Environmental controls in reducing house dust mites and nasal symptoms in patients with allergic rhinitis. Allergic rhinitis due to house dust mites: evaluation of the efficacy of specific sublingual immunotherapy. Clinical evaluation of a double-blind dust-mite avoidance trial with mite-allergic rhinitic patients. Continuous avoidance measures with or without acaricide in dust mite-allergic asthmatic children. House dust mite allergen avoidance and self-management in allergic patients with asthma: randomised controlled trial. Allergen-avoidance measures in homes of house-dust-mite-allergic asthmatic patients: effects of acaricides and mattress encasings.
A randomized comparison group pretest-posttest experimental design was used to quantitatively determine the effects of environmental control measures on patients with allergic rhinitis. Environmental controls included wrapping the mattress with a vinyl cover, washing the top bedding cover with 55 degrees C hot water every two weeks, removal of soft furniture, and wet cleaning of the bedroom floor every day. Thirty subjects were randomly assigned to experimental and control groups. The amount of house dust mites in dust samples collected from the bedroom floor, bedding and mattress, as well as the nasal symptoms of patients, were measured twice at one-month intervals. A significant decrease in house dust mites in dust samples and relief in patients' nasal symptoms were observed in the experimental group who had environmental controls. The efficacy and safety of sublingual immunotherapy (SLIT) in patients with chronic rhinitis related to sensitization to house dust mites are still controversial.
                After application of an anti-mite mattress cover, patients were only included in the study when the cumulative symptom score over a fortnight was greater than 70 out of a possible total of 168. Thirty-two of the 120 patients selected were randomized to receive SLIT for 2 years: 17 received placebo and 15 received the Dermatophagoides pteronyssinus and D. farinae 50/50 allergen extract.
                Significant between-group differences were observed after 1 year and persisted at the end of the second year for the rhinitis total score (P < 0.02), blocked nose score (P < 0.01) and nasal itching score (P < 0.01). Skin reactivity to house dust mites was significantly reduced in the group receiving house dust mite extract (P < 0.03). No statistical difference was observed between the two groups for medication scores, but a low medication consumption was observed in all patients. No serious and no systemic adverse reactions were reported.
                This study indicates the superiority of active treatment vs. placebo, evaluated on efficacy criteria (rhinitis score) or objective criteria (skin reactivity). The availability of a solid form (tablet) could represent a progress in terms of patient acceptability. Inheritance and allergen exposure are key factors in the development and the course of atopic allergy, expressed as conjunctivitis, rhinitis, asthma or dermatitis. This study concerns the clinical significance of mite and mite-allergen avoidance measures based on intensive cleaning with acaricide (solidified benzylbenzoate) added (10 dwellings), and without biocidal activity (10 other homes) as a control in a double-blind trial with matched pairs. Twenty subjects with persisting rhinitic complaints were selected. They lived in 20 different dwellings and were all sensitized to pyroglyphid mites; 12 of them were also sensitized to stored product mites (Acari). Daily symptoms and medication score, guanine and dust exposure, total and mite-specific IgE in serum, eosinophilia in the blood and in the nasal smear, intracutaneous tests with house dust mite and storage mite extracts were compared in both pairs and groups. Acarological data, physiochemical aspects and exposure assessment are discussed in detail elsewhere. Symptom scores dropped significantly, as did the total IgE and exposure to dust and mite products in the acaricidal cleaner treatment group. After 1 year, the daily symptoms median was 47% (P = 0.025), total IgE was 38% (P = 0.0049), and exposure to dust and mite products (guanine exposure) was 53% (P = 0.0449) better or lower than in the controls. Intensive cleaning, without acaricidal treatment performed twice a year, resulted in clinical improvement in four out of 10 subjects, of whom none became free of complaints. In the Acarosan treatment group (cleaning + benzylbenzoate) eight out of 10 subjects improved, in three cases subjective symptoms disappeared.(ABSTRACT TRUNCATED AT 250 WORDS) Improvement in the quality of life in the Western world and increased time spent indoors by children have enhanced the spread of house dust mites and increased the exposure time for sensitive children. Also, exposure to house dust mites in infancy and subsequent development of childhood asthma have been clinically linked. Recently, new acaricides have been developed.
                To test the efficacy of the new acaricide (esdepallethin and piperonyl butoxide--"Acardust") combined with environmental control compared with continuous house dust mite avoidance measures.
                Forty-six house dust mite-allergic, asthmatic children were evaluated for 6 months in a prospective, randomized, double-blind, and placebo-controlled study. Patients were randomly allocated to active and placebo acaricide treatment combined with avoidance measures, whereas only continuous avoidance measures were taken in the third group. Symptom score, medication usage, and peak flow measurements were recorded daily. The amount of house dust mite allergen in the dust vacuumed from the bedrooms was also measured.
                Morning and evening peak expiratory flow rates and forced expiratory volume in one second remained unchanged throughout the study period. In all groups, the symptom scores improved significantly, whereas the amount of house dust mite allergen decreased significantly at the end of the trial.
                Continuous house dust mite avoidance measures have a significant positive effect on the symptomology of children with mild or moderate asthma. "Acardust" combined with continuous house dust mite avoidance measures is not more effective than continuous house dust mite avoidance measures alone in the treatment of house dust mite-allergic, asthmatic children. The efficacy of bed covers that are impermeable to house dust mites has been disputed.
                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.
                Prospective, randomised, double blind, placebo-controlled trial.
                Primary care in a south-eastern region of the Netherlands.
                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.
                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.
                House dust mite impermeable bed covers combined with self-management do not lead to reduced use of ICS compared with self-management alone. This double-blind, placebo-controlled study investigated whether the application of an acaricide (Acarosan) on mattresses and on textile floor coverings in living rooms and bedrooms can contribute to improvement in lung function and airway hyperresponsiveness in 40 adult asthmatic patients sensitized to house-dust mite. In a second group of 19 patients who refused chemical intervention, the clinical effects of application of allergen-impermeable mattress encasings were studied. In all three treatment groups, Der p 1 levels in mattress dust were statistically significantly decreased after 12 months. However, this decrease was much greater in the group who received mattress encasings (final mean level 430 ng/g) than in groups with acaricide- or placebo-treated mattresses (final mean levels 1730 and 2100 ng/g, respectively). Treatment of textile floors with either Acarosan or placebo chemical caused a statistically significant decrease in the level of the house-dust-mite allergen Der p1 in floor dust. In the group with mattress encasings, no significant changes of floor dust Der p 1 were found. Airway hyperresponsiveness (as measured by the PC20 histamine) improved significantly in the mattress cover group after 6 months. The Acarosan group also showed a small but statistically significant improvement after 12 months.
Trials to date have on the whole been small and of poor methodological quality, making it difficult to offer any definitive recommendations on the role, if any, of house dust mite avoidance measures in the management of house dust mite sensitive perennial allergic rhinitis. The results of these studies suggest that use of acaricides and extensive bedroom-based environmental control programmes may be of some benefit in reducing rhinitis symptoms and, if considered appropriate, these should be the interventions of choice. Isolated use of house dust mite impermeable bedding is unlikely to prove effective.