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Time for Allergists to Consider the Role of Mouse Allergy in Non-Inner City Children with Asthma
Abstract
Mouse allergen is endemic in the inner cities of the United States, with research predominantly in the Northeastern United States. A recent practice parameter notes the effect of mouse exposure in asthma in inner cities. However, studies are emerging that find a role of mouse allergen in non–inner cities as well. Mouse sensitization is associated with mouse allergen exposure and has been linked with adverse asthma outcomes including increased asthma symptoms, poorer lung function, and increased risk of exacerbations. There are commercially available extracts for testing for mouse sensitization although they are not standardized. Pest management studies have had varying results, but with decreased allergen exposure, there is a trend toward improved asthma outcomes. Physicians should be aware of the potential for rodent exposure and sensitization and consider screening for mouse allergy in asthmatic children, especially if they are located in the inner city, have poorly controlled asthma, or have a history of mouse infestation in their location. Evidence is emerging that this allergen should be considered in non–inner-city asthmatics as well. Finally, advocacy efforts are necessary to ensure that removal of this allergen is accomplished, when possible, in the environments of asthmatic children sensitized to mouse.
... 55−587 The major rat allergen is Rat n 1. 58 Mouse allergen has been found primarily in inner-city homes and schools, although it is found in other demographics as well. 59 While the concentration of mouse allergen varies as much as 1000-fold between inner-city and non-inner-city environments, 60 Mus m 1 was found in 82% of homes in a cross-sectional survey of the United Stated (US) population. 50 A study of predominantly high-income allergic children in Boston found mouse allergen in 42% of their homes. ...
... 63 The majority of the literature regarding the role of rodent allergy in asthma derives from the US, where rodent sensitization has been associated with adverse clinical outcomes in children with asthma including poorer lung function and an increased risk of asthma exacerbations. 58,59 A prospective study of 144 children with asthma noted a significant association between mouse sensitization and acute asthma care visits (prevalence ratio [PR] 1.33; 95% CI: 1.07-1.65), higher FE NO levels (P<0.01), and increased bronchodilator reversibility (PR 1.54; 95% CI: 1.09-2.19), ...
... 82 Mouse and cockroach exposure in inner-city homes has been described as endemic. 59 Studies have found cockroach and mouse allergen to be present in up to 85-95% of inner-city homes within the US 23,83 and up to 81% of school classrooms. 84 In a study of 150 urban-dwelling children with asthma, every tenfold increase in bed mouse allergen https://doi.org/10.2147/JAA.S276994 ...
Children exposed to various indoor and outdoor allergens are placed at an increased risk of developing asthma in later life, with sensitization in these individuals being a strong predictor of disease morbidity. In addition, aeroallergen exposure influences asthma outcomes through an interplay with adverse determinants of health. The goal of this review is to provide an introductory overview of factors related to aeroallergen exposure in type 2-high childhood asthma. These include the relevance of exposure in asthma exacerbations and severity, and the evidence-base for avoidance and treatment for sensitization to these allergens. This review will focus on both indoor aeroallergens (house dust mite, pet, cockroach, mold, and rodent) and outdoor aeroallergens (pollens and molds). Treatment of aeroallergen sensitization in children with asthma includes avoidance and removal measures, although there is limited evidence of clinical benefit especially with single-strategy approaches. We will also address the interplay of aeroallergens and climate change, adverse social determinants, and the current COVID-19 pandemic, when we have seen a dramatic reduction in asthma exacerbations and emergency department visits among children. While there are many factors that are hypothesized to contribute to this reduction, among them is a reduced exposure to outdoor seasonal aeroallergens.
... They report that exposure to the mouse allergen does not only concern people living in villages, but also occurs in the centers of large cities. The authors encourage mouse allergy to be taken into account during the diagnosis and treatment of patients with bronchial asthma, especially if the disease is not well controlled, despite a seemingly optimal treatment regimen [14]. ...
Allergy to fur animals is becoming an increasingly common clinical problem in everyday medical practice. Depending on the route of exposure to the allergen, patients present with many, often non-specific symptoms. The most common illnesses among people with allergies to the above-mentioned allergens are as follows: allergic rhinitis, allergic conjunctivitis, atopic bronchial asthma, food allergy, allergic contact dermatitis, and sometimes anaphylactic shock. In recent years, there has been a change in the holistic approach to the treatment of allergy patients. The method of treatment should be tailored to a specific patient, taking into account his or her predispositions, economic possibilities, and therapeutic goals. The article describes the main methods of treating allergies, fo-cusing primarily on allergies to fur animals. Allergy treatment always requires great care, and qualification for specific types of therapy should be preceded by a thorough and accurate diagnosis.
... Mouse allergen is ubiquitous and more prevalent in urban environments, with multiple studies identifying up to 95% of homes and apartments affected in the United States, whereas the estimated respective proportion in Europe and Central America is around 50-60%. [45][46][47][48] While often co-existing with cockroach, 45 evidence suggests that in some cities, mouse allergen is the major allergen in urban cities. [49][50][51] Moreover, a nationally representative survey of homes in the United States found detectable levels of mouse allergen in 82% of homes; 52 mouse allergen was also prevalent in homes of suburban, middleclass children with asthma. 53 Mouse sensitization and exposure has been associated with increased acute care visits and decreased FEV1/FVC percentage values, independent of cockroach allergen, 49 and at-risk school aged children demonstrate higher asthma severity scores and require higher treatment steps. ...
Allergen exposure may exacerbate asthma symptoms in sensitized patients. Allergen reduction or avoidance measures have been widely utilized; however, there is ongoing controversy on the effectiveness of specific allergen control measures in the management of children with asthma. Often, allergen avoidance strategies are not recommended by guidelines because they can be complex or burdensome, although individual patients may benefit. Here we explore the potential for intervention against exposure to the major allergens implicated in asthma (ie, house dust mites, indoor molds, rodents, cockroaches, furry pets, and outdoor molds and pollens), and subsequent effects on asthma symptoms. We critically assess the available evidence regarding the clinical benefits of specific environmental control measures for each allergen. Finally, we underscore the need for standardized and multifaceted approaches in research and real-life settings, which would result in the identification of more personalized and beneficial prevention strategies.
... Epidemiologic studies have linked housing insecurity and poor housing conditions with worsening chronic conditions such as asthma, and with increased risk of respiratory infections that can precipitate asthma exacerbations. 4 Pest infestations including mouse infestation have also been linked broadly to pediatric asthma outcomes. 5 Pre-pandemic, more than 500,000 families have experienced homelessness in the US at some point over the last decade. 6 A fact often missed is that up to 59% of people experiencing homelessness are children, and in a one year period close to 5% of adolescents reported homelessness unaccompanied by an adult caregiver. ...
Objective
To describe the impact of social determinants on the experience of the COVID-19 pandemic within the pediatric population, how this impact may influence the long-term health and security of children, and what measures can be taken to ameliorate this impact moving forward.
