Epidemiology of eczema among Lebanese adolescents

OBJECTIVE: The study aims to determine the prevalence of eczema among Lebanese adolescents and identify demographic, nutritional and environmental characteristics associated with eczema. METHODS: A cross-sectional study conducted on a convenient sample of 3 153 students (13-14 years) selected from five different provinces in Lebanon. Significant unadjusted demographic, nutritional and environmental variables were considered in a stepwise regression model. RESULTS: Ever having an itchy rash that lasted for a period more than six months was reported by 788 (25.0%) adolescents, while 404 (12.8%) reported ever having eczema. Females and passive smokers were at 1.5 increased risk of having eczema than their counterparts. Exercising regularly, living near a busy area, and frequent eating of eggs were positively associated with eczema. Finally, adolescents who suffered from allergic diseases, asthma (Odds ratio (OR): 1.64, 95% CI: 1.16-2.32), rhinitis (OR: 1.35, 95% CI: 1.07-1.70) and hay fever (OR: 2.77; 95% CI: 2.12-3.62) also reported having had eczema. CONCLUSION: Environmental factors were found to play an important role in the prevalence of eczema among adolescents.     

Changes in the prevalence of asthma, eczema and hay fever in pre-pubertal children: a 40-year perspective

Surveys of primary schools children in Aberdeen carried out in 1964, 1989, 1994 and 1999 suggested a slowing of the increase in parent-reported wheeze between 1994 and 1999. To assess whether this pattern had continued, questionnaires were distributed to 5712 children aged 7–12 years in the same schools in 2004. A total of 3271 (57.3%) completed questionnaires were returned. As in earlier surveys the results were divided into those for younger children (school years 3–4; age 7–9 years) and older children (school years 5–7; age 9–12 years).
Compared with 1999, the 2004 results showed a decrease in the proportion of children with wheeze in the last 3 years from 30.1% to 23.3% ( P  < 0.001) in the younger group and from 27.6% to 25.1% ( P  = 0.052) in the older group. There was no significant change in the lifetime prevalence of asthma in either the younger or the older group, but the lifetime prevalence of eczema and hay fever increased by around 10% in both the younger and older groups (all P  < 0.001). The differences in the time trends for the different conditions suggest that the causal factors for wheeze and asthma differ from those for other allergic diseases of childhood.     

Antibiotic sales and the prevalence of symptoms of asthma, rhinitis, and eczema: The International Study of Asthma and Allergies in Childhood (ISAAC)

BACKGROUND: It has been hypothesized that antibiotic use early in life may increase the subsequent risk of asthma. We have conducted an ecologic analysis of the relationship between antibiotics sales and the prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and atopic eczema in 99 centres from 28 countries. METHODS: Data for antibiotics sales for 28 countries were obtained from the Institute for Medical Statistics (IMS), Health Global Services, UK and converted to defined daily doses (DDD). Data on the prevalence of symptoms of asthma, rhinitis, and eczema in 13-14 year olds were based on the responses to the written and video questionnaires from the International Study of Asthma and Allergies in Childhood (ISAAC). The analysis was adjusted for gross national product (GNP) as an estimate of the level of affluence. RESULTS: In general, there was a positive association between per capita antibiotics sales and the prevalence of symptoms for asthma, rhinitis, and eczema, but the associations generally became negative once the analyses had been adjusted for GNP. In particular, there were non-significant negative associations between total antibiotics sales and the prevalence of wheeze ever, wheeze in the last 12 months, nose problems with itchy-watery eyes, itchy rash in the last 12 months, and eczema ever. On the other hand there were weak non-significant positive associations for asthma ever, nose problems ever, nose problems in the last 12 months, and itchy rash ever. There was a statistically significant positive association with wheeze at rest as measured by the asthma video questionnaire; however, even this association was weak and would not account for more than a 1% difference in asthma prevalence between countries. CONCLUSIONS: These findings are generally not consistent with the hypothesis that antibiotic use increases the risk of asthma, rhinitis, or eczema. If there is a causal association of antibiotic use with asthma risk, it does not appear to explain the international differences in asthma prevalence.     

