Environmental exposures and asthma morbidity in children living in urban neighborhoods

A substantial disparity in asthma prevalence and morbidity among urban children compared with their nonurban counterparts has been recognized for more than two decades. Because of the nature of urban neighborhoods, pest allergens, such as cockroach and mouse, are present in high concentrations in US urban housing and have both repeatedly been linked to asthma morbidity in sensitized children. In addition, there is a growing body of evidence demonstrating that concentrations of many pollutants are higher indoors than outdoors in both US and European urban communities and that exposures to indoor pollutants such as particulate matter (PM) and nitrogen dioxide (NO₂) are independently associated with symptoms in children with asthma. Although environmental interventions are challenging to implement, when they reduce relevant indoor allergen and pollutant exposures, they are associated with clear improvements in asthma. Other modifiable risk factors in urban childhood asthma that have emerged include dietary and nutritional factors. Overweight and obese children, for example, may be more susceptible to the pulmonary effects of pollutant exposure. Insufficiency of vitamin D and folate has also emerged as modifiable risk factors for asthma morbidity in children. The identification of these modifiable risk factors for urban childhood asthma morbidity offers a ripe opportunity for intervention.     

Exposure to bisphenols and asthma morbidity among low-income urban children with asthma

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Home-based asthma education of young low-income children and their families

OBJECTIVE: To conduct a controlled trial of a home-based education program for low-income caregivers of young children with asthma. METHODS: Participants were randomized to treatment-eight weekly asthma education sessions adapted from the Wee Wheezers program (n = 49)-or usual care (n = 46). Baseline and 3- and 12-month follow-up data were gathered from caregivers and from children's medical records. RESULTS: Treatment was associated with less bother from asthma symptoms, more symptom-free days, and better caregiver quality of life at follow-up for children 1-3, but not those 4-6, years of age. Treatment and control groups did not differ in caregiver asthma management behavior or children's acute care utilization. CONCLUSIONS: This home-based asthma education program was most effective with younger children; perhaps their caregivers were more motivated to learn about asthma management. Targeting psychosocial factors associated with asthma morbidity might also enhance the efficacy of asthma education for these families.     

The behavioral management of asthma and asthma-related problems in children: A critical review of the literature

This review focuses upon the behavioral approach to childhood asthma. Asthma is defined as intermittent, variable, and reversible airways obstruction with a complex multidimensional etiology. The major measures of asthma include physiological, symptomatic, and collateral measures. The behavioral management of childhood asthma has been restricted to relaxation training, systematic desensitization, assertive training, biofeedback, and deconditioning of exercise induced asthma. The efficacy of such intervention strategies for asthmatic children is in doubt, although the management of asthma-related problems in children appears to be a more promising area of research. The author suggests that the power of intervention programs for asthmatic children may be strengthened by the development of multifaceted treatment programs contingent upon the antecedents and consequences of the individual case. Also, behavior therapy may be of assistance to mild asthmatic children.     

Asthma control and future asthma-related morbidity in inner-city asthmatic children

BACKGROUND: Asthma guidelines recommend routine evaluation of asthma control, which includes measurements of impairment and risk. It is unclear whether rigorous asthma control changes risk of asthma morbidity. OBJECTIVE: To examine whether the degree of asthma control in inner-city asthmatic children results in differential risk reduction of future asthma-related morbidity. METHODS: This retrospective observational study examines 960 inner-city children with asthma who were highly engaged in an asthma-specific disease management program for a minimum of 2 years. Degree of asthma control was determined during the first year of enrollment and was categorized as well controlled (> or = 80% of visits in control), moderately controlled (50%-79% of visits in control), or difficult to control (< 50% of visits in control). Risk and probability of asthma-related morbidity at each visit were determined during the second year of enrollment and included self-reported asthma exacerbations requiring systemic corticosteroid rescue and emergency department visits or hospitalizations. RESULTS: Increasing the degree of asthma control measured during the first year of enrollment led to statistically significant incremental reductions in risk of acute asthma exacerbations and emergency department visits or hospitalizations during the second year of enrollment. CONCLUSIONS: Achieving and maintaining asthma control in inner-city children with asthma results in significant reductions in asthma-related morbidity. Systematic assessments of asthma control may be useful for predicting future risk in children with asthma.     

The role of parental coping in children with asthma's psychological well-being and asthma-related quality of life

OBJECTIVE: The primary purpose of our study was to examine the relationship between parental coping and children with asthma's psychological well-being and asthma-related quality of life (ArQL). METHODS: Eighty-nine mother-child dyads with a child with asthma ranging in age from 8 to 12-years old participated. During baseline and 6 month follow-up visits, children completed questionnaires assessing anxiety and ArQL; mothers completed questionnaires assessing coping, ArQL, an index of recent stressors, and demographic/medical history forms. RESULTS: Mothers who relied more on active coping strategies at baseline had children with better ArQL 6 months later, and those who relied on more avoidance coping strategies at baseline had children with poorer ArQL of life 6 months later. CONCLUSIONS: These results reveal that maternal coping plays an important role in the ArQL of children with asthma. Implications for interventions aimed at improving the physical and mental health of children with asthma are discussed.     

