Most published environmental remediation interventions have been directed at single allergens and have employed demanding strategies; few have been performed in the homes of inner-city children disproportionately burdened by asthma. Our objective was a) to describe the allergen sensitivities, environmental tobacco smoke (ETS) exposure, and home environmental characteristics of a national sample of inner-city children with moderate to severe asthma and b) to develop and implement a multifaceted, home-based comprehensive intervention to reduce home allergens and ETS, tailored to the specific sensitization and exposure profiles of those children. Allergen skin testing and a home evaluation were performed to determine the presence of ETS and factors known to be associated with increased indoor allergen levels. Based on published remediation techniques, a home environmental intervention, organized into modules, each addressing one of five specific allergen groups or ETS, was designed. Of 994 allergic children from seven U.S. urban communities, 937 successfully completed baseline interviews and home allergen surveys and were enrolled. More than 50% of children had positive skin tests to three or more allergen groups. Cockroaches were reported in 58% of homes, wall-to-wall carpeting in the child's bedroom in 55%, a smoker in 48%, mice or rats in 40%, and furry pets in 28%. More than 60% of enrolled families received four or more modules, and between 94% and 98% of all modules were completed. We conclude that most inner-city children with moderate to severe asthma are sensitized to multiple indoor allergens and that environmental factors known to be associated with asthma severity are commonly present in their homes. The intervention developed for the Inner-City Asthma Study employs accepted methods to address an array of allergens and ETS exposure while ensuring that the intervention is tailored to the specific sensitization profiles and home characteristics of these children.

Home and allergic characteristics of children with asthma in seven U.S. urban communities and design of an environmental intervention: the Inner-City Asthma Study.

In recent years the role of allergen exposure and atopy, and the interaction between them in the clinical expression of allergic disease, has been examined in a quantitative manner in epidemiologic studies. Such analyses suggest that avoidance of exposure to domestic allergens is a critical element in integrated strategies for both the prevention and the management of asthma. The promise of primary intervention in high-risk infants, as shown in the Isle of White study, has been confirmed in a recent study in Japan, and at least 4 similar trials are in progress. Applying these principles to the management of symptoms in patients with chronic asthma has proved more difficult, and it is likely that many earlier studies were poorly designed to test the hypothesis that allergen avoidance was clinically useful. Recent studies with patients moved to high altitudes during seasonal reductions in mite exposure and randomized controlled interventions in houses have all shown improvements in clinical manifestations of asthma. These recent trials have also demonstrated something that was less certain-that massive reductions in domestic allergen exposure can be achieved and that people will adopt the significant changes to their domestic environment and lifestyles if the risks and benefits are known. In the future, it seems likely that better study designs, as well as improvements in methods to monitor exposure and clinical outcomes, will provide further support for the role of allergen avoidance in the prevention and management of asthma.

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Methods and effectiveness of environmental control.

Avoidance of exposure to indoor allergens is an important element in the treatment of allergic disease. The results of several studies provide strong evidence in support of a role for allergen avoidance; however, strategies that optimize allergen reduction in houses have not been determined. Complex issues regarding the efficacy of physical and chemical measures that target house dust mite, pet, and cockroach allergens in the home are discussed. The greatest challenge is to educate allergic patients so that they can play an important role in controlling their own disease.

The role of intervention in established allergy: Avoidance of indoor allergens in the treatment of chronic allergic disease

Iconographies supplémentaires de l'article : The role of intervention in established allergy: Avoidance of indoor allergens in the treatment of chronic allergic disease

Background: High-quality vacuum cleaners and vacuum cleaner bags are often recommended to allergic patients as a means of reducing indoor allergen exposure. A number of vacuum cleaners on the market today claim to capture 99.9% of particles 0.3 μm or larger entering the vacuum cleaner, and many vacuum cleaner bags are now being sold as microfiltration bags. Objective: The purpose of this study was to compare the allergen-trapping abilities of vacuum cleaners and to use a new technique for testing vacuum cleaner bags that are recommended for allergic patients. Methods: Vacuum cleaners were tested in an 18-m 3 laboratory room permeated with dust containing high levels of cat allergen by using techniques previously described. Air was sampled with parallel filters in conjunction with a particle counter. The filters were assayed by ELISA for cat allergen (Fel d 1). Vacuum cleaner bags were tested by using a modified dust trap to pull sieved house dust containing a known amount of Fel d 1 across the material used for the bag. Allergen passing through the bag was trapped on a filter covering the exit of the trap and analyzed for Fel d 1. Results: In general, vacuum cleaners designed for allergic patients leaked lower amounts of allergen ( 3 ) than that found in our previous studies ( 3 ). Single-layer vacuum cleaner bags performed poorly (1250-2640 ng recovered) compared with most of the 2- and 3-layer microfiltration bags (0.53-2450 ng recovered). The range of allergen recovered from the 2-layer bags (0.93-2450 ng recovered) highlighted the variability found between manufacturers. Conclusion: The results suggest that although allergen leakage has been reduced, there is still room for improvement. A method of testing allergen leakage by using Fel d 1 should be applied to vacuum cleaners and bags recommended for allergic patients. (J Allergy Clin Immunol 1999;104:1079-83.)

Assessment of vacuum cleaners and vacuum cleaner bags recommended for allergic subjects

The faeces of the dust mite are the most significant source of allergy for those allergic to the dust mite. During vacuum cleaning, faecal particles are emitted from the cleaner and into the air to form pathological concentrations. The aim of the study was to discover if these extreme concentrations could be prevented by the use of appropriate filters. As the allergen source, dust mite faeces were used. A Miele vacuum cleaner type S424i was used without filter, with S-Class filter, and with Super Air Clean Filter. In the first test 1 g, and in the second test 2 g of dust mite faecal particles were evenly spread and then vacumed up. While using each filter in turn, the expelled air was measured for faecal concentrations. The analysis was performed by counting the number of faecal particles, and determining the content of major allergen Der p I in the expelled air. Without a filter there was a massive concentration of faecal particles in the expelled air. The simple filter Type (S-class-filter) achieved a significant reduction on the emission of allergens. The more complex special filter (Super air clean filter), was able to remove all traces of allergens from the expelled air.

F Horak

Papers

Clinical study of the effectiveness of filters in vacuum cleaners for reducing the concentration of dust mites in the household