Search

BACKGROUND: Although outdoor particulate matter (PM) has been linked to mortality and asthma morbidity, the impact of indoor PM on asthma has not been well established. OBJECTIVE: This study was [...]

A study aims to find a possible association between bacterial colonization of the hypopharynx in asymptomatic neonates and later development of recurrent wheeze, asthma and allergy within 5 years of age. The results reveal that neonates colonized in the hypopharyngeal region with Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis have higher risk for recurrent wheeze and asthma in early life.

Asthma is one of the leading causes of childhood hospitalization, and its incidence is on the rise throughout the world. Currently, the standard treatment for asthma is the use of corticosteroids to try to suppress the inflammatory reaction taking place in the bronchial tree. Using a murine model of atopic allergic asthma employing a methacholine-hyperresponsive (A/J) as well as a hyporesponsive (C57BL/6) strain of mice sensitized and challenged with ovalbumin, we show that treatment with a synthetic Toll-like receptor 7 (TLR7) ligand (S-28463, a member of the imidazoquinoline family) prevents development of the asthmatic phenotype. Treatment with S-28463 resulted in a reduction of airway resistance and elastance following ovalbumin sensitization and challenge. This was accompanied by a dramatic reduction in infiltration of leukocytes, especially eosinophils, into the lungs of both C57BL/6 and A/J mice following OVA challenge. Treatment with S-28463 also abolished both the elevation in serum IgE level as well as the induction of IL-4, IL-5, and IL-13 by OVA challenge. The protective effects of S-28463 were also observed in MK2 knockout, but not MYD88 knockout, mice. We did not observe a switch in cytokine profile from [T.sub.H]2 to [T.sub.H]1, as both 1L-12p70 and IFN-[gamma] levels were reduced following S-28463 treatment. These results clearly demonstrate the anti-inflammatory effect of imidazoquinolines in an allergic asthma model as well as the clinical potential of TLR7 ligands in the treatment of allergic diseases. Toll-like receptors; asthma; eosinophils; lung; inflammation; mitogen-activated protein kinase-activated protein-2

Despite evidence that stressful experience can exacerbate the symptoms of asthma, little is known about the biological mechanisms through which this occurs. This study examined whether life stress reduces expression of the genes coding for the glucocorticold receptor and the [[beta].sub.2]-adrenergic receptor. A total of 77 children were enrolled in the study (59% male; mean age, 13.5 years). Thirty-nine of them were physician-diagnosed with asthma, and 38 were healthy. After an in-depth interview regarding stressful experiences, leukocytes were collected through antecubital venipuncture, and real-time RT-PCR was used to quantify mRNA. Chronic stress was associated with reduced expression of mRNA for the [[beta].sub.2]-adrenergic receptor among children with asthma. In the sample of healthy children, however, the direction of this effect was reversed. The occurrence of a major life event in the 6 months before the study was not sufficient to influence patterns of gene expression. When such events occurred in the context of a chronic stressor, however, their association with patterns of gene expression was accentuated. Children with asthma who simultaneously experienced acute and chronic stress exhibited a 5.5-fold reduction in glucocorticoid receptor mRNA and a 9.5-fold reduction in [[beta].sub.2]adrenergic receptor mRNA relative to children with asthma without comparable stressor exposure. These findings suggest that stressful experience diminishes expression of the glucocorticoid and [[beta].sub.2]-adrenergic receptor genes in children with asthma. To the extent that it diminishes sensitivity to the antiinflammatory properties of glucocorticoids or the bronchodilatory properties of [beta]-agonists, this process could explain the increased asthma morbidity associated with stress.

