House dust mite allergen avoidance and self-management in allergic patients with asthma: randomised controlled trial.
BACKGROUND
The efficacy of bed covers that are impermeable to house dust mites has been disputed.


OBJECTIVE
The aim of the present study was to investigate whether the combination of 'house dust mite impermeable' covers and a self-management plan, based on peak flow values and symptoms, leads to reduced use of inhaled corticosteroids (ICS) than self-management alone.


METHODS
Prospective, randomised, double blind, placebo-controlled trial.


METHODS
Primary care in a south-eastern region of the Netherlands.


METHODS
Asthma patients aged between 16 and 60 years with a house dust mite allergy requiring ICS were randomised to intervention and placebo groups. They were trained to use a self-management plan based on peak flow and symptoms. After a 3-month training period, the intervention commenced using house dust mite impermeable and placebo bed covers. The follow-up period was 2 years. Primary outcome was the use of ICS; secondary outcomes were peak expiratory flow parameters, asthma control, and symptoms.


RESULTS
One hundred and twenty-six patients started the intervention with house dust mite impermeable or placebo bed covers. After 1 and 2 years, significant differences in allergen exposure were found between the intervention and control groups (P<0.001). No significant difference between the intervention and control groups was found in the dose of ICS (P = 0.08), morning peak flow (P = 0.52), peak flow variability (P = 0.36), dyspnoea (P = 0.46), wheezing (P = 0.77), or coughing (P = 0.41). There was no difference in asthma control between the intervention and control groups.


CONCLUSIONS
House dust mite impermeable bed covers combined with self-management do not lead to reduced use of ICS compared with self-management alone.
de Vries
Marjolein P
MP
Department of General Practice, Research Institute Caphri, Maastricht University, The Netherlands.
van den Bemt
Lisette
L
Aretz
Karen
K
Thoonen
Bart P A
BP
Muris
Jean W M
JW
Kester
Arnold D M
AD
Cloosterman
Sonja
S
van Schayck
C P Onno
CP
D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage*; D000328:Adult; D000818:Animals; D001249:Asthma / Q000188:drug therapy / Q000517:prevention & control*; D001512:Bedding and Linens / Q000469:parasitology / Q000592:standards; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D010366:Peak Expiratory Flow Rate; D011446:Prospective Studies; D039981:Pyroglyphidae; D012646:Self Administration; D013983:Tick Control / Q000379:methods*; D016896:Treatment Outcome
D000305:Adrenal Cortex Hormones