Data Sources
Non-systematic review of relevant literature and news sources Study Selections: Relevant literature and news sources Results: There have been increases in housing insecurity and food insecurity during the pandemic, as well as global increases in poverty. Public policies such as school closures have had a disproportionate impact on those facing adverse social determinants. There has been a dramatic increase in reports of abuse-related injuries, and other injuries indicative of child abuse during the pandemic. In addition, there are disproportionate impacts of COVID-19 based on race and ethnicity within the United States. It is clear that children are facing more adverse determinants as a result of this pandemic, and that there are both short-term and long-term implications associated. For those living in poverty or with other adverse social determinants of health, the pandemic has made a bad situation worse. Ongoing studies are required to measure the impact of COVID-19 on those with adverse social determinants, in particular among children.
Conclusion
Social determinants of health must be part of pandemic research priorities, public health and vaccination goals, and economic policy implementation. The impact of the COVID-19 pandemic has further served to shed a light on the broad disparities that exist within our society and their direct and indirect impact on health outcomes.
Objective:
Among animals defined as "pests", cockroaches and rodents (mouse and rat) represent the most common cause of airway allergic sensitization and bronchial asthma worldwide. Their frequency of sensitization has been widely assessed in US and other countries but poorly in Western Europe. This narrative review aims to provide a synthesis of data resulting in MEDLINE concerning allergic sensitization/asthma to pests as well as their related environmental/social risk factors, specifically in the European area.Data Sources: We performed a literature research in MEDLINE for clinical trials, randomized controlled trials, systematic reviews and meta-analyses.Study Selections: We selected studies to the following key words: allergic sensitization, allergic rhinitis, bronchial asthma, cockroach, hypersensitivity, integrated pest management, material hardship, medication compliance, mouse, pest, poverty, rat, rodents.
Results:
Current evidence indicates that residence in poor and urban areas, exposure to outdoor/indoor pollutants and tobacco smoke, poverty, material hardship, poor-quality housing, differences in health care quality, medication compliance, heath care access contribute to increased pest-related allergic sensitization and asthma morbidity.
Conclusion:
Further research should be done on many aspects of pest allergy such as a better characterization of allergens and epidemiological aspects. Relevant social actions should be carried out against poverty, healthcare disparities, psycho-social stress, poor compliance to therapy, with economic contributions to improve private and public living environments. Allergic sensitization to pests and pest-allergic respiratory diseases like asthma are "paradoxical" conditions, as they typically affect the poorest communities but can only be corrected by high-cost (diagnostic and preventive) interventions. We hope that progress can be made in this direction in the future.
Exposure and sensitization to environmental factors play a fundamental role in asthma development and is strongly associated with asthma morbidity. While hereditary factors are critical determinants of asthma, exposures to environmental factors are implicated in the phenotypic expression of asthma and have been strongly associated in the risk of its development. Significant interest has thus been geared toward potentially modifiable environmental exposures which may lead to the development of asthma. Allergen exposure, in particular indoor allergens, plays a significant role in the pathogenesis of asthma, and remediation is a primary component of asthma management. In the home, multifaceted and multitargeted environmental control strategies have been shown to reduce home exposures and improve asthma outcomes. In addition to the home environment, assessment of the school, daycare, and workplace environments of patients with asthma is necessary to ensure appropriate environmental control measures in conjunction with medical care. This article will discuss the role of the environment on asthma, review targeted environmental therapy, and examine environmental control measures to suppress environmental exposures in the home and school setting.
Asthma is the most common chronic disease of childhood. Disparities in asthma outcomes have led to international attention on the biologic, social, economic, and other factors that impact the health of children with asthma. Studies indicate that social determinants of health such as housing, neighborhood safety, and access to care significantly impact the health of children with asthma. However, screening for socioeconomic and environmental factors that impact asthma can be difficult to integrate into clinical practice. In addition, it is not yet clear which interventions to address these factors are most effective. This paper will review recent studies of determinants and social determinants of health and propose a framework for identifying and addressing them in the care of children with asthma in a clinical setting.
To examine the associations between pet keeping in early childhood and asthma and allergies in children aged 6-10 years.
Pooled analysis of individual participant data of 11 prospective European birth cohorts that recruited a total of over 22,000 children in the 1990s. EXPOSURE DEFINITION: Ownership of only cats, dogs, birds, rodents, or cats/dogs combined during the first 2 years of life. OUTCOME DEFINITION: Current asthma (primary outcome), allergic asthma, allergic rhinitis and allergic sensitization during 6-10 years of age.
Three-step approach: (i) Common definition of outcome and exposure variables across cohorts; (ii) calculation of adjusted effect estimates for each cohort; (iii) pooling of effect estimates by using random effects meta-analysis models.
We found no association between furry and feathered pet keeping early in life and asthma in school age. For example, the odds ratio for asthma comparing cat ownership with "no pets" (10 studies, 11489 participants) was 1.00 (95% confidence interval 0.78 to 1.28) (I(2) = 9%; p = 0.36). The odds ratio for asthma comparing dog ownership with "no pets" (9 studies, 11433 participants) was 0.77 (0.58 to 1.03) (I(2) = 0%, p = 0.89). Owning both cat(s) and dog(s) compared to "no pets" resulted in an odds ratio of 1.04 (0.59 to 1.84) (I(2) = 33%, p = 0.18). Similarly, for allergic asthma and for allergic rhinitis we did not find associations regarding any type of pet ownership early in life. However, we found some evidence for an association between ownership of furry pets during the first 2 years of life and reduced likelihood of becoming sensitized to aero-allergens.
Pet ownership in early life did not appear to either increase or reduce the risk of asthma or allergic rhinitis symptoms in children aged 6-10. Advice from health care practitioners to avoid or to specifically acquire pets for primary prevention of asthma or allergic rhinitis in children should not be given.
Most studies investigating the role of residential mouse allergen exposures in asthma have focused on inner-city populations.
We examined whether elevated mouse allergen levels were associated with occupants' asthma status in a nationally representative sample of U.S. households.
Data for this study were collected as part of the National Survey of Lead and Allergens in Housing. This cross-sectional study surveyed 831 housing units inhabited by 2,456 individuals in 75 different locations throughout the United States. The survey obtained information on demographics, household characteristics, and occupants' health status by questionnaire and environmental observations. We used a polyclonal immunoassay to assess concentrations of mouse urinary protein (MUP) in vacuumed dust collected from various indoor sites.
Of the surveyed homes, 82% had detectable levels of MUP, and in 35% of the homes, MUP concentrations exceeded 1.6 microg/g, a level that has been associated with increased mouse allergen sensitization rates. Current asthma, defined as having doctor-diagnosed asthma and asthma symptoms in the preceding 12 months, was positively associated with increased MUP levels. The observed association was modified by atopic status; in allergic individuals, elevated MUP levels (>1.6 microg/g) increased the odds of having asthma symptoms [adjusted OR=1.93; 95% confidence interval (CI), 1.14-3.27], but we found no association in those who did not report allergies (adjusted OR=0.69; 95% CI, 0.33-1.44).
In allergic asthma, residential mouse allergen exposure is an important risk factor for asthma morbidity.