BACKGROUND. Several studies conducted during the 1990s indicated an increase in the prevalence of symptoms of asthma; more recent investigations suggest that the trend is stabilizing or may even be reversing. OBJECTIVE. We compared 2 cross-sectional surveys conducted in 1994 and 2002 in 8 areas in northern and central Italy, to evaluate prevalence changes for asthma, allergic rhinitis, and eczema. METHODS. The International Study of Asthma and Allergies in Childhood methods and questionnaires were used to investigate 6- to 7-year-old children (16 115 and 11 287 questionnaires completed by parents in 1994-1995 and 2002, respectively) and 13- to 14-year-old adolescents (19 723 and 10 267 questionnaires completed by adolescents in 1994-1995 and 2002, respectively). In each phase, the overall response rate was >90%. Prevalence changes were calculated as the absolute difference between the prevalence recorded on the 2 occasions. RESULTS. The prevalence of wheeze (past 12 months) increased slightly among children (change: 0.8%; 95% confidence interval [CI]: 0.0% to 1.6%) and was rather stable among adolescents. Symptoms of allergic rhinitis (children: change: 5.2%; 95% CI: 4.0% to 6.4%; adolescents: change: 4.1%; 95% CI: 1.9% to 6.3%) and symptoms of atopic eczema (children: change: 4.4%; 95% CI: 3.6% to 5.2%; adolescents: change: 2.1%; 95% CI: 1.2% to 3.0%) increased clearly in both age groups. There was some heterogeneity across the centers among adolescents, especially for allergic rhinitis, with larger increases seen in the 3 metropolitan areas. The changes observed paralleled profound family changes, ie, better parental education, higher rates of maternal employment, and lower rates of exposure to parental smoke. These factors, however, do not explain all of the observed changes in prevalence. CONCLUSIONS. The results indicate that the epidemiologic features of asthma and allergies in Italy are changing rapidly, although the causes are still uncertain. www.pediatrics.org/cgi/doi/10.1542/ peds.2004-2709 doi:10.1542/peds.2004-2709 Key Words asthma, rhinitis, eczema, children, adolescents Abbreviations SIDRIA--Italian Studies of Respiratory Diseases in Childhood and the Environment ISAAC--International Study of Asthma and Allergies in Childhood CI--confidence interval ECRHS--European Community Respiratory Health Survey, DURING THE 1990S, the prevalence of childhood asthma increased considerably, as observed in several countries. The general interpretation was that the phenomenon was real and not merely attributable to changes [...]

A study on the correlation between air pollution, socio-economic status and child hospitalization for asthma is presented.

Objective To investigate the prevalence and risk factors for wheezing disorders in early childhood in Sao Paulo, Brazil, the largest metropolitan area of South America. Methods A population-based cross-sectional survey of 1132 children aged 6-59 months was carried out between 1995 and 1996 to obtain information on recent wheezing and on independent variables such as demographic, socioeconomic, environmental, maternal and nutritional variables and immunization status. Intestinal parasitic infections were diagnosed using standard techniques. Multiple unconditional logistic regression was used to describe associations between outcome and independent variables. Findings The prevalence of recent wheezing (one or more reported episodes in the past 12 months) was 12.5%; 93% of children with wheezing were also reported to have a medical diagnosis of asthma. Recent wheezing was associated with low per capita income, poor quality of housing, day-care attendance, low birth weight and infection with intestinal helminths. Conclusion Wheezing in early childhood in Sao Paulo, although more common than in most developing countries, remains less prevalent than in urban areas of industrialized countries. Low income and conditions associated with poverty (poor housing, low birth weight and parasitic infections) are some of the main risk factors for wheezing disorders among young children in this city. Keywords Respiratory tract diseases/epidemiology; Asthma/epidemiology; Prevalence; Risk factors: Helminths; Giardiasis; Air pollution, Indoor; Socioeconomic factors; Housing; Vaccination; Child; Cross-sectional studies; Brazil (source: MESH, NLM). Mots cles Respiratoires, Maladies/epidemiologie; Asthme/epidemiologie; Prevalence: Facteur risque; Helminthe; Giardiase; Pollution air ambiant; Facteur socio-economique; Logement; Vaccination; Enfant; Etude section efficace; Bresil (source: MESH, INSERM). Palabras clave Enfermedades respiratorias/epidemiologia; Asma/epidemiologia; Prevalencia; Factores de riesgo; Helmintos; Giardiasis; Contaminacion del aire interior; Factores socioeconomicos; Vivienda; Vacunacion; Nino; Estudios transversales; Brasil (fuente: DeCS, BIREME). [TEXT NOT REPRODUCIBLE IN ASCII.] Bulletin of the World Health Organization 2004;82:516-522., Voir page 520 le resume en francais. En la pagina 520 figura un resumen en espanol. [TEXT NOT REPRODUCIBLE IN ASCII.] Introduction The rising prevalence of asthma, one of the [...]

