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Boyle RJ, Pedroletti C, Wickman M, Bjermer L, Valovirta E, Dahl R, Von Berg A, Zetterström O, Warner JO. Nocturnal temperature controlled laminar airflow for treating atopic asthma: a randomised controlled trial. Thorax 2011; 67:215-21. [PMID: 22131290 PMCID: PMC3282042 DOI: 10.1136/thoraxjnl-2011-200665] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To determine whether environmental control using nocturnal temperature controlled laminar airflow (TLA) treatment could improve the quality of life of patients with persistent atopic asthma. DESIGN Randomised, double-blind, placebo-controlled, parallel-group trial. Setting Nineteen European asthma clinics. PARTICIPANTS 312 patients aged 7-70 with inadequately controlled persistent atopic asthma. MAIN OUTCOME MEASURE Proportion of patients with an increase of ≥0.5 points in asthma quality of life score after 1 year of treatment. RESULTS TLA devices were successfully installed in the bedrooms of 282 (90%) patients included in the primary efficacy analysis. There was a difference in treatment response rate between active (143 of 189, 76%) and placebo (56 of 92, 61%) groups, difference 14.8% (95% CI 3.1 to 26.5, p=0.02).3 In patients aged ≥12, on whom the study was powered, the difference in response rate was similar-active 106 of 143 (74%), placebo 42 of 70 (60%), difference 14.1% (0.6 to 27.7, p=0.059). There was a difference between groups in fractional exhaled nitric oxide change of -7.1 ppb (-13.6 to -0.7, p=0.03). Active treatment was associated with less increase in cat-specific IgE than placebo. There was no difference in adverse event rates between treatment groups. CONCLUSION Inhalant exposure reduction with TLA improves quality of life, airway inflammation and systemic allergy in patients with persistent atopic asthma. TLA may be a treatment option for patients with inadequately controlled persistent atopic asthma. Trial registration number Clinical Trials NCT00986323.
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Affiliation(s)
- Robert J Boyle
- Department of Paediatrics, Imperial College London, Wr, London W2 1PG, UK
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Abstract
A child with atopy produces IgE antibodies after exposure to common environmental allergens. The atopic diseases (eczema, asthma and rhinoconjunctivitis) are clinical syndromes each defined by a group of symptoms and signs. Not all children with atopy will have atopic disease or develop symptoms after exposure to an allergen. Both genetic and environmental factors determine the development of atopic disease. The presence of specific IgE antibodies to environmental allergens is determined with skin prick or radioallergosorbent testing in children with atopy. Test results should be interpreted in the context of the clinical history and further investigations (eg, allergen avoidance or challenge). Management of atopic disease is frequently symptomatic, but it is important to avoid identified allergen triggers. Immunotherapy may be considered in selected school-age children with severe rhinoconjunctivitis. Preventing atopic disease in high-risk infants and hindering progression of disease in children with established disease are the areas of active research.
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Affiliation(s)
- Michael S Gold
- Department of Paediatrics, Adelaide University, Women's and Children's Hospital, North Adelaide, Adelaide, SA 5000, Australia.