Reported prevalence of allergy and asthma in children from urban and rural Egypt

Previous studies have shown an association between the urban environment and the risk of developing asthma and allergic rhinitis (AR) in children. This is the first longitudinal study to examine risk factors associated with asthma, eczema and AR in a comparison between Cairo, one of the world’s most polluted cities, and a rural area, Shben El-Kom. Two groups of school children were selected. One group was from inner-city Cairo, and the other was from a low-polluted rural area, Shben El-Kom in the Nile Delta region. The children were studied four times, with testing taking place every 6 months over an 18-month period using the ISAAC questionnaire. Two generalized mixed logistic regressions showed that living in Cairo increased the risk of current wheeze, wheeze ever, asthma ever, current AR, AR ever, hay fever ever, current rash, rash ever and eczema ever. Other risk factors that effected asthma included maternal eczema, paternal asthma, maternal asthma and passive smoking. Exposure to farm animals decreased the odds of having asthma. Children living in urban Cairo had a higher risk of allergic conditions than those living in the rural area of Shben El-Kom. This was not fully explained by passive smoking, breastfeeding, parental allergy or exposure to animals.     

Associations between socioeconomic position and asthma: findings from a historical cohort

Understanding the association between asthma and socioeconomic position (SEP) is key to identify preventable exposures to prevent inequalities and lessen overall disease burden. We aim to assess the variation in asthma across SEP groups in a historical cohort before the rise in asthma prevalence. Male students participating in a health survey at Glasgow University from 1948 to 1968 (n?=?11,274) completed medical history of bronchitis, asthma, hay fever, eczema/urticaria, and reported father's occupation. A subsample responded to postal follow-up in adulthood (n?=?4,101) that collected data on respiratory diseases, early life and adult SEP. Lower father's occupational class was associated with higher odds of asthma only (asthma without eczema/urticaria or hay fever) (trend adjusted multinomial odds ratio (aMOR)?=?1.23, 95?% CI 1.03-1.47) but with lower odds of asthma with atopy (asthma with eczema/urticaria or hay fever) (trend aMOR?=?0.66, 95?% CI 0.52-0.83) and atopy alone (trend aMOR?=?0.84, 95?% CI 0.75-0.93). Household amenities (<3), in early life was associated with higher odds of adult-onset asthma (onset?>?30?years) (OR?=?1.48, 95?% CI 1.07-2.05) though this association attenuated after adjusting for age. Adult SEP (household crowding, occupation, income and car ownership) was not associated with adult-onset asthma. Lower father's occupational class in early life was associated with higher odds of asthma alone but lower odds of asthma with atopy in a cohort that preceded the 1960s rise in asthma prevalence. Different environmental exposures and/or disease awareness may explain this opposed socioeconomic patterning, but it is important to highlight that such patterning was already present before rises in the prevalence of asthma and atopy.     

Heredity of asthma in Saudi population

In a cross-sectional study, the prevalence of asthma, hay fever and eczema was studied in 1150 schoolchildren attending school in Jeddah Western region of Saudi Arabia. The family histories of asthma, hay fever and eczema were examined in first degree relatives. The age range of children studied was 7–12 years, with a mean of 9.3 years (47% boys and 53% girls). A self-administered questionnaire was completed by the parents of the child to collect information concerning bronchial asthma, hay fever, and eczema in the target child and family history of respiratory allergy. A detailed family history and personal histories of asthma were available for 1035 Saudi children aged 7–12 years old. The rate of asthma and hay fever were significantly higher among siblings and offspring (cases) compared to their parents (p < 0.001). The results showed a high positive correlation between the relatives of affected children with respect to asthma and hay fever. These findings support the hypothesis that asthma and hay fever may be inherited in the Saudi population, but the mode of inheritance has yet to be determined.Corresponding author.     

