Doctor-diagnosed Atopic Dermatitis Research Articles

Impact of atopic dermatitis on occupational contact dermatitis among young people: A retrospective cohort study.

Occupational contact dermatitis (OCD) is a common occupational disease. Atopic dermatitis (AD) is a known risk factor for OCD. To determine the prevalence of previously diagnosed AD among young workers with recognized OCD and assess its impact on OCD prognosis. A retrospective cohort study. A questionnaire was sent to 6251 workers with recognized OCD who were under 35 years at notification (response rate: 47%). Of the respondents, 2392 answered a question about previous doctor-diagnosed AD and were included in the study. Eczema severity, occupational consequences and quality of life were examined using statistical analyses comparing workers with and without previously diagnosed AD. The prevalence of previously diagnosed AD was 41.8% (95% CI: 39.8-43.8). Women had a higher AD prevalence, and workers with AD reported OCD at a younger age. Workers with AD reported more frequent and severe eczema symptoms and had a higher risk of OCD negatively affecting job and occupation choices. Health-related quality of life was more adversely affected in workers with AD. AD significantly impacts severity and has long-term consequences for young people with OCD. Targeted prevention strategies need to be developed.

Low-Density Lipoprotein Cholesterol Is Associated with Atopic Dermatitis in Korean Adolescents

Introduction: Atopic dermatitis (AD) is one of the most common chronic inflammatory skin diseases. Several studies have investigated the relationship between obesity and AD prevalence, but the results have been conflicting. This study investigated the association between obesity and AD in Korean adolescents. Methods: We used nationally representative data regarding 1,617 Korean adolescents aged 12–18 years, which were obtained from the cross-sectional Korea National Health and Nutrition Examination Survey 2017–2019. Multiple logistic regression analysis (including age, sex, region of residence, number of household members, economic status, lipid profile, and stress level) was used to evaluate the relationships of obesity and abdominal obesity with doctor-diagnosed AD. Results: Although the results were not statistically significant, obese adolescents were diagnosed with AD (20.8%) more often than non-obese adolescents (20.8% vs. 14.5%, p = 0.055). This tendency was more prominent in male adolescents than in female adolescents, but the finding was not statistically significant. Body mass index and the prevalence of abdominal obesity did not differ between the AD and non-AD groups. Adolescents with AD had significantly higher total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels, compared with adolescents who did not have AD. In the adjusted model, an LDL-C level ≥130 mg/dL was a risk factor for AD (adjusted odds ratio, 1.03; 95% confidence interval, 1.01–1.05). Conclusions: A high LDL-C level may be a risk factor for AD. Proper management of dyslipidemia through lifestyle modification may aid in AD prevention and control. Further large-scale prospective studies are needed to assess the associations of AD with obesity and dyslipidemia.

Factors Associated With Atopic Dermatitis In Elementary School Children In Suburban Area In Indonesia: Original Research

<p><strong>Background</strong>: There was limited data of Atopic Dermatitis (AD) prevalence and its associated factors in Indonesia. Therefore, the aim of this study was to identify and evaluate the AD prevalence and factors associated with AD in elementary school children in suburban area in Banten.</p><p><strong>Methods</strong>: A cross-sectional study was conducted in 3 elementary schools children age 6–7 years old who were randomly selected. Information was obtained through an Indonesian version of the International Study of Asthma and Allergies in Childhood questionnaire (ISAAC).</p><p><strong>Results</strong>: From 304 school children in semi-urban area, AD was reported as ever had an itchy rash which was reccurent for at least 6 months in 17.4% of the children, 19.5% of the children had this itchy rash at any time in the past 12 months, and 11.4 % reported doctor-diagnosed AD. The factors found to be associated with an increased risk of AD were allergic rhinitis (OR 2.151 CI: 1.086-4.261), history of premature birth (<37 weeks) (OR 5.306, CI:1.577-17.858), exclusive breastfeeding (OR 3.126 CI:1.314-7.439), and food allergy (OR 2.912 CI:1.386-6.119).</p><p><strong>Conclusion</strong>: The results of this study showed that allergic rhinitis, history of premature birth (<37 weeks), exclusive breastfeeding, and food allergy were factors associated with AD in Indonesian schoolchildren. </p>

Factors Associated With Atopic Dermatitis In Elementary School Children In Suburban Area In Indonesia: Original Research