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Peat JK, Mihrshahi S, Ampon R, Tovey ER, Marks GB, Mellis CM. Effect of Allergen Concentrations on Symptoms of Asthma at 18 Months. ACTA ACUST UNITED AC 2004. [DOI: 10.1089/pai.2004.17.237] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Karlsson AS, Renström A, Hedrén M, Larsson K. Allergen avoidance does not alter airborne cat allergen levels in classrooms. Allergy 2004; 59:661-7. [PMID: 15147452 DOI: 10.1111/j.1398-9995.2004.00519.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Some schools in Sweden offer allergen avoidance classrooms for allergic children with severe asthma. However, the measures commonly used to achieve a reduction in allergen levels have not been properly evaluated. The aim of the present prospective study was to study whether the levels of airborne cat allergen are altered after introducing feasible intervention measures in classrooms, without interfering with peoples' freedom of choice regarding pet ownership. METHODS Twenty-five classes, including five established allergy prevention classrooms participated in the study during a school year. After one term, six classes underwent a number of intervention measures recommended by the Swedish National Institute of Public Health. Curtains, upholstery and plants were removed, bookshelves were replaced with cupboards and regular cleaning was increased. Airborne dust was collected weekly (32 weeks) using duplicate Petri dishes (n = 1574) and on six occasions using two personal air samplers in each class (n = 264). RESULTS Airborne cat allergen levels were showing a similar variability throughout the whole study in all classes. Despite extensive measures in order to reduce allergen exposure, cat allergen levels were unaltered in the six classes after intervention. Allergen levels were not significantly lower in the established allergy prevention classes, compared with the other classes. Cat allergen levels differed, however, significantly between classes with few and many cat owners (P < 0.05). CONCLUSIONS We conclude that the recommended allergen avoidance measures used in this study did not reduce airborne cat allergen. It seems plausible that measures that fail to reduce allergen levels also fail to influence health status in allergic children but this remains to be shown.
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Affiliation(s)
- A-S Karlsson
- Lung and Allergy Research, National Institute of Environmental Medicine, Karolinska Institutet, Box 287, S-171 77 Stockholm, Sweden
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Mahakittikun V, Komoltri C, Nochot H, Angus AC, Chew FT. Laboratory assessment of the efficiency of encasing materials against house dust mites and their allergens. Allergy 2003; 58:981-5. [PMID: 14510714 DOI: 10.1034/j.1398-9995.2003.00095.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND The current recommendation to reduce mite allergen exposure for mite-sensitive individuals is to use allergen-impermeable bed coverings. As these covers are made of various kinds of materials, they vary in quality. The objective of this study was to investigate the efficiency of different covering materials against house dust mites and their allergens in vitro. METHODS Four types of materials including (1) plastic cover, (2) polyurethane-coated cover, (3) non-woven covers, (4) tightly woven microfiber covers and a regular cotton bed sheet (as a control) were evaluated using three methods: (i) heat escape method, (ii) Siriraj chamber method and stereomicroscopy, scanning electron microscopy and (iii) enzyme-linked immunosorbent assay (ELISA). RESULTS We found that there was a statistically significant difference in allergen permeability among four types of coverings (P < 0.001). In terms of the impermeability to mites and their allergens, plastic- and polyurethane-coated covers were observed to be the best, followed by non-woven, woven and cotton-based bed sheets. A regular cotton-based bed sheet allows a significant amount of leakage of mite allergens. Both woven and non-woven material are efficient barriers against mite allergen in terms of impermeability. However, with regard to mite colonization, non-woven covers have the drawback of mites being able to penetrate and colonize within the fabric fibers. Woven covers are therefore recommended because of their major advantages of not allowing the colonization of mites within the fabric, being easy to clean, and comfortable. CONCLUSION The three assessment methods used in this study could be useful as a primary approach to evaluate the quality of covering materials in vitro using both pore size and ability to be colonized by mites on the materials as the key factors.
