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.     

Dietary factors associated with physician-diagnosed asthma and allergic rhinitis in teenagers: analyses of the first Nutrition and Health Survey in Taiwan

The occurrence of asthma and allergy are related to lifestyle factors, and dietary pattern may be one of the contributing factors. To examine the possible association between dietary intake and the prevalence of asthma and allergic rhinitis in teenagers. In a population-based cross-sectional survey, the relationship was sought between food frequency and physician-diagnosed asthma and allergic rhinitis in 1166 adolescents aged 13-17. The prevalence was 4.0% for asthma and 12.4% for rhinitis. Living in an urbanized area was a significant predictor of asthma and rhinitis. In univariate analysis, higher frequencies of oily fish, butcher's meat, liver and deep-fried foods were associated with asthma. Relevant food frequency variables were dichotomized at the 75th percentile for multivariate logistic regression analysis, which included adjustment for two levels of urbanization. Asthma was associated with intakes of liver (OR = 2.32, 95%CI 1.11-4.80), deep-fried foods (OR = 2.13, 95%CI 1.06-4.30) and butcher's meat (OR 1.84, 95%CI 0.89-3.80). In a similar analysis, allergic rhinitis was associated with liver (OR = 1.67, 95%CI 1.06-2.63). No protective effect was demonstrated for any of the food items examined. Protein-rich and fat-rich foods of animal origin were associated with a higher prevalence of asthma in teenagers.     

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.     

The role of climate on the geographic variability of asthma, allergic rhinitis and respiratory symptoms: results from the Italian study of asthma in young adults

BACKGROUND: Variations in the prevalence of respiratory symptoms according to geo-climatic factors could provide important clues to the knowledge of the aetiology of asthma. METHODS: Geo-climatic variations in the prevalence of current asthma, allergic rhinitis and chronic cough, and phlegm were assessed on a random sample of 18 873 subjects (response rate = 72.7%) from different climatic regions of Italy. An ecological analysis, supported by robust statistical methods, was employed to investigate potential trends. RESULTS: The prevalence of all symptoms was significantly heterogeneous throughout the peninsula. Only asthma-like symptoms showed a north-south trend: the prevalence increased at a decreasing latitude [odds ratio (OR) varies from 0.92 to 0.96, P < 0.05], at a decreasing distance from the sea (OR: 0.90-0.93 for 30 km distance, P < 0.05), at higher annual mean temperatures (OR: 1.11-1.14, P < 0.05) and at smaller annual temperature ranges (OR: 0.94-0.95, P < 0.05). Of the geo-climatic variables considered, temperature range had the greatest influence on most asthma-like symptoms. No association was found between geo-climatic variables and allergic rhinitis or chronic cough and phlegm. CONCLUSIONS: Asthma prevalence seems to be significantly affected by climate as asthma-like symptoms were more common in central-southern Italy, with a Mediterranean climate, than in areas with a continental climate (northern Italy).     

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.     

Does the pill make a difference? Previous maternal use of contraceptive pills and allergic diseases among offspring

BACKGROUND: Maternal use of oral contraceptive pills (OCPs) might increase the prevalence of allergic diseases among offspring. The aim of the study was to clarify if there are differences between OCP types in this association. METHODS: Primary outcomes were asthma, allergic rhinitis and atopic eczema among 1182 children (618 asthmatic and 564 controls) aged 5-6 years. RESULTS: Maternal previous use of desogestrel, gestodene or cyproterone acetate before pregnancy, each combined with ethinyloestradiol (EO), increased the risk of allergic rhinitis among offspring compared with those children whose mothers had not used OCPs (OR 1.67, 95% CI 1.07-2.59, P < 0.024), and this risk was increased mainly in those children with parental allergy (OR 1.78, 95% CI 1.11-2.86, P < 0.018), especially in boys (OR 2.12, 95% CI 1.17-3.84, P < 0.014). No associations were observed between maternal use of OCPs before pregnancy and asthma or atopic eczema among offspring. The association between the previous use of OCPs and allergic rhinitis was not mediated through maternal sex steroid levels during early pregnancy, but women who had used more androgenic types of progestin formulas had higher serum levels of progesterone during early pregnancy. CONCLUSION: Maternal previous use of desogestrel, gestodene or cyproterone acetate before pregnancy, each combined with EO, increased the risk of allergic rhinitis among offspring compared with those children whose mothers had not used OCPs and this risk was detected mainly in boys and in children with parental allergy.     