Allergic conditions and brain tumor risk

An inverse association between allergic conditions and glioma risk has been reported previously. In this large population-based case-control study, the authors identified cases diagnosed with glioma or meningioma in Denmark, Norway, Finland, Sweden, and southeast England between 2000 and 2004. Detailed information on self-reported physician-diagnosed allergic conditions was collected from 1,527 glioma cases, 1,210 meningioma cases, and 3,309 randomly selected controls. Logistic regression showed an odds ratio of 0.70 (95% confidence interval: 0.61, 0.80) for glioma associated with a diagnosis of any of asthma, hay fever, eczema, or other type of allergy. The risk estimates for glioma were around 0.65 for each allergic condition (asthma, eczema, hay fever, and food allergy), and the 95% confidence intervals were equally consistent, at around 0.55, 0.80. The reduced risks of glioma related to eczema, hay fever, and allergy overall, but not asthma, were confined to current rather than past conditions. Meningioma risk was not associated with allergic conditions, except for eczema (odds ratio = 0.74, 95% confidence interval: 0.60, 0.91). Our results show a reduced risk for glioma associated primarily with current allergic conditions. If this is etiologic, it has implications for the understanding of how allergic conditions might reduce the tumor risk.     

Allergies in adults

Only few epidemiological studies have assessed allergic diseases in adults. In a follow-up study of the MONICA survey S3 (1994/95), which was performed 1997-1999, a total of 1,537 persons were interviewed and tested by skin prick and patch test. Furthermore data of the MONICA survey (RAST, cholesterol, food diaries) could be used. Within survey S4 (1999/2001) a total of 4,261 subjects were interviewed concerning their personal history of atopic diseases and the corresponding history of their partners. In survey S3 the prevalence of allergic sensitisation was 20.5 % for persons without formal graduation from school and 48.1 % for those with a university degree. 20.8 % reported a hypersensitivity to food and about one quarter exhibited a positive reaction in skin prick test. Atopic eczema and hay fever increased over quartiles of HDL cholesterol. Similar, allergic sensitisation (RAST) increased over quartiles of uptake of unsaturated fatty acids in men. 40 % of those who were patch tested exhibited a positive reaction, with perfume mix, nickel, thimerosal and balsam of Peru being the most prominent allergens. Inhabitants of the City of Augsburg were sensitised more often (34.0 % overall, 23.9 % pollen) than inhabitants of villages with (29.4 %, 17.0 %). Full time farmers were sensitised less frequently (22.0 %, 8.4 %). In survey S4 the lifetime prevalence of atopic diseases diagnosed by doctors was 5.1 % for atopic eczema, 6.1 % for asthma and 13.7 % for hay fever. Subjects who lived together with a partner who suffered from hay fever were affected in 19.6 % whereas 13.1 % had hay fever when the partner was not affected. Future studies will offer an unique opportunity to analyse the incidence and remission of manifestations of atopy in adults.     

Fertility rates in women with asthma, eczema, and hay fever: a general population-based cohort study

The protective association between having older siblings and the risk of subsequent allergic disease may be due to decreased fertility among women with allergic disease. In this study, the authors compared fertility rates among women with asthma, eczema, or hay fever with those in the general female population. Computerized primary-care data from the United Kingdom were used to conduct a cohort analysis of 491,516 women. General fertility rates and age-specific fertility rates for 1994-2004 were estimated. Using Poisson regression, the authors compared fertility rates among women with asthma, eczema, or hay fever with rates in women without these diagnoses. Fertility rates were 53.0 and 52.3 livebirths per 1,000 person-years in women with and without asthma, respectively. The fertility rate ratio for women with asthma compared with women without asthma was 1.02 (95% confidence interval (CI): 1.00, 1.04) after adjustment for age, smoking, body mass index, and socioeconomic status. Equivalent fertility rate ratios for eczema and hay fever were 1.15 (95% CI: 1.13, 1.17) and 1.08 (95% CI: 1.06, 1.10), respectively. The authors found no evidence that the fertility rates of women with asthma, eczema, or hay fever are lower than those of women in the general population.     

