PREVENTIVE EFFECT OF BEDDING ENCASEMENT WITH MICROFINE FIBERS ON MITESENSITIZATION

Background: The indoor levels of mite allergens are known to determine the thresholds of sensitization and asthma exacerbation. However, the method for preventing mite sensitization by reducing the levels of ho use dust mites (HDMs) is not well established. Objective: We investiga ted whether mite-blocking bedding encasing made from microfine fibers can prevent infants from being sensitized to HDMs. Methods: Fifty-seve n Japanese infants with atopic dermatitis who had high levels of IgE a ntibodies against either egg white, cow's milk, or soybean (but not ag ainst HDMs) were randomly chosen and divided into two groups. Thirty f amilies of atopic infants (group A) were instructed to decrease HDMs b y controlling the indoor environment, including bedding cleaning, wher eas 27 families receiving the same instructions (group B) were further guided to use the Allerguard encasing for quilts and mattresses of al l family members. We repeatedly examined Der p 1 + Der f 1 in the infa nts' mattresses and anti-Dermatophagoides farinae (Df) IgE in the infa nts' sera, and we performed skin prick tests with Df extract for 1 yea r. Results: The mite-blocking encasing markedly reduced the levels of Der p 1 + Der f 1 (3.0 mu g/g dust for group A vs 0.77 mu g/g dust for B, p < 0.001). It also prevented the increase in serum levels of anti -Df IgE (2.5 U/ml for group A vs 0.7 U/ml for group B, p < 0.05) and p ositive reactions to skin prick testing with Df extract (63% for group A vs 31% for group B, p < 0.02) over 1 year. Conclusion: The bedding encasement with the mite-blocking fibers was effective for preventing atopic infants from being sensitized to HDMs, and it seems to be benef icial to modern busy housekeepers.