Farm environment in childhood prevents the development of allergies

BACKGROUND: A protective effect of infections in early life might explain the firmly reported finding of an inverse association between atopic disorders and large sibships. OBJECTIVE: To study the effect of childhood farm, rural non-farm and urban environment, as well as family size and other factors on the occurrence of asthma, wheezing and atopic disorders up to young adulthood. METHODS: Data on lifetime prevalence of physician-diagnosed asthma, allergic rhinitis and/or allergic conjunctivitis, atopic dermatitis, as well as self-reported episodic wheezing from 10 667 Finnish first-year university students aged 18-24 years were collected by a postal questionnaire. Associations of lifetime prevalence of the diseases with living on a farm, in a rural non-farm and urban environment during childhood were estimated by logistic regression analysis. Adjustment was made for potential confounding by gender, parental atopy, parental education, number of older siblings, day care outside the home and passive smoking. RESULTS: The childhood farm environment independently reduced the risk for physician-diagnosed allergic rhinitis and/or allergic conjunctivitis (adjusted odds ratio 0.63, 95% CI 0.50-0.79, P < 0.001), and for diagnosed asthma and episodic wheezing analysed together (OR 0.71, 95% CI 0.54-0.93, P < 0.05), but not for atopic dermatitis during lifetime. Urban childhood environment did not show independent increased risk when compared with rural non-farm residence. The inverse association of sibship size with the occurrence of allergic rhinitis and/or allergic conjunctivitis was found among subjects with one (OR 0.86, 95% CI 0.77-0.96, P < 0.01) or at least four older siblings (OR 0.47, 95% CI 0.26-0.84, P < 0.05). CONCLUSION: Childhood farm environment seems to have a protective effect against allergic rhinitis and/or conjunctivitis, and more weakly against asthma and wheezing irrespective of family size. Environmental exposure to immune modulating agents, such as environmental mycobacteria and actinomycetes, favouring manifestation of a nonatopic phenotype could explain the finding.     

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.     

The diagnosis of asthma using a self-questionnaire in those suffering from allergic rhinitis: a pharmaco-epidemiological survey in everyday practice in France

BACKGROUND: All recent guidelines recommend a search for asthma utilizing both specific interrogation and pulmonary function tests in patients suffering from allergic rhinitis. Although the mandatory place of spirometry has not been confirmed, a self-questionnaire containing nine specific questions on asthma symptoms in different daily life situations was found to be capable of discriminating asthmatics from nonasthmatics in a rhinitic population. OBJECTIVE: We addressed the questions of prevalence of asthma using a validated self-questionnaire and what might be the risk factors of being asthmatic according to that specific self-questionnaire. METHODS: Between April 2003 and September 2004, nearly 12,000 rhinitis patients were enrolled by more than 2300 physicians (78% general practitioners, 22% ear nose and throat specialists). Patients were consulting for an exacerbation of chronic rhinitis and did not have a previous diagnosis of asthma. Both doctors and patients filled out a specific questionnaire on rhinitis and asthma. RESULTS: Almost 30% of the patients had at least three positive answers to the self-questionnaire and could possibly be considered as asthmatics. We found five independent clinical risk factors for having >or=3 positive answers to the self-questionnaire. Severity of rhinitis (moderate-severe vs mild, OR=1.84; 95% CI=1.68-2.00), diagnosis of allergy (yes vs no) (OR=1.86; 95% CI=1.68-2.00), body mass index (30) (OR=0.51; 95% CI=0.39-0.66), type of rhinitis (persistent vs intermittent) (OR=1.25; 95% CI=1.15-1.37), and patient age (47) (OR=0.73; 95% CI=0.65-0.80). CONCLUSION: Asthma symptoms are frequent in rhinitics without a prior history of asthma. Several variables were shown to be predictive of asthma in these patients.     

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.     