Environmental exposures may increase a child's risk of developing asthma and also may increase the risk of asthma exacerbations. This article reviews several environmental exposures and suggests whether they contribute to asthma prevalence, asthma exacerbations, or both. Outdoor air exposures and violence are not likely to cause the increase in asthma prevalence. Exposure to outdoor air pollutants primarily leads to increased exacerbations, sometimes manifested as asthma clusters. Clinicians should be alert for space-time clusters of asthma exacerbations in the community, because these clusters may suggest a modifiable point-source exposure. Indoor air exposures are more strongly linked to the increase in asthma prevalence. Exposure to dust mites and tobacco smoke are risk factors for the development of asthma and may also exacerbate existing asthma. Effective measures to prevent exposures to these pollutants are available. With proper management, the amount of environmental exposures can be decreased. Whether decreasing these exposures will result in decreases in asthma prevalence and exacerbations is not yet documented., ABBREVIATION. ppb, parts per billion. Rates of asthma morbidity and mortality are increasing. (1-17) From 1980 to 1994, the prevalence of asthma in the United States increased 75%. (8) Asthma [...]

Objectives. This study tested the efficacy of coaching to reduce environmental tobacco smoke (ETS) exposure among asthmatic Latino children. Design. After asthma management education, families were randomly assigned to no additional service (control condition) or to coaching for ETS exposure reduction (experimental condition). Setting. The study was conducted in San Diego, California. Participants. Two hundred four Latino children (ages 3-17 years) with asthma participated. Intervention. Approximately 1.5 hours of asthma management education was provided; experimental families also obtained 7 coaching sessions (~45 minutes each) to reduce ETS exposure. Outcome Measures. Reported ETS exposure and children's urine cotinine were measured. Results. Parents in the coached condition reported their children exposed to significantly fewer cigarettes than parents of control children by 4 months (postcoaching). Reported prevalence of exposed children decreased to 52% for the coached families, but only to 69% for controls. By month 4, mean cotinine levels decreased among coached and increased among control children. Cotinine prevalence decreased from 54% to 40% among coached families, while it increased from 43% to 49% among controls. However, cotinine levels decreased among controls to the same level achieved by coached families by the 13-month follow-up. Conclusions. Asthma management education plus coaching can reduce ETS exposure more than expected from education alone, and decreases in the coached condition may be sustained for about a year. The delayed decrease in cotinine among controls is discussed. Pediatrics 2002;110:946-956; environmental tobacco smoke, passive smoking, coaching, Latino, women, children, asthma, cotinine., Asthma prevalence and incidence rates have increased worldwide. (1) US prevalence has increased 75% from 1980 to 1994, (2) with the greatest increase during this period taking place among children [...]

Serious lower respiratory tract respiratory syncytial virus (RSV) infections in infancy appears to be associated with later development of asthma and sensitivity to allergens. Forty-seven infants who were hospitalized with RSV bronchiolitis before one year old were each matched to two control children for age, sex, and area of residence. At one year, all children were tested for RSV antibodies, and at three years they were screened for sensitivity to common allergens. At one year, 89% of the bronchiolitis group had RSV antibodies versus 27% of control children. At three years, 23% of the bronchiolitis group had been diagnosed with asthma versus 1% of control children. Thirty-two percent of bronchiolitis children had positive allergy tests versus 9% of control children. Asthma and allergies associated with history of bronchiolitis. A family history of allergic skin rashes or asthma further increased risk. The fact that 27% of control children had antibodies to RSV suggests that only serious RSV infection is associated with asthma and allergies., ABSTRACT. Objective. To study the occurrence of bronchial obstructive symptoms and immunoglobulin (Ig) E antibodies after respiratory syncytial virus (RSV) bronchiolitis in infancy. Previous studies of this subject have mostly [...]