Questionnaire predictors of atopy in a US population sample: findings from the National Health and Nutrition Examination Survey, 2005-2006

Allergic conditions and biochemical measures are both used to characterize atopy. To assess questionnaires' ability to predict biochemical measures of atopy, the authors used data on 5 allergic conditions (allergy, hay fever, eczema, rhinitis, and itchy rash) and serum-specific immunoglobulin E (IgE) levels from the 2005-2006 National Health and Nutrition Examination Survey. Atopy was defined as 1 or more positive specific IgEs (≥0.35 kU/L). Questionnaire responses were assessed for sensitivity, specificity, and positive and negative predictive values for atopy. In this population-based US sample, 44% of participants were specific IgE-positive and 53% reported at least 1 allergic condition. Discordance between atopy and allergic conditions was considerable; 37% of persons with atopy reported no allergic condition, and 48% of persons who reported an allergic condition were not atopic. Thus, no combination of self-reported allergic conditions achieved both high sensitivity and high specificity for IgE. The positive predictive value of reported allergic conditions for atopy ranged from 50% for eczema to 72% for hay fever, while the negative predictive value ranged from 57% for eczema to 65% for any condition. Given the high proportion of asymptomatic participants who were specific IgE-positive and persons who reported allergic conditions but were specific IgE-negative, it is unlikely that questionnaires will ever capture the same participants as those found to be atopic by biochemical measures.     

Prävalenz von somatischen Erkrankungen bei Kindern und Jugendlichen in Deutschland

In the German Health Interview and Examination Survey for Children and Adolescents (KiGGS), which was conducted from 2003 to 2006, data on acute/infectious and chronic diseases were collected from a population-based sample of 17,641 subjects aged 0 to 17 years. The annual prevalence rates among acute diseases vary widely. Children and adolescents are most frequently affected by acute (infectious) respiratory conditions. 88.5 % of the surveyed children and adolescents experienced at least one episode of common cold within the last 12 months. Among the other acute respiratory infections, bronchitis and tonsillitis were the most frequently encountered conditions with 19.9 % and 18.5 %, respectively. The 12-month prevalence of otitis media and pseudocroup was 11 % and 6.6 %, respectively. 1.5 % of the children and adolescents experienced an episode of pneumonia. Apart from respiratory infections, gastrointestinal infections were very frequently stated as reasons for acute illness. Furthermore, 12.8 % of the children and adolescents experienced a herpetic infection, 7.8 % a conjunctivitis and 4.8 % a urinary tract infection. Lifetime prevalence rates of infectious diseases were as follows: pertussis 8.7 %, measles 7.4 %, mumps 4.0 %, rubella 8.5 %, varicella 70.6 %, scarlet fever 23.5 %. The various chronic somatic diseases in children and adolescents had different lifetime prevalence rates. Most frequently, children and adolescents were affected by obstructive bronchitis (13.3 %), neurodermatitis/atopic eczema (13.2 %) and hay fever (10.7 %). Scoliosis and asthma had been diagnosed by a doctor in 5.2 % and 4.7 % of subjects aged 0-17 years, respectively. The lifetime prevalence rates of the remaining diseases varied between 0.14 % for diabetes mellitus and 3.6 % for convulsions/epileptic fits. For the first time ever, these survey results provide nationwide representative information on the prevalence rates of acute/infectious and chronic diseases in children and adolescents which is based on a population-representative sample.     