Increasing prevalence of allergic rhinitis symptoms in an adult Danish population

There is evidence that the prevalence of respiratory allergy is increasing. This is mainly based on studies in children and young adults. The aim of the study was to compare the prevalences of self-reported symptoms of respiratory allergy among Danish adults in two surveys 8 years apart. Identical questionnaires were mailed to two random general population samples in 1989 and 1997. The response rates were 86.1% (n = 3603) and 86.4% (n = 817), respectively. The sampling frame and sampling method were identical in both surveys. The changes in the prevalences of symptoms were expressed by sex- and age-adjusted odds ratios comparing 1997 to 1989. We found a significant increase in the prevalence of seasonal rhinitis symptoms (OR=1.6, 95% CI 1.4-1.9), rhinitis symptoms on exposure to pollen (OR =1.6, 95% CI 1.4-1.9), rhinitis symptoms on exposure to furry animals (odds ratio 1.6, 95% CI 1.3-2.0), rhinitis symptoms on exposure to house dust (OR = 1.3, 95% CI 1.1-1.6), and breathlessness on exposure to pollen (OR = 1.5, 95% CI 1.0-2.0). The observed increases were independent of sex and age. The questionnaire was validated in relation to allergen skin test reactivity in a subgroup of the responders to the 1989 survey. When the estimated associations between symptoms and skin test reactivity were considered, the results suggested an increase in allergy to pollen and animal dander. In conclusion, we found evidence of increased prevalence of allergic rhinitis symptoms associated with skin test reactivity.     

Prevalence and risk factors for allergic rhinitis and atopic eczema among schoolchildren in Israel: results from a national study.

BACKGROUND: There is growing evidence that the prevalence rates of asthma and allergic diseases are increasing, especially among children. Several risk factors are under investigation. OBJECTIVE: To evaluate the prevalence and risk factors for allergic diseases, including allergic rhinitis (AR) and atopic eczema (AE), among 13- to 14-year-old schoolchildren in Israel. METHODS: A modified version of the International Study of Asthma and Allergies in Childhood written questionnaire was administered to a national sample of schoolchildren 13 to 14 years old in Israel. The questionnaire was completed by the schoolchildren themselves. RESULTS: There were 10,057 complete questionnaires available for analysis. The prevalence of AR symptoms ever and current AR were 41.6% and 9.4%, respectively. Allergic rhinoconjunctivitis symptoms ever were reported by 15.8% of the children. The prevalence rates of 6 months of itchy rash ever and AE were 5.9% and 7.8%, respectively. After adjustment for demographic and environmental factors, current asthma, parental history of asthma, and population group were the most significant risk factors for current AR (odds ratio [OR], 4.47; 95% confidence interval [CI], 3.70-5.40; OR, 1.30; 95% CI, 1.02-1.66; and OR, 1.75; 95% CI 1.45-2.13; respectively) and AE (OR, 2.30; 95% CI, 1.80-2.90; OR, 1.80; 95% CI, 1.40-2.30; and OR, 1.70; 95% CI, 1.40-2.00; respectively). CONCLUSIONS: Israeli children have a low prevalence rate of current AR and a midrange rate of AE. Arabs have lower prevalence rates of allergic diseases than Jews, and the prominent risk factors for those diseases are current asthma and parental history of asthma.     

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.     

Adherence to the Mediterranean diet and fresh fruit intake are associated with improved asthma control

Background: The traditional Mediterranean diet is claimed to possess antioxidant and immune‐regulatory properties in several chronic diseases. Typical Mediterranean foods have recently been associated with improvement of symptoms of asthma and rhinitis in children. However the effect of adherence to Mediterranean diet on adult asthma outcomes is unknown. We aimed to investigate the association between adherence to Mediterranean diet and asthma control. Methods: Cross sectional study of 174 asthmatics, mean (SD) age of 40 (15) years. The patients were defined as controlled, in contrast to noncontrolled, if they showed FEV1 ≥ 80% of predicted, exhaled nitric oxide (NO) ≤35 ppb, and Asthma Control Questionnaire score <1. Dietary intake was obtained by a food frequency questionnaire, and Mediterranean diet was assessed by alternate Mediterranean Diet (aMED) Score. Logistic regression models adjusting for confounders were performed to estimate the association between Mediterranean diet and asthma control. Results: Controlled asthmatics (23%) had significantly higher aMED Score, intake of fresh fruit, and lower intake of ethanol compared to noncontrolled (77%). High adherence to Mediterranean diet reduced 78% the risk of noncontrolled asthma after adjusting for gender, age, education, inhaled corticosteroids and energy intake (OR = 0.22; 95% CI = 0.05–0.85; P‐trend = 0.028). The higher intake of fresh fruit decreased the probability of having noncontrolled asthma (OR = 0.29; 95% CI = 0.10–0.83; P‐trend = 0.015), while the higher intake of ethanol had the opposite effect (OR = 3.16; 95% CI = 1.10–9.11; P‐trend = 0.035). Conclusion: High adherence to traditional Mediterranean diet increased the likelihood of asthma to be under control in adults. The study introduces a novel link between diet and asthma control, as measured by symptoms, lung function and exhaled NO.     

