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At least 19 recordsLinked to original sources

PubMed2000

House dust mite control measures for asthma.

BACKGROUND: The major allergen in house dust comes from mites. Chemical, physical and combined methods of reducing mite allergen levels are intended to reduce asthma symptoms in people who are sensitive to house dust mites. OBJECTIVES: The objective of this review was to assess the effects of reducing exposure to house dust mite antigens in the homes of mite-sensitive asthmatics. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register, checked reference lists of articles and hand-searched Respiration (1980 to 1996) and Clinical and Experimental Allergy (1980 to 1996). SELECTION CRITERIA: Randomised trials of mite control measures in asthmatic people known to be sensitive to house dust mites. DATA COLLECTION AND ANALYSIS: Two reviewers applied the trial inclusion criteria and extracted the data independently. One reviewer applied the trial quality assessment criteria. Study authors were contacted to clarify information. MAIN RESULTS: Twenty-three trials were included, with four trials awaiting assessment. There was little difference in improvement of asthma between people in experimental groups compared to control groups (odds ratio 1.2, 95% confidence interval 0.66 to 2.18). Asthma symptom scores were also similar for the experimental and control groups (standardised mean difference -0. 06, 95% confidence interval -0.54 to 0.41). These scores showed a high degree of heterogeneity. No significant difference was noted for medication usage (standardised mean difference -0.14, 95% confidence interval -0.43 to 0.15). Peak flow in the morning showed no significant difference between the experimental and the control groups (standardised mean difference -0.03, 95% confidence interval -0.25 to 0.19). REVIEWER'S CONCLUSIONS: Current chemical and physical methods aimed at reducing exposure to house dust mite allergens seem to be ineffective and cannot be recommended as prophylaxis for mite sensitive asthmatics.

Allergens↗

PubMed1999

Spider mite allergy in apple-cultivating farmers: European red mite (Panonychus ulmi) and two-spotted spider mite (Tetranychus urticae) may be important allergens in the development of work-related asthma and rhinitis symptoms.

BACKGROUND: Recent investigations have suggested that the citrus red mite (Panonychus citri) is the most important allergen affecting citrus-cultivating farmers with asthma, allergic rhinitis, or both. OBJECTIVE: We sought to evaluate type I hypersensitivity to spider mites, particularly the European red mite (Panonychus ulmi) and the two-spotted spider mite (Tetranychus urticae), and to determine the relationship between hypersensitivity to spider mites and respiratory dysfunction. METHODS: We performed a cross-sectional survey. Questionnaires were given, and skin prick tests for 11 inhalant allergens common in Korea and 2 species of spider mites (European red mite and two-spotted spider mite) were performed in 725 apple-cultivating farmers in Korea. RESULTS: Results of skin prick tests in the apple farmers indicated that European red mite (23.2%) was the most common sensitizing allergen, followed by Tyrophagus putrescentiae (21.2%), two-spotted spider mite (16.6%), Dermatophagoides farinae (16.3%), D pteronyssinus (14.4%), cockroach (13.1%), and Hop Japanese (Humulus Japonicus) pollen (12.0%). Positive skin responses (mean wheal size >/=3 mm) to one or more of 13 inhalant allergens were found in 48.2% of farmers tested, whereas 40 subjects (8.6%) had an isolated skin response to the spider mites. Among 119 farmers with work-related asthmatic symptoms, the positive skin response rates to European red mite and two-spotted spider mite were 40.4% and 27.0%, respectively. These figures were significantly higher than those found among farmers without work-related symptoms (19.1% and 14.1%, respectively; P <.01). The prevalence of work-related asthma symptoms was higher in farmers with positive skin responses to spider mites than in those with negative skin responses to spider mites and those with positive skin responses to any allergen tested (31.4% vs 15.0% vs 21.0%, respectively; P <.05). CONCLUSION: Spider mites, particularly European red mite and 2-spotted spider mite, are common sensitizing allergens in apple-cultivating farmers. These spider mites may be important causative allergens in the development of work-related respiratory symptoms in these workers.