Sensitization to laboratory animals (LA) has a high prevalence among laboratory workers. It is unknown whether transportation of LA allergens can be a risk factor for sensitization of subjects outside the laboratory environment. The aim of the study was to investigate the prevalence of sensitization to LA among children whose parents were and were not occupationally exposed to LA. The first group consisted of 50 children (age 12.3+/-4.3 yrs) whose parents were occupationally exposed to mice, rats and hamsters. The second group consisted of 40 children (age (mean+/-SD) 10.8+/-3.0 yrs) whose parents were not occupationally exposed to LA. Children having LA at home were eliminated from the study. All children responded to a questionnaire, underwent spirometry and were also tested with skin prick tests with the use of common allergens and prick tests with hair extracts from mouse, hamster and rat. Total immunoglobulin (Ig)E levels and the presence of specific IgE against LA were also estimated. Children of parents occupationally exposed to LA presented significantly more positive skin prick tests against allergens from the hair of laboratory animals compared to children of nonexposed parents. Five children from the first group were also found to have specific IgE against LA, with three of these five children complaining of rhinitis and cough while visiting their parents' workplace. It is concluded that the observed increased sensitization to laboratory animals among children of occupationally exposed parents could be the result of poor hygienic conditions at their parents' workplace. Hence, parents' job seems to be an additional risk factor of sensitization and should be taken into consideration when recording an allergic history.
Exposure to mouse allergen is a known cause of asthma in occupational settings and exhibits high prevalence and association with allergic sensitization in inner-city home environments. It has never been characterized on a nationally representative scale.
This study was designed to characterize mouse allergen prevalence in a representative sample of US homes and to assess risk factors for increased concentrations.
Allergen, questionnaire, and observational data were analyzed from the first National Survey of Lead and Allergens in Housing, a cross-sectional survey of 831 US housing units. Allergen levels were characterized and related to demographic factors and household characteristics.
Detectable levels of mouse allergen (Mus m 1) exist in 82% of US homes. Kitchen floor concentrations exceed 1.6 microg/g, a level associated with increased sensitization rates, in 22% of homes. Increased concentrations (>1.6 microg/g) were observed in high-rise apartments and mobile homes, older homes, and low-income homes. Odds of having increased concentrations were increased when rodent (odds ratio [OR], 3.38) or cockroach (OR, 1.81) problems were reported and when floor mopping (OR, 2.17) was performed instead of vacuuming.
Household mouse allergen is widespread in many settings at levels that might contribute to asthma morbidity. The likelihood of exposure can be assessed by consideration of demographic and household determinants.
Importance:
Professionally delivered integrated pest management (IPM) interventions can reduce home mouse allergen concentrations, but whether they reduce asthma morbidity among mouse-sensitized and exposed children and adolescents is unknown.
Objective:
To determine the effect of an IPM intervention on asthma morbidity among mouse-sensitized and exposed children and adolescents with asthma.
Design, setting, and participants:
Randomized clinical trial conducted in Baltimore, Maryland, and Boston, Massachusetts. Participants were mouse-sensitized and exposed children and adolescents (aged 5-17 years) with asthma randomized to receive professionally delivered IPM plus pest management education or pest management education alone. Enrollment occurred between May 2010 and August 2014; the final follow-up visit occurred on September 25, 2015.
Interventions:
Integrated pest management consisted of application of rodenticide, sealing of holes that could serve as entry points for mice, trap placement, targeted cleaning, allergen-proof mattress and pillow encasements, and portable air purifiers. Infestation was assessed every 3 months, and if infestation persisted or recurred, additional treatments were delivered. All participants received pest management education, which consisted of written material and demonstration of the materials needed to set traps and seal holes.
Main outcomes and measures:
The primary outcome was maximal symptom days defined as the highest number of days of symptoms in the previous 2 weeks among 3 types of symptoms (days of slowed activity due to asthma; number of nights of waking with asthma symptoms; and days of coughing, wheezing, or chest tightness) across 6, 9, and 12 months.
Results:
Of 361 children and adolescents who were randomized (mean [SD] age, 9.8 [3.2] years; 38% female; 181 in IPM plus pest management education group and 180 in pest management education alone group), 334 were included in the primary analysis. For the primary outcome, there was no statistically significant between-group difference for maximal symptom days across 6, 9, and 12 months with a median of 2.0 (interquartile range, 0.7-4.7) maximal symptom days in the IPM plus pest management education group and 2.7 (interquartile range, 1.3-5.0) maximal symptom days in the pest management education alone group (P = .16) and a ratio of symptom frequencies of 0.86 (95% CI, 0.69-1.06).
Conclusions and relevance:
Among mouse-sensitized and exposed children and adolescents with asthma, an intensive year-long integrated pest management intervention plus pest management education vs pest management education alone resulted in no significant difference in maximal symptom days from 6 to 12 months.
Trial registration:
clinicaltrials.gov Identifier: NCT01251224.
Background:
Mouse sensitization and exposure are associated with uncontrolled asthma, but whether they are associated with asthma severity, an intrinsic disease characteristic and long-term outcome predictor, is unclear.
Objective:
To examine relationships between mouse sensitization and/or exposure and asthma severity in urban children.
Methods:
A total of 645 children (5-17 years) with uncontrolled asthma underwent mouse sensitization evaluation. Sensitized children had mouse allergen measured in bedroom dust. Relationships between mouse sensitization, allergen levels, and asthma severity measures (treatment step and Composite Asthma Severity Index [CASI]) were examined using regression models adjusted for age, sex, atopy, study site, race, ethnicity, and insurance.
Results:
The study population was predominantly minority (69.6% black, 20.8% Hispanic), low income (61.8%), and mouse sensitized (54.4%). Mean ± SD treatment step was 3.2 ± 1.6, equivalent to medium-dose inhaled corticosteroid. Mean ± SD CASI was 6.5 ± 3.4, reflecting moderate persistent asthma. Mouse sensitization was associated with higher treatment step (3.5 vs 2.9, mouse-sensitized vs nonsensitized, P < .001), independent of potential confounders (β [95% CI], 0.36 [0.07-0.64]; P = .01). Mouse sensitization was associated independently with CASI (β [95% CI], 0.82 [0.16-1.47]; P = .02). Among mouse-sensitized participants, higher bedroom floor and bed Mus m 1 were independently associated with treatment step (β [95% CI], 0.26 [0.09-0.43]; P = .002 and β [95% CI], 0.22 [0.01-0.43]; P = .04), respectively. Higher bedroom floor Mus m 1 was independently associated with CASI (β [95% CI], 0.43 [0.05-0.81]; P = .03).
Conclusions:
Mouse sensitization and exposure are associated with asthma severity, among low-income, minority children. Further studies are needed to determine whether reducing allergen exposure among mouse-sensitized patients with asthma can reduce severity, ultimately altering childhood asthma natural history.
Importance:
Home aeroallergen exposure is associated with increased asthma morbidity in children, yet little is known about the contribution of school aeroallergen exposures to such morbidity.
Objective:
To evaluate the effect of school-specific aeroallergen exposures on asthma morbidity among students, adjusting for home exposures.
Design, setting, and participants:
The School Inner-City Asthma Study was a prospective cohort study evaluating 284 students aged 4 to 13 years with asthma who were enrolled from 37 inner-city elementary schools in the northeastern United States between March 1, 2008, and August 31, 2013. Enrolled students underwent baseline clinical evaluations before the school year started and were then observed clinically for 1 year. During that same school year, classroom and home dust samples linked to the students were collected and analyzed for common indoor aeroallergens. Associations between school aeroallergen exposure and asthma outcomes during the school year were assessed, adjusting for home exposures.
