Higher Prevalence Of Atopy Research Articles

Sex Differences in Exercise-Induced Bronchoconstriction in Athletes: A Systematic Review and Meta-Analysis.

Exercise-induced bronchoconstriction (EIB) is a common complication of athletes and individuals who exercise regularly. It is estimated that about 90% of patients with underlying asthma (a sexually dimorphic disease) experience EIB; however, sex differences in EIB have not been studied extensively. With the goal of better understanding the prevalence of EIB in males and females, and because atopy has been reported to occur at higher rates in athletes, in this study, we investigated sex differences in EIB and atopy in athletes. A systematic literature review identified 60 studies evaluating EIB and/or atopy in post-pubertal adult athletes (n = 7501). Collectively, these studies reported: (1) a 23% prevalence of EIB in athletes; (2) a higher prevalence of atopy in male vs. female athletes; (3) a higher prevalence of atopy in athletes with EIB; (4) a significantly higher rate of atopic EIB in male vs. female athletes. Our analysis indicates that the physiological changes that occur during exercise may differentially affect male and female athletes, and suggest an interaction between male sex, exercise, and atopic status in the course of EIB. Understanding these sex differences is important to provide personalized management plans to athletes with underlying asthma and/or atopy.

Prevalence and risk factors for asthma, rhinitis, eczema, and atopy among preschool children in an Andean city.

Limited data are available on prevalence and associated risk factors for atopy and allergic diseases from high-altitude urban settings in Latin America. To estimate the prevalence of atopy, asthma, rhinitis, and eczema, and associations with relevant risk factors in preschool children in the Andean city of Cuenca. A cross-sectional study was undertaken using a representative sample of 535 children aged 3-5 years attending 30 nursery schools in the city of Cuenca, Ecuador. Data on allergic diseases and risk factors were collected by parental questionnaire. Atopy was measured by skin prick test (SPT) reactivity to a panel of relevant aeroallergens. Associations between risk factors and the prevalence of atopy and allergic diseases were estimated using multivariable logistic regression. Asthma symptoms were reported for 18% of children, rhinitis for 48%, and eczema for 28%, while SPT reactivity was present in 33%. Population fractions of asthma, rhinitis, and eczema attributable to SPT were 3.4%, 7.9%, and 2.9%, respectively. In multivariable models, an increased risk of asthma was observed among children with a maternal history of rhinitis (OR 1.85); rhinitis was significantly increased in children of high compared to low socioeconomic level (OR 2.09), among children with a maternal history of rhinitis (OR 2.29) or paternal history of eczema (OR 2.07), but reduced among children attending daycare (OR 0.64); eczema was associated with a paternal history of eczema (OR 3.73), and SPT was associated with having a dog inside the house (OR 1.67). A high prevalence of asthma, rhinitis, and eczema symptoms were observed among preschool children in a high-altitude Andean setting. Despite a high prevalence of atopy, only a small fraction of symptoms was associated with atopy. Parental history of allergic diseases was the most consistent risk factor for symptoms in preschool children.

Persistent asthma phenotype related with late-onset, high atopy, and low socioeconomic status in school-aged Korean children

BackgroundTreatment guidelines for asthma have been established based on asthma severity; there are limitations in the identification of underlying pathophysiology and prediction of prognosis in heterogeneous phenotypes of asthma. Although the complex interactions between environmental and genetic factors affect the development and progression of asthma, studies on asthma phenotypes considering environmental factors are limited. This study aimed to identify asthma phenotypes using latent class analysis including environmental factors in school-age children.MethodsWe included 235 children (6–8 years) with parent-reported, physician-diagnosed asthma from the Children’s HEalth and Environmental Research (CHEER) study, which is a 4-year prospective follow-up study with 2-year intervals. At every survey, pulmonary function tests, methacholine challenge tests and blood tests with questionnaire were conducted.ResultsFour asthma phenotypes were identified. Cluster 1 (22% of children) was characterized by high prevalence of atopy and mild symptoms; subjects in cluster 2 (17%) consisted of less atopy and normal lung function, but intermittent troublesome; cluster 3 (29%) experienced late-onset atopic troublesome asthma with decreased lung function in combination with low socioeconomic status; and cluster 4 was associated with early-onset and less-atopic infrequent asthma.ConclusionsLate-onset, high atopy, and low socioeconomic status are associated with troublesome persistent asthma phenotype in school-age children. Environmental factors might be implicated in the clinical heterogeneity of asthma. Asthma phenotypes considering diverse factors might be more helpful in the identification of asthma pathogenesis and its prevention.