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Affiliation(s)
- V Mahakittikun
- Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
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Tovey ER, Mitakakis TZ, Sercombe JK, Vanlaar CH, Marks GB. Four methods of sampling for dust mite allergen: differences in 'dust'. Allergy 2003; 58:790-4. [PMID: 12859560 DOI: 10.1034/j.1398-9995.2003.00228.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Measurement of exposure to the dust mite allergen Der p 1 is important in asthma research and is potentially useful in managing asthma. As no single measure can capture all characteristics of an exposure, it is important to recognize differences in the available methods of measuring exposure to Der p 1. METHODS Fourteen bedrooms and living rooms were sampled using four methods for 1 week. Airborne allergen was sampled by static Institute of Occupational Medicine samplers. Settling dust was collected on Petri dishes and an adhesive-membrane system (A-book). Vacuumed reservoir dust samples were collected from floors at the end of 1 week. Der p 1 was measured in all samples by enzyme-linked immunosorbent assay, except A-books, in which it was measured by Halogen immunoassay. RESULTS All four methods intercorrelated moderately (r range = 0.40-0.64, P = 0.04), except between allergen in reservoir dust (as microg/m2 and microg/g dust) and settling dust by Petri dishes (P = 0.2). Reservoir allergen, expressed as microg/m2, did not correlate with any measure, except reservoir allergen expressed as microg/g (r = 0.39, P = 0.04). No differences in these associations occurred between bedrooms and living rooms. CONCLUSIONS While the four methods examined correlated moderately, all have practical advantages and difficulties. No method can be considered as ideal for measuring individual exposure. For practicality, use of vacuum cleaner and Petri dish methods are recommended.
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Affiliation(s)
- E R Tovey
- Cooperative Research Centre for Asthma, University of Sydney, Sydney, NSW, Australia
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Terreehorst I, Hak E, Oosting AJ, Tempels-Pavlica Z, de Monchy JGR, Bruijnzeel-Koomen CAFM, Aalberse RC, Gerth van Wijk R. Evaluation of impermeable covers for bedding in patients with allergic rhinitis. N Engl J Med 2003; 349:237-46. [PMID: 12867607 DOI: 10.1056/nejmoa023171] [Citation(s) in RCA: 162] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Encasing bedding in impermeable covers reduces exposure to house-dust mites, but the clinical benefit of this intervention as part of mite-avoidance measures for patients with allergic rhinitis is not known. We performed a multicenter, randomized, placebo-controlled trial of one year of use of impermeable bedding covers in the bedrooms of patients with rhinitis who were sensitized to house-dust mites to determine the effects on the signs and symptoms of disease. METHODS Three participating university medical centers enrolled 279 patients with allergic rhinitis who were randomly assigned to receive impermeable or non-impermeable (control) covers for their mattress, pillow, and duvet or blanket. At the start of the study, all participants received information on general allergen-avoidance measures. The severity of rhinitis was measured on a rhinitis-specific visual-analogue scale and by means of a daily symptom score and nasal allergen provocation testing. We also measured the concentrations of Dermatophagoides pteronyssinus (Der p1) and D. farinae (Der f1) in dust from patients' mattresses, bedroom floors, and living-room floors at base line and after 12 months as a measure of the efficacy of the intervention. RESULTS A total of 232 patients completed the study. There was a significant reduction in Der p1 and Der f1 concentrations in the mattresses of the impermeable-cover group, whereas there was no significant reduction in the control group. However, there was no significant effect on the clinical outcome measures. Analyses of subgroups defined according to age, level of exposure, type and severity of sensitization, or characteristics of the patient's home had similar results. CONCLUSIONS Mite-proof bedding covers, as part of a structured allergy-control program, reduced the level of exposure to mite allergens. Despite the success of the intervention, this single avoidance measure did not lead to a significant improvement of clinical symptoms in patients with allergic rhinitis.
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Affiliation(s)
- Ingrid Terreehorst
- Department of Allergology, Erasmus Medical Center, Rotterdam, Netherlands
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Høst A, Andrae S, Charkin S, Diaz-Vázquez C, Dreborg S, Eigenmann PA, Friedrichs F, Grinsted P, Lack G, Meylan G, Miglioranzi P, Muraro A, Nieto A, Niggemann B, Pascual C, Pouech MG, Rancé F, Rietschel E, Wickman M. Allergy testing in children: why, who, when and how? Allergy 2003; 58:559-69. [PMID: 12823111 DOI: 10.1034/j.1398-9995.2003.00238.x] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Arlian LG, Vyszenski-Moher DL, Morgan MS. Mite and mite allergen removal during machine washing of laundry. J Allergy Clin Immunol 2003; 111:1269-73. [PMID: 12789228 DOI: 10.1067/mai.2003.1547] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
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.