Administration, Inhalation↗

PubMed1992

[Control of house dust mites and mite allergens by special mite-preventive futon].

We studied the effect of a recently-developed special mite-preventive futon (bedding) on mite population and mite allergen contents (Der I and Der II) in asthmatic children and their families (23 sets) for 2 years. 1. The number of mites (vacuumed samples) in the 124 sets of futon for 2 years was 6.4 (SD +/- 8.8) in average in the mite-preventive futon which was significantly smaller than the number (about 1/10) in the control futon: 70.0 (SD +/- 99) (p less than 0.001). 2. Follow-up studies were made on the mite population about 2 years (3, 6, 9 12 and 27 months afterwards). The numbers of mites in all the mite-preventive futon was always 1/10 or less than that of in the control futon (p less than 0.01). 3. The mite allergens (Der I and Der II) were measured in the cotton stuffing of the futon used for 2 years. The mite allergen counts in the mite-preventive futon averaged about 1/24 of those in the control futon. 4. Airborne mite allergens (Der I and Der II) obtained by beating the futon were measured. The ratio of the mite allergen count in the mite-preventive futon to the control futon was found to be 1:22-264. These results indicate that the special mite-preventive futon always inhibit mite infestation at least 1/10 of that in the ordinary (control) futon and that the count of mite allergens in the cotton stuffing and in the airborne particles was even lower in the mite-preventive futon.

Adult↗

PubMedDate not supplied

House dust mite allergy in Florida. Mite survey in households of mite-sensitive individuals in Tampa, Florida.

This study evaluated the prevalence of positive house dust mite skin tests in a population of atopic individuals and identified the mite species present in mattress and house dust samples in homes of the Tampa Bay area. Four hundred consecutive individuals were evaluated for respiratory complaints and skin tested with standardized extracts of Dermatophagoides pteronyssinus (Dp) and Dermatophagoides farinae (Df). Two hundred forty individuals (60%) had a positive skin test to the mite extracts. Dust samples were collected in 40 homes of mite-allergic individuals and analyzed by light microscopy. Mite species were found in 53 of the 60 dust samples (20 mattresses and 40 carpets). Mite numbers ranged from 110-6200 mites/g of mattress dust and from 120-5500 mites/g of carpet dust. Eleven different mite species were identified and Blomia tropicalis (Bt), not previously identified in the United States, was found in 30% of the samples. Dp and Df wee the predominant species. These observations suggest that house dust mite allergy is common in the Tampa Bay area and that the house dust mite fauna comprises several mite species besides Dp and Df. Prospective studies in progress are designed to confirm the role of different mite species in house dust mite allergy.

Air Pollutants↗

PubMed2003

Providing dust mite-proof covers improves adherence to dust mite control measures in children with mite allergy and asthma.

INTRODUCTION: The most critical dust mite avoidance technique for asthmatic children with mite allergy is the use of dust mite-proof bedding covers. Adherence to allergen control measures is poor due to cost. The purpose of this study was to determine whether giving families mite-proof bedding encasings at the time of the diagnosis with mite allergy would improve adherence at a home visit 2 months later. METHODS: Parents of children (mean age 7.7 years) with asthma and positive skin tests for dust mite were assigned either to an intervention group, which received dust mite covers upon enrollment or a comparison group, which did not. Both groups were instructed in dust mite control measures by a medical provider and told to invest in the covers as part of standard care. Two months after enrollment, parent report and observational measures from each family were obtained during a home visit. RESULTS: The group provided allergen encasings was found to be significantly more likely to have used the casings at the home visit, t(22) = 2.77, P < 0.05. There were no differences between groups in adherence to other mite control strategies. Parenting stress was significantly related to poorer mite control compliance. The most common reason reported for nonadherence to control measures was cost. CONCLUSIONS: Providing mite bedding encasings at the time of diagnosis significantly increases compliance at a 2-month home visit. Medicaid and insurance companies should be encouraged to pay for casings as a cost effective measure to improve asthma care in children with mite allergy.

Adolescent↗

PubMed1990

Mite allergy and exposure to storage mites and house dust mites in farmers.

