Mouldy houses influence symptoms of asthma among atopic individuals (original) (raw)

Background The in¯uence of current levels of indoor fungi on asthma is a controversial issue that needs to be resolved in order to advise patients appropriately. Objective To assess the seasonal variation in indoor fungal levels and the impact of these levels on asthma among mould-sensitized individuals. Methods Thirty-®ve young adults with current asthma and sensitization to fungi were visited four times over 1 year. At each home visit a questionnaire was administered and samples of dust and air were collected. Participants also recorded information on symptoms, peak expiratory¯ows (PEF) and medication use. Dust samples were analysed for house dust mite allergen (Der p 1) and total fungal biomass (ergosterol). Total and genus-speci®c fungal propagules were identi®ed in air samples. Seasonal variation in allergen levels and signi®cant independent effects of fungal levels on peak¯ow variability (PFV) were identi®ed by repeated measures analysis of variance. Results Signi®cant seasonal variations were observed in viable airborne fungi, ergosterol levels in the¯oor dust and PFV. PFV correlated signi®cantly with symptom scores and the dose of reliever medication. PFV was also signi®cantly associated with smoking and visible mould. The association between visible mould and PFV was independent of season, smoking and the dose of reliever medication. However, there was no association between total fungi, speci®c fungi or ergosterol and PFV. Der p 1 levels had no signi®cant in¯uence on asthma, even in HDM-sensitized individuals. Conclusions Mouldy homes adversely in¯uence asthma in asthmatics sensitized to fungi.