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Affiliation(s)
- Larry G Arlian
- Department of Biological Sciences, Wright State University, Dayton, OH 45435-0001, USA
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Arbes SJ, Cohn RD, Yin M, Muilenberg ML, Burge HA, Friedman W, Zeldin DC. House dust mite allergen in US beds: results from the First National Survey of Lead and Allergens in Housing. J Allergy Clin Immunol 2003; 111:408-14. [PMID: 12589364 DOI: 10.1067/mai.2003.16] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Although exposure to house dust mite allergen is a major risk factor for allergic sensitization and asthma, nationwide estimates of dust mite allergen levels in US homes have not been reported. OBJECTIVE The purpose of this study was to estimate the prevalence of dust mite allergen in beds of US homes and to identify predictors of dust mite allergen concentration. METHODS Data were obtained from the first National Survey of Lead and Allergens in Housing, a cross-sectional survey of 831 permanently occupied noninstitutional housing units that permitted resident children. Dust mite allergen concentration (Der f 1 plus Der p 1) was determined from a dust sample collected from a bed. The percentages of homes with concentrations at or greater than detection, 2.0 microg/g bed dust, and 10.0 microg/g bed dust were estimated. Independent predictors of allergen concentration were assessed with multivariable linear regression. RESULTS The percentages of US homes with dust mite allergen concentrations at or greater than detection, 2.0 microg/g, and 10.0 microg/g were 84.2% (SE, 1.73), 46.2% (SE, 2.0), and 24.2% (SE, 2.1), respectively. Independent predictors of higher levels were older homes, non-West census regions, single-family homes, no resident children, lower household income, heating sources other than forced air, musty or mildew odor, and higher bedroom humidity. CONCLUSION Most US homes have detectable levels of dust mite allergen in a bed. Levels previously associated with allergic sensitization and asthma are common in US bedrooms. Predictors can be used to identify conditions under which homes are more likely to have increased dust mite allergen levels.
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Affiliation(s)
- Samuel J Arbes
- Division of Intramural Research, National Institute of Environmental Health Sciences/NIH, 111 Alexander Drive, Research Triangle Park, NC 27709, USA
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Halken S, Høst A, Niklassen U, Hansen LG, Nielsen F, Pedersen S, Osterballe O, Veggerby C, Poulsen LK. Effect of mattress and pillow encasings on children with asthma and house dust mite allergy. J Allergy Clin Immunol 2003; 111:169-76. [PMID: 12532114 DOI: 10.1067/mai.2003.5] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND House dust mite (HDM) allergy is a frequent cause of allergic asthma in children. Reduction of exposure seems to be the most logical way to treat these patients. OBJECTIVE Our aim was to investigate whether mattress and pillow encasings resulted in an effective long-term control of HDM allergen levels, thereby reducing the need for asthma medication in children with asthma and HDM allergy. METHODS In a prospective, double-blind, placebo-controlled study 60 children (age range, 6-15 years) with asthma and HDM allergy were randomized to active (allergy control) or placebo mattress and pillow encasings. After a 2-week baseline period, follow-up was performed every 3 months for 1 year. During the entire study period, the dose of inhaled steroids was tapered off to the lowest effective dose according to well-defined criteria. RESULTS Fifty-two patients completed the trial, and 5 were excluded, leaving data from 47 children (26 in the active treatment group and 21 in the placebo group) for analysis. A significant perennial reduction in HDM allergen concentrations was seen only for the active treatment group. Also, a significant decrease in the dose of inhaled steroids (mean, 408 to 227 microg/d; P <.001) was found for the active treatment group only, with significant differences between groups after 9 and 12 months. After 1 year, the dose of inhaled steroids was reduced by at least 50% in significantly more children in the active treatment group than in the placebo group (73% vs 24%, P <.01). CONCLUSION Encasing of mattresses and pillows resulted in a significant long-term reduction in HDM allergen concentrations in mattresses and in the need for inhaled steroids in children with asthma and HDM allergy.