Infants and children younger than two years of age who are routinely exposed to passive smoke are at greater risk for wheezing and viral infection. Researchers assessed the prevalence of viral infection, passive smoke exposure and immunoglobulin E (IgE) measurements in infants and children under two years. These children had a high rate of viral infection and a low rate of IgE antibody to inhalant allergens. When exposed to passive smoke, these children registered elevated levels of salivary cotinine that suggested considerable exposure. Beyond two years of age, sensitization to inhaled allergens became ever more important, and viruses continued to be a major risk factor. Odds ratios for wheezing were significant for virus and cotinine in children under the age of two. Young patients should have reduced tobacco smoke exposure at home and be sensitized to inhaled allergens and avoid allergens to prevent wheezing., Objective. To examine the prevalence of viral infection, passive smoke exposure, and IgE antibody to inhaled allergens in infants and children treated for acute wheezing. Design. Case-control study of actively wheezing children who were compared with children without respiratory tract symptoms. Setting. University of Virginia Pediatric Emergency Room. Patients. Convenience sample of 99 wheezing patients (2 months to 16 years of age) and 57 control patients (6 months to 16 years of age). Measurements and results. Serum IgE antibody to inhalant allergens, measured by radioallergosorbent test (RAST), was uncommon in wheezing and control patients under age 2. After 2 years of age, the percentage of Rast-positive patients increased markedly and was significantly higher in wheezing patients than controls after age 4 (72%, n = 54, and 30%, n = 40, respectively, P age, particularly after age 2 years.

The incidence of bronchial hyperresponsiveness, an increased sensitivity of the lung airways, may be higher among children suffering from atopic dermatitis than among other children regardless of whether or not they have been diagnosed with asthma. Atopic dermatitis is a skin disorder caused by an allergic reaction to substances such as food. Among 61 children between seven and 15 years old who underwent testing for bronchial hyperresponsiveness, 21 children were suffering from atopic dermatitis and asthma, 22 were suffering from atopic dermatitis without any symptoms of asthma and 18 were suffering from neither atopic dermatitis or asthma. Bronchial hyperresponsiveness occurred in 95% of the children with atopic dermatitis and asthma, 78% of those with atopic dermatitis who did not experience any symptoms of asthma and 17% of the healthy children., Using histamine provocation tests, bronchial responsiveness was measured in 43 children with atopic dermatitis, aged 7 to 15 years, who had attended pediatric dermatology clinics within the past 5 years. The children were divided into two groups, one group of 21 children in whom asthma had been previously diagnosed and in whom symptoms of asthma had occurred in the preceding year, and the other comprising 22 children who denied any such symptoms. Bronchial hyperresponsiveness (as defined by a 20% fall in forced expiratory volume in 1 second at a provoking dose of histamine of 7.8 umol or less [PD.sub.20]) was demonstrated in all but 1 of the children with atopic dermatitis alone, but in only 3 of a control group of 18 children without atopic dermatitis or asthma. The asthmatic subjects (median [PD.sub.20] = 0.22 umol) had more severe bronchial hyperresponsiveness than the nonasthmatic subjects (median [PD.sub.20] = 2.10 umol). This study confirms the strong association between atopic dermatitis and bronchial hyperresponsiveness, even in the absence of overt asthmatic symptoms. Pediatrics 1993;91:13-16; eczema, atopic dermatitis, bronchial hyperresponsiveness, asthma.

The incidence of respiratory symptoms and asthma may be higher among children suffering from severe atopic dermatitis than among other children. Atopic dermatitis is a skin disorder caused by an allergic reaction to substances such as food. A survey compared the incidence of respiratory symptoms among 250 children between one and 15 years old with atopic dermatitis to that among 250 healthy children in the same age group. Eighty-five percent of the children with atopic dermatitis suffered from at least one respiratory symptom, compared with 26% of the healthy children. Sixty-eight percent of the children with atopic dermatitis were diagnosed with asthma, compared with 6% of the healthy children. Respiratory symptoms included wheezing, breathlessness and coughing during the night and early morning or after exercise., A postal questionnaire, completed by parents, was used to study the prevalence of respiratory symptoms in 250 children with atopic dermatitis who had attended pediatric dermatology clinics in London within the past 5 years. A response rate of 84% was achieved. Each child had a control matched for age and sex, whose parents filled in an identical questionnaire. The prevalence of wheezing was 76% in the atopic dermatitis group and 12% in the control group. Of the children with atopic dermatitis who wheezed, 87% had been given a diagnosis of asthma by a doctor, compared with 40% of the control children who wheezed. Overall, 68% of the children with atopic dermatitis had been given a diagnosis of asthma by a doctor. This prevalence of respiratory symptoms and of diagnosed asthma is substantially higher than has been shown in previous studies. As the test population consisted of children who had been referred to a tertiary center for management of their skin disease, this higher prevalence may partially reflect the increased severity of atopic dermatitis in the study group, as well as the heightened awareness of the association between these two diseases by their parents and physicians. Pediatrics 1993;91:8-12; atopic dermatitis, asthma, wheeze, epidemiology, atopic eczema.