Exercice-induced bronchoconstriction among athletes: Assessment of bronchial provocation tests

Diagnosis of exercise-induced bronchoconstriction (EIB) requires the use of bronchial provocation tests (BPTs). We assessed exercise-induced respiratory symptoms (EIRS), EIB and asthma in athletes and evaluated the validity of BPTs in the diagnosis of EIB. Rhinitis and atopy were also assessed.Athletes with (n=55) and without previous asthma diagnosis (n=145) were tested by skin prick tests, lung function and eNO measurements. EIRS were recorded and EIB was assessed by methacholine (Mch), eucapnic voluntary hyperpnoea (EVH), mannitol and exercise test.EIRS were highly reported and history of asthma was common among athletes. A high prevalence of atopy (48.7%) and allergic rhinitis (30.5%) was found. Athletes with asthma had a higher response rate to Mch and to EVH, as compared with athletes without a previous asthma diagnosis (P=0.012 and P=0.017 respectively). Report of EIRS, rhinitis and atopy were not associated with a positive BPT response.Screening athletes for EIB using BPTs is suggested, irrespective of reported EIRS or a previous asthma diagnosis.

Genetic Association Analysis Reveals Differences in the Contribution of NOD2 Variants to the Clinical Phenotypes of Orofacial Granulomatosis.

Orofacial granulomatosis (OFG) is a rare, inflammatory disorder of the mouth, in which some patients also have intestinal Crohn's disease (CD). The etiology remains largely unknown, although there is a high prevalence of atopy, and oral granulomas are also seen in other immune disorders particularly CD and sarcoidosis. We investigated whether genetic variants associated with an increased risk of CD, sarcoidosis, or atopy were also associated with susceptibility to OFG. Patients were stratified clinically as isolated oral manifestations (OFG only) or concurrent intestinal CD (OFG+CD). We genotyped 201 patients and 1023 healthy controls for risk variants in NOD2, IRGM, IL23R, ATG16L1 (CD), BTNL2 (sarcoidosis), and FLG (atopy). The coding regions of the NOD2 gene were screened for rare, potentially pathogenic variants in OFG. A combined analysis of 3 CD-risk variants in NOD2 showed no association with any OFG subgroup. NOD2 p.L1007insC was associated with OFG+CD (P = 0.023) and IL23R p.R381Q with all OFG (P = 0.031). The sarcoidosis risk variant rs2076530 in BTNL2 was associated with all OFG (P = 0.013). We identified 7 rare missense NOD2 alleles in 8 individuals with OFG, 4 OFG-only patients and 4 patients with OFG+CD. There was a significant enrichment of NOD2 variants in the OFG+CD group compared to the OFG-only group (P = 0.008, common variants; P = 0.04, all common and rare variants). Our findings suggest that genetic variants in NOD2 are only associated with OFG in patients with concurrent intestinal disease. A genome-wide association scan is needed to fully define the genetic architecture of OFG.

High Prevalence of Atopy in Severe Persistent Pediatric Asthmatics in Memphis, Tennessee

Objective: Asthma is a heterogeneous disease that affects millions of adults and children in the United States. The patho-mechanism of asthma is still being elucidated and therapies that control this disease have limitations. It is important to be able to distinguish various asthma phenotypes to allow personalized treatments. Methods: Pediatric asthmatics from one single institution were enrolled for genomic DNA repository study if they fit the WHO guidelines for severe persistent asthmatics. Various personal health information of the first 100 children were reviewed including gender, age, smoke exposure, lung function test, ICU admissions, controller medication, insurance, body mass index, and allergy skin testing results. Results: Review of the cohort showed a younger population with a median age of 9 years old. Most importantly, 97% of the patients were found to be atopic. Other findings include a predominantly African American population (89%), mainly holding public insurance (76%), and a significantly overweight and obese (56%) cohort. Conclusion: The rate of atopy in our cohort of pediatric severe asthmatic children is extremely high, likely due to a warm and humid climate leading to high pollination, mold spores and dust mite content. Early aggressive environmental control and allergen immunotherapy, weight control and social changes are needed. Keywords: Severe asthma; Pediatric; Phenotype; Atopy; Obesity

