House dust mite allergen avoidance: a randomized controlled trial of surface chemical treatment and encasement of bedding

Clin Exp Allergy. 1994 Nov;24(11):1078-83. doi: 10.1111/j.1365-2222.1994.tb02746.x.


To test the effectiveness of a house dust mite (HDM) allergen avoidance strategy we conducted a randomized controlled trial in 35 atopic subjects with asthma, aged 13 to 60 living in Sydney - a high HDM allergen environment. After a 3 month run-in period, subjects were randomized to active allergen avoidance treatment (n = 17) or placebo (n = 18) groups and followed for 6 months. The active treatment involved placing impermeable covers over the mattress, pillows and duvet and spraying the remaining bedding, as well as the carpets and furniture, with a tannic acid/acaricidal spray. Subjects kept a daily record of symptoms and peak expiratory flow rates and had 3 monthly assessments of lung function and airway hyperresponsiveness (AHR). Dust samples were collected from the bed, the bedroom floor and the living room floor at 3 monthly intervals and 2 weeks after the treatment. Mean HDM allergen levels at baseline at these sites were, in the active group, 15.5, 9.6 and 10.2 micrograms Der p I/g of fine dust, and, in the placebo group 25.7, 11.8 and 6.3 micrograms/g. Two weeks after the allergen avoidance treatment the HDM allergen level in the beds was reduced to 29% of baseline (95% CI 16-50%, P = 0.038 compared with placebo), but was not significantly different at 3 or 6 months. There was also no significant effect of the allergen avoidance treatment on symptom scores, peak flow variability, lung function or AHR P > 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Allergens / adverse effects*
  • Animals
  • Antigens, Dermatophagoides
  • Asthma / etiology
  • Asthma / physiopathology
  • Asthma / prevention & control*
  • Bedding and Linens*
  • Female
  • Glycoproteins / adverse effects*
  • Humans
  • Hydrolyzable Tannins / administration & dosage*
  • Insecticides / administration & dosage*
  • Lung / physiology
  • Male
  • Middle Aged
  • Mite Infestations / prevention & control
  • Mites*
  • Single-Blind Method


  • Allergens
  • Antigens, Dermatophagoides
  • Glycoproteins
  • Hydrolyzable Tannins
  • Insecticides