious for eczema and hay fever. Low gestational age (LGA) was more frequent in children with any atopy or with an allergic asthma (odds ratio (OR) 1.7; 95% confidence interval (CI) 1.02-2.97; OR 2.8; 95% CI 1.5-5.4). Hay fever and allergic asthma occurred less frequently in girls (OR 0.5; 95% confidence interval 0.3-0.8; OR 0.6; 95% CI 0.4-0.9). In conclusion, our data underline the importance of parental atopy for the clinical outcome in the offspring. In addition, LGA appears to be a risk factor for allergic asthma and for general atopy in later life.     

Atopic eczema in children: another harmful sequel of divorce

BACKGROUND: Different lifestyle factors seem to be associated with the risk for atopic diseases and some studies suggest that stress increases the risk of allergic sensitization, asthma and atopic eczema. Only few studies have investigated the association of early stressful life events and atopic eczema (AE) in children. SUBJECTS AND METHODS: Parents of participants of the ongoing LISA birth cohort study were asked to give information on life events, such as severe disease or death of a family member, unemployment, or divorce of the parents. Lifetime prevalence of AE and incidence after the assessment period for life events were compared. RESULTS: Prevalence of AE until the age of 4 years was 21.4%. Reported life events within the first 2 years were: severe disease (17.5%) or death (8.4%) of a family member, divorce/separation (3.4%), and unemployment (2.7%). Divorce/separation was associated with a significantly [odds ratio (OR) 3.59, 95% confidence interval (CI) 1.69-7.66] increased and disease with a significantly (OR 0.29, 95% CI 0.13-0.68) decreased incidence of AE for the subsequent 2 years of life. No effect was seen for unemployment. CONCLUSIONS: Divorce/separation of the parents and severe disease of a family member influence the risk of developing AE.     

Prevalence of respiratory and atopic disorders in Chinese schoolchildren

BACKGROUND: Epidemiological surveys have shown that the prevalence of asthma in the Asian population is relatively low. Within the Chinese population, schoolchildren from Hong Kong were found to have the highest rate of asthma. OBJECTIVE: To compare the prevalence of respiratory and atopic disorders, and to assess the role of atopy in the development of asthma, in Chinese schoolchildren from Hong Kong, Beijing and Guangzhou. METHODS: Community-based random samples of schoolchildren aged 9-11 years from three Chinese cities (Hong Kong, Beijing and Guangzhou) 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 = 10902), skin-prick tests (n = 3479) and skin examination (n = 3479). RESULTS: The prevalence rates of current wheeze, speech limiting wheeze, rhinoconjunctivitis and flexural dermatitis were significantly more common in Hong Kong than in Beijing or Guangzhou. The atopy rate was also higher in Hong Kong (41.2%) than in Beijing (23.9%) or Guangzhou (30.8%). Atopy was strongly correlated with current wheeze (OR 7.74; 95% CI = 5.70-10.51). Subgroup analyses of children from Hong Kong revealed that children born in mainland China who had subsequently migrated to Hong Kong had a significantly lower rate of allergic symptoms and atopy than those children born in Hong Kong. CONCLUSION: Using a standardized written questionnaire along with a skin prick test and skin examination, we confirmed that the prevalence of asthma, allergic diseases and atopy was highest in schoolchildren from Hong Kong. Atopic sensitization is an important factor associated with asthma in Chinese children.     

Asthma during the primary school ages--prevalence, remission and the impact of allergic sensitization

BACKGROUND: Childhood is the most important time for asthma development. The aims of this study were to study changes in prevalence of asthma and wheeze, remission of asthma and changes in risk factor pattern from age 7-8 to age 11-12 in a cohort of school children. METHODS: In 1996, 3525 children aged 7-8 years in northern Sweden were invited to participate in a parental expanded ISAAC questionnaire survey. The cohort has been followed prospectively with yearly follow-ups to age 11-12, with a 97% yearly response rate. Skin prick tests were conducted at age 7-8 and 11-12. RESULTS: The prevalence of physician-diagnosed asthma increased from 5.7% at age 7-8 to 7.7% at age 11-12. Life-time prevalence of wheeze was 34.7% at age 11-12. The remission of asthma was 10% yearly and inversely related to allergic sensitization. Relapses were common, and remission persisting throughout the observation period was 5% yearly. Allergic sensitization was associated with current asthma at age 7-8 [adjusted odds ratio (OR) 4.9 (95% confidence interval (CI) 3.3-7.3)] and when the children were 4 years older [OR 5.6 (3.9-8.2)]. A family history of asthma was associated with current asthma at age 7-8 [OR 3.0 (2.1-4.5)] and 11-12 (OR 2.8 [2.0-3.9]). Ever having lived with a cat was significantly negatively associated with current asthma. CONCLUSIONS: The prevalence of asthma increased continuously during the primary school ages. Among several significant risk factors, allergic sensitization and a family history of asthma were the most important. With increasing age many known risk factors lost significance. Remission was inversely related to allergic sensitization.     

Prevalence of allergic diseases in schoolchildren in relation to family history upper respiratory infections, and residential characteristics

The prevalences of asthma, allergic rhinitis (AR), and eczema were analyzed in relation to retrospective risk factors from birth in a questionnaire study of schoolchildren in two areas covering the whole climatic span of Sweden: the Göteborg area on the southwestern coast (7-year-olds, n = 1649) and Kiruna, a mining town in the northernmost inland mountains (7–9-year-olds, n = 832). The strongest background factor, a family history of the diseases, was more common in children with another strong risk factor, particularly for asthma: high frequency of upper respiratory tract infection (URTI). Other significant risk factors related to high indoor humidity caused an increased prevalence of both allergic diseases and URTI. Active mechanical ventilation of the homes caused a slight reduction of the prevalence of allergic diseases, and repainting or new wallpaper in the bedroom of the child after birth caused a moderately increased risk of allergic disease. This study illustrates the interaction between genetic and environmental risk factors with special emphasis on factors related to an unventilated indoor climate, which may have substantially contributed to the current increase of the diseases in the country.