<p><strong>Background</strong>: There was limited data of Atopic Dermatitis (AD) prevalence and its associated factors in Indonesia. Therefore, the aim of this study was to identify and evaluate the AD prevalence and factors associated with AD in elementary school children in suburban area in Banten.</p><p><strong>Methods</strong>: A cross-sectional study was conducted in 3 elementary schools children age 6 – 7 years old who were randomly selected. Information was obtained through an Indonesian version of the International Study of Asthma and Allergies in Childhood questionnaire (ISAAC).</p><p><strong>Results</strong>: From 304 school children in semi-urban area, AD was reported as ever had an itchy rash which was reccurent for at least 6 months in 17.4% of the children, 19.5% of the children had this itchy rash at any time in the past 12 months, and 11.4 % reported doctor-diagnosed AD. The factors found to be associated with an increased risk of AD were allergic rhinitis (OR 2.151 CI: 1.086-4.261), history of premature birth (<37 weeks) (OR 5.306, CI:1.577-17.858), exclusive breastfeeding (OR 3.126 CI:1.314-7.439), and food allergy (OR 2.912 CI:1.386-6.119).</p><p><strong>Conclusion</strong>: The results of this study showed that allergic rhinitis, history of premature birth (<37 weeks), exclusive breastfeeding, and food allergy were factors associated with AD in Indonesian schoolchildren. </p>

Modelling trajectories of parentally reported and physician-confirmed atopic dermatitis in a birth cohort study.

In a population-based birth cohort, we aimed to identify longitudinal trajectories of atopic dermatitis (AD) during childhood using data from different sources (validated questionnaires and healthcare records). We investigated the impact of different AD definitions on such trajectories and their relationships with various risk factors. Of the 1184 children born into the study, 1083 had information on current AD for at least three follow-ups from birth to age 11 years and were included in the analysis for parentally reported AD (PRAD). Data were transcribed from healthcare records for 916 of 1184 children for the analysis of doctor-diagnosed AD (DDAD). We also derived a composite definition of AD (CDAD) (at least two of the following: PRAD, DDAD, current use of AD treatment). Using latent class analysis (LCA), we determined longitudinal profiles of AD using the three definitions. Filaggrin (FLG) genotype data were available for 803 white participants. For PRAD, LCA identified four AD classes ('no AD', 'persistent', 'early-onset remitting' and 'late-onset'). For DDAD and CDAD, the optimal number of phenotypes was three ('no AD', 'persistent' and 'early-onset remitting'). Although AD classes at population level appeared similar in different models, a considerable proportion of children (n = 485, 45%) moved between classes. The association with FLG genotype, atopic diseases and early-life risk factors was inconsistent across different definitions, but the association with oral food challenge-confirmed peanut allergy was similar, with a nine- to 11-fold increase among children in the persistent AD class. In a CDAD model, compared with the early-onset remitting class, those with persistent AD were significantly more likely to have (at age 3 years) moderate/severe AD, polysensitization and current wheeze, and were less likely to have been breastfed. Standardized composite definitions of AD may help to define AD cases with more precision and identify more consistent long-term trajectories.

Allergy - Patients with Atopic Dermatitis Express Themselves Through a Questionnaire.

IntroductionAllergies are becoming more prevalent across the globe and can be linked to several skin diseases, particularly atopic dermatitis (AD). Disruption of the immune system in the skin can lead to inflammatory diseases such as atopic and contact dermatitis, skin infections, and allergies. This is especially evident in processes such as “atopic march”, where in childhood, the development of atopic dermatitis can later lead to food allergies, allergic rhinitis and asthma.ObjectiveThe aim of this international online survey is to study the link between self-reported doctor-diagnosed AD and allergy prevalence.MethodologyOur survey queried a representative sample of the general population over the age of 18 from five countries (Brazil, China, Russia, the USA and France).ResultsA total of 9399 participants answered the entire online questionnaire. Among them, 2483 (26.4%) had an allergy diagnosed by a doctor (1243 with food allergies (13.2%), 1564 with respiratory allergies (16.6%) and 1669 with skin allergies (17.7%)). There were 794 (31.9%) participants with current AD in the allergy group and 640 (9.25%) in the group without allergies (p<0.001), and there were 1299 (52.3%) participants with CAD in the allergy group versus 1368 (19.8%) in the group without allergies (p<0.001). Multivariate analysis showed ORs of 3.24 [2.98, 3.63] (p<0.001) for current AD and 2.4 [2.09, 2.74] (p<0.001) for CAD. There was no significant interaction between AD and CAD (p=0.6).ConclusionA total of 26.4% of survey respondents reported having doctor-diagnosed allergies. Among these patients, half reported having AD during childhood, and 1/3 reported having a current AD. CAD and AD patients clearly have a higher risk of having an allergy than patients without CAD or AD.