Traffic at residential address, respiratory health, and atopy in adults: the National German Health Survey 1998

Motor vehicle traffic contributes to more than 50% of PM10 in Europe and might have far reaching impacts on human health. We investigated the relationship between residential street type as a surrogate for traffic intensity and the prevalence of respiratory symptoms, atopic diseases, and allergic sensitization in adults. Data from 6896 subjects of the German Health Survey 1998 with complete information on residential street type were used. Multiple logistic regression analyses were applied to model associations between street type categories, and respiratory and atopic outcomes were assessed by screening questionnaire of The European Respiratory Health Survey and specific IgE measurements. Living at extremely or considerably busy roads (23.9% of total study population) compared to roads with no or rare traffic (64.5%) was statistically significantly associated with chronic bronchitis (aOR 1.36 (95% CI) (1.01-1.83)) while nocturnal coughing attacks (past 12 months) (1.24 (0.98-1.57)), wheeze during the past 12 months (1.21 (0.93-57)), and hay fever (1.16 (0.94-1.42)) were marginally increased after adjustment for several potential confounders and for multiple testing. No increased risks were found for asthma (0.97 (0.67-1.42)) and allergic sensitization (1.05 (0.91-1.20)). We conclude that exposure to traffic-related air pollutants increases the risk of nonallergic respiratory symptoms and to a lesser degree the risk of hay fever and allergic sensitization but not the risk of asthma in adults.     

A comparison of genetic and environmental variance structures for asthma, hay fever and eczema with symptoms of the same diseases: a study of Norwegian twins

BACKGROUND: We compared patterns of genetic and environmental influences on variation in liability for asthma, hay fever and eczema with those for symptoms of the same diseases, and determined how common sets of genes and environmental factors contribute to the relationship between diseases and symptoms among Norwegian twins. METHODS: Analyses were based on self-reported asthma, hay fever and eczema and symptoms of the same diseases among 3334 pairs of Norwegian twins aged 18-35 years. Structural equation modelling was conducted to estimate the genetic and environmental variance structures. RESULTS: For all diseases the concordances and the twin correlations were higher among monozygotic than among dizygotic twins. The results of the modelling confirmed that genetic effects were substantial for the diseases, and were more moderate for symptoms. The phenotypic correlation between disease and symptom was 0.67 for asthma and wheeze (a/w), 0.64 for hay fever and sneeze (hf/s), and 0.54 for eczema and itch (e/i). Decomposition of these correlations into genetic (G) and environmental (E) pathways revealed that G = 0.48 and E = 0.19 for a/w, G = 0.40 and E = 0.24 for hf/s, and G = 0.34 and E = 0.20 for e/i. For the diseases, the specific sources of genetic variance accounted for more variation than the specific environmental variance. Variance decomposition revealed that specific sources of variance were primarily explained by genetic effects for diseases and by environmental influences for symptoms. CONCLUSIONS: Genetic effects account for greater variation in reported diseases than symptoms. Co-occurrence of diseases and symptoms is mainly explained by genetic effects common to both phenotypes, but non-shared environment is also important.     

Prevalence of asthma and wheeze in relation to passive smoking in Japanese children

PURPOSE: Evidence remains inconclusive as to whether environmental tobacco smoke is a risk factor for allergic disorders in childhood. The present large-scale cross-sectional study examined the relationship between passive smoking at home and the prevalence of allergic disorders in Japanese schoolchildren. METHODS: Study subjects were 23,044 children aged 6 to 15 years in Okinawa. Outcomes were based on diagnostic criteria from the International Study of Asthma and Allergies in Childhood. Adjustment was made for sex, age, region of residence, number of siblings, paternal and maternal history of asthma, atopic eczema, or allergic rhinitis, as well as paternal and maternal educational level. RESULTS: The prevalence of wheeze, asthma, atopic eczema, and allergic rhinoconjunctivitis in the previous 12 months was 10.7%, 7.6%, 6.8%, and 7.7%, respectively. Current heavy passive smoking and 7.0 or more pack-years of smoking in the household were independently related to an increased prevalence of wheeze and asthma, especially in children 6 to 10 years of age and children with a positive parental allergic history. There was no dose-response relationship between pack-years of smoking in the household and atopic eczema or allergic rhinoconjunctivitis. CONCLUSIONS: Our findings suggested that environmental tobacco smoke might be associated with an increased prevalence of wheeze and asthma in Japanese children.     