Exposures:
Indoor aeroallergens, including rat, mouse, cockroach, cat, dog, and dust mites, measured in dust samples collected from inner-city schools.
Main outcomes and measures:
The primary outcome was maximum days in the past 2 weeks with asthma symptoms. Secondary outcomes included well-established markers of asthma morbidity, including asthma-associated health care use and lung function, measured by forced expiratory volume in 1 second.
Results:
Among 284 students (median age, 8 years [interquartile range, 6-9 years]; 148 boys and 136 girls), exposure to mouse allergen was detected in 441 (99.5%) of 443 school dust samples, cat allergen in 420 samples (94.8%), and dog allergen in 366 samples (82.6%). Levels of mouse allergen in schools were significantly higher than in students' homes (median settled dust level, 0.90 vs 0.14 µg/g; P < .001). Exposure to higher levels of mouse allergen in school (comparing 75th with 25th percentile) was associated with increased odds of having an asthma symptom day (odds ratio, 1.27; 95% CI, 1.05-1.54; P = .02) and 4.0 percentage points lower predicted forced expiratory volume in 1 second (95% CI, -6.6 to -1.5; P = .002). This effect was independent of allergic sensitization. None of the other indoor aeroallergens were associated with worsening asthma outcomes.
Conclusions and relevance:
In this study of inner-city students with asthma, exposure to mouse allergen in schools was associated with increased asthma symptoms and decreased lung function. These findings demonstrate that the school environment is an important contributor to childhood asthma morbidity. Future school-based environmental interventions may be beneficial for this important public health problem.
Highlights of the National Asthma Education and Prevention Program's Expert Panel Report 3 (EPR-3): Guidelines for the Diagnosis and Management of Asthma-Full Report 2007 are presented in this EPR-3 summary report. The updated guidelines emphasize the importance of asthma control. Asthma control is the degree to which the manifestations of asthma are minimized by therapeutic intervention and the goals of therapy are met. Because asthma is highly variable, the level of control must be monitored on a periodic basis to determine whether therapy should be maintained or adjusted (stepped up if necessary, stepped down if possible). On the other hand, asthma severity is the intrinsic intensity of the disease process, most easily and directly measured in a patient not receiving long-term control therapy. For managing asthma, the recommendation is to assess severity to initiate therapy and assess control to adjust therapy. Recommendations for managing asthma include an expanded section on childhood asthma with addition of an age group 5 to 11 years old (earlier guidelines combined this group with adults). The guidelines provide new recommendations on patient education in settings beyond the physician's office, and new advice for controlling environmental factors that can cause asthma symptoms. The concepts of current impairment (frequency and intensity of symptoms, low lung function, and limitations of daily activities) and future risk (likelihood of exacerbations, progressive loss of lung function, or adverse side effects from medications) support a new approach to assessing and monitoring the patient's level of asthma control through use of multiple measures. The guidelines stress that some patients can still be at high risk for frequent exacerbations even if they have few day-to-day effects of asthma.Moreover, EPR-3 confirms the importance of teaching patients skills to self-monitor and manage asthma and to use a written asthma action plan, which should include instructions for daily treatment and ways to recognize and handle worsening asthma. New recommendations encourage expanding educational opportunities to reach patients in a variety of settings, such as pharmacies, schools, community centers, and patients' homes. A new section addresses the need for clinician education programs to improve communication with patients and to use system-wide approaches to integrate the guidelines into health care practice. The guidelines describe new evidence for using multiple approaches to limit exposure to allergens and other substances that can worsen asthma; research shows that single steps are rarely sufficient. EPR-3 also expands the section on common conditions that can affect asthma and notes that management of these conditions may help to improve asthma control. Expert Panel Report 3 continues the use of a stepwise approach to control asthma. When assessing the level of asthma control to determine the need for adjusting therapy, EPR-3 reconfirms the importance of assessing patient adherence to medication, inhaler technique, and environmental control measures before making a step up in therapy. The stepwise approach expands from 4 steps to 6 steps of care. Medications have been repositioned within these 6 steps. Recommendations on medications are updated to reflect the latest evidence on effectiveness and safety. EPR-3 reaffirms that patients with persistent asthma need both long-term control medications to control asthma and prevent exacerbations and quick-relief medication for symptoms, as needed. EPR-3 also reaffirms that inhaled corticosteroids are the most effective long-term control medication across all age groups. New recommendations on treatment options such as leukotriene receptor antagonists and cromolyn for long-term control; long-acting beta-agonists as adjunct therapy with inhaled corticosteroids; omalizumab for severe asthma; and albuterol, levalbuterol, and corticosteroids for acute exacerbations are included.
Background:
Wheezing illnesses cause major morbidity in infants and are frequent precursors to asthma.
Objective:
We sought to examine environmental factors associated with recurrent wheezing in inner-city environments.
Methods:
The Urban Environment and Childhood Asthma study examined a birth cohort at high risk for asthma (n = 560) in Baltimore, Boston, New York, and St Louis. Environmental assessments included allergen exposure and, in a nested case-control study of 104 children, the bacterial content of house dust collected in the first year of life. Associations were determined among environmental factors, aeroallergen sensitization, and recurrent wheezing at age 3 years.
Results:
Cumulative allergen exposure over the first 3 years was associated with allergic sensitization, and sensitization at age 3 years was related to recurrent wheeze. In contrast, first-year exposure to cockroach, mouse, and cat allergens was negatively associated with recurrent wheeze (odds ratio, 0.60, 0.65, and 0.75, respectively; P ≤ .01). Differences in house dust bacterial content in the first year, especially reduced exposure to specific Firmicutes and Bacteriodetes, was associated with atopy and atopic wheeze. Exposure to high levels of both allergens and this subset of bacteria in the first year of life was most common among children without atopy or wheeze.
Conclusions:
In inner-city environments children with the highest exposure to specific allergens and bacteria during their first year were least likely to have recurrent wheeze and allergic sensitization. These findings suggest that concomitant exposure to high levels of certain allergens and bacteria in early life might be beneficial and suggest new preventive strategies for wheezing and allergic diseases.
Home characteristics and aeroallergen exposure in rural US children with asthma are poorly described.
To examine the relationship between cockroach and mouse allergen concentrations and home characteristics of children with asthma in the rural Arkansas Delta.
The home environments of rural children with asthma were examined using home environment questionnaire and home inspection. Bedroom and kitchen dust was analyzed for cockroach and mouse allergen concentrations.
The median age of participants was 9 years, and 84% were African American. Most participants (78%) resided in single-family homes. Evidence of cockroaches was detected in 13% of homes and evidence of rodents was detected in 23% of homes. Detectable Bla g 1 was found in 58% of kitchens and 43% of bedrooms, Bla g 2 was detected in 37% of kitchens and 28% of bedrooms, and Mus m 1 was found in 81% of kitchens and 97% of bedrooms. Evidence of cockroaches in any room was associated with Bla g 1 concentrations of ≥2 U/g (odds ratio 21.71, 95% confidence interval 4.26-118.39) and Bla g 2 concentrations of ≥2 U/g (odds ratio 21.90 95% confidence interval 4.30-138.91). Multifamily vs single-family dwellings were more likely to have Bla g 2 concentrations of ≥2 U/g (odds ratio 3.52, 95% confidence interval 1.0-11.82). Home characteristics were not associated with Mus m 1.
