The 8-year follow-up of the PIAMA intervention study assessing the effect of mite-impermeable mattress covers.
BACKGROUND
Exposure to high levels of house dust mite (HDM) allergens is associated with the development of allergic sensitization to HDM, a risk factor for the development of asthma, rhinitis, and allergic dermatitis. We studied the effect of an early intervention with mite-impermeable mattress covers on HDM allergen levels and the development of asthma and mite allergy throughout the first 8 years of life.


METHODS
High-risk children (allergic mother) were prenatally recruited and randomly allocated to two groups receiving mite allergen-impermeable (n = 416) and placebo mattress covers (n = 394) or no intervention (n = 472). Asthma and allergies were assessed yearly by questionnaire. Specific immunoglobulin E and bronchial hyper-responsiveness were measured at the age of 8 years. Mattress dust samples collected at different time points were analyzed for HDM allergens.


RESULTS
At the age of 8 years, levels of HDM allergen Der f1 but not Der p1 were lower in the active than the placebo mattress cover group. In repeated measures analyses, we found a temporary decreased risk of asthma symptoms at the age of 2 years in the intervention group compared to the placebo group and a temporary association between higher HDM allergen exposure at the age of 3 months and more asthma symptoms.


CONCLUSIONS
Early intervention with mite-impermeable mattress covers is successful in reducing exposure to Der f1; it only temporarily reduces the risk of asthma symptoms and does not reduce the risk of hay fever, eczema, and allergic sensitization.
Institute for Risk Assessment Sciences, Utrecht University, The Netherlands. u.gehring@uu.nl
U
U
Gehring
J C
JC
de Jongste
M
M
Kerkhof
M
M
Oldewening
D
D
Postma
R T
RT
van Strien
A H
AH
Wijga
S M
SM
Willers
A
A
Wolse
J
J
Gerritsen
H A
HA
Smit
B
B
Brunekreef
D000818:Animals; D039741:Antigens, Dermatophagoides / Q000276:immunology*; D001249:Asthma / Q000276:immunology / Q000517:prevention & control*; D001512:Bedding and Linens / Q000469:parasitology*; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology / Q000517:prevention & control*; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D039981:Pyroglyphidae / Q000276:immunology*; D013997:Time Factors
D039741:Antigens, Dermatophagoides