Environmental controls in reducing house dust mites and nasal symptoms in patients with allergic rhinitis. Efficacy of the acaricide: acardust for the prevention of asthma and rhinitis due to dust mite allergy, in children. A double-blind study of the effectiveness of a high-efficiency particulate air (HEPA) filter in the treatment of patients with perennial allergic rhinitis and asthma. The effect of encasings on quality of life in adult house dust mite allergic patients with rhinitis, asthma and/or atopic dermatitis. Clinical evaluation of a double-blind dust-mite avoidance trial with mite-allergic rhinitic patients. Efficacy of an air-cleaning device equipped with a high efficiency particulate air filter in house dust mite respiratory allergy.
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. A double blind, randomized, comparative study versus placebo, was done during 6 months in 32 children, aged 4-12 years, who suffer from either allergic asthma or rhinitis or both, slept in a bedroom rich in dust mite, have well documented allergy solely to house dust mite (H.D.M.), and a condition severe enough to require continuous medication. After thorough cleaning, their bedrooms were sprayed on day 0 and day 90 with the total content of a canister containing either Acardust or Placebo. Rooms were cleaned regularly throughout the study period. Each child completed an individual daily score card (scales from 0-3) for asthma, and rhinitis symptoms, medication taken, and any additional symptoms. Peak flow was recorded twice weekly. All the children were examined every month (at the clinic) when also PFF, FEVI, doctor's and patient's opinion of clinical symptoms were recorded according to the same scale (0-3) and dust samples from child's bedroom were examined for H.D.M. antigen content. At day 0, 90 and 180, total IgE and dust mite specific IgE determination was done. At the end of the study, patient's and doctor's opinion about the spray's efficacy were recorded on a scale from 0-3. The results were in favor of Acardust for asthma, according to patient's opinion (p = 0.001), doctor's opinion (p = 0.04) and individual score cards (p = 0.03), and for nasal secretion (p = 0.01), sneezing and lacrimation (p = 0.02); concurrent medication dropped significantly (p = 0.01) in the Acardust group. No side-effects were reported. We consider Acardust a safe and valuable preventive treatment in H.D.M. allergy. This study was designed to assess the effectiveness of a high-efficiency particulate air (HEPA) filter in alleviating allergic respiratory symptoms. Thirty-two patients were studied who had symptomatic perennial rhinitis and/or asthma during the fall and winter months and had a positive skin test with house dust or house dust--mite extract. An ENVIRACAIRE room air cleaner was placed in the bedroom for 8 weeks. In a random manner, the active filter was used for 4 weeks and a blank filter for 4 weeks. There was an average 70% reduction in the particulate matter greater than or equal to 0.3 micron with the HEPA filter. In a double-blind design, results were assessed by analysis of the patients' symptom/medication scores and subjective evaluation. For the total study, there was no difference in the total symptom/medication scores or individual symptom scores during the placebo and active-filter periods. Analysis of the last 2 weeks of each filter period in which respiratory infection was absent demonstrated definite differences in total and individual symptoms, suggesting active-filter benefit. Patients' subjective responses also suggested benefit from the filter. The overall impression is that the HEPA filter can reduce allergic respiratory symptoms. Environmental control has been put forward as an integral part of the management of house dust mite (HDM) allergy in sensitized patients. To validate this statement allergic disorders involved in HDM allergy--allergic asthma, rhinitis and atopic eczema/dermatitis syndrome (AEDS)--should be taken together and studied in terms of the efficacy of environmental control. Because a generic quality of life questionnaire exceeds the border of disease, this may be used as major outcome parameter.
                To study the effects of bedding encasings in HDM allergic patients with asthma, rhinitis and AEDS.
                A total of 224 adult HDM allergic patients with rhinitis and/or asthma and/or dermatitis were randomly allocated impermeable or nonimpermeable encasings for mattress, pillow and duvet. Short form 36 (SF-36) was filled in at baseline and after 12 months. Results: Lower physical (P = 0.01) and emotional (P < 0.001) sumscores were seen in females. Also, the presence of asthma resulted in lower physical sumscore (P = 0.01). However, no effect was seen of encasings on either sumscore.
                Bedding encasings do not improve quality of life in a mixed population of subjects with combinations with rhinitis, asthma and atopic dermatitis and sensitized to HDMs. 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) The efficacy of an air-cleaning device equipped with a high efficiency particulate air (HEPA) filter (without further avoidance measures) was studied in patients allergic to house dust mite. The effects of the air-cleaner on indoor Dermatophagoides sp. levels, symptom score and bronchial hyperresponsiveness in nine mite-allergic patients were assessed using a cross-over controlled study. No significant effect was demonstrated on indoor Dermatophagoides sp. levels when comparing the period of air-cleaner activity (2 months) with the control period (2 months). The Dermatophagoides sp. levels in the houses studied were lower than the risk level for asthmatic attacks, making it difficult to assess any effect on asthma; however, neither bronchial hyperresponsiveness nor rhinitis symptom score were changed by air-cleaner activity. During the trial period, however the mean level of Dermatophagoides sp. allergen in the houses changed spontaneously from 4.4 micrograms/g (mean level in the first 2 trial months) to 1.75 micrograms/g of dust (second 2 months) (P less than 0.05). Owing to this change, the mean rhinitis symptom score also decreased (P less than 0.05), even if no significant correlation was demonstrated (r = 0.4 P = 0.089). HEPA filter air-cleaners appear insufficient as substitutes for standard avoidance measures in mite allergic patients.
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.