Immunoglobulin deficiency in patients with chronic rhinosinusitis: Systematic review of the literature and meta-analysis

Several studies have shown a high prevalence of immunoglobulin deficiencies in patients with chronic rhinosinusitis (CRS). We sought to perform a systematic review and meta-analysis to estimate this prevalence more precisely and to identify patients who need substitution treatment. All case series published after 1990 describing patients with CRS, which was defined as symptomatic rhinosinusitis for more than 12 weeks and documented immunoglobulin deficiencies (including deficiencies of IgG with subclasses, IgA, and IgM; specific antibody deficiencies; and potential common variable immunodeficiency), were retrieved. A meta-analysis of the proportion of any combination of common variable immunodeficiency, IgG deficiency, IgA deficiency, and IgM deficiency in patients with CRS was performed by using logit transformation of the prevalence. Recurrent CRS was defined as rhinosinusitis not controlled by appropriate conservative management for 4 months, and difficult-to-treat CRS was defined as noncontrollable rhinosinusitis despite successful sinus surgery and appropriate conservative management for at least 1 year. The meta-analysis revealed a prevalence of pooled IgG, IgA, and IgM deficiencies in 13% of patients with recurrent CRS and 23% of patients with difficult-to-treat CRS. The prevalence of IgG subclass deficiency (5% to 50%) and specific antibody deficiency (8% to 34%) was increased in patients with CRS, as was the prevalence of respiratory allergies in patients with recurrent CRS (31% to 72%). Immunoglobulin deficiency is a frequent condition in patients with CRS. An even higher prevalence of atopy was observed in patients with recurrent CRS. Therefore immunoglobulin titers and accurate allergy diagnostic workups are strongly recommended in these patients to provide specific treatments for symptom alleviation. However, there is a need for larger prospective studies addressing the effect of specific therapeutic interventions for CRS.

Functional and biological characteristics of asthma in cleaning workers

Cleaning workers have an increased risk of asthma but the underlying mechanisms are largely unknown. We studied functional and biological characteristics in asthmatic cleaners and compared these to healthy cleaners. Forty-two cleaners with a history of asthma and/or recent respiratory symptoms and 53 symptom-free controls were identified. Fractional exhaled nitric oxide (FeNO) was measured and forced spirometry with reversibility testing was performed. Total IgE, pulmonary surfactant protein D and the 16kDa Clara Cell secretory protein were measured in blood serum. Interleukins and other cytokines, growth factors, cys-leukotrienes and 8-isoprostane were measured in exhaled breath condensate. Information on occupational and domestic use of cleaning products was obtained in an interview. Associations between asthma status, specific characteristics and the use of cleaning products were evaluated using multivariable linear and logistic regression analyses. Asthma was associated with an 8% (95% confidence interval (CI) 1-15%) lower postbronchodilator FEV1, a higher prevalence of atopy (42% vs. 10%) and a 2.9 (CI 1.5-5.6) times higher level of total IgE. Asthma status was not associated with the other respiratory biomarkers. Most irritant products and sprays were more often used by asthmatic cleaners. The use of multiuse products, glass cleaners and polishes at work was associated with higher FeNO, particularly in controls. Asthma in cleaning workers is characterised by non-reversible lung function decrement and increased total IgE. Oxidative stress, altered lung permeability and eosinophilic inflammation are unlikely to play an important underlying role, although the latter may be affected by certain irritant cleaning exposures.

Risk factors and characteristics of respiratory and allergic phenotypes in early childhood