Mouse and cockroach allergens were detected in most rural homes; however, concentrations were relatively low compared with those previously reported in inner-city homes. Few home characteristics predicted allergen concentrations. Further studies are needed to establish clinically relevant associations that might place rural children with asthma at risk for poor clinical outcomes.
Although rodent allergy has long been recognized as an occupational disease, it has only been in the past decade that it has been recognized as a community-based disease that affects children. Most homes in the US have detectable mouse allergen, but the concentrations in inner-city homes are orders of magnitude higher than those found in suburban homes. Home mouse allergen exposure has been linked to sensitization to mouse, and children with asthma who are both sensitized and exposed to high mouse allergen concentrations at home are at greater risk for symptoms, exacerbations and reduced lung function. Rat allergen is found primarily in inner-city homes and has also been linked to asthma morbidity among sensitized children. The objective of this review is to summarize the scientific literature on rodents and their allergens, the effects of exposure to these allergens on allergic respiratory disease, and to make recommendations, based on this evidence base, for the evaluation and management of mouse allergy in the pediatric population.
Cockroach and mouse allergens have both been implicated as causes in inner-city asthma morbidity in multicenter studies, but whether both allergens are clinically relevant within specific inner-city communities is unclear.
Our study aimed to identify relevant allergens in Baltimore City.
One hundred forty-four children (5-17 years old) with asthma underwent skin prick tests at baseline and had clinical data collected at baseline and 3, 6, 9, and 12 months. Home settled dust samples were collected at the same time points for quantification of indoor allergens. Participants were grouped based on their sensitization and exposure status to each allergen. All analyses were adjusted for age, sex, and serum total IgE level.
Forty-one percent were mouse sensitized/exposed, and 41% were cockroach sensitized/exposed based on bedroom floor exposure data. Mouse sensitization/exposure was associated with acute care visits, decreased FEV1/forced vital capacity percentage values, fraction of exhaled nitric oxide levels, and bronchodilator reversibility. Cockroach sensitization/exposure was only associated with acute care visits and bronchodilator reversibility when exposure was defined by using bedroom floor allergen levels. Mouse-specific IgE levels were associated with poor asthma health across a range of outcomes, whereas cockroach-specific IgE levels were not. The relationships between asthma outcomes and mouse allergen were independent of cockroach allergen. Although sensitization/exposure to both mouse and cockroach was generally associated with worse asthma, mouse sensitization/exposure was the primary contributor to these relationships.
In a community with high levels of both mouse and cockroach allergens, mouse allergen appears to be more strongly and consistently associated with poor asthma outcomes than cockroach allergen. Community-level asthma interventions in Baltimore should prioritize reducing mouse allergen exposure.
Home mouse allergen exposure is associated with asthma morbidity, but little is known about the shape of the dose-response relationship or the relevance of location of exposure within the home. Asthma outcome and allergen exposure data were collected every three months for 1 year in 150 urban children with asthma. Participants were stratified by mouse sensitization and relationships between continuous measures of mouse allergen exposure and outcomes of interest were analyzed. Every ten-fold increase in the bed mouse allergen level was associated with an 87% increase in the odds of any asthma-related health care use among mouse sensitized (OR (95% CI): 1.87 (1.21-2.88)), but not non-mouse sensitized participants. Similar relationships were observed for emergency department visit and unscheduled doctor visit among mouse sensitized participants. Kitchen floor and bedroom air mouse allergen concentrations were also associated with greater odds of asthma-related healthcare utilization; however, the magnitude of the association was less than that observed for bed mouse allergen concentrations. In this population of urban children with asthma, there is a linear dose-response relationship between mouse allergen concentrations and asthma morbidity among mouse-sensitized asthmatics. Bed and bedroom air mouse allergen exposure compartments may have a greater impact on asthma morbidity than other compartments. © 2012 John Wiley & Sons A/S.
Most studies of indoor allergens have focused on the home environment. However, schools may be an important site of allergen exposure for children with asthma. We compared school allergen exposure to home exposure in a cohort of children with asthma. Correlations between settled dust and airborne allergen levels in classrooms were examined.
Settled dust and airborne samples from 12 inner-city schools were analyzed for indoor allergens using multiplex array technology (MARIA). School samples were linked to students with asthma enrolled in the School Inner-City Asthma Study (SICAS). Settled dust samples from students' bedrooms were analyzed similarly.
From schools, 229 settled dust and 197 airborne samples were obtained. From homes, 118 settled dust samples were obtained. Linear mixed regression models of log-transformed variables showed significantly higher settled dust levels of mouse, cat and dog allergens in schools than homes (545% higher for Mus m 1, estimated absolute difference 0.55 μg/g, p < 0.0001; 198% higher for Fel d 1, estimated absolute difference 0.13 μg/g, p = 0.0033; and 144% higher for Can f 1, estimated absolute difference 0.05 μg/g, p = 0.0008). Airborne and settled dust Mus m 1 levels in classrooms were moderately correlated (r = 0.48; p < 0.0001). There were undetectable to very low levels of cockroach and dust mite allergens in both homes and schools.
Mouse allergen levels in schools were substantial. In general, cat and dog allergen levels were low, but detectable, and were higher in schools. Aerosolization of mouse allergen in classrooms may be a significant exposure for students. Further studies are needed to evaluate the effect of indoor allergen exposure in schools on asthma morbidity in students with asthma.
Epidemiologic studies have shown an association between mouse allergen exposure and asthma morbidity among urban populations, but confirmatory challenge studies in community populations have not been performed. This study was designed to examine the clinical relevance of mouse sensitization using a nasal challenge model. Forty-nine urban adults with asthma underwent skin-prick testing (SPT) and intradermal testing (IDT) with mouse epithelia extract. A positive SPT was defined as a net wheal size ≥3 mm and a positive IDT was defined as a net wheal size ≥6 mm using a 1:100 dilution of extract (1:10 w/v was obtained from Greer Laboratories (Lenoir, NC) as a single lot [Mus m 1 concentration = 2130 ng/mL]). Mouse-specific IgE (m-IgE) was measured by ImmunoCAP (Phadia, Uppsala, Sweden). Nasal challenge was performed with increasing concentrations of mouse epithelia extract and symptoms were assessed by visual analog scale. A positive challenge was defined as a 20-mm increase in the scale. The age range of the 49 participants was 18-50 years; 41% were men and 86% were black. Fourteen participants were SPT(+) to mouse, 15 participants were SPT(-) but (IDT(+)), and 20 participants were negative on both SPT(-) and IDT(-) (SPT(-)/IDT(-)). Sixty-four percent of the SPT(+) group, 40% of the IDT(+) group, and 20% of the SPT(-)/IDT(-) group had a positive nasal challenge. Sixty-seven percent (10/15) of those who were either SPT(+) or m-IgE(+) had a positive nasal challenge. SPT or the combination of SPT plus m-IgE performed best in diagnosing mouse allergy. The great majority of mouse-sensitized urban adults with asthma appear to have clinically relevant sensitization. Urban adults with asthma should be evaluated for mouse sensitization using SPT or SPT plus m-IgE testing.