Association of control and risk of severe asthma-related events in severe or difficult-to-treat asthma patients

BACKGROUND: Clinical tools for predicting poor outcomes in asthma patients are lacking. This study investigated the association of asthma control and subsequent severe asthma-related healthcare events in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study. METHODS: The extent of asthma control problems was determined from baseline values of the Asthma Therapy Assessment Questionnaire (ATAQ). Patients self-reported the presence of severe asthma-related events at 6- and 12-month follow up. Poisson regression models determined the adjusted association between baseline control and the likelihood of severe asthma-related events. RESULTS: At baseline, 2942 patients (mean age, 49.6 years; female, 71.9%) had an ATAQ score (no control problems, 17.0%; 1 control problem, 20.0%; 2 control problems, 30.8%; 3 or 4 control problems, 32.2%) and at least one severe asthma-related event. After adjustment, subjects with three or four control problems were at greater risk for unscheduled office visits [relative risk (RR) = 2.8; 95% confidence interval (CI): 2.4-3.2], course of oral steroids (RR = 2.9; 95% CI: 2.5-3.3), emergency room visits (RR = 4.1; 95% CI: 2.7-6.2) or hospitalization (RR = 13.6; 95% CI: 7.4-24.9), vs no control problems. Progressively poorer levels of asthma control are associated with increasing risk of severe asthma-related events. CONCLUSIONS: This study provides evidence of an association between poor asthma control and future severe asthma-related healthcare events. A validated questionnaire may help clinicians identify patients requiring intervention to prevent future severe asthma-related events.     

Effect of environmental allergen sensitization on asthma morbidity in inner-city asthmatic children

Background Asthma causes significant morbidity in children, and studies have demonstrated that environmental allergies contribute to increased asthma morbidity.
Objective We investigated the differences between allergen skin tests and specific IgE (SIgE) and the role of IgG in regards to allergen exposure levels, and asthma morbidity in inner-city children.
Methods Five hundred and six serum samples from the National Cooperative Inner City Asthma Study (NCICAS) were evaluated for SIgE to cockroach ( Blattella germanica ), dust mite ( Dermatophagoides farinae ), and Alternaria as well as specific IgG (SIgG) and IgG₄ to cockroach ( B. germanica) and total IgE levels. Associations between sensitization to these allergens, exposures, and asthma morbidity were determined.
Results Sensitization to environmental allergens and total IgE correlated with increased health care and medication use, but not with symptoms of wheeze. Sensitization with exposure to cockroach was associated with increased asthma morbidity, whereas dust mite sensitization was correlated with asthma morbidity independent of exposure. There was also a strong correlation between SIgE levels and skin test results, but the tests did not always agree. The relationship between SIgE and asthma morbidity is linear with no obvious cutoff value. Increased Bla g 1 in the home was a good predictor for sensitization; however, this relationship was not demonstrated for Der f 1. Cockroach SIgG correlated with increased health care use, however, there was no modifying effect of SIgG or SIgG₄ on the association between cockroach SIgE and asthma morbidity.
Conclusions SIgE levels and skin prick test results to environmental allergens can serve as markers of severe asthma for inner-city children. Asthma morbidity increased in a linear manner with SIgE levels. IgG was not an important predictor or modifier of asthma morbidity.     

Allergens on desktop surfaces in preschools and elementary schools of urban children with asthma

Desktop dust has been studied as a source of food allergen, but not as a source of potential aeroallergen exposure. Thirty‐six wiped samples from desktop surfaces were collected from preschools and schools. Samples were analyzed for detectable levels of common aeroallergens including Alternaria, cockroach, dog, dust mite, cat, mouse, and rat allergens by immunoassay. Mouse allergen was the most prevalent, detectable in 97.2% of samples. Cat allergen was detectable in 80.6% of samples, and dog allergen was detectable in 77.8% of samples. Other allergens were not as prevalent. Mouse was the only allergen that was highly correlated with settled floor dust collected from the same rooms (r = 0.721, P < 0.001). This is the first study to detect aeroallergens on desktop surfaces by using moist wipes. Allergens for mouse, cat, and dog were highly detectable in wipes with mouse desktop surface levels correlating with levels in vacuumed floor dust.     

Pediatric asthma morbidity: the importance of symptom perception and family response to symptoms

OBJECTIVE: To determine whether family response to asthma symptoms mediates the relationship between child symptom perception and morbidity. METHODS: A total of 122 children with asthma, aged between 7 and 17 years (47% females; 25% ethnic minorities), were recruited from three sites. Participants completed a family asthma management interview and 5-6 weeks of symptom perception assessment. RESULTS: Family response to symptoms mediated the relationship between child underestimation of symptoms and asthma morbidity and partially mediated the relationship between accurate symptom perception and morbidity. In contrast, although child overestimation of symptoms and family response to symptoms were independently related to asthma morbidity, a mediational model was not supported. CONCLUSIONS: Our study found support for the role of family response to symptoms in mediating the relationship between child symptom perception and morbidity, particularly with regard to underestimation of symptoms, underscoring the need for behavioral tools to accurately recognize and optimally respond to exacerbations.     