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Affiliation(s)
- Susanne Halken
- Department of Pediatrics, Sønderborg Hospital, Sønderborg, Denmark
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Abstract
Environmental allergen control is one of the four primary goals of good asthma management. The American Academy of Allergy, Asthma, and Immunology has published a position statement [78] that endorses the National Asthma Education and Prevention Program management guidelines [23] and recommends that every patient with persistent asthma be evaluated for environmental allergen sensitivity. Patients who have sensitivities should receive practical advice on allergen avoidance. An accumulating body of knowledge indicates that such measures, when strictly applied for a sufficient period of time, can indeed reduce asthma symptoms, need for medication, and airway hyperresponsiveness. Ongoing prospective trials in large numbers of patients are being conducted and should enhance the ability to make proper recommendations to patients.
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Affiliation(s)
- Robert K Bush
- Department of Allergy, William S. Middleton Memorial Veterans Hospital, 2500 Overlook Terrace, Madison, WI 53705, USA.
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Høst A, Halken S. Can we apply clinical studies to real life? Evidence-based recommendations from studies on development of allergic diseases and allergy prevention. Allergy 2002; 57:389-97. [PMID: 11972477 DOI: 10.1034/j.1398-9995.2002.00154.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Arne Høst
- Department of Pediatrics, Odense University Hospital, DK-5000 Odense C, Denmark
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Affiliation(s)
- K P Jones
- School of Applied Sciences, University of Wales Institute Cardiff, Western Avenue, Cardiff CF5 2YB, United Kingdom.
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Affiliation(s)
- O Michel
- Clinic of Allergology and Respiratory Diseases, Saint-Pierre University Hospital (ULB, Free University of Brussels), Belgium.
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Affiliation(s)
- E Tovey
- Institute of Respiratory Medicine, Department of Medicine D06, University of Sydney, NSW, Australia.
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Tovey ER, Taylor DJ, Mitakakis TZ, De Lucca SD. Effectiveness of laundry washing agents and conditions in the removal of cat and dust mite allergen from bedding dust. J Allergy Clin Immunol 2001; 108:369-74. [PMID: 11544455 DOI: 10.1067/mai.2001.117799] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND There is limited information about the removal of allergens by laundry washing. OBJECTIVE The purpose of this investigation was to determine the dynamics of the removal of mite allergen (Der p 1) and cat allergen (Fel d 1) from bed dust during simulated laundry processes. METHODS Three studies were performed. The first compared combinations of 4 laundry agents (water alone, soap, detergent with enzymes, and detergent without enzymes), 4 temperatures (15 degrees, 25 degrees, 45 degrees, and 60 degrees C), and 3 extraction times (5, 20, and 60 minutes). The second study examined allergen extraction by 11 common brands of detergents at 25 degrees and 45 degrees C for 5 minutes. The third study compared 4 detergents containing enzymes before and after the denaturation of their enzymes. To measure the quantity of allergens extracted, each study used an ELISA assay as well as a more sensitive but semiquantitative Halogen immunoassay to detect any allergens remaining after the simulated laundry extraction. RESULTS Study 1 showed that detergents extracted more of both Fel d 1 and Der p 1 than either soap or water alone and that almost all allergens were extracted within 5 minutes at 25 degrees. However, washing at 60 degrees C extracted slightly more Fel d 1 and denatured Der p 1, resulting in lower residual amounts of both allergens. Study 2 showed that all of the commercial detergents performed similarly. Study 3 showed that the presence of enzymes in detergent formulations did not produce a significant effect on the extraction of allergens. CONCLUSION Using detergent solutions at 25 degrees for at least 5 minutes was sufficient to extract most mite and cat allergen from dust of bedding.
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Affiliation(s)
- E R Tovey
- Institute of Respiratory Medicine, Royal Prince Alfred Hospital, Australia
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