Investigating International Time Trends in the Incidence and Prevalence of Atopic Eczema 1990-2010: A Systematic Review of Epidemiological Studies

The prevalence of atopic eczema has been found to have increased greatly in some parts of the world. Building on a systematic review of global disease trends in asthma, our objective was to study trends in incidence and prevalence of atopic eczema. Disease trends are important for health service planning and for generating hypotheses regarding the aetiology of chronic disorders. We conducted a systematic search for high quality reports of cohort, repeated cross-sectional and routine healthcare database-based studies in seven electronic databases. Studies were required to report on at least two measures of the incidence and/or prevalence of atopic eczema between 1990 and 2010 and needed to use comparable methods at all assessment points. We retrieved 2,464 citations, from which we included 69 reports. Assessing global trends was complicated by the use of a range of outcome measures across studies and possible changes in diagnostic criteria over time. Notwithstanding these difficulties, there was evidence suggesting that the prevalence of atopic eczema was increasing in Africa, eastern Asia, western Europe and parts of northern Europe (i.e. the UK). No clear trends were identified in other regions. There was inadequate study coverage worldwide, particularly for repeated measures of atopic eczema incidence. Further epidemiological work is needed to investigate trends in what is now one of the most common long-term disorders globally. A range of relevant measures of incidence and prevalence, careful use of definitions and description of diagnostic criteria, improved study design, more comprehensive reporting and appropriate interpretation of these data are all essential to ensure that this important field of epidemiological enquiry progresses in a scientifically robust manner

Foetal exposure to heavy metals and risk of atopic diseases in early childhood

Background: Accumulating evidence suggests that in utero exposures can influence the development of the immune system and thus contribute to disease development. Studies investigating the association between prenatal exposures to heavy metals and atopic diseases, however, are scarce. Methods: Children from the EDEN birth cohort were prospectively followed up using parental questionnaires with validated questions on asthma, allergic rhinitis, eczema, and food allergy symptoms. The questionnaires were administered every 4 months during the children's first year, and then every year until the age of 5, with a final survey at the age of 8. Serum concentrations of lead (Pb), cadmium (Cd), and manganese (Mn) were assessed in maternal blood samples collected during mid-pregnancy and in cord blood of 651 mother-children pairs. Hazard ratios (HR) for the incidence of each atopic disease in relation to the exposure to metals were calculated using Cox proportional hazard models. Results: Levels of Cd in cord blood were associated with greater risk of asthma (hazard ratio [95% confidence interval] for upper vs lower quartile: 1.81 [1.00-3.29]), eczema (1.60 [1.09-2.35]), and food allergy (3.17 [1.36-7.38]), while Mn levels in maternal serum were associated with eczema (1.55 [1.05-2.28]). These associations were similar in males and females and were confirmed using log concentrations of metals as exposures. Conclusions: Our results support the hypothesis that fetal exposure to heavy metals may affect the development of asthma, eczema, and food allergy in childhood and suggest that timing of exposure in utero may have a role in these associations

Foetal exposure to heavy metals and risk of atopic diseases in early childhood

Background: Accumulating evidence suggests that in utero exposures can influence the development of the immune system and thus contribute to disease development. Studies investigating the association between prenatal exposures to heavy metals and atopic diseases, however, are scarce.Methods: Children from the EDEN birth cohort were prospectively followed up using parental questionnaires with validated questions on asthma, allergic rhinitis, eczema, and food allergy symptoms. The questionnaires were administered every 4 months during the children's first year, and then every year until the age of 5, with a final survey at the age of 8. Serum concentrations of lead (Pb), cadmium (Cd), and manganese (Mn) were assessed in maternal blood samples collected during mid-pregnancy and in cord blood of 651 mother-children pairs. Hazard ratios (HR) for the incidence of each atopic disease in relation to the exposure to metals were calculated using Cox proportional hazard models.Results: Levels of Cd in cord blood were associated with greater risk of asthma (hazard ratio [95% confidence interval] for upper vs lower quartile: 1.81 [1.00-3.29]), eczema (1.60 [1.09-2.35]), and food allergy (3.17 [1.36-7.38]), while Mn levels in maternal serum were associated with eczema (1.55 [1.05-2.28]). These associations were similar in males and females and were confirmed using log concentrations of metals as exposures.Conclusions: Our results support the hypothesis that fetal exposure to heavy metals may affect the development of asthma, eczema, and food allergy in childhood and suggest that timing of exposure in utero may have a role in these associations

Prevalência e associação de asma e rinite em adolescentes de 13 e 14 anos de Fortaleza, Ceará, Brasil Asthma and rhinitis prevalence and co-morbidity in 13-14-year-old schoolchildren in the city of Fortaleza, Ceará State, Brazil

Objetivou-se avaliar a prevalência e associação de asma e rinite. Trata-se de estudo transversal envolvendo 3.015 adolescentes de 13-14 anos de Fortaleza, Ceará, Brasil, de escolas públicas e privadas, utilizando-se o protocolo do International Study of Asthma and Allergies in Childhood (ISAAC), em 2006/2007. A prevalência de asma foi 22,6%; de rinite, 43,2% e de rinoconjuntivite, 18,7%, predominando no sexo feminino (p = 0,002, p < 0,001 e p < 0,001, respectivamente) e nos adolescentes das escolas privadas (p < 0,001). Entre os adolescentes que relataram asma, a taxa de rinite foi de 64,4% e de rinoconjuntivite, 35,3%. A taxa da associação asma-rinite na população foi de 14,6%, e asma-rinoconjuntivite, 8%, predominando no sexo feminino (p < 0,001 e p < 0,001, respectivamente) e associando-se a sibilos com limite da fala (p = 0,037 e p = 0,004, respectivamente). O estudo pode contribuir para alertar os profissionais de saúde quanto à importância da abordagem integrada dessas enfermidades, considerando o conceito da "via aérea única" e buscando opções de tratamento que atuem nas duas condições quando presentes simultaneamente.<br>This study aimed to measure the prevalence rates for asthma and rhinitis and the association between the two conditions. This was a cross-sectional study of 3,015 adolescents (13-14 years of age) in Fortaleza, Ceará State, Brazil, in public and private schools, using the protocol from the International Study of Asthma and Allergies in Childhood (ISAAC), in 2006-2007. Prevalence rates were 22.6% for asthma, 43.2% for rhinitis, and 18.7% for rhinoconjunctivitis, with a predominance of females (p = 0.002, p < 0.001, and p < 0/001, respectively) and private school students (p < 0.001). Among adolescents that reported asthma, the rhinitis rate was 64.4% and the rhinoconjunctivitis rate was 35.3%. The rates of association were 14.6% between asthma and rhinitis and 8% between asthma and rhinoconjunctivitis, with a predominance of females (p < 0.001 and p < 0.001, respectively) and associated with speech-limiting wheezing (p = 0.037 and p = 0.004, respectively). The study can help call health professionals' attention to the importance of an integrated approach to these illnesses, considering the "single airway" concept and seeking treatment options that act on both asthma and rhinitis when the two conditions present simultaneously