Mouldy houses influence peak flow variability in adult asthmatics with allergy to fungi

The importance of indoor exposure to moulds in adult asthma is controversial. Aim: To identify the influence of indoor fungal exposure in atopic adults with asthma. Methods: A community sample of 40 asthmatics who were allergic to one of the major allergenic fungi (ie. Cladosporium, Altemaria, Epicoccum, Aspergil/us or Penicilium) was followed up over one year. They recorded asthma symptoms, peak expiratory flow and medications on diary cards for 14 days each season. Bedroom floor dust was collected each season and analyzed for ergosterol by HPLC. An Andersen sampler was used to collect fungal propagules in bedroom air and viable genera were identified by standard methods. A validated interviewer administered questionnaire was used to collect information on the residential characteristics. Associations were examined using repeated measures analysis of variance. Results: Peak flow variability (PFV) was highest in winter and lowest in summer with a decline over time between the two seasons but this association was not significant. PFV correlated significantly with symptom scores and use of reliever medication. PFV was also significantly associated with smoking, visible mould and ergosterol levels in house dust, but not viable fungal spore levels. The significant independent predictors of PFV were smoking, visible mould and the dose of reliever medication. Conclusions: Moulds influence symptoms and PFV in atopic adults with asthma, who should be educated about the methods to reduce indoor fungal exposure.