Unsupervised approaches can be used to analyze complex respiratory and allergic disorders. We investigated the respiratory and allergic phenotypes of children followed in the Pollution and Asthma Risk: An Infant Study (PARIS) birth cohort. Information on respiratory and allergic disorders, medical visits, and medications was collected during medical examinations of children at 18 months of age; biomarker data were also collected (total and allergen-specific IgE levels and eosinophilia). Phenotypes were determined by using latent class analysis. Associated risk factors were determined based on answers to questionnaires about environmental exposures. Apart from a reference group, which had a low prevalence of respiratory symptoms or allergies (n=1271 [69.4%]), 3 phenotypes were identified. On the basis of clinical signs of severity and use of health care resources, we identified a mild phenotype (n=306 [16.7%]) characterized by occasional mild wheeze and 2 severe phenotypes separated by atopic status. The atopic severe phenotype (n=59 [3.2%]) included 49 (83%) children with wheezing and was characterized by a high prevalence of atopy (61% with allergenic sensitization) and atopic dermatitis (78%). In contrast, atopy was rare among children with the nonatopic severe phenotype (n=195 [11%]); this group included 88% of the children with recurrent wheezing. Risk factors for respiratory disease included parental history of asthma, male sex, siblings, day care attendance, exposure to tobacco smoke or molds, indoor renovations, and being overweight, although these factors did not have similar affects on risk for all phenotypes. Atopy should be taken into account when assessing the risk of severe exacerbations (that require hospital-based care) in wheezing infants; precautions should be taken against respiratory irritants and molds and to prevent children from becoming overweight.

Commentary on “Chronic Idiopathic Urticaria in Taiwan: A Clinical Study of Demographics, Aggravating Factors, Laboratory Findings, Serum Autoreactivity and Treatment Response”

In this issue, Lee et al performed a prospective cross-sectional, single-center study which included 62 chronic idiopathic urticaria (CIU) patients in Taiwan.1 A higher prevalence of atopy, especially allergic rhinitis, occurred in CIU patients than in general adult population in this study. The authors did not find any associations between the severities of CIU but patients with atopy were associated with poorer therapeutic response of secondgeneration antihistamine with standard dose. The role of atopy in CIU has been controversial. Despite the higher prevalence of atopy in CIU in this paper, a selection bias may be present because patients with poor response to standard dose of anti-histamine may be overrepresented in a tertiary referral hospital. Urticaria has been considered as a condition that the local dermal edema occurs because of the release of histamine from mast cells. However, recent studies have found the roles of other vasoactive mediators, such as prostaglandin, kinin, and interleukin-31 in the pathogenesis of CIU.2 The involvement of cytokines other than histamine provides an explanation for the ineffectiveness of antihistamine and the needs of immunomodulatory therapy in selected cases of CIU. Chronic urticaria is an enigmatic condition and search for a specific cause is often futile despite an extensive work-up. Food allergy is the most frequently sought after cause for chronic urticaria for the patients, and hence tests for specific IgE are often performed. However, only rarely can food be incriminated as the cause for chronic urticaria. Instead, there is emergent evidence to suggest an autoimmune basis in up to 60% of patients with CIU.3 Severe itching, extensive disease, more systemic symptoms, resistant to antihistamine treatment and need of immunosuppressant therapy are key clinical features described for this group of patients.4 Autologous serum skin test (ASST) is a nonspecific screening test which evaluates the presence of serum histamine-releasing factors and has been used as a surrogate test for the detection

Wheeze in the absence of asthma at age 8-10 is not associated with atopy in Manitoba children

Background Atopy in children with recurrent wheeze is the best predictor for persistent asthma. A high prevalence of atopy was found in children with recurrent wheeze who were at high risk of developing persistent asthma based on the Asthma Predictive Index (API)[1]. A newly modified API now includes allergic sensitization to aeroallergens and to foods as criteria for the risk assessment of persistent asthma in children with recurrent wheeze. However, associations between wheeze and atopy in the absence of asthma have not been extensively examined. Since atopy is considered a risk marker for asthma in children with recurrent wheeze, we predicted that it would not be associated with wheeze when asthma was absent.

Serum carotenoids and atopy among children of different ethnic origin living in Germany

The manifestation of atopy in early life is thought to be influenced by the diet. We hypothesized that the previously reported lower prevalence of atopy among Turkish immigrant children in Germany might be related to a different pattern of serum carotenoids. Serum carotenoid concentrations were measured in pre-school children of different ethnic origin from Berlin, D. German children (D, N = 49) were compared to Turkish children with well (TR-D, N = 32) or weak cultural adaptation (TR-TR, N = 41). Serum levels of pro-vitamin A carotenoids (α- and β-carotene, β-cryptoxanthin) and non-pro-vitamin A carotenoids (lutein, zeaxanthin, lycopene) were measured by high performance liquid chromatography. Serum IgE to common inhalant allergens was measured by immunoassay. Median levels of pro-vitamin A carotenoids were lower in Turkish children if compared to German children: D 135 μg/L, TR-D 100 μg/L (p = 0.025), TR-TR 82 μg/L (p = 0.001). By contrast, median levels of non-pro-vitamin A carotenoids were not higher in German children. The ratio of pro-vitamin A to non-pro-vitamin A carotenoid median levels was highest among D (2.05), lower among TR-D (1.32; p = 0.001) and lowest among TR-TR (1.26; p < 0.001)). A higher ratio was not significantly associated with atopy (atopic 1.79, non-atopic 1.36; p = 0.067). Pro-vitamin A carotenoids are higher in children originating from a cultural population with a higher prevalence of atopy, but atopy seems not to be directly related to the current carotenoid serum levels in children at school age. The distinct pattern of carotenoid levels among Turkish migrant and German children indicates changed nutrition patterns with acculturation.

