Hay fever, eczema, and wheeze: a nationwide UK study (ISAAC, international study of asthma and allergies in childhood)

12-month prevalence of atopic dermatitis in resource-rich countries: a systematic review and meta-analysis

There is a lack of robust prevalence estimates of atopic dermatitis (AD) globally and trends over time due to wide variation of populations and age groups studied, different study methodologies and case definitions used. We sought to characterize 12-month AD prevalence across the life span and change over time in resource-rich countries focusing on population-based studies and using a standardized AD case definition. This systematic review was conducted according to PRISMA guidelines. Medline (Ovid), Embase, WOS core collection, Cinahl, and Popline were searched for studies published since inception through August 15, 2016. Studies were synthesized using random effects meta-analysis. Sources of heterogeneity were investigated using subgroup analyses and meta-regression. From 12,530 records identified, 45 studies met the inclusion criteria. Meta-analysis with random effects revealed the 12-month period prevalence of 9.2% (95% confidence interval 8.4-10.1%). The prevalence was significantly higher among 0-5-year-old children (16.2%; 95% confidence interval 14.2-18.7%) than in older age groups. Studies using a random sampling strategy yielded lower prevalence estimates than studies relying on other sampling methods. There was no clear time trend in AD prevalence over the period of 1992-2013.

New Insights on the Role of pentraxin-3 in Allergic Asthma

Pentraxins are soluble pattern recognition receptors that play a major role in regulating innate immune responses. Through their interaction with complement components, Fcγ receptors, and different microbial moieties, Pentraxins cause an amplification of the inflammatory response. Pentraxin-3 is of particular interest since it was identified as a biomarker for several immune-pathological diseases. In allergic asthma, pentraxin-3 is produced by immune and structural cells and is up-regulated by pro-asthmatic cytokines such as TNFα and IL-1β. Strikingly, some recent experimental evidence demonstrated a protective role of pentraxin-3 in chronic airway inflammatory diseases such as allergic asthma. Indeed, reduced pentraxin-3 levels have been associated with neutrophilic inflammation, Th17 immune response, insensitivity to standard therapeutics and a severe form of the disease. In this review, we will summarize the current knowledge of the role of pentraxin-3 in innate immune response and discuss the protective role of pentraxin-3 in allergic asthma.

Prevalences of Allergic Disorders in Children with Terra Firma-Forme Dermatosis

Background:

Terra firma-forme dermatosis (TFFD) is a clinical condition that may be defined as a dirty appearance of skin. Although it has been defined for many years, its clinical value is not well known.

Objective:

We aimed to determine the prevalence of allergic disorders (asthma, allergic rhinitis, and eczema) to investigate if this clinical condition is associated with allergic disorders in children with TFFD.

Materials and Methods:

A questionnaire descriptive of allergic disorders [International Study of Asthma and Allergies in Children (ISAAC)] was applied to all children diagnosed with TFFD at the pediatric clinics during a 6-month period specified for the study. The results were compared with the two ISAAC studies that have been previously conducted in our region.

Results:

The prevalence of TFFD among 1695 children examined at our outpatient clinic was found to be 3.18% (n = 54). The youngest of the children was 6 months old and the oldest 13 years, with an average age of 6.08 ± 2.69 years. Our study group had significantly greater rates and intensities of lifetime wheezing, wheezing in the last 12 months (current wheezing), lifetime allergic rhinitis, allergic rhinitis in the last 12 months; and the rate of physician-diagnosed allergic rhinitis compared to the comparator groups (P < 0.005).

Conclusions:

The results support the view that TFFD may be a sign of associated asthma and allergic rhinitis.

Multiple environmental exposures in early-life and allergy-related outcomes in childhood

INTRODUCTION

Early onset and high prevalence of allergic diseases result in high individual and socio-economic burdens. Several studies provide evidence for possible effects of environmental factors on allergic diseases, but these are mainly single-exposure studies. The exposome provides a novel holistic approach by simultaneously studying a large set of exposures. The aim of the study was to evaluate the association between a broad range of prenatal and childhood environmental exposures and allergy-related outcomes in children.