Sensitization to house dust mites, storage mites and other common inhalation allergens was studied in 144 farmers using SPT and RAST. The study population was selected from a random sample of 808 farmers and consisted of 47 persons who had declared themselves to suffer from asthma, 63 persons who had reported respiratory symptoms, and 34 healthy persons without respiratory symptoms. The most prevalent RAST was towards storage mites and was found in 17% of farmers who suffered from asthma and was estimated to occur in 5% of the random sample of farmers. A positive RAST to house dust mites was found in 17% of farmers who reported to suffer from asthma. Sensitization to pollens, animal dander and grain species was rare. A positive RAST to moulds was not found. There was a strong association between a positive RAST to house dust mites and a positive RAST to storage mites (odds ratio 21.0). A positive RAST to storage mites was significantly associated with living in a dwelling in the past which was recalled as damp (odds ratio 4.9). A high number of house dust mites was found in nearly all dwellings (median count 148 mites/0.1 g dust) and a high number of storage mites was found in some dwellings. This study suggests that in humid and temperate regions of Europe, allergy to storage mites in farmers is not caused exclusively by occupational exposure but damp housing conditions and indoor exposure to storage mites may also be important.

Agriculture↗

PubMed1995

High-molecular-size mite allergens with high carbohydrate content in mite extract containing mite feces of Dermatophagoides farinae.

A series of mite allergens with high carbohydrate content was fractionated from mite extract containing mite feces by ultrafiltration, and successive chromatography on Ultrogel AcA 54, Sepharose CL-6B, and DEAE Toyopearl 650S. The final fractions isolated were termed HM1-2-Eff, -0.1A, -0.1B, -0.3A, -0.3B, and -1M according to the eluted salt concentration. These six fractions were stained weakly with Coomassie Brilliant Blue but strongly with periodate-Schiff's reagent on SDS-PAGE. Their molecular weight were estimated to be 150-155 KD on Sepharose CL-6B. All of these six fractions provoked strong erythema in skin of mite-sensitive and asthmatic patients. HM1-2-Eff, -0.1A, -0.1B and -0.3B reacted with 73% of mite-sensitive patients' IgE by the nitrocellulose dot blotting. One ng/ml of 4 fractions (HM1-2-0.1A, 0.3A, 0.3B and -1M) released histamine from mite allergic patient's blood cells. HM1-2-0.3A induced proliferation of T cell from immunized mouse by mite extract containing mite feces (Dff).

Allergens↗

PubMed1998

[Sensitization to storage mites--studies of the incidence of sensitivity to storage mites in comparison with house dust mites. Experiences in allergologic ambulatory care].

We examined the prevalence of sensitisation to storage mites and house dust mites in patients attending a pneumologist and allergologist in the office and clinical outpatient department. Our findings show sensitisations to storage mites up to 12%, to house dust mites in 26%. From a total of 3213 patients 914 patients (= 28%) showed positive skin reactions against at least one storage mite. There is a relationship of about 2:1 between house dust mites and storage mites in skin test results. From these data, safe conclusions as to the prevalence of storage mite sensitisation among the general population may not be drawn.

Ambulatory Care↗

PubMed2000

Mechanical ventilation and high-efficiency vacuum cleaning: A combined strategy of mite and mite allergen reduction in the control of mite-sensitive asthma.