Association between Obesity and the Prevalence of Allergic Diseases, Atopy, and Bronchial Hyperresponsiveness in Korean Adolescents

Background: Although several mechanisms underlying the asthma-obesity connection have been proposed, debates still remain. This study was to determine whether overweight is associated with a higher prevalence of atopy, asthma symptoms, airway obstruction, bronchial hyperresponsiveness (BHR) or biomarkers of inflammation in a sample of Korean adolescents. Methods: We conducted a cross-sectional survey involving questionnaires, skin tests, spirometry and methacholine challenge tests among 717 adolescents from Seoul (South Korea). Overweight status was defined as a BMI greater than the local age- and gender-specific 85th percentile. Results: Overweight subjects more frequently reported ever having wheezing (24.6 vs. 14.0%, p = 0.001) and wheezing in the previous 12 months (11.5 vs. 6.3%, p = 0.02) than normal-weight subjects, especially in boys. Atopy was more common among overweight adolescents than among those of normal weight (61.5 vs. 49.2%, p = 0.002), especially in boys (65.0 vs. 52.8%, p = 0.005). Overweight subjects had higher total WBC counts and eosinophil counts, especially boys. The presence of BHR was more common only among overweight girls (32.8 vs. 18.0%, p = 0.028). Overweight status was a significant risk factor for the presence of atopy (odds ratio = 1.49; 95% CI 1.06–2.10), after adjusting for various confounders by logistic regression analysis. Conclusions: An association was found between overweight status and both atopy and an increased prevalence of wheezing in adolescent Korean boys. These findings suggest that being overweight in puberty may be one of several risk factors responsible for atopy, BHR, and asthma symptoms.

Atopy in HIV-infected children in Pretoria.

The development or aggravation of a pre-existing atopic state in patients with human immunodeficiency virus (HIV) has not been thoroughly investigated in South Africa. HIV-infected adults have been shown to have a higher prevalence of atopy in some international studies, but this has not been documented in children. A prospective convenience sample of 50 children aged between 3 months and 12 years attending the Tshwane District Hospital Paediatric HIV Clinic in Pretoria was recruited. Their personal and family histories of atopy, World Health Organization (WHO) HIV clinical staging and Centers for Disease Control (CDC) immunological staging with CD4 counts were documented. An age- and sex-matched control group of 50 HIV-negative children was included. Skin prick tests (SPTs) to identify common aeroallergens were conducted on all patients. One hundred children were enrolled, with 50 in each group. Ten per cent of the HIV-infected patients compared with 16% of controls had positive SPTs to aeroallergens. A higher percentage of the HIV-infected patients had chronic rhinitis and eczema (60% and 68%, respectively). There was no relationship between CD4 count and positive SPTs (p = 0.61), mean log CD4 count and presence of reported asthma (p = 0.71), and CD4 count and presence of reported dermatitis (p = 0.84). The CD4 count was not statistically different between children with and without a family history of atopy (p = 0.68). It appears that the stage of HIV disease does not influence the development or expression of allergy. There is a high prevalence of dermatitis and chronic rhinitis in HIV-infected children, probably not atopic in origin.