Asthma is usually thought to be caused by the interaction of hereditary and environmental influences, but the contribution of each is unknown. It is known that airway responsiveness (reaction of the breathing passages), indicating asthma, is present during the first year of life, but it is not known when it first develops. A second question is whether infants respond identically at birth, or if a difference is already present. Recently it has become possible to measure respiratory function in infants, providing objective measurements of the presence of asthma. Sixty-three infants between the ages of two and 10 weeks were studied. Airway responsiveness to inhaled histamine (a compound found in cells that is released by allergic or inflammatory reactions) was present in all but five of the infants, suggesting that the reaction may be present from birth. A family history of asthma was associated with an increased level of airway responsiveness, suggesting a genetic link. Airway responsiveness was also greater among infants whose parents reported smoking during pregnancy, although this study could not distinguish between effects before and after birth. On the other hand, it was found that immunoglobulin E (IgE) level did not predict airway responsiveness, although other studies have indicated otherwise. The conclusion is that responsiveness is present from birth, and is both inherited and environmental, caused in some cases by exposure to parental smoking. Whether or not airway responsiveness among infants predicts later levels of responsiveness, respiratory problems, or allergies is not clear. (Consumer Summary produced by Reliance Medical Information, Inc.)

In 1978, a group of 93 British couples who had children born in 1977 or 1978 were recruited for a study of the association between house-dust mite allergen concentration and the development of asthma in their children. At least one member of each of the couples had asthma or hay fever. In all, 67 children were enrolled in the study. The houses of 57 children were visited during their infancy, and samples of house dust were collected at that time and again in 1989. The children were skin tested and subjected to other tests designed to diagnosis atopy, a tendency to react strongly to allergic stimulation. Individuals with atopy react immediately to inhaled allergens (material to which they are allergic, such as house-dust mite allergens). The majority of children with asthma in the United Kingdom are extremely sensitive to house-dust mite allergens; 80 percent of these children have a positive skin test for this allergen compared with only 30 percent of nonasthmatic children. Of the 67 children included in this study, 35 were atopic and 32 were nonatopic (not sensitive). Seventeen children had active asthma by the conclusion of the experiment. Sixteen of the asthmatic children were found to be atopic, all of whom were found to be allergic to house-dust mites. The development of atopy was statistically related to the concentration of mites in the dust samples taken from the children's homes. In all but one of the children with asthma, exposure to house-dust mites had occurred before the age of one year. Children exposed to higher levels of the allergen had an earlier age of onset of asthma. Although family genetic history plays a role in the development of asthma in children, it is concluded that the level of house-dust mite allergen is a significant factor in the development of asthma. (Consumer Summary produced by Reliance Medical Information, Inc.)

Research has shown that many children who eventually develop asthma had poor lung function when they were very young. This supports the idea that some environmental factor in the lives of young children may be responsible for predisposing them to asthma. Also, doctors may come up with treatments for young children that can prevent them from developing chronic asthma.

PCR-denaturing gradient gel analysis was used to evaluate the effects of environmental exposures typically associated with asthma protection or risk on the microbial community structure of household dust. The findings indicated that specific bacterial populations within the bacterial community structure are associated with either risk or protection from asthma.

A study was conducted to examine hypothesized model of the relationship between maternal depression and child psychological and physical dysfunction mediated by parenting and medication adherence. Findings show that the maternal depression was linked to child psychological dysfunction both directly and indirectly through negative parenting but linked to physical dysfunction only indirectly through psychological dysfunction.

Callahan KA, Eggleston PA, Rand CS, Kanchanaraksa S, Swart LJ, Wood RA. Ann Allergy Asthma Immunol. 2003; 90:302-307 Purpose of the Study. To compare the knowledge and practice of environmental [...]

