House Dust and Their Effect on the Development and Severity of Asthma
House Dust and Their Effect on the Development and Severity of Asthma
Objectives: We assessed whether any household dust reduction intervention has the effect of increasing or decreasing the development or severity of atopic disease.
Data sources: Electronic searches on household intervention and atopic disease were conducted in January 2007 in EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials. No date or language restriction was placed on the literature search.
Data extraction: We included randomized controlled trials comparing asthma outcomes in a household intervention group with either placebo intervention or no intervention.
Data sysnthesis: Fourteen studies met the inclusion criteria. Eight recruited antenatally and measured development of atopic disease. Six recruited known atopic individuals and measured disease status change. Meta-analyses on the prevention studies found that the interventions made no difference to the onset of wheeze but made a significant reduction in physician-diagnosed asthma. Meta-analysis of lung function outcomes indicated no improvement due to the interventions but found a reduction in symptom days. Qualitatively, health care was used less in those receiving interventions. However, in one study that compared intervention, placebo, and control arms, the reduction in heath care use was similar in the placebo and intervention arms.
Conclusions: This review suggests that there is not sufficient evidence to suggest implementing hygiene measures in an attempt to improve outcomes in existing atopic disease, but interventions from birth in those at high risk of atopy are useful in preventing diagnosed asthma but not parental-reported wheeze.
During the 1960s, hospital admission rates in England and Wales for childhood asthma steadily increased. This trend continued into the 1980s and began a steady decline in the 1990s, with no apparent explanation for this trend (van Schayck and Smit 2005). By 2000, annual admissions for asthma in England and Wales were 48 and 16 per 10,000 in children younger than 5 and those 5-14 years, respectively (National Statistics 2007). In 2004, asthma caused 1,266 deaths in England and Wales, 38 of which were children younger than 14 years, accounting for 2.9% of all deaths of 1- to 14-year-olds (National Statistics 2007). In the United States, the prevalence of self-reported asthma reached a peak of 60.5 per 1,000 population in children 0-4 years of age and 82.5 in children 5-14 years of age in 1995 and has since declined (Mannino et al. 2002).
A known risk factor for the development of atopic asthma is exposure and sensitisation to the house dust mite Dermatophagoides pteronyssinus. A meta-analysis of measures to reduce house dust mite exposure concluded there was no evidence to suggest implementing avoidance measures (Gøtzsche et al. 1998). However, the review did not include any prospective studies examining potential avoidance of atopic disease development. If the etiology of asthma and the role of household interventions in mitigating the disease can be more fully understood, there is an increased likelihood that asthma can be treated more appropriately and perhaps prevented.
Our primary objective was to assess whether any household intervention aimed at ameliorating exposure to house dust mite could reduce the incidence of asthma in high-risk children or reduce the severity of asthma in individuals already diagnosed with the disease.
Objectives: We assessed whether any household dust reduction intervention has the effect of increasing or decreasing the development or severity of atopic disease.
Data sources: Electronic searches on household intervention and atopic disease were conducted in January 2007 in EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials. No date or language restriction was placed on the literature search.
Data extraction: We included randomized controlled trials comparing asthma outcomes in a household intervention group with either placebo intervention or no intervention.
Data sysnthesis: Fourteen studies met the inclusion criteria. Eight recruited antenatally and measured development of atopic disease. Six recruited known atopic individuals and measured disease status change. Meta-analyses on the prevention studies found that the interventions made no difference to the onset of wheeze but made a significant reduction in physician-diagnosed asthma. Meta-analysis of lung function outcomes indicated no improvement due to the interventions but found a reduction in symptom days. Qualitatively, health care was used less in those receiving interventions. However, in one study that compared intervention, placebo, and control arms, the reduction in heath care use was similar in the placebo and intervention arms.
Conclusions: This review suggests that there is not sufficient evidence to suggest implementing hygiene measures in an attempt to improve outcomes in existing atopic disease, but interventions from birth in those at high risk of atopy are useful in preventing diagnosed asthma but not parental-reported wheeze.
During the 1960s, hospital admission rates in England and Wales for childhood asthma steadily increased. This trend continued into the 1980s and began a steady decline in the 1990s, with no apparent explanation for this trend (van Schayck and Smit 2005). By 2000, annual admissions for asthma in England and Wales were 48 and 16 per 10,000 in children younger than 5 and those 5-14 years, respectively (National Statistics 2007). In 2004, asthma caused 1,266 deaths in England and Wales, 38 of which were children younger than 14 years, accounting for 2.9% of all deaths of 1- to 14-year-olds (National Statistics 2007). In the United States, the prevalence of self-reported asthma reached a peak of 60.5 per 1,000 population in children 0-4 years of age and 82.5 in children 5-14 years of age in 1995 and has since declined (Mannino et al. 2002).
A known risk factor for the development of atopic asthma is exposure and sensitisation to the house dust mite Dermatophagoides pteronyssinus. A meta-analysis of measures to reduce house dust mite exposure concluded there was no evidence to suggest implementing avoidance measures (Gøtzsche et al. 1998). However, the review did not include any prospective studies examining potential avoidance of atopic disease development. If the etiology of asthma and the role of household interventions in mitigating the disease can be more fully understood, there is an increased likelihood that asthma can be treated more appropriately and perhaps prevented.
Our primary objective was to assess whether any household intervention aimed at ameliorating exposure to house dust mite could reduce the incidence of asthma in high-risk children or reduce the severity of asthma in individuals already diagnosed with the disease.