Relationship between atopic asthma and the population prevalence rates for asthma or atopy in children: Atopic and nonatopic asthma in epidemiology

Innumerable articles have tried to solve the "continuing enigma of atopic and nonatopic asthma" but notwithstanding the strenuous efforts to substantiate the few well-known clinico-epidemiologic differences between these two forms of asthma most studies have hitherto generated inconclusive statements. In a recent study based on the review of epidemiologic studies conducted worldwide in unselected populations of children, we documented that the prevalence of atopic asthma (AA) was high in the populations with a high prevalence of atopy. We systematically reviewed 36 articles that studied 48 populations of unselected children and reported prevalence rates for asthma and atopy in the total sample and in the subpopulations. No significant difference was found in the prevalence of asthma cases in the quartiles of childhood populations subdivided for the prevalence of atopy. In addition, atopy did not increase significantly in the subgroups of populations subdivided by asthma quartiles. In both subgroups, however, AA increased with increasing atopy or with increasing asthma (p < 0.001). Using a positive skin-prick test reaction to define cases of asthma as cases of AA is misleading because the prevalence of subjects so defined is heavily influenced by the environmentally generated changes in the prevalence of atopy or asthma. Asthma in a child should be labeled as a case of AA only if skin-prick tests yield a positive reaction and the clinical history documents asthma symptoms triggered by allergen exposure.

Maternal exposure to paternal antigens can modulate the foetus immune system and is associated with reduced atopy in the childhood

The influence of the maternal immune system on pregnancy and on the foetus immune system have given rise to a variety of observations and interesting hypotheses. For example, the higher prevalence of atopy in first-born children as compared to their brotherhood is known as the “birth order effect”. The “hygienic hypothesis” states that more hygienic live conditions, and consequently reduced exposure to pathogens in young age (included the period of foetal development), increases the risk of atopy. Here we review the ideas concerning maternal exposure to paternal antigens and immunomodulation. In particularly, we discuss the idea that this phenomenon may induce a regulatory environment in women that interfere with the developing foetal immune system. This regulatory environment could be responsible for protecting children to the development of atopy during adulthood. We propose that maternal exposure to paternal antigens through different situations, such as pregnancy, repeated exposure to sperm or Paternal Leukocyte Immunization (PLI) would combine the “birth order effect” and the “hygienic hypothesis” and thus lower the risk to atopy in children through the transference of a regulatory environment to the foetus.

High prevalence of atopy, but not of asthma, among children in an industrialized area in North Italy: The role of familial and environmental factors – a population‐based study

The prevalence of atopy and asthma, and their association with familial and environmental factors were investigated among 13- to 14-yr-old children living in Brescia, an industrialized town in North Italy. All the 1450 children attending primary school in the town were invited to participate, and 967 of them (66.7%, 493 males) provided a valid questionnaire filled in by their parents at home. We used a modified version of the questionnaire adopted in the Italian Study of Respiratory Disorders in Childhood and Environment, which is an extended version of the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Six hundred and twenty-eight subjects underwent skin prick test (SPT), and 308 of them (49%) were positive for at least one of the 12 allergen extracts commonly employed. Ninety-nine children (10.2%) had a physician's diagnosis of asthma - 12.4% of the males and 8.0% of the females (p = 0.03). The prevalence of wheezing in the past 12 months was 6.2%. Atopy was found in 76.8% of the subjects with, and in 45.6% of those without physician's diagnosis of asthma (p < 0.001). Analysis by multiple logistic regression showed an inverse association between physician-diagnosed asthma and female sex (odds ratio, OR = 0.5); presence of relatives in the bedroom in initial years of life (OR = 0.6); attending day care (OR = 0.4) and infant school (OR = 0.4); a positive association with parental history of wheezing (OR = 2.5) and asthma (OR = 3.8); and the child's history of asthmatic bronchitis (OR = 31.9) and atopic eczema (OR = 3.8) in the first 2 yr of life. The strength of the associations did not change when restricting the analysis to atopic asthma. In conclusion, atopy and clinical asthma among 13- to 14-yr-old adolescents are significantly associated with some familial and environmental factors, providing further support for the hygiene hypothesis. Prevalence of atopy, but not of asthma, is high in this industrialized area. The strong association found between atopy and clinical asthma suggests that atopy may play a role in causing asthma in genetically predisposed children only.