Influence of age at complementary food introduction on the development of asthma and atopic dermatitis in Korean children aged 1-3 years.

BackgroundComplementary food in infancy is necessary for human growth, neurodevelopment, and health. However, the role of allergen consumption in early infancy and its effects on the development of food allergy or tolerance remain unclear.PurposeTo investigate the influence of age at the time of complementary food introduction on the development of asthma and atopic dermatitis in Korean children aged 1–3 years.MethodsWe combined data from the Korea National Health and Nutrition Examination Survey collected from 2010 to 2014 and analyzed 1619 children aged 1–3 years who were included in the survey. Multivariate regression analysis was used to identify associations among type of feeding, age at the time of complementary food introduction, and doctor-diagnosed atopic dermatitis and asthma.ResultsAge at the time of complementary food introduction was not significantly associated with doctor-diagnosed atopic dermatitis and asthma in children aged 1–3 years. In the univariate analysis, children with asthma showed higher water and sodium intake levels than nonasthmatic children. However, this relationship was not significant in the multivariate regression analysis.ConclusionThe present study revealed no statistically significant relationship between age at the time of complementary food introduction and the risk of atopic dermatitis and asthma in young Korean children. A national prospective study is needed to clarify the influence of age at the time of complementary food introduction on the development of allergic diseases.

IL17F rs763780 single nucleotide polymorphism is associated with asthma after bronchiolitis in infancy.

Interleukin-17F (IL-17F) is involved with asthma. The aim of this study was to evaluate the association of IL17F polymorphisms with childhood asthma after bronchiolitis in infancy. We invited 166 children who were hospitalised for bronchiolitis at younger than 6months of age to follow-up visits at 5-7years and 11-13years of ages. Asthma and allergy diagnoses, asthma-presumptive symptoms and use of inhaled corticosteroids (ICSs) were registered. Blood samples were available for IL17F rs763780 (T/C), rs11465553 (C/T) and rs7741835 (C/T) determinations in 165 cases. The presence of IL17F rs11465553 and rs7741835 variations showed no significant associations with any asthma or allergy outcome at either 5-7years or 11-13years of ages. Instead, children with the variant IL17F rs763780 genotype had used more often ICSs between the follow-up visits from 5-7 to 11-13years (adjusted OR 3.58) than those with the wild genotype. Children with the variant IL17F rs763780 genotype reported more often doctor-diagnosed atopic dermatitis (adjusted OR 2.71) at 11-13years of age than those with the wild genotype. This prospective long-term follow-up study provided preliminary evidence on the association of the IL17F rs763780 polymorphism with asthma at school age after bronchiolitis in infancy.

Prevalence and Incidence of Atopic Dermatitis: A Systematic Review

The primary objective of this study was to systematically review and analyse epidemiological studies of the prevalence and incidence of atopic dermatitis (AD) during childhood and adulthood, focusing on data from the 21st century. A systematic search of PubMed, EMBASE and Google (manual search) was performed in June 2019, followed by data abstraction and study quality assessment (Newcastle–Ottawa Scale). Cross-sectional and longitudinal epidemiological studies of individuals with AD (doctor-diagnosed or standardized definition) were included. Of 7,207 references reviewed, 378 moderate/good-quality studies were included: 352 on prevalence of AD and 26 on incidence of AD. In the 21st century, the 1-year prevalence of doctor-diagnosed AD ranged from 1.2% in Asia to 17.1% in Europe in adults, and 0.96% to 22.6% in children in Asia. The 1-year incidence ranged from 10.2 (95% confidence interval (95% CI) 9.9– 10.6) in Italy to 95.6 (95% CI 93.4–97.9) per 1,000 person-years in children in Scotland. There were few recent studies on incidence of AD in the 21st century and no studies on adults only; most studies were conducted in Europe and the USA. Epidemiological studies on childhood and adulthood AD in different continents are still needed, especially on the incidence of AD during adulthood.

