Atopic dermatitis and indoor use of energy sources in cooking and heating appliances.

BACKGROUND: Atopic dermatitis (AD) prevalence has considerably increased worldwide in recent years. Studying indoor environments is particularly relevant, especially in industrialised countries where many people spend 80% of their time at home, particularly children. This study is aimed to identify the potential association between AD and the energy source (biomass, gas and electricity) used for cooking and domestic heating in a Spanish schoolchildren population. METHODS: As part of the ISAAC (International Study of Asthma and Allergies in Childhood) phase III study, a cross-sectional population-based survey was conducted with 21,355 6-to-7-year-old children from 8 Spanish ISAAC centres. AD prevalence, environmental risk factors and the use of domestic heating/cooking devices were assessed using the validated ISAAC questionnaire. Crude and adjusted odds ratios (cOR, aOR) and 95% confidence intervals (CIs) were obtained. A logistic regression analysis was performed (Chi-square test, p-value < 0.05). RESULTS: It was found that the use of biomass systems gave the highest cORs, but only electric cookers showed a significant cOR of 1.14 (95% CI: 1.01-1.27). When the geographical area and the mother's educational level were included in the logistic model, the obtained aOR values differed moderately from the initial cORs. Electric heating was the only type which obtained a significant aOR (1.13; 95% CI: 1.00-1.27). Finally, the model with all selected confounding variables (sex, BMI, number of siblings, mother's educational level, smoking habits of parents, truck traffic and geographical area), showed aOR values which were very similar to those obtained in the previous adjusted logistic analysis. None of the results was statistically significant, but the use of electric heating showed an aOR close to significance (1.14; 95% CI: 0.99-1.31). CONCLUSION: In our study population, no statistically significant associations were found between the type of indoor energy sources used and the presence of AD.

The impact of atmospheric pollutants on the prevalence of atopic eczema in 6-7-year-old schoolchildren in Spain; ISAAC Phase III.

Atopic Eczema (AE) is a chronic inflammatory skin disease that affects children and adults, and alters quality of life with a high morbidity rate and severe economic burden. The objective of the present work was to analyse specific atmospheric pollutants (O3, NO, PM10 and SO2) affecting the prevalence of diagnosed AE and its symptoms among 6-7-year-old schoolchildren.The participants included 21311 schoolchildren aged 6-7 years from 8 Spanish regions, whose parents completed the ISAAC Phase III questionnaire to ascertain AE diagnosis and symptoms. The mean levels (µg/m3) of O3, NO, PM10 (particles 10 micrometers or less in diameter) and SO2 were determined in each geographical area. Participating in this study.According to these mean levels, three levels of exposure to each pollutant were considered: level 1 (percentiles 0-25); level 2 (percentiles 26-74); level 3 (percentiles 75-100). Exposure to O3 was associated with increased prevalence of rashes (exposure level 2, Odds Ratio (OR): 1.22, 95% Confidence Interval (95%CI): 1.02-1.45; level 3 OR: 1.33, 95%CI: 1.10-1.61) and diagnosed AE (level 2, OR: 1.27, 95%CI: 1.17-1.39; level 3 OR: 1.27, 95%CI: 1.15-1.41). An association was found between the level of NO and a drop in the prevalence of diagnosed AE (exposure level 2, OR: 0.88, 95%CI: 0.81-0.95; level 3 OR: 0.85, 95%CI: 0.74-0.97). There was also an association between the highest exposure level to PM10 and a reduced prevalence of rashes (level 3 OR: 0.42, 95%CI: 0.22-0.81) and diagnosed AE (level 3 OR: 0.53, 95%CI: 0.38-0.75). Future studies into exposure to O3 and its relationship with allergic diseases may be conducted in order to prevent this association.