Mouldy houses influence symptoms of asthma among atopic individuals.
BACKGROUND
The influence 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-five 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 flows (PEF) and medication use. Dust samples were analysed for house dust mite allergen (Der p 1) and total fungal biomass (ergosterol). Total and genus-specific fungal propagules were identified in air samples. Seasonal variation in allergen levels and significant independent effects of fungal levels on peak flow variability (PFV) were identified by repeated measures analysis of variance.


RESULTS
Significant seasonal variations were observed in viable airborne fungi, ergosterol levels in the floor dust and PFV. PFV correlated significantly with symptom scores and the dose of reliever medication. PFV was also significantly 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, specific fungi or ergosterol and PFV. Der p 1 levels had no significant influence on asthma, even in HDM-sensitized individuals.


CONCLUSIONS
Mouldy homes adversely influence asthma in asthmatics sensitized to fungi.
Dharmage
S
S
Department of Public Health, School of Population Health, The University of Melbourne, Australia. s.dharmage@unimelb.edu.au
Bailey
M
M
Raven
J
J
Abeyawickrama
K
K
Cao
D
D
Guest
D
D
Rolland
J
J
Forbes
A
A
Thien
F
F
Abramson
M
M
Walters
E H
EH
D016902:Air Pollution, Indoor / Q000032:analysis*; D039741:Antigens, Dermatophagoides / Q000032:analysis; D000946:Antigens, Fungal / Q000032:analysis*; D060829:Arthropod Proteins; D001249:Asthma / Q000503:physiopathology*; D003546:Cysteine Endopeptidases; D006801:Humans
D039741:Antigens, Dermatophagoides; D000946:Antigens, Fungal; D060829:Arthropod Proteins; D003546:Cysteine Endopeptidases; C451162:Dermatophagoides pteronyssinus antigen p 1