MATERIAL AND METHODS

Analyses of associations between 90 prenatal and 107 childhood exposures and allergy-related outcomes (last 12 months: rhinitis and itchy rash; ever: doctor-diagnosed eczema and food allergy) in 6-11 years old children (n = 1270) from the European Human Early-Life Exposome cohort were performed. Initially, we used an exposome-wide association study (ExWAS) considering the exposures independently, followed by a deletion-substitution-addition selection (DSA) algorithm considering all exposures simultaneously. All the exposure variables selected in the DSA were included in a final multi-exposure model using binomial general linear model (GLM).

RESULTS

In ExWAS, no exposures were associated with the outcomes after correction for multiple comparison. In multi-exposure models for prenatal exposures, lower distance of residence to nearest road and higher di-iso-nonyl phthalate level were associated with increased risk of rhinitis, and particulate matter absorbance (PM_abs) was associated with a decreased risk. Furthermore, traffic density on nearest road was associated with increased risk of itchy rash and diethyl phthalate with a reduced risk. DSA selected no associations of childhood exposures, or between prenatal exposures and eczema or food allergy.

DISCUSSION

This first comprehensive and systematic analysis of many environmental exposures suggests that prenatal exposure to traffic-related variables, PM_abs and phthalates are associated with rhinitis and itchy rash.

@choo: Tracking Pollen and Hayfever in the UK Using Social Media

Allergic rhinitis (hayfever) affects a large proportion of the population in the United Kingdom. Although relatively easily treated with medication, symptoms nonetheless have a substantial adverse effect on wellbeing during the summer pollen season. Provision of accurate pollen forecasts can help sufferers to manage their condition and minimise adverse effects. Current pollen forecasts in the UK are based on a sparse network of pollen monitoring stations. Here, we explore the use of “social sensing” (analysis of unsolicited social media content) as an alternative source of pollen and hayfever observations. We use data from the Twitter platform to generate a dynamic spatial map of pollen levels based on user reports of hayfever symptoms. We show that social sensing alone creates a spatiotemporal pollen measurement with remarkable similarity to measurements taken from the established physical pollen monitoring network. This demonstrates that social sensing of pollen can be accurate, relative to current methods, and suggests a variety of future applications of this method to help hayfever sufferers manage their condition.

A programme of research to set priorities and reduce uncertainties for the prevention and treatment of skin disease

Background

Skin diseases are very common and can have a large impact on the quality of life of patients and caregivers. This programme addressed four diseases: (1) eczema, (2) vitiligo, (3) squamous cell skin cancer (SCC) and (4) pyoderma gangrenosum (PG).

Objective

To set priorities and reduce uncertainties for the treatment and prevention of skin disease in our four chosen diseases.

Design

Mixed methods including eight systematic reviews, three prioritisation exercises, two pilot randomised controlled trials (RCTs), three feasibility studies, two core outcome initiatives, four funding proposals for national RCTs and one completed national RCT.

Setting

Secondary care, primary care and the general population.

Participants

Patients (and their caregivers) with eczema, vitiligo, SCC and PG, plus health-care professionals with an interest in skin disease.

Interventions

Our three intervention studies included (1) barrier enhancement using emollients from birth to prevent eczema (pilot RCT); (2) handheld narrowband ultraviolet light B therapy for treating vitiligo (pilot RCT); and (3) oral ciclosporin (Neoral®, Novartis Pharmaceuticals) compared with oral prednisolone for managing PG (pragmatic national RCT).