Negative association of Enterobius infestation with asthma and rhinitis in primary school children in Taipei

BACKGROUND: The relationship between allergy and parasites has been controversial, especially in non-tropical countries. Enterobius vermicularis (human pinworm) is the most prevalent intestinal parasite in industrialized countries. OBJECTIVE: To examine the association between pinworm infestation and allergy in primary school children. METHOD: Peri-anal tape test for pinworm is routinely performed in Taipei primary schools. We collected data from school records and questionnaires distributed to all children in four primary schools grades 1 through 6 (n = 3107). RESULTS: The prevalence of physician-diagnosed asthma (9.3% vs. 14.1%, P = 0.007) and allergic rhinitis (27.4% vs. 38.3%, P = 0.001) was lower in pinworm-positive compared to uninfested children. Pinworm was not correlated with atopic dermatitis or parent allergy. With logistic regression controlling for sex, parent allergy and lower respiratory infection, current asthma (OR = 0.25, 95% CI 0.10-0.63) and rhinitis (OR = 0.61, 95% CI 0.45-0.84) were negatively associated with pinworm. Among children in grades 3-6 who had no asthma or rhinitis before age 7, those with early infestation (pinworm diagnosis at or before grade 1) had a lower risk of having diagnosis of rhinitis during school years, compared to the uninfected group (5.4% vs. 12.3%, P = 0.03; adjusted OR = 0.47, 95% CI 0.21-1.02). CONCLUSIONS: We identified a negative association between pinworm infestation and allergic airway diseases, which could in part be attributed to protective effect of pinworm infestation on development of allergic symptoms. Other mechanisms of association could not be ruled out.     

Respiratory allergy in apprentice bakers: do occupational allergies follow the allergic march?

BACKGROUND: This prospective study describes the incidence, risk factors and natural history of occupational respiratory allergy in apprentice bakers. METHODS: Two hundred and eighty-seven apprentice bakers were examined using a questionnaire, skin prick tests (SPTs) to common and occupational allergens, evaluation of total serum IgE level and specific anti-flour and alpha-amylase IgE, before, 1 year and 2 years after the onset of vocational training. To diagnose occupational respiratory disease, spirometry, histamine and allergen-specific inhalation challenge tests were performed. RESULTS: The incidence of work-related chest symptoms was 4.2% in the first year and 8.6% in the second year of exposure. Hypersensitivity to occupational allergens developed in 4.6 and 8.2% of subjects, respectively. The incidence of occupational allergic rhinitis was 8.4% after 1 year and 12.5% after 2 years, and that of occupational asthma/cough-variant asthma 6.1 and 8.7%, respectively. The latency period of work-related rhinitis symptoms was 11.6 +/- 7.1 months and chest symptoms 12.9 +/- 5.5 months. Only in 20% of occupational asthmatics could allergic rhinitis be diagnosed a stage earlier. In 21 out of 25 subjects with occupational asthma, chronic cough was the sole clinical manifestation of the disease. Stepwise logistic regression analysis revealed that positive SPT to common allergens was a significant risk factor of hypersensitivity to occupational allergens (OR = 10.6, 95% CI 5.27; 21.45), occupational rhinitis (OR = 3.9, 95% CI 1.71; 9.14) and occupational asthma (OR = 7.4, 95% CI 3.01; 18.04). Moreover, positive SPT to occupational allergens on entry to the training was a significant risk factor of asthma (OR = 6.9, 95% CI 0.93; 51.38). CONCLUSIONS: The incidence of occupational asthma and rhinitis in apprentice bakers is high and increases z with the duration of exposure. Skin reactivity to common and occupational allergens is the main risk factor of bakers' asthma. Most cases of work-related respiratory symptoms among apprentice bakers are related to a specific sensitization. In most subjects who developed occupational asthma, rhinitis occurred at the same time as the chest symptoms did.     