Different slopes for different folks: socioeconomic and racial/ethnic disparities in asthma and hay fever among 173,859 U.S. men and women

Although allergic diseases such as asthma and hay fever are a major cause of morbidity in industrialized countries, most studies have focused on patterns of prevalence among children and adolescents, with relatively few studies on variations in prevalence by race/ethnicity and socioeconomic position among adults. Our study examined racial/ethnic and socioeconomic patterns in the prevalence of asthma overall, asthma with hay fever, asthma without hay fever, and hay fever overall, in a population of 173,859 women and men in a large prepaid health plan in northern California. Using education as a measure of socioeconomic position, we found evidence of a positive gradient for asthma with hay fever with increasing level of education but an inverse gradient for asthma without hay fever. Hay fever was also strongly associated with education. Compared with their White counterparts, Black women and men were more likely to report asthma without hay fever, and Black women were less likely to have asthma with hay fever. Asian men were also more likely to report asthma with hay fever, and Asian women and men were much more likely to have hay fever. Racial/ethnic disparities in prevalence of allergic diseases were largely independent of education. We discuss implications for understanding these social inequalities in allergic disease risk in relation to possible differences in exposure to allergens and determinants of immunologic susceptibility and suggest directions for future research.     

Does a higher number of siblings protect against the development of allergy and asthma? A review

STUDY OBJECTIVE: To review the "protective" effects of having a higher number of siblings for the risk of atopic eczema, asthma wheezing, hay fever, and allergic sensitisation. METHOD: Review of the literature (Medline since 1965 and references). MAIN RESULTS: 53 different studies were identified. For eczema, 9 of 11 studies reported an inverse relation with number of siblings; for asthma and wheezing, 21 of 31 reported the inverse association; for hay fever, all 17 studies showed the effect; for allergic sensitisation or immunoglobulin E reactivity 14 of 16 studies supported the "protective" effect of a higher number of siblings. The studies emphasise a "theory" that is based exclusively on epidemiological associations. CONCLUSIONS: Research has not yet answered the question of which causal factors explain the sibling effect. Causal factors must meet two criteria; they must vary with sibship size and they must protect against atopic manifestations. The prevailing "hygiene hypothesis" failed to explain the findings adequately. Alternative explanations include in utero programming or endocrine explanatory models. The epidemiology research into siblings and atopic disorders has entered an intellectually challenging phase. Possessing sufficient knowledge about the causal factors might prevent at least 30% of all cases of asthma, eczema, and hay fever.     

Prevalence and severity of asthma, allergic rhinoconjunctivitis and atopic eczema in "Grand Tunis" schoolchildren: ISAAC

The aim of this study was to assess the prevalence and severity of asthma, allergic rhinoconjunctivitis and atopic eczema in 13-14 year old children living in "Grand Tunis". Using the international study of asthma and allergies in childhood (ISAAC) questionnaire, 3350 schoolchildren aged 13-14 years, from the Grand Tunis (Ariana, Ben Arous, Manouba, Tunis) were studied. Our results showed that in the past year 13.2% of children had wheezed, 1.4% had more than 12 attacks and 4.3% had experienced a speech limiting attack. 29.7% had symptoms of allergic rhinoconjunctivitis and 8.3% atopic eczema. The classic preponderance of asthma in boys has not been retrieved in our study. The highest level of wheeze was found in an agricultural area. According the published data, asthma prevalence in Tunisian schoolchildren is intermediate and allergic diseases are perhaps a common childhood diseases in Tunisia.     