Relationships among allergen-specific IgE levels, allergen exposure and asthma severity are poorly understood since sensitization has previously been evaluated as a dichotomous, rather than continuous characteristic.
Five hundred and forty-six inner-city adolescents enrolled in the Asthma Control Evaluation study underwent exhaled nitric oxide (FE(NO)) measurement, lung function testing, and completion of a questionnaire. Allergen-specific IgE levels and blood eosinophils were quantified. Dust samples were collected from the participants' bedrooms for quantification of allergen concentrations. Participants were followed for 12 months and clinical outcomes were tracked.
Among sensitized participants, allergen-specific IgE levels were correlated with the corresponding settled dust allergen levels for cockroach, dust mite, and mouse (r = 0.38, 0.34, 0.19, respectively; P < 0.0001 for cockroach and dust mite and P = 0.03 for mouse), but not cat (r = -0.02, P = 0.71). Higher cockroach-, mite-, mouse-, and cat-specific IgE levels were associated with higher FE(NO) concentrations, poorer lung function, and higher blood eosinophils. Higher cat, dust mite, and mouse allergen-specific IgE levels were also associated with an increasing risk of exacerbations or hospitalization.
Allergen-specific IgE levels were correlated with allergen exposure among sensitized participants, except for cat. Allergen-specific IgE levels were also associated with more severe asthma across a range of clinical and biologic markers. Adjusting for exposure did not provide additional predictive value, suggesting that higher allergen-specific IgE levels may be indicative of both higher exposure and a greater degree of sensitization, which in turn may result in greater asthma severity.
The relationships between cockroach and mouse allergen exposure, anti-cockroach and anti-mouse IgE, and wheeze, rhinitis, and atopic dermatitis in children as young as age 3 years are of public health importance but have not been thoroughly evaluated.
We hypothesized that inner-city children might have anti-cockroach and anti-mouse IgE by age 3 years, and their presence would be associated with respiratory and atopic symptoms.
Children were followed prospectively from birth through age 3 years (n = 404). Residential levels of cockroach and mouse allergens, sera levels of anti-cockroach and anti-mouse IgE, and parental report of wheeze, rhinitis, and atopic dermatitis were measured.
The odds of early wheeze were significantly higher among children who had IgE to cockroach (odds ratio [OR], 3.3; 95% CI, 1.8-6.2), mouse (OR, 4.6; 95% CI, 2.3-9.0), or both (OR, 9.7; 95% CI, 3.4-27.3). The odds of rhinitis or atopic dermatitis were also higher among children with IgE to cockroach, mouse, or both. Higher IgE class to cockroach and mouse was associated with wheeze and atopic dermatitis (tests for trend, P < .002).
Children age 2 to 3 years who have anti-cockroach and anti-mouse IgE are at increased risk of wheeze and atopy. Moreover, a dose-response relationship was found between higher IgE class and increased prevalence of wheeze, rhinitis, or atopic dermatitis. These findings indicate the importance of reducing exposure to cockroach and mouse allergens for susceptible children.
Mouse allergens are prevalent in inner-city households, and increasing levels of exposure are associated with sensitization in children with asthma.
To examine mouse allergen sensitization and exposure in inner-city children, mouse allergen as an independent risk factor for asthma morbidity, and the efficacy of a rodent environmental intervention.
We conducted a subanalysis of children with asthma aged 5 to 11 years enrolled in the Inner-City Asthma Study. After randomization, 150 participants received a home rodent-specific environmental intervention. Asthma morbidity measures were obtained bimonthly. Bedroom dust was collected and analyzed for Mus m 1 at baseline and every 6 months for 2 years.
Twenty-two percent of children tested positive to mouse. Most bedrooms (80%) had detectable mouse allergen. Sensitization occurred at low levels of exposure. Sensitization and exposure were associated with increased asthma morbidity, including hospitalizations. Mouse allergen levels on the bedroom floor decreased 27.3% (95% confidence interval, -46.1% to -1.9%) in intervention homes. Mouse allergen reduction was associated with less missed school, sleep disruption, and caretaker burden but not symptoms or medical utilization.
Mouse allergen is prevalent in inner-city homes. Sensitization seems to occur at low levels of exposure. Mouse allergen is an independent risk factor for asthma morbidity. The described environmental intervention reduced mouse allergen levels and asthma-related sleep and activity disturbance.
Laboratory animal allergy is a serious occupational diseases of many workers and scientists engaged in animal experimentation. Control measures depend upon characterization of allergens including airborne particles. This study measured the particle size of crude mouse urine and pelt aeroallergens generated in mouse housing rooms and compared them with mouse serum albumin, a defined major allergen. Allergens were detected by specific immunological methods. Most crude and defined allergens (74.5-86.4%) concentrated on a filter with a retention size greater than 7 microns. In distrubed air, allergen concentration increased 1.4 (albumin) to 5 (crude) fold and the proportion of small particles increased from 1.4% in calm air to 4.5% in distrubed air. This information on the generation and size distribution of aeroallergens will be important in the development of effective counter measures.
The major allergens from the mouse, including mouse serum albumin (MSA) and mouse urinary protein complex, are present in various concentrations in urine, serum, and pelts of mice. Subjects clinically sensitive to laboratory animals were screened by the RAST for specific IgE antibodies to mouse urine (MU), MSA, and mouse pelt extract (MPE). Twenty-four hour air samples from both a mouse-care room (2000 mice) and an immunology laboratory (five to 100 mice) were collected with a high-volume air sampler that retained particles greater than 0.3 micron with 95% efficiency. Eluates from the filter sheets were dialyzed, lyophilized, reconstituted in water, and used as fluid-phase inhibitors in the MU RAST and MPE RAST. MPE allergenic activity could be quantitated in filter eluates from both locations, but MU allergenic activity could be quantitated only in the mouse-care room. Airborne allergen content ranged from 1.8 to 825 ng/m3 and varied with both the number of mice and the degree of work activity in the rooms. The sampling and assay techniques described can be used to accurately quantitate amorphous airborne allergens.
Antigens from CBA/H, BALB/c and C57BL mouse urine and CBA/H mouse pelts were studied to identify allergens that sensitize laboratory workers exposed to mice. Potent allergens in mouse urine were identified within the major urinary protein (MUP)‡ complex, which was found to have a molecular weight of 16,500 daltons (unreduced) and 22,000 daltons (reduced). The isoelectric point of the major component was 4.9. CBA/H, BALB/c and C57BL urine also contained material of low molecular weight (< 15,000 daltons) which was only slightly less potent than MUP allergens, but was present in relatively small amounts. In the three mouse strains, purified MUP proteins that bound to IgE antibodies cross-reacted extensively with one another, and with allergens in dust from a mouse room. There was complete antigenic cross-reactivity between urinary protein of pI 4.9 and low molecular weight fractions of CBA/H pelt antigens at the same isoelectnc point, suggesting that part of the allergenicity of pelt material may result from its content of components of the MUP complex. However, other allergens with a higher molecular weight (62,000 daltons) and isoelectric points between 5.5 and 6.7 were identified by gel filtration chromatography and preparative isoelectric focusing of CBA/H pelt material.