Atopic dermatitis: Interaction between genetic variants of GSTP1, TNF, TLR2, and TLR4 and air pollution in early life.

Associations between traffic-related air pollution (TRAP) and childhood atopic dermatitis (AD) remain inconsistent, possibly due to unexplored gene-environment interactions. The aim of this study was to examine whether a potential effect of TRAP on AD prevalence in children is modified by selected single nucleotide polymorphisms (SNPs) related to oxidative stress and inflammation. Doctor-diagnosed AD up to age 2years and at 7-8years, as well as AD symptoms up to age 2years, was assessed using parental-reported questionnaires in six birth cohorts (N=5685). Associations of nitrogen dioxide (NO2 ) estimated at the home address of each child at birth and nine SNPs within the GSTP1, TNF, TLR2, or TLR4 genes with AD were examined. Weighted genetic risk scores (GRS) were calculated from the above SNPs and used to estimate combined marginal genetic effects of oxidative stress and inflammation on AD and its interaction with TRAP. GRS was associated with childhood AD and modified the association between NO2 and doctor-diagnosed AD up to the age of 2years (P(interaction)=.029). This interaction was mainly driven by a higher susceptibility to air pollution in TNF rs1800629 minor allele (A) carriers. TRAP was not associated with the prevalence of AD in the general population. The marginal genetic association of a weighted GRS from GSTP1, TNF, TLR2, and TLR4SNPs and its interaction with air pollution supports the role of oxidative stress and inflammation in AD.

Do young adults with atopic dermatitis avoid harmful workplace exposure at their first job? A prospective cohort study.

Patients with atopic dermatitis (AD) are at high risk of chronic hand eczema. In this prospective cohort study, we assessed the influence of pre-hire-onset AD on the first job choice. We also analysed the potential association between AD and usage of preventive measures in high-risk occupations. Subjects (aged 19-24 years) who were followed from childhood until the second Study on Occupational Allergy Risks and indicated a job were included (n = 1566). We defined AD as doctor-diagnosed AD and symptoms of an itchy rash during the past 12 months before the study. Pre-hire-onset AD was having AD prior to the first job. Preventive measure usage was self-reported gloves use or use of ointment or moisturizer. We performed multiple imputations to deal with missing values and analysed associations using logistic regression models adjusted for several potential confounders. Risk categories of the first job did not differ between participants with pre-hire-onset AD and those without (odds ratio 1.05, 95 % confidence interval 0.59-1.87). AD status was not statistically significantly associated with usage of preventive measures (1.22, 0.56-2.64). Conversely, having received job counselling (2.76, 1.15-6.63) and a family history of AD (2.09, 1.01-4.31) were associated with a higher use of such measures. We could not confirm a healthy hire effect in this cohort of young adults. Although subjects with AD in high-risk occupations do not seem to use more preventive measures than their non-affected peers, job counselling seems to be an effective approach to encourage secondary prevention.

Atopic Dermatitis in Early Life: Evidence for at Least Three Phenotypes? Results from the GUSTO Study

Background: Atopic dermatitis (AD) has been highlighted as a likely first step in the ‘atopic march', emphasizing the need to define predisposing factors. Methods: We evaluated AD risk factors and phenotypes in an Asian mother-offspring cohort. We defined three phenotypes of doctor-diagnosed AD based on the time of onset of the disease: early AD occurring within the first 6 months of life, AD occurring between 6 and 12 months and late-onset AD starting after the age of 12 months. Results: Maternal allergic history was associated with an increased risk of developing early-onset AD (adjusted odds ratio (aOR) 20.46, 95% confidence interval (CI) 2.73-153.15, p < 0.01). Maternal allergic history and attendance at a daycare centre increased the odds of the development of AD between 6 and 12 months (aOR 4.19, 95% CI 1.01-17.45, p = 0.049 and aOR 11.42, 95% CI 1.49-87.50, p = 0.02, respectively). Risk factors associated with increased odds of late-onset AD from 12 months were the consumption of probiotics between the age of 9 and 12 months and antibiotic treatment in the first 6 months of life (aOR 4.32, 95% CI 1.07-17.45, p = 0.04 and aOR 3.11, 95% CI 1.10-8.76, p = 0.03, respectively). Early-onset AD was associated with an increased risk of developing allergic sensitization (aOR 46.51, 95% CI 3.44-628.81, p < 0.01). Conclusion: We found that early-onset AD was mainly associated with familial factors, while late-onset AD was associated with the consumption of antibiotics or probiotics. The findings support the concept that different phenotypes of AD exist in young children.

