Are There Effective Methods to Reduce Exposure to House Dust Mite Allergens? A Meta-Analysis of Randomized Clinical Trials.

Background: House dust mites (HDMs) are the most common cause of atopic sensitivities and allergic diseases worldwide. Therefore, we decided to conduct a meta-analysis of randomized clinical trials to evaluate the effect of different methods of HDM avoidance.

Methods: PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials databases were searched to find articles of control-compared randomized clinical trials, which investigated the following analyzed outcomes: total amount of dust (g); Der1 (Der p1 plus Der f1) concentrations (µg/g); Der p1 concentrations (µg/g); Der p2 concentrations (µg/g); Der f1 concentrations (µg/g); measurements of peak expiratory flow (PEF) (L/min); respiratory, pulmonary, or nasal symptoms according to various scales, including visual analog scale; exacerbations; Asthma Control Questionnaire score measurements; and change in quality of life scales (overall change, activity change, symptom change, and emotional function change). The relative risk with 95% confidence interval (CI) and the mean difference or the standardized mean difference with 95% CI were calculated to compare the effect. A random effects model was used to calculate effect sizes.

Results: Our meta-analysis was based on 17 studies. We indicated the significant differences between interventional and control groups in total amount of dust (MD = ‒0.24; 95% CI [‒0.37; ‒0.11]; p < 0.001; I² = 57%) and Der1 (Der p1 plus Der f1) concentrations (MD = ‒0.97; 95% CI [‒1.81; ‒0.13]; p = 0.02; I² = 82%). However, they are not sufficient to improve diseases, such as asthma and allergic rhinitis, or to improve the quality of life of patients.

Conclusions: HDM allergen avoidance methods are effective in reducing dust and Der1 concentrations.