ABSTRACT
House dust mites and their faecal pellets are the most important indoor allergen causing allergic rhinitis and asthma. Reducing exposure to these allergens will result in relief to allergic persons. Encasement with mite-proof covers (pillow, mattress and quilt) is highly recommended for avoidance of dust mite allergens. The aim of this study is to assess the effectiveness of bed sheets and various mite-proof covers. Six materials were examined by the heat escape method, scanning electron microscope and two-site monoclonal antibody based-ELISA. The results demonstrated leakage of dust mite and its faecal pellets through bed sheets. This was due to such materials having pores larger than the dust mites. Plastic material provided the best protection against dust mite and their allergens but the material was not comfortable when used. Barrier that were made from impermeable cloth are recommended for dust mite allergen avoidance but the leakage of mite allergen through such materials need to be assessed in the laboratory.