Diphtheria tetanus pertussis poliomyelitis vaccination and reported atopic disorders in 8-12-year-old children

BACKGROUND: Evidence for the relationship between the diphtheria tetanus pertussis (DTP) vaccination and atopic disorders is inconclusive, because the available studies that constitute the evidence are liable to confounding by indication. STUDY OBJECTIVE: To assess the relationship between diphtheria-tetanus-pertussis-(inactivated) poliomyelitis vaccination (DTP-IPV) in the first year of life and reported atopic disorders at primary school age. METHOD: 1875 children attending Orthodox Reformed (Protestant) primary schools in the Netherlands returned questionnaires with data on vaccination status, atopic symptoms and lifetime atopic disorders (asthma, hay fever, eczema and food allergy), and possible confounders. RESULTS: The adjusted odds ratio of any atopic disorder (vaccinated/unvaccinated) was 1.00 (CI95%: 0.80-1.24). For asthma, hay fever, eczema and food allergy the results were respectively: 1.04 (CI95%: 0.76-1.42), 0.79 (CI95%: 0.55-1.12), 0.87 (CI95%: 0.66-1.14) and 1.13 (CI95%: 0.71-1.81). CONCLUSION: The DTP-IPV vaccination was not related to reported atopic disorders at primary school age.     

Association between asthma and family size between 1977 and 1994.

STUDY OBJECTIVES: Several recent reports show a negative association between asthma and family size or birth order, but this association was not detected in data collected between 10 and 30 years ago. This study compared the association between sibship size and asthma in three surveys using the same methodology in 1977, 1985/86, and 1993/94. DESIGN: Cross sectional comparison of the 1977, 1985/86, and 1993/94 surveys. SETTINGS: Study areas in England and Scotland. PARTICIPANTS: Parents of children between 5 to 11 years in England and Scotland were asked about asthma and bronchitis attacks in the last 12 months, and wheeze in their child. Approximately 9000 children participated in each of the surveys. RESULTS: The overall association between asthma, defined as asthma attacks or wheeze, and total number of siblings was not significant (p = 0.22), but an only child had a higher prevalence of asthma than children with siblings (OR 0.87 95% CI 0.76 to 0.98). The interaction between year of survey and sibship size on asthma was not significant (p = 0.36). There was no association between asthma and birth order. A significant interaction between social class and year of survey on asthma was detected (p = 0.004). In the 1993/94 survey children whose fathers had a semi or unskilled manual occupation had a higher prevalence of asthma (16%) than children whose fathers belonged to other social classes (13%). CONCLUSIONS: This study provides only marginal support for a change over time of the association between sibship size and asthma. Based on recent reports the nature of the exposure agent that may explain the association remains controversial. This study suggests a disproportionate increase of asthma in lower social classes.     

Allergische Erkrankungen

In the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) from 2003-2006 information was collected on allergic diseases (asthma, atopic dermatitis, hay fever, allergic contact eczema) from a population-based sample of 17,641 0-to 17-year-olds, and blood samples were studied for specific IgE antibodies to 20 common allergens. The lifetime prevalence (LTP) of at least one atopic disease was 22.9 % (95 % CI: 22.0-23.7 %), the 12-month prevalence (12MP) was 16.1 % (15.4-16.8 %); boys (17.3; 16.3-18.2 %) were more frequently affected than girls (14.9; 14.0-15.8 %). Children with a background of migration were less often currently affected by an atopic disease, as were children from families of low social status. According to parents' accounts, the LTP of allergic contact eczema was 9.9 % (9.4-10.5 %); girls (13.8;12.9-14.8) were more frequently affected than boys (6.2; 5.6-6.9 %). Of the 3- to 17-year-olds, 40.8 % (39.6-42.0 %) were sensitised to at least one of the allergens tested; boys (45.0; 43.5-46.5 %) more frequently so than girls (36.4; 35.0-37.9 %). In the states of the former FRG, the LTP of allergic contact eczema was higher (10.2; 9.6-10.9 %) than those in the former GDR (8.4 % 7.4-9.6 %); otherwise there were no East-West differences. The KiGGS data provide the first nationally representative data on allergic diseases and sensitisation. The differences in prevalence observed correspond to a great extent with previous studies and may support the hygiene hypothesis. The prevalences in East and West Germany now seem to have equalised.