Damp Housing and Childhood Respiratory Symptoms: The Role of Sensitization to Dust Mites and Molds

In 1990, a case-control study was conducted in the Netherlands into the association between damp housing, childhood respiratory symptoms, and sensitization to house dust mites and mold allergens. In this study, 259 children with chronic respiratory symptoms and 257 control children were involved. Total serum immunoglobulin E (IgE) and specific IgE against house dust mites and a mixture of molds were determined. A visual inspection for signs of home dampness was performed in all homes. A questionnaire was given to the parents of the children to elicit information about the presence of signs of dampness in the previous 2 years and about risk factors for childhood respiratory disease. In the case group, 94 children had elevated serum IgE levels to house dust mites and 24 children to the mixture of molds. In the control group, house dust mite allergy was found in 31 children and mold allergy in two children. In a crude analysis, cases were slightly more likely to have been living in homes where damp or mold was reported or observed than were the controls. In cases as well as controls, home dampness was associated with increased sensitization to dust mites and molds. There was no relation between home dampness and case-control status after stratification for sensitization, however. Restriction of the analysis to cases with elevated serum IgE levels against dust mites and/or molds, and to controls without elevated serum IgE, increased the odds ratios, and several became significant at p < 0.05. This supports a connection between damp housing and sensitization to dust mites and/or molds and childhood respiratory symptoms. Only five children were sensitized to molds without also being sensitized to dust mite allergen. It was therefore not possible to evaluate the role of sensitization to molds in the absence of sensitization to dust mites. For the circumstances studied in the Netherlands, the results suggest that sensitization to dust mites, and possibly mold allergen, plays an important role in the relation between living in a damp home and childhood respiratory symptoms.