BACKGROUND: The relationship between exposure to house dust mite (HDM) allergens and prevalence of sensitization to these allergens in patients with asthma has been confirmed in many studies. Mite population growth is regulated by humidity. Reducing humidity and removing allergen by efficient vacuuming should control mite allergen and reduce symptoms. OBJECTIVE: We sought to investigate the effect of mechanical ventilation and high-efficiency vacuuming on HDM numbers and Der p 1 concentrations in the homes of mite-sensitive asthmatic subjects and to evaluate the effect of any reductions on symptoms. METHODS: The homes of 40 HDM-sensitive asthmatic subjects were randomized to receive (1) mechanical ventilation and a high-efficiency vacuum cleaner (HEVC); (2) mechanical ventilation alone; (3) an HEVC alone; and (4) no intervention. Homes and patients were monitored for 12 months. Change in absolute humidity, mite numbers, Der p 1 concentrations, lung function, bronchial hyperresponsiveness, and symptom scores were analyzed. RESULTS: Homes with mechanical ventilation achieved significantly lower humidity levels than those without (P <.001), with an associated reduction of mite numbers (P <.05) and Der p 1 concentrations (P <.001 ¿in nanograms per gram, P =.006 ¿in milligrams per square meter) in bedroom carpets and some other mite sources in the ventilated areas of the homes. The addition of a vacuum cleaner enhanced this effect. There was a trend for an improvement in histamine PC(20) (P =.085) in the patients whose homes were ventilated. CONCLUSION: The use of a mechanical ventilation system in suitable homes resulted in some reduction in numbers of HDM and Der p 1 concentrations. The addition of an HEVC slightly enhanced the effect but not sufficiently to see an improvement in symptoms.

Adolescent↗

PubMed1986

Cross-reactivity between the house dust mite Dermatophagoides pteronyssinus and the mange mites Psoroptes cuniculi and P. ovis. I. Demonstration of antibodies to the house dust mite allergen Dpt 12 in sera from P. cuniculi-infested rabbits.

The cross-reactivity of the mange mites Psoroptes cuniculi (PC) and Psoroptes ovis (PO) antigens with the house dust mite Dermatophagoides pteronyssinus (DP) antigens has been studied. Cross-reactivity between mange mite and house dust mite antigens was demonstrated by both ELISA and immunoelectrophoresis by use of a sheep anti-DP antiserum. Both PC and PO were demonstrated to contain eight cross-reacting antigens. Sera from rabbits infested with PC were demonstrated to produce antibodies to the homologous immunogen, to PO antigens, and to DP antigens. Of the seven sera from infested rabbits tested, four were demonstrated to produce a strong antibody response to a major DP antigen Dpt 12, and two were demonstrated to produce a weak response that was judged empirically by double-diffusion analysis. Two sera were judged to react with the DP lipoprotein, Dpt 4. Sera from control rabbits did not demonstrate reactivity with any extract tested. Despite the detection of anti-Dpt 12 antibodies, however, an antigen corresponding to Dpt 12 was not detected in either PC or PO extracts. The findings that mange mite-infested rabbits produce antibodies that recognize DP antigens probably explain previous observations in which it was demonstrated that commercially obtained rabbit anti-immunoglobulin antisera contain anti-DP antibodies, a finding that suggests caution in the use of such reagents in studies designed to measure antibody responses to DP allergens.

Animals↗

PubMed2002

Which predatory mite can control both a dominant mite pest, Tetranychus urticae, and a latent mite pest, Eotetranychus asiaticus, on strawberry?

After biological control of Tetranychus urticae using Phytoseiulus persimilis, a latent mite pest, Eotetranychus asiaticus, was found on strawberries growing in a plastic greenhouse in western Japan. To determine whether the release of P. persimilis, an exotic natural enemy of T. urticae, enhanced the occurrence of the latent pest, the efficiency of P. persimilis in controlling E. asiaticus was compared with the efficiency of two indigenous phytoseiid mites, Amblyseius californicus and A. womersleyi, under laboratory conditions. Phytoseiulus persimilis and A. californicus attacked not only T. urticae but also E. asiaticus. However, the predators produced very few eggs and their offspring rarely reached adulthood when fed on E. asiaticius, so their potential as control agents for the latent mite appears to be low. In contrast, A. womersleyi feeding on E. asiaticus reproduced as well as when fed on T. urticae, and exterminated both species of spider mite. This suggests that A. womersleyi has greater potential as a biological control agent in crops where both species may occur.

Animals↗

PubMed1998

House-dust mites and asthma. A review on house-dust mites as a domestic risk factor for mite asthma.

