House Dust Mite Allergen Reduction in Bedding: Purotex Impregnated Covers of Bekaert Textiles

Inclusion Criteria: * Subjects must be willing to give/sign informed consent * Subjects (male or female) must be at least 18 years old and maximum 65 years old at screening * Clinical history of allergic rhinitis for at least 1 year * Positive skin prick test for D. Pteronyssinus ± D. Farinae * Positive nasal provocation test with the house-dust-mite allergen * Specific IgE: Unicap positive to D. Pteronyssinus (d1) and D. Farinae (d2) (\> 0.7U/ml) * VAS score for global discomfort caused by nasal- or other allergic symptoms during the previous 4 weeks ≥ 5. * The concentration of Der p1 in the dust collected from own bedding (mattress and pillow), measured by ELISA is above the detection limit (≥ 0.488 ng/ml). Exclusion Criteria: * Patients sensitized to animals should not be included if they are symptomatic upon exposure and regularly exposed to animals: positive SPT to pets and pets at home * Patients with an allergy to tree pollen (symptoms during the season + positive skin prick test) should not be included * Subject pregnant or lactating * Completed allergen specific immunotherapy (SCIT or SLIT) with HDM within the last 5 years * SCIT or SLIT during the study period * Regular use of oral corticosteroids for exacerbations of asthma * Daily use of oral corticosteroids * Daily use of cyclosporine or other immunosuppressant drugs * Regular use of antibiotics * History of anaphylactic reaction to an allergen * Severe general diseases (especially cardiopulmonary disease with reduced lung capacity)