Long-term exposure to background air pollution related to respiratory and allergic health in schoolchildren

BACKGROUND: The impact of air pollution on asthma and allergies still remains a debate. OBJECTIVE: Our cross-sectional study was intended to analyse the associations between long-term exposure to background air pollution and atopic and respiratory outcomes in a large population-based sample of schoolchildren. METHODS: Six thousand six hundred and seventy-two children aged 9-11 years recruited from 108 randomly schools in six French cities underwent a clinical examination including a skin prick test (SPT) to common allergens, exercise-induced bronchial reactivity (EIB) and skin examination for flexural dermatitis. The prevalence of asthma, allergic rhinitis (AR) and atopic dermatitis was assessed by a standardized health questionnaire completed by the parents. Three-year-averaged concentrations of air pollutants (NO2, SO2, PM10 and O3) were calculated at children' schools using measurements of background monitoring stations. RESULTS: After adjusting for confounders, EIB, lifetime asthma and lifetime AR were found to be positively related to an increase in the exposure to SO2, PM10 and O3. The adjusted odds ratios (aOR) per increase of 5 microg/m3 of SO2 was 1.39 (95% confidence interval (CI)=1.15-1.66) for EIB and 1.19 (1.00-1.41) for lifetime asthma. The aOR for lifetime AR per increase of 10 microg/m3 of PM10 was 1.32 (CI=1.04-1.68). Moreover, SPT positivity was associated with O3 (aOR=1.34; CI=1.24-1.46). Associations with past year symptoms were consistent, even if not always statistically significant. Results persisted in long-term resident (current address for at least 8 years) children. However, no consistent positive association was found with NO2. CONCLUSIONS: A moderate increase in long-term exposure to background ambient air pollution was associated with an increased prevalence of respiratory and atopic indicators in children.     

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.     

Relevance of the hygiene hypothesis to early vs. late onset allergic rhinitis

Introduction The hygiene hypothesis proposes that reduced exposure to infections in early life increases the risk of developing allergic conditions including allergic rhinitis. We examined the association between markers of the hygiene hypothesis and allergic rhinitis that developed before 7 years of age and allergic rhinitis that developed after 7 years of age. Methods The Tasmanian Longitudinal Health Study (TAHS) is a population‐based cohort (n=8583) study of respiratory disease. Participants have been followed from 7 to 44 years of age. Information on potential risk factors, allergies and respiratory symptoms was collected longitudinally. Using multi‐nomial logistic regression, exposure to siblings, infections, tonsillectomy and farm residence during childhood were examined as risk factors for allergic rhinitis that developed before or after 7 years of age. All analyses were adjusted for gender, maternal and paternal atopy, mother's age at participant's birth, paternal socio‐economic status in 1968 and personal socio‐economic status in 2004. Results Greater cumulative exposure to siblings before the age of 2 years was strongly inversely associated with early onset allergic rhinitis (<1 year sib exposure: OR=0.6, 95% CI 0.3–1.0; 1–3 years sib exposure: OR=0.6, 95% CI 0.4–0.9; >3 years sib exposure: OR=0.4, 95% CI 0.3–0.8) less so with later onset allergic rhinitis. The risk of early onset allergic rhinitis decreased with increasing viral infections (OR=0.7, 95% CI 0.5–0.9) during childhood. Having a tonsillectomy before 7 years of age increased the risk of early onset allergic rhinitis (OR=1.7, 95% CI 1.2–2.5). None of these factors was associated with later onset allergic rhinitis. Conclusions Exposures relevant to the hygiene hypothesis were important predictors for the development of early onset but less so for later onset allergic rhinitis. The exact mechanisms by which siblings and infections protect against allergic rhinitis are unclear. The stronger findings for earlier onset allergic rhinitis suggest that family structure and infections have most impact on disease risk in early life. Further research should focus on early onset allergic rhinitis when exploring causal explanations for any sibling effect.     

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.