High level of fecal calprotectin at age 2 months as a marker of intestinal inflammation predicts atopic dermatitis and asthma by age 6.

Gut microbiota and intestinal inflammation regulate the development of immune-mediated diseases, such as allergies. Fecal calprotectin is a biomarker of intestinal inflammation. We evaluated the association of early-age fecal calprotectin levels to the later development of allergic diseases in children from farming and non-farming environments and further studied the effect of gut microbiota on the fecal calprotectin levels. Fecal calprotectin was measured from 758 infants participating in the PASTURE study at the age of 2 months using the ELISA method. Serum-specific IgE levels were measured at 6 years of age. Data of environmental factors, doctor-diagnosed atopic dermatitis (AD) and asthma were collected by questionnaire. Multivariate logistic regression models were used for analysis. The composition of fecal microbiota was analysed in a subgroup of 120 infants with 16S rRNA pyrosequencing. The effect of Escherichia coli lipopolysaccharide (LPS) on in vitro monocyte IL-10 secretion was studied by flow cytometry. The infants with high fecal calprotectin levels at 2 months, that is above the 90th percentile, had an increased risk of developing AD and asthma/asthmatic bronchitis by the age of 6 years (aOR 2.02 (1.06-3.85) and 2.41 (1.25-4.64), respectively). High fecal calprotectin levels correlated negatively with fecal Escherichia. LPS from E. coli stimulated production of IL-10 in monocytes. High degree intestinal inflammation at 2 months of age, detected as high fecal calprotectin, predicted asthma and AD by the age of 6 years and was linked to low abundance of fecal Escherichia. Impaired IL-10 activation due to the lack of colonization with E. coli could explain the intestinal inflammation associated high fecal calprotectin and later risk of asthma and AD. Our results have implications for the design of probiotic treatments and suggest that early intestinal colonization has long-term health effects.

Inflammatory response and IgE sensitization at early age

Microbial exposure may induce low-grade inflammation at an early age and decrease the risk of allergic diseases, as suggested by the hygiene hypothesis. We examined the associations between low-grade inflammation and the development of allergic sensitization, atopic dermatitis (AD), and asthma at the age of 4.5yr. We studied 636 children participating in the PASTURE study in Finland, Germany, Austria, France, and Switzerland. Data of environmental factors, doctor-diagnosed AD, and asthma were collected by questionnaire. The serum high-sensitivity C-reactive protein (CRP) values were measured at the age of 1yr, and serum-specific IgE concentrations (sIgE) at the age of one and 4.5yr. Analyses were made by logistic regression analysis. The risk of allergic sensitization at the age of 4.5yr was decreased in children who had increased CRP levels at the age of 1yr (level in the highest vs. lowest quartile: aOR 0.48, 95% CI 0.24-0.95; p=0.014). The risk of AD and asthma was not significantly related to CRP. The findings confirm that elevated levels of CRP at early age showed association with decreased allergic sensitization later in life. Our results suggest that poor inflammatory response could predispose for IgE sensitization.

Mislabelled cow's milk allergy in infants: a prospective cohort study

BackgroundAlthough cow's milk allergy (CMA) is one of the most common food allergies, mislabelling non-allergic infants as being allergic to cow's milk is more common. Despite this, characteristics of families...

Effect of Living Close to Major Roadway on Allergic Diseases: Results of the Childrenʼs Health and Environmental Research (CHEER)

