ALLERGEN REDUCTION MEASURES IN HOUSES OF ALLERGIC ASTHMATIC-PATIENTS - EFFECTS OF AIR-CLEANERS AND ALLERGEN-IMPERMEABLE MATTRESS COVERS

Recommendations for allergen avoidance or allergen reduction measures play an important part in the treatment of allergic asthmatic patients . The purpose of this study was to test recently developed air-cleaner s with respect to their capacity to capture airborne allergen particle s and to improve clinical parameters of asthmatic patients sensitized to aeroallergens. Forty five allergic asthmatic patients were studied in a double-blind procedure for 6 months, The patients were divided in to three groups of 15 patients. In Group 1, the intervention consisted of the application of active air-cleaners in living-rooms and bedroom s, In Group 2, placebo air-cleaners were used in combination with alle rgen-impermeable mattress covers, In Group 3, the same intervention wa s performed as in Group 2 but with active air-cleaners. Allergen level s in mattress and floor dust were measured before, and 3 and 6 months after the interventions, After 6 months, the air-cleaners were dismant led and the filters were analysed for the amount of dust collected and allergen content, Immunological and lung function parameters were mea sured before, and 3 and 6 months after the interventions. Considerable amounts of airborne dust and allergenic particles were captured in th e filters of the air-cleaners, Up to the 18.9 g of dust, 4,513 ng of h ouse dust mite allergen, Der p 1, and 50,000 mU of cat allergen, Fel d 1, (in houses with cats) were collected by air-cleaners in living-roo ms, Only in Group 3 (in which both active air-cleaners and mattress co vers were used) was a small (less than 1 doubling dose) but statistica lly significant improvement of provocative concentration of histamine causing a 20% fall in forced expiratory volume in one second (PC20) ob served (from 5.96 to 9.02 mg mL(-1)). The amount of dust and house dus t mite allergen collected in the filters was significantly correlated with an improvement of peak flow variation. In combination with other allergen avoidance measures, the examined air-cleaners can contribute to diminished allergen exposure and improvement of airway hyperrespons iveness in asthmatic patients.