Evaluation of the Efficacy of Prednisolone in Early Wheezing Induced by Rhinovirus or Respiratory Syncytial Virus

The role of systemic corticosteroids in the treatment of early childhood wheezing in children is not clear. We sought to determine whether prednisolone is effective in rhinovirus-induced early wheezing. We conducted a controlled trial comparing oral prednisolone (2 mg/kg per day in three divided doses for 3 days) with placebo in 78 hospitalized children (mean age, 1.1 year; standard deviation, 0.7) experiencing their first or second episode of wheezing induced by rhinovirus or respiratory syncytial virus. Mixed viral infections were excluded. Our primary end point was the time until the patient was ready for discharge; secondary end points included oxygen saturation during hospitalization, duration of symptoms, occurrence of relapses during the next 2 months and blood eosinophil counts at discharge and 2 weeks later. In multivariate regression analysis, prednisolone did not influence the time until ready for discharge, but it decreased relapses during the subsequent 2-month period in rhinovirus-affected children (prednisolone versus placebo, 22% versus 56%; odds ratio, 19.06; 95% confidence interval, 2.52-144.03; P = 0.004) and in children with blood eosinophils > or = 0.2 x 10/L (respectively, 24% versus 71%; odds ratio, 10.57; 95% confidence interval, 1.99-56.22; P = 0.006). Rhinovirus-affected children had more blood eosinophils on admission (mean, 0.44 versus 0.086 x 10/L), had a higher prevalence of atopy (44% versus 8%) and were older (mean, 1.4 versus 0.9 years, P < 0.001 for all) than respiratory syncytial virus-infected children. Prednisolone reduced relapses during a 2-month period after first episodes of wheezing associated with rhinovirus infection or blood eosinophils > or = 0.2 x 10/L.

Bronchial Hyperresponsiveness, Airway Inflammation, and Airflow Limitation in Endurance Athletes

Whereas a high prevalence of bronchial abnormalities has been reported in endurance athletes, its underlying mechanisms and consequences during exercise are still unclear. The purpose of this study was to assess the following: (1) bronchial responsiveness to methacholine and to exercise; (2) airway inflammation; and (3) airflow limitation during intense exercise in endurance athletes with respiratory symptoms. Cross-sectional observational study. Lung function and exercise laboratory at a university hospital. Thirty-nine endurance athletes and 13 sedentary control subjects were explored for the following: (1) self-reported respiratory symptoms; (2) bronchial hyperresponsiveness (BHR) to methacholine and exercise; (3) airflow limitation during intense exercise; and (4) bronchial inflammation using induced sputum and nitric oxide (NO) exhalation. Fifteen athletes (38%) showed BHR to methacholine and/or exercise in association with bronchial eosinophilia (mean [+/- SD] eosinophil count, 4.1 +/- 8.5% vs 0.3 +/- 0.9% vs 0%, respectively), higher NO concentrations (19 +/- 10 vs 14 +/- 4 vs 13 +/- 4 parts per billion, respectively), a higher prevalence of atopy, and more exercise-induced symptoms compared with non-hyperresponsive athletes and control subjects (p < 0.05). Furthermore, airflow limitation during intense exercise was observed in eight athletes, among whom five had BHR. Athletes with airflow limitation reported more symptoms and had FEV1, FEV1/FVC ratio, and forced expiratory flow at midexpiratory phase values of 14%, 9%, and 29%, respectively, lower compared with those of nonlimited athletes (p < 0.05). BHR in endurance athletes was associated with the criteria of eosinophilic airway inflammation and atopy, whereas airflow limitation during exercise was primarily a consequence of decreased resting spirometric values. Both BHR and bronchial obstruction at rest with subsequent expiratory flow limitation during exercise may promote respiratory symptoms during exercise in athletes.

The hygiene hypothesis: does it function worldwide?

This article intends to be a systematic review of papers published during 2003-2004 quoted in a Medline search for 'hygiene hypothesis'. The worldwide perspective of the article does not refer just to a geographical concept, but tries also to address the question of whether the consensus on the hypothesis is global or whether it applies to all types of allergic or immunologic disease, to any age sample or infectious agent. Furthermore, the article outlines those clinical and experimental studies which, in the authors' opinion, may represent significant contributions to a better understanding of the hygiene hypothesis and may guide further investigations on the subject. The association between a reduced exposure to infectious agents (as a part of a changed lifestyle) and a higher prevalence of atopy seems now to be confirmed by consistent evidence. Mechanisms underlying this association, however, are not yet completely clear (immune deviation or immune regulation). Further experimental and clinical studies are needed, with special reference to the time, duration and intensity of exposure to any specific infectious agent which is related to well-defined allergy outcomes. The background information for using microbial products in allergy prevention and treatment is still limited.