Increased exposure to house-dust mites entails a greatly increased frequency of sensitization and increased frequency of mite asthma in the population. The available case-control studies demonstrate large variations worldwide in sensitization and disease risk dependent on the actual level of population exposure. In areas with comparatively low population exposure to house-dust mites, there is a strong association between exposure and effect, while other areas with a more or less uniformly high population exposure do not demonstrate significant differences between patients and controls because the unexposed groups are too small. As to the existence of a hygienic maximum threshold exposure level, current data all point to a single value of 100 mites/g of dust, corresponding to 2 microg allergen/g of dust. This applies to the risk of sensitization and risk of disease, and when programs of prevention imply exposure below this value, convincing clinical improvement is always observed. Today, the magnitude of the health problem related to population exposure to house-dust mites in many areas is comparable to the effects of active tobacco smoking and traffic accidents.

Animals↗

PubMed1988

Investigations of patients allergic to the house dust mite Dermatophagoides pteronyssinus by crossed radioimmunoelectrophoresis using purified mite bodies and whole mite culture extracts.

Sera of 20 patients allergic to the house dust mite Dermatophagoides pteronyssinus were investigated by crossed radioimmunoelectrophoresis (CRIE) using extracts prepared from purified mite bodies (PMB) and whole mite culture (WMC). By CRIE, different allergen patterns and different numbers of allergens were detected in the two extracts. By summarizing the values of the CRIE patterns of the 20 patients' sera into allergograms, 6 out of 16 allergens in PMB and 5 out of 10 allergens in WMC extracts could be identified as major allergens. These diverging results, together with the published literature, emphasize the necessity to reevaluate the International Standard for D. pteronyssinus.

Allergens↗

PubMedDate not supplied

[Comparison, using RAST-inhibition, of the allergenic potency of Dermatophagoides pteronyssinus extracts obtained from: whole mite culture, fraction of enriched mite culture, fraction of feces enriched culture, purified mite bodies, commercial extracts].

The RAST-inhibition potency has been obtained from five extracts prepared by: whole mite culture, mites-enriched culture, faeces-enriched culture, purified mite bodies, commercial extract. The present study demonstrates that extracts of: a) purified bodies, and b) faeces-enriched culture are both potent preparations in RAST-inhibition.

Allergens↗

PubMedDate not supplied

Identification of immunoglobulin E binding components of the two-spotted spider mite Tetranychus urticae: allergenic relationships with the citrus red mite and house-dust mite.

The two-spotted mite (TSM) is commonly found on fruit trees, herbaceous plants, and greenhouse flowers. However, a recent investigation indicated that the sensitization rate to TSM was as high as that of house-dust mites (HDMs) in nonfarmers as well as in farmers working in orchards in this country. The aim of this study was to identify immunoglobulin E (IgE)-binding components within TSM and to evaluate the allergenic relationship with the citrus red mite (CRM) and HDM. Sera were collected from eight patients who were not farmers and who had asthma with high serum-specific IgE to the TSM and from unexposed controls showing negative responses to the TSM on skin-prick test. Twelve percent sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis were applied. To evaluate allergenic relationships with HDMs and CRMs, two kinds of sera pools were used: one (A) showing positive responses to both TSMs and HDMs and the other (B) showing an isolated positive response to TSMs. ELISA inhibition tests using A and B pooled sera were conducted. The TSM-ELISA inhibition test using sera A showed significant inhibition with addition of TSMs and CRMs, partial inhibition with HDMs, and minimal inhibition with other inhalant allergens. The ELISA inhibition test using sera B showed significant inhibition with TSMs and CRMs and minimal inhibition was noted with HDMs as well as other inhalant allergens. Immunoblot analysis using individual sera showed seven IgE-binding components (75, 56, 47, 41, 37, 28, and 14 kDa) and two (75 and 14 kDa) of them were bound to IgE in > 50% of the sera tested. Seven IgE-binding components were identified within the TSM extract and two (75 and 14 kDa) could be considered major allergens. It is suggested that the TSM contains species-specific allergen in addition to shared allergens with CRMs and HDMs.

Adolescent↗

PubMed1991

Investigation of house dust mite (Dermatophagoides pteronyssinus) allergen extracts prepared from purified mite bodies and whole mite culture.

