Dampness and Moulds in Relation to Asthma Symptoms in Children: Results from Phase Two of the International Study of Asthma and Allergies in Childhood (Isaac Phase Two)

Abstract

ISEE-0298 Introduction: Dampness and mould are thought to negatively affect respiratory health in children. We investigated the relation to asthma symptoms and possible effect modifiers in a large international study. Methods: A cross-sectional study of approximately 25000 children was carried out in 22 centres in 17 countries worldwide. Random samples (n = 1000) of 8 to 12 year old children were studied using standardized parental questionnaires with detailed questions on asthma symptoms and potential risk factors including “damp spots” and “visible moulds or fungus” on the walls or ceiling. In addition, standardized protocols were applied for skin prick testing to assess atopic sensitization. Odds ratios (OR) for each centre and combined estimates from meta-analysis random effects models were calculated. Results: “Damp spots” and “moulds” in the first year of life and at present were significantly associated with wheeze in the past year (combined crude and adjusted ORs from 1.60 to 1.79). The effect did not vary by skin prick test positivity or parental allergic disease. The crude OR for damp spots but not for moulds was significantly higher (P = 0.028) among children that used feather bedding in their first year of life (OR: 2.64; 95%CI: 1.81 to 3.86) compared to children using blankets only (OR: 1.68; 95%CI: 1.38 to 1.85). After adjustment for age, sex, parental allergic disease and maternal education, significance was lost (P = 0.17; ORs of 2.23 and 1.60, respectively). The presence of double glazing compared to single glazing did not influence the effect of either moulds or damp spots. Conclusions: These results confirm that self reported dampness and moulds are associated with an increased risk of asthma symptoms. Atopy, parental allergic disease and type of window did not modify the observed associations. Initially observed differences between types of bedding might be confounded by parental disease and maternal education.