Although mouse allergen is a well-defined cause of IgE-mediated hypersensitivity in occupational settings, it has not been well studied in the general population.
We sought to determine the prevalence of mouse allergen in inner-city homes.
A subset of 608 homes from the National Cooperative Inner-City Asthma Study population had dust samples adequate for analysis of mouse allergen. In addition, data regarding the demographics and housing of the subjects were related to the mouse allergen levels.
Ninety-five percent of all homes had detectable mouse allergen (Mus m 1) in at least one room, with the highest levels found in kitchens (kitchen: range, 0-618 microg/g; median, 1.60 microg/g; bedroom: range, 0-294 microg/g; median, 0.52 microg/g; television-living room: range, 0-203 microg/g; median, 0. 57 microg/g). By city, 100% of the kitchens in Baltimore had detectable mouse allergen, with the lowest percentage (74%) in Cleveland. Mouse allergen levels correlated among rooms (R = 0.65-0. 75). Forty-nine percent of the homes had reported problems with mice within the last year, and 29% of the homes had evidence of mice in one or more rooms on home inspection and had higher levels of mouse allergen (P =.0001). Higher allergen levels were also associated with evidence of cockroach infestation in any room (P =.006). None of the other subject or housing demographics evaluated were associated with a higher prevalence or level of mouse allergen.
We conclude that mouse allergen is widely distributed in inner-city homes and that cockroach infestation is associated with high mouse allergen levels.
Recent studies have suggested that mouse allergen exposure and sensitization are common in urban children with asthma. The effectiveness of environmental intervention in reducing mouse allergen exposure has not been established.
To evaluate whether environmental intervention of mouse extermination and cleaning results in a reduction in mouse allergen levels.
Eighteen homes of children with positive mouse allergen skin test results and at least mild persistent asthma in urban Boston, MA, with evidence of mouse infestation or exposure were randomized in a 2:1 ratio (12 intervention and 6 control homes). The intervention homes received an integrated pest management intervention, which consisted of filling holes with copper mesh, vacuuming and cleaning, and using low-toxicity pesticides and traps. Dust samples were collected and analyzed for major mouse allergen (Mus m 1) and cockroach allergen (Bla g 1) at baseline and 1, 3, and 5 months after the intervention was started and compared with control homes.
Mouse allergen levels were significantly decreased compared with control homes by the end of the intervention period at month 5 in the kitchen and bedroom (kitchen intervention, 78.8% reduction; control, 319% increase; P = .02; bedroom intervention, 77.3% reduction; control, 358% increase; P < .01; and living room intervention, 67.6% reduction; control, 32% reduction; P = .07).
Mouse allergen levels were significantly reduced during a 5-month period using an integrated pest management intervention.
Exposure to mouse allergen is prevalent in inner-city homes and is associated with an increased risk of mouse skin test sensitivity in inner-city children with asthma.
To determine the distribution of mouse allergen and its relationship to mouse skin test sensitivity in a primarily suburban, middle-class population of asthmatic children.
Children with asthma, 6 to 17 years old, were recruited from 3 pediatric practices located in counties surrounding the city of Baltimore and from 1 practice located within the city limits. Participants underwent skin prick testing and completed a baseline questionnaire. Their homes were inspected, and settled dust samples were collected for allergen analysis.
Two hundred fifty-seven of 335 (76.7%) participants resided outside the city, and 53.7% had annual incomes >$50,000. Mouse allergen was detected in 74.9% of bedrooms, and 13.1% were sensitized to mouse. Lower maternal education (odds ratio [OR], 2.17; 95% CI, 1.28-3.67), city residence (OR, 5.39; 95% CI, 2.23-13.02), and higher bedroom cockroach allergen levels (OR, 9.61; 95% CI, 1.17-79.03) were independent predictors of high bedroom mouse allergen. The risk of mouse skin test sensitivity increased with increasing bedroom Mus m 1 exposure (OR, 1.43; 95% CI, 1.04-1.96, with each increase in quartile), and dog skin test sensitivity was a strong independent predictor of mouse skin test sensitivity (OR, 7.23; 95% CI, 3.03-17.22).
Mouse allergen exposure is common among suburban, middle-class asthmatic children. Increasing bedroom levels of Mus m 1 and dog skin test sensitivity are risk factors for mouse skin test sensitivity.
Airborne mouse allergen has not previously been measured in inner-city homes, and its relationship to settled dust mouse allergen levels is unknown.
To quantify airborne and settled dust Mus m 1 levels in homes of inner-city patients with asthma and to identify risk factors for mouse allergen exposure.
One hundred inner-city school-age children with asthma in Baltimore underwent skin testing to a panel of aeroallergens, and their homes were inspected by a trained technician. Air and settled dust were sampled in the child's bedroom. Mus m 1, particulate matter smaller than 10 microns (PM 10 ), and particulate matter smaller than 2.5 microns were quantified in air samples, and Mus m 1 was quantified in settled dust samples.
Mus m 1 was detected in settled dust samples from 100% of bedrooms. Airborne mouse allergen was detected in 48 of 57 (84%) bedrooms, and the median airborne mouse allergen concentration was 0.03 ng/m 3 . The median PM 10 concentration was 48 microg/m 3 . Airborne and settled dust mouse allergen levels were moderately correlated ( r = .52; P < .0001), and airborne Mus m 1 and PM 10 levels were weakly correlated ( r = .29; P = .03). Having cracks or holes in doors or walls, evidence of food remains in the kitchen, and mouse infestation were all independently associated with having detectable airborne mouse allergen.
Airborne mouse allergen concentrations in many inner-city homes may be similar to those found in animal facilities, where levels are sufficiently high to elicit symptoms in sensitized individuals. Exposed food remains, cracks and holes in doors or walls, and evidence of mouse infestation appear to be risk factors for having detectable airborne Mus m 1.
Mouse allergen exposure is prevalent among urban children with asthma. Little is known about mouse allergen exposure in children at risk for the development of allergic diseases.
To assess indoor mouse allergen exposure in early life among children with parental history of asthma or allergies.
Prospective birth cohort study of 498 children with a history of allergy or asthma in at least one parent living in metropolitan Boston.
Of the 498 participating children, 357 (71.7%) resided outside the city of Boston and 439 (90.7%) lived in households with incomes > 30,000 dollars. Mouse allergen was detected in 42% of the homes of study participants. In a multivariate analysis adjusting for sex, income, and endotoxin, black race [odds ratio (OR) = 3.0; 95% confidence interval (CI) = 1.3-6.6, P = 0.009], signs of mice in the home at age 2-3 months (OR = 3.0; 95% CI = 1.6-5.6, P = 0.0006), and kitchen cockroach allergen levels > or = 0.05 to < 2 U/g (OR = 1.8; 95% CI = 1.1-3.2, P = 0.02) were associated with detectable mouse allergen in the kitchen. In this model, living in a single detached house was inversely associated with detectable kitchen mouse allergen levels (OR = 0.4; 95% CI = 0.2-0.6, P = 0.0001).
Infants with a parental history of asthma or allergies are commonly exposed to mouse allergen in their homes. Among infants at high risk for atopy, predictors of increased mouse allergen levels included black race, reported mice exposure, and moderate levels of cockroach allergen.