Purpose of the Study. To examine the association between the frequency of use of antibiotics in the first year of life and the occurrence of asthma, allergic rhinitis, and eczema at 5 years. This was a prospective study that examined the association of antibiotic use and the development of allergic disease. Methods. The study reports on 498 infants who had a history of allergy or asthma in at least 1 parent. At 2 months of life and subsequently every 2 months until age 2, a questionnaire was given to the primary caregiver. After the second year of life, the questions were asked every 6 months. Every 2 months questions were asked about the use of antibiotics. The multivariate analysis included a large number of variables including the child's race, household income, and daycare attendance in the first year of life. Parental and familial factors included in utero cigarette smoke exposure, number of months of breastfeeding, parents' history of asthma, allergic rhinitis, or eczema, number of siblings in the household, and the average number of cigarettes smoked by adults in the household. At 5 years of age, asthma was defined as a physician diagnosis and 1 or more episodes of wheezing in the previous 12 months. Similarly, allergic rhinitis was defined as a physician diagnosis of allergic rhinitis and a history of nasal symptoms in the past 12 months, and eczema had to be physician-diagnosed with the presence of a pruritic rash at least 6 months in the past year. Beginning with the second year of life, the primary caregiver was asked about the number of attacks of wheezing in the past 12 months. The children were categorized as having transient, late-onset, or persistent wheezing. Transient wheezing was defined as 1 or more episodes of wheezing before the age of 3 years but none between the ages 4 and 5. Late-onset wheezing was the occurrence of wheezing between the ages of 4 and 5 years, and persistent wheezing was the occurrence of wheezing before and after age 3 years. Results. Three hundred fifty-two (70.7%) of the 498 participants received 752 courses of oral antibiotics in their first year of life. These antibiotics were given for ear infections (62.1%), wheezing (21.4%), cough (10.9%), nasal congestion/discharge (3.9%), difficulty breathing (1%), and difficulty eating (0.7%). Ninety percent of the group were monitored up to age 5 years (n = 448). A subset of the group underwent an evaluation for total immunoglobulin E (IgE) (n = 230; 46.2%) at age 2 years. No significant association was found between the use of oral antibiotics in the first year of life and asthma, allergic rhinitis, or eczema at age 5 years. Among the 448 children, 90 had at least 1 allergic disorder at age 5 years. Within the group that developed these disorders, 30 (33.3%) received no antibiotic, 17 (18.9%) received 1 course, and 43 (47.8%) received 2 or more courses of antibiotics in the first year of life. Antibiotic use was significantly associated with transient wheezing; however, the association became weaker after adjustments for other variables. Transient wheezing was significantly associated with low household income. There was no association between antibiotic use in the first year of life and asthma in the persistent wheezing group. Persistent wheezing was more associated with male sex and a maternal history of asthma. A "reverse causation" was also looked into. When those children who were given antibiotics for wheezing were taken out of the analysis, there still was no association found. There was also no association in the late-onset wheezing group. Serum IgE levels were not different between those who had antibiotics and those who did not receive them in the first year of life. Conclusions. In this prospective study of children from Boston, born to parents who had a history of allergy, there was no support for the theory that the use of antibiotics in early childhood is associated with the development of asthma or allergy at age 5 years. Reviewer's Comments. This is a negative study and frequently such studies only tell us what did not work. I do think that although this is a "negative" study, it is important, well-done, and makes a significant contribution. Recently, a hypothesis has been put forth that suggests that the increase in the prevalence of allergic diseases may be associated with reduced exposure to infections and perhaps the use or frequent use of antibiotics in young children. The implication was that an antibiotic permits the immature immune system to remain in the allergy favoring TH-2 mode. The authors of this article point out that the support for the hypothesis had come from 5 retrospective studies. This may be the first prospective study on this issue and the conclusions are that antibiotic use in the first year of life does not seem to be associated with the subsequent development of asthma, allergic rhinitis, or eczema., Celedon JC, Litonjua AA, Ryan L, Weiss ST, Gold DR. Am J Respir Crit Care Med. 2002;166:72-75 FREDERICK E. LEICKLY, MD Indianapolis, [...]

A study conducted by the Cincinnati Children's Hospital Medical Center shows that exposure to environmental tobacco smoke, even at extremely low levels, is associated with behavior problems in children and [...]