ALLERGEN-AVOIDANCE MEASURES IN HOMES OF HOUSE-DUST-MITE-ALLERGIC ASTHMATIC-PATIENTS - EFFECTS OF ACARICIDES AND MATTRESS ENCASINGS

This double-blind, placebo-controlled study investigated whether the a pplication of an acaricide (Acarosan(R)) on mattresses and on textile floor coverings in living rooms and bedrooms can contribute to improve ment in lung function and airway hyperresponsiveness in 40 adult asthm atic patients sensitized to house-dust mite. In a second group of 19 p atients who refused chemical intervention, the clinical effects of app lication of allergen-impermeable mattress encasings were studied. In a ll three treatment groups, Der p 1 levels in mattress dust were statis tically significantly decreased after 12 months. However, this decreas e was much greater in the group who received mattress encasings (final mean level 430 ng/g) than in groups with acaricide-or placebo-treated mattresses (final mean levels 1730 and 2100 ng/g, respectively). Trea tment of textile floors with either Acarosan or placebo chemical cause d a statistically significant decrease in the level of the house-dust- mite allergen Der p 1 in floor dust. In the group with mattress encasi ngs, no significant changes of floor dust Der p 1 were found. Airway h yperresponsiveness (as measured by the PC20, histamine) improved signi ficantly in the mattress cover group after 6 months. The Acarosan grou p also showed a small but statistically significant improvement after 12 months.