Unlabelled:
Considering that high school students spend a large proportion of their waking hours in the school environment, this could be an important location for exposure to indoor allergens. We have investigated the levels of mouse and cockroach allergens in the settled dust and air from 11 schools in a major northeastern US city. Settled dust samples were vacuumed from 87 classrooms, three times throughout the school year. Two separate air samples (flow = 2.5 lpm) were collected by 53 students over a 5-day period from both their school and their home. Mouse allergen (MUP) in the dust varied greatly between schools with geometric means ranging from 0.21 to 133 microg/g. Mouse allergen was detectable in 81% of the samples collected. Cockroach allergen (Bla g 2) ranged from below limit of detection (<0.003 microg/g) to 1.1 microg/g. Cockroach allergen was detected (>0.003 microg/g) in 71% of the dust samples. Bla g 2 was detected in 22% of airborne samples from the schools. By comparison, mouse allergen was only detected in 5%. These results indicate that the school may be an important location for exposure to allergens from mice and cockroaches and is an indoor environment that should be considered in an overall allergen intervention strategy.
Practical implications:
To date, cockroach and mouse allergen intervention strategies have been mainly focused on the home environment. Considering that children spend a significant amount of time in schools, some studies have assessed cockroach allergen levels in schools. This study provides a clearer picture of the distribution and variability of not only cockroach allergen, but also mouse allergen in the school environment. In addition, this study describes limitations of personal air sampling in a student population. Our results suggest that although cockroach and mouse allergens are commonly recovered in classroom dust samples of inner city schools, cockroach allergens are recovered in the personal air samples with a greater frequency relative to mouse allergens.
Inner-city children experience disproportionate asthma morbidity, and suspected reasons include indoor environmental exposures.
To determine if mouse allergen exposure is a risk factor for asthma morbidity.
Preschool children with asthma were recruited from inner-city Baltimore, MD. Skin testing was performed and blood was collected at the baseline visit for quantification of mouse allergen specific IgE. A questionnaire evaluated symptoms, medication, and health care use at baseline, 3 months, and 6 months. A trained technician collected dust samples from the child's home for analysis of Mus m 1 at baseline, 3 months, and 6 months. Outcomes were compared between mouse-sensitized, highly exposed children and all other children.
A total of 127 children had complete data for mouse sensitization status and bedroom settled dust mouse allergen levels at baseline. The mean age of the children was 4.4 years, 92% were African American, and 26% were sensitized to mouse. Mouse-sensitized children exposed to higher levels of Mus m 1 (>0.5 microg/g) had 50% more days of symptoms (incidence rate ratio [IRR], 1.5; 95% confidence interval [CI], 1.1-2.1) and 80% more days of beta-agonist use than other children (IRR, 1.8; 95% CI, 1.3-2.5). Children in the sensitized and highly exposed group were also more likely to have an unscheduled physician visit (odds ratio [OR], 3.1; 95% CI, 1.6-6.3), emergency department visit (OR, 2.1; 95% CI, 1.1-4.1), and hospitalization (OR, 36.6; 95% CI, 4.1-327.3) than other children. These associations between mouse allergen exposure and asthma symptoms and morbidity remained statistically significant after adjusting for potential confounders, including atopy and cockroach sensitization and exposure.
In mouse-sensitized inner-city children, exposure to mouse allergen may be an important cause of asthma morbidity.
Asthma is a serious health problem throughout the world. During the past two decades, many scientific advances have improved our understanding of asthma and ability to manage and control it effectively. However, recommendations for asthma care need to be adapted to local conditions, resources and services. Since it was formed in 1993, the Global Initiative for Asthma, a network of individuals, organisations and public health officials, has played a leading role in disseminating information about the care of patients with asthma based on a process of continuous review of published scientific investigations. A comprehensive workshop report entitled "A Global Strategy for Asthma Management and Prevention", first published in 1995, has been widely adopted, translated and reproduced, and forms the basis for many national guidelines. The 2006 report contains important new themes. First, it asserts that "it is reasonable to expect that in most patients with asthma, control of the disease can and should be achieved and maintained," and recommends a change in approach to asthma management, with asthma control, rather than asthma severity, being the focus of treatment decisions. The importance of the patient-care giver partnership and guided self-management, along with setting goals for treatment, are also emphasised.
Mouse sensitization is assessed by using skin testing and serum levels of mouse allergen-specific IgE (m-IgE). However, it is unknown whether a positive skin test response or m-IgE result accurately identifies those with clinically relevant mouse sensitization.
We sought to compare skin testing and m-IgE measurement in the diagnosis of mouse allergy.
Sixty-nine mouse laboratory workers underwent skin prick tests (SPTs), intradermal tests (IDTs), and serum IgE measurements to mouse allergen, followed by nasal challenge to increasing concentrations of mouse allergen. Challenge response was assessed by nasal symptom score.
Thirty-eight women and 31 men with a mean age of 30 years were studied. Forty-nine workers reported mouse-related symptoms, of whom 10 had positive m-IgE results and 12 had positive SPT responses. Fifteen had negative SPT responses but positive IDT responses. Positive nasal challenges were observed in 70% of workers with positive m-IgE results, 83% of workers with positive SPT responses, 33% of workers with negative SPT responses/positive IDT responses, and 0% of workers with negative IDT responses. SPTs performed best, having the highest positive and negative predictive values. Among participants with a positive challenge result, those with a positive SPT response or m-IgE result had a significantly lower challenge threshold than those with a positive IDT response (P = .01). Workers with a positive challenge result were more likely to have an increase in nasal eosinophilia after the challenge compared with those with a negative challenge result (P = .03).
SPTs perform best in discriminating patients with and without mouse allergy. Mouse-specific IgE and IDTs appear to be less useful than SPTs in the diagnosis of mouse allergy.
The impact of preschool environmental conditions on classroom aeroallergen concentrations is not fully understood.
To examine the relationship between school environmental conditions and classroom aeroallergen concentrations in the Pulaski County Head Start (HS) Program.
Thirty-three HS centers in Pulaski County, Arkansas, underwent a detailed environmental evaluation. Classroom settled dust samples were analyzed for the presence of common indoor allergens.
Classroom eating (70%), wall-to-wall carpeting (58%), and water damage (33%) were common. Median classroom allergen levels were as follows: dust mite (Der p 1 and Der f 1), 0.6 microg/g; Fel d 1, 0.4 microg/g; Can f 1, 1.7 microg/g; cockroach, below detection; Mus m 1, 0.18 microg/g; and mold spores, 17,800 CFU/g. Can f 1 and Mus m 1 allergens were detected in 100% of HS centers. Facilities with carpeting, increased humidity, and single-use facilities showed trends toward increased dust mite concentrations. Detectable cockroach allergen was more common in classrooms cleaned by teachers than by professional housekeepers.
Aeroallergens were commonly detected in Pulaski County HS center classrooms, with dog and mouse allergens detected in 100% of centers. Median classroom allergen concentrations were low, and classroom characteristics were not strongly predictive of increased allergen exposure.
Mouse sensitivity is an independent risk factor for rhinitis in children with asthma
- Sedaghat