PP-29-050 Background/Aims: The prevalence of allergic diseases has increased during past decades in Korea, with an increasing tendency of exposure to traffic-related air pollutants being a potential risk factor of allergic diseases in children. The objective of our study is to assess the relationship between living near major roadways and allergic diseases in Korean children. Methods: We studied 2754 children aged 6–8 years from 16 schools in 7 South Korean cities as part of the first Children's Health and Environmental Research (CHEER) survey. The prevalence of allergic diseases (asthma, allergic rhinitis, and atopic dermatitis) was assessed by an International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire completed by the parents. Residential distance to the nearest major roadway and road density within a 200 m buffer were used as surrogates for traffic-related air pollutants. We used a GIS to measure distance to and density of roadways. We used logistic regression to assess the association between living close to major roadways and allergic diseases. Results: Inverse associations were found between distance to the nearest major roadway and allergic diseases. The highest adjusted odds ratios (ORs) for children living less than 75 m from major roadway were found for lifetime wheeze (OR = 1.39; 95% confidence interval [CI]: 1.06–1.83), past year wheeze (OR = 1.46; 95% CI: 1.02–2.08), doctor-diagnosed allergic rhinitis (AR) (OR = 1.31; 95% CI: 0.99–1.74), lifetime atopic dermatitis (OR = 1.32; 95% CI: 1.03–1.70), doctor-diagnosed atopic dermatitis (OR = 1.46; 95% CI: 1.12–1.89), and current atopic dermatitis (OR = 1.46; 95% CI: 1.06–2.00). Moreover, distance to major roadway had an inverse dose-response relationship with asthma, AR, and atopic dermatitis. Adjusted OR per 100 m decline in distance were elevated for past year wheeze (OR = 1.16; 95% CI: 1.04–1.30), doctor-diagnosed AR (OR = 1.10; 95% CI: 1.01–1.20), current AR (OR = 1.09; 95% CI: 1.00–1.20), and current atopic dermatitis (OR = 1.10; 95% CI: 1.00–1.22). Conclusion: We found that residential distances from major roadways and road density near homes are associated with the prevalence of allergic diseases in school children.

Timing of Solid Food Introduction in Relation to Atopic Dermatitis and Atopic Sensitization: Results From a Prospective Birth Cohort Study

Prophylactic feeding guidelines recommend a delayed introduction of solid foods for the prevention of atopic diseases. Scientific evidence for this is scarce. This study investigates whether a delayed introduction of solids (past 4 months or 6 months) is protective against the development of atopic dermatitis (AD) and atopic sensitization when considering reverse causality. Data from 2612 infants in an ongoing birth cohort study were analyzed at 2 years of age. Information on diet and on symptoms and diagnoses of AD was collected semiannually, and information on specific immunoglobulin E levels was collected at 2 years of age. Solid food introduction past the first 4 months of life decreased the odds of symptomatic AD but not for doctor-diagnosed AD, combined doctor-diagnosed and symptomatic AD, or atopic sensitization. Postponing the introduction beyond the sixth month of life was not protective in relation to either definition of AD or atopic sensitization. There was also no evidence for a protective effect of a delayed introduction of solids on AD and atopic sensitization in children of atopic parents. There was clear evidence for reverse causality between early skin or allergic symptoms and the introduction of solids. This study does not find evidence supporting a delayed introduction of solids beyond the sixth month of life for the prevention of AD and atopic sensitization. We cannot rule out that delaying the introduction of solids for the first 4 months of life might offer some protection. Measures to avoid reverse causality have to be considered in the conduction, analysis, and interpretation of cohort studies on the topic.

The epidemiology of atopic dermatitis in Italian schoolchildren.

Atopic dermatitis (AD) is common in children in industrialized countries. Only one large population study on its prevalence has been conducted in Italy, based on self-report questionnaire. The present study was designed to estimate the prevalence of AD in schoolchildren in Italy by dermatologists' assessment and by UK Working Party criteria, and to investigate associated symptoms and factors. Cross-sectional survey on a random sample of 9-year-old schoolchildren from seven Italian cities. Children were examined by experienced dermatologists. Parents and teachers answered standardized questionnaires. Of the 1369 children examined, 88 had a diagnosis of AD, with an estimated point prevalence of 5.8% (95% CI 4.5-7.1) in the reference population. The reported lifetime prevalence was 15.2 (95% CI 12.2-18.2) for AD, 11.9% (95% CI 9.0-14.8) for asthma, and 17.6% (95% CI 14.6-20.7) for rhino-conjunctivitis. The strongest associated factor was the presence of AD in at least one parent. No association of AD with maternal smoking during pregnancy, birth weight, maternal age at the time of the child birth and breast-feeding was observed. The environmental characteristics of the house and the school did not correlate with the prevalence of AD. Episodes of lower respiratory tract infections were associated with asthma, and to a lower extent also with AD and rhinitis. The prevalence of doctor-diagnosed AD in Italian schoolchildren is comparable to those reported for other developed countries. Family history of atopy was the single most important associated factor, while the complex interplay of environmental factors remains to be elucidated.