Negative association of Enterobius infestation with asthma and rhinitis in primary school children in Taipei

BACKGROUND: The relationship between allergy and parasites has been controversial, especially in non-tropical countries. Enterobius vermicularis (human pinworm) is the most prevalent intestinal parasite in industrialized countries. OBJECTIVE: To examine the association between pinworm infestation and allergy in primary school children. METHOD: Peri-anal tape test for pinworm is routinely performed in Taipei primary schools. We collected data from school records and questionnaires distributed to all children in four primary schools grades 1 through 6 (n = 3107). RESULTS: The prevalence of physician-diagnosed asthma (9.3% vs. 14.1%, P = 0.007) and allergic rhinitis (27.4% vs. 38.3%, P = 0.001) was lower in pinworm-positive compared to uninfested children. Pinworm was not correlated with atopic dermatitis or parent allergy. With logistic regression controlling for sex, parent allergy and lower respiratory infection, current asthma (OR = 0.25, 95% CI 0.10-0.63) and rhinitis (OR = 0.61, 95% CI 0.45-0.84) were negatively associated with pinworm. Among children in grades 3-6 who had no asthma or rhinitis before age 7, those with early infestation (pinworm diagnosis at or before grade 1) had a lower risk of having diagnosis of rhinitis during school years, compared to the uninfected group (5.4% vs. 12.3%, P = 0.03; adjusted OR = 0.47, 95% CI 0.21-1.02). CONCLUSIONS: We identified a negative association between pinworm infestation and allergic airway diseases, which could in part be attributed to protective effect of pinworm infestation on development of allergic symptoms. Other mechanisms of association could not be ruled out.     

Psychological morbidity and coping skills in patients with brittle and non-brittle asthma: a case-control study

Background An association between psychological morbidity and asthma is well recognized and an increase in negative psychosocial factors in brittle asthma has been previously reported. Stich factors, apart from affecting patient perceptions, may alter patients’ self-management of their condition. Methods We have undertaken a case-control study on 29 well characterized brittle and non-brittle asthmatics in the West Midlands Region to assess their level of psychological morbidity, using the General Health Questionnaire (GHQ) and the living with asthma questionnaire, and their responses to changes in asthma symptoms, using the Asthma Symptom Checklist and a taped interview. Results Significant differences in GHQ (mean score brittle 19.5 vs non-brittle 7.2, P = 0.0002) and living with asthma (mean score brittle 1.30 vs non-brittle 1.00, P = 0.002) reinforced the presence of psychological factors in this group of patients with severe asthma. Interviews regarding responses to hypothetical asthma attacks showed that patients with brittle asthma delayed seeking medical attention more often than those with non-brittle asthma and instead preferred to self-administer beta-agonist medication. Sixteen (55.2%) of the 29 patients with brittle asthma would have delayed 7 days before seeking medical attention in a slow onset attack compared with 6/29 (20.7%) in the non-brittle group. In a fast onset attack 14 (48.3%) patients with brittle asthma would not have summoned help, despite finding it difficult to walk to the kitchen for a drink whereas in the non-brittle group 24 out of 29 (82.8%) would have summoned help. Levels of family support tended to be lower in patients with brittle asthma (mean family APGAR 7.3 vs 8.65 P = 0.09). Conclusions Brittle asthma is associated with greater psychological morbidity and altered strategies for coping with deteriorating asthma symptoms. Attention should be paid to the presence of such factors in the management of patients with brittle asthma.     

Ultrastructure of airways in children with asthma

This study describes the histopathology and ultrastructure of bronchial mucosa in lung biopsies from two children with bronchial asthma in remission, and compares them with lung samples from two children who died in status asthmaticus. Light microscopy of all samples showed changes typical of bronchial asthma, e.g. mucus plugging, goblet cell hyperplasia, 'thickening of bronchial basement membrane', peribronchial smooth muscle hypertrophy and eosinophilic infiltration. Electron microscopy revealed that the mucus plugs consisted of moderately electron-dense floccular material containing degenerate epithelial cells, macrophages and cell fragments. The luminal surfaces of ciliated cells showed cytoplasmic blebs and abnormal cilia. Mast cells in various stages of degranulation were scattered between bronchial epithelial cells. The subepithelial hyaline layer, commonly referred to as "thickened basement membrane", consisted of collagen fibrils in plexiform arrangement. The basement membrane proper appeared intact. These electron microscopic changes, particularly the presence of mast cells and subepithelial collagen deposits, were also found in autopsy samples. This combined light and electron microscopic study shows that marked, possibly irreversible changes may be present in the lungs of patients with severe bronchial asthma, even when they are asymptomatic. These pulmonary changes could be the direct consequence of mast cell activation and the release of various mediators. No evidence of immune complex deposition was found.