Background: We compared the effects of an acaricide, benzyl benzoate,
with the effects of baking soda control applied to bedroom and living
room carpets on house dust mite allergen levels, lung function, and me
dication use in 12 adult patients with asthma for it months. Methods:
This was a randomized, double-blind placebo-controlled study. Patients
were enrolled from the allergy clinic of a large tertiary care center
in a metropolitan area. All patients had positive dust mite puncture
test results. Sir patients used benzyl benzoate, and sir used baking s
oda. Other aggressive mite control measures were implemented uniformly
in each group. Subjects were to make two carpet applications, at base
line and at 6 months according to the manufacturer's recommendations.
Dust samples were collected in bedroom and living room carpets at 0 3,
6, 9, and 12 months; and quantities of Der p I and Der f I allergens
were determined Spirometry was done every 3 months, and peak flow rate
s were recorded for to days after each dust sampling. Results: There w
ere no significant differences in mean allergen levels between the two
groups over time at either site. There were no significant changes in
lung function or medication use for either group. Conclusions: Benzyl
benzoate powder applications may not be effective when done according
to manufacturer's instructions. Further studies are necessary to test
effectiveness when applied more frequently and for longer periods.