A reintroduction of environmental mite allergen control strategies for asthma treatment and the debate on their effectiveness

Abstract

SummaryAsthma affects three hundred million people worldwide. The effectiveness of house dust mite allergen control for asthma treatment is debatable. One aspect that has been little discussed in existing meta‐analyses is the possible role of environmental strategies. Here, we reintroduce the previously defined strategies for mite allergen control and discuss their importance to the debate on clinical effectiveness. The strategy of concurrent bedroom interventions is related to the combined use of a priori defined interventions, while the strategy of exposure‐based control relates to the treatment of relevant textiles after assessing exposure. The air purification strategy aims to purify the human breathing zone of airborne allergens. In Western European patient practice, the use of these strategies differs. A post hoc study of the dominant Cochrane review by Gøtzsche and Johansen (Cochrane Database of Systematic Reviews, 2008, Art. No: CD001187) appears to indicate that a majority of the underlying trials reported on the strategy of concurrent bedroom interventions, which were mainly executed in a minimal manner. Some trials have reported on the air purification strategy and may potentially alter the debate on effectiveness. No trial has reported on the strategy of exposure‐based control. We therefore hypothesize that the absence of evidence for the effectiveness of mite allergen control for asthma treatment applies to the strategy of concurrent bedroom interventions. The evidence‐based effectiveness of the exposure‐based control strategy appears to be undetermined. The results of our post hoc reanalysis urge that future meta‐analyses of mite allergen control should a priori define the environmental strategy under study. Future trials of mite allergen control are warranted to test the exposure‐based strategy as well as the sparsely tested strategy of air purification.

Update on House Dust Mite Allergen Avoidance Measures for Asthma

“…The most recent Cochrane meta-analysis published in 2008 included 54 clinical trials which evaluated the efficacy of chemical methods, physical barriers, or the combination of different mite allergen avoidance measures on asthma control; the authors concluded that mite avoidance had no significant benefit on different asthma outcomes (lung function, symptoms, or anti-asthma medications use) [56]. The authors concluded that strategies aimed to reduce exposure to mite allergens cannot be recommended to mite-allergic patients with asthma, raising uncertainty and a considerable disagreement among clinicians and experts [58][59][60][61]. Furthermore, findings from a recent systematic reviews which included 67 trials (8 of which not randomized) evaluating single (37 trials) or multicomponent avoidance strategies (30 trials) showed inconclusive results or no benefit in asthma [57].…”

A meta-analysis of baseline characteristics in trials on mite allergen avoidance in asthmatics: room for improvement

“…In addition to the substantial meta-analysis by Gøtzsche and Johansen [7], several other meta-analyses on mite allergen avoidance for the treatment of asthma report varying results for the effectiveness of avoidance [8][9][10][11]. The variation in the complex interventions as well as the heterogeneity of several study outcomes urges further exploration [12,13].…”

Effectiveness of the Air Purification Strategies for the Treatment of Allergic Asthma: A Meta-Analysis

“…Evidence of clinical benefits of textile-based avoidance strategies has not been demonstrated in rigorous systematic reviews [3][4][5]. In a scoping review, Boven et al [6] observed potential success with the strategy of air purification for the treatment of house dust mite allergy-related asthma. Previously, Mc-Donald et al [7] reported improvements in asthma symptom scores (ASS) associated with air purification in a small patient subgroup (n = 88).…”