Allergen extracts prepared from purified mite bodies (PMB) and whole mite culture (WMC) were investigated by using in vivo and in vitro methods. PMB showed a more complex allergen pattern than WMC. In PMB, 6 out of 16 allergens could be detected as major allergens. In WMC, 5 out of 10 allergens could be detected as major allergens. Both extracts contained the same amount of the major allergen Der p I. By skin prick testing comparable results were obtained with both extracts. Investigation of the reproducibility showed that 15 production lots of PMB could be produced in a high conformity according to their allergenic potency and their protein and allergen composition.

Allergens↗

PubMed1999

Biologic activity of Dermatophagoides siboney and Blomia tropicalis allergens in exposed and unexposed mite-allergic individuals. Effect of patient selection on the biologic standardization of mite extracts.

BACKGROUND: This study aimed to investigate the influence of patient selection criteria, i.e., mite-allergic individuals exposed and not exposed to Dermatophagoides siboney and Blomia tropicalis, on the biologic activity of mite extracts. Determination of the potency of mite extracts in vivo requires selection of patients with a clinical history of mite allergy. In Scandinavia, there are some anamnestic criteria for mite allergy, whereas in the tropics, where patients are continuously exposed to high levels of mites, selection of patients with mite allergy by clinical history is difficult. METHODS: A total of 210 Cuban asthmatics with continuous symptoms, and 43 Swedes with a clinical history of mite allergy were investigated. Skin prick tests were performed with D. siboney, D. pteronyssinus, D. farinae, B. tropicalis, Acarus siro, Lepidoglyphus destructor, and Tyrophagus putrescentiae extracts. For analysis of the biologic activity of mite extracts, Cuban patients were divided into four groups: 1) all patients skin-test-positive to mites 2) patients positive to mites, but not to other inhalant allergens 3) patients reacting most to the mite species analyzed 4) patients reactive only to mites and reacting most to the mite species analyzed. The biologic potency was calculated according to the Nordic Guidelines. RESULTS: Due to cross-reactivity between mites, Swedish mite-sensitive patients, with a clear clinical history of mite allergy, but not exposed to D. siboney and B. tropicalis, were more skin reactive to these mites than were Cubans. The estimated potency increased gradually to >200% in group 4. In group 1 Cubans, the reactivity to all mites but B. tropicalis was lower than that in mite-sensitive Swedes. CONCLUSIONS: According to the influence of patient selection criteria on the estimation of the potency of mite extracts, the determination of the biologic activity of allergenic extracts in subjects without a clear-cut clinical history should be replaced by new methods when available.

Adolescent↗

PubMed2003

Mite and mite allergen removal during machine washing of laundry.

BACKGROUND: Few studies have investigated live house dust mite and mite allergen removal from clothing and bedding by washing machines. No studies have investigated the transfer of mites from infested to uninfested clothing and bedding during washing. OBJECTIVE: The purpose of this study was to wash different types of clothing and bedding in residential washing machines to determine the live Dermatophagoides farinae mite and allergen removal and the mite transfer from mite-infested items to mite-free items. METHODS: Clothing and bedding items were machine washed in 6- and 8-lb loads in warm (36 degrees C-38 degrees C) or cold (22 degrees C-27 degrees C) water with and without recommended concentrations of laundry detergent and sodium hypochlorite bleach. Live mites and allergen present in washed versus unwashed and washed mite-infested versus washed mite-free items were compared. RESULTS: Washing clothing and bedding in water alone, detergent, or detergent plus bleach removed 60% to 83% of the live mites. Washing removed more mites from some items than from others. When mite-infested items were washed with identical sets of mite-free items, many live mites were transferred to the previously mite-free items. Overall, 84% of Der f 1 was removed from items washed in water alone or in detergent and 98% from items washed in detergent plus bleach. CONCLUSIONS: Washing clothing and bedding in cold or warm water with detergent or detergent plus bleach removed most allergen and a significant (P <.05) portion of live mites. Repeated washing is required to further reduce mite levels. Live mites were transferred from mite-infested to mite-free items during washing.

Air Pollution, Indoor↗