Results

Systematic reviews included two overarching systematic reviews of RCTs of treatments for eczema and vitiligo, an umbrella review of systematic reviews of interventions for the prevention of eczema, two reviews of treatments for SCC (one included RCTs and the second included observational studies), and three reviews of outcome measures and outcome reporting. Three prioritisation partnership exercises identified 26 priority areas for future research in eczema, vitiligo and SCC. Two international consensus initiatives identified four core domains for future eczema trials and seven core domains for vitiligo trials. Two pilot RCTs and three feasibility studies critically informed development of four trial proposals for external funding, three of which are now funded and one is pending consideration by funders. Our pragmatic RCT tested the two commonly used systemic treatments for PG (prednisolone vs. ciclosporin) and found no difference in their clinical effectiveness or cost-effectiveness. Both drugs showed limited benefit. Only half of the participants’ ulcers had healed by 6 months. For those with healed ulcers, recurrence was common (30%). Different side effect profiles were noted for each drug, which can inform clinical decisions on an individual patient basis. Three researchers were trained to PhD level and a dermatology patient panel was established to ensure patient involvement in all aspects of the programme.

Conclusions

Findings from this programme of work have already informed clinical guidelines and patient information resources. Feasibility studies have ensured that large national pragmatic trials will now be conducted on important areas of treatment uncertainty that address the needs of patients and the NHS. There is scope for considerable improvement in terms of trial design, conduct and reporting for RCTs of skin disease, which can be improved through wider collaboration, registration of trial protocols and complete reporting and international consensus over core outcome sets. Three national trials have now been funded as a result of this work. Two international initiatives to establish how best to measure the core outcome domains for eczema and vitiligo are ongoing.

Trial registration

Current Controlled Trials Barrier Enhancement for Eczema Prevention (BEEP) (ISRCTN84854178 and NCT01142999), Study of Treatments fOr Pyoderma GAngrenosum Patients (STOP GAP) (ISRCTN35898459) and Hand Held NB-UVB for Early or Focal Vitiligo at Home (HI-Light Pilot Trial) (NCT01478945).

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 4, No. 18. See the NIHR Journals Library website for further project information.

Atopic dermatitis, asthma and allergic rhinitis in general practice and the open population: a systematic review

OBJECTIVE

To examine whether significant differences exist between the self-reported prevalence of atopic disorders in the open population compared with physician diagnosed prevalence of atopic disorders in general practice.

METHODS

Medline (OvidSP), PubMed Publisher, EMBASE, Google Scholar and the Cochrane Controlled Clinical Trials Register databases were systematically reviewed for articles providing data on the prevalence of asthma, allergic rhinitis and eczema in a GP setting. Studies were only included when they had a cross-sectional or cohort design and included more than 100 children (aged 0-18 years) in a general practice setting. All ISAAC studies (i.e. the open population) that geographically matched a study selected from the first search, were also included. A quality assessment was conducted. The primary outcome measures were prevalence of eczema, asthma and allergic rhinitis in children aged 0-18 years.

RESULTS

The overall quality of the included studies was good. The annual and lifetime prevalences of the atopic disorders varied greatly in both general practice and the open population. On average, the prevalence of atopic disorders was higher in the open population.

CONCLUSION

There are significant differences between the self-reported prevalence of atopic disorders in the open population compared with physician diagnosed prevalence of atopic disorders in general practice. Data obtained in the open population cannot simply be extrapolated to the general practice setting. This should be taken into account when considering a research topic or requirements for policy development. GPs should be aware of the possible misclassification of allergic disorders in their practice. Key Points Epidemiological data on atopic disorders in children can be obtained from various sources, each having its own advantages and limitations. On average, the prevalence of atopic disorders is higher in the open population. GPs should take into account the possible misclassification of atopic disorders in their practice population. Policymakers should be aware that data obtained in the open population cannot simply be extrapolated to the general practice setting.

Helicobacter pylori-Mediated Protection from Allergy Is Associated with IL-10-Secreting Peripheral Blood Regulatory T Cells

Helicobacter pylori infections are usually established in early childhood and continuously stimulate immunity, including T-helper 1 (Th1), Th17, and regulatory T-cell (Treg) responses, throughout life. Although known to be the major cause of peptic ulcer disease and gastric cancer, disease occurs in a minority of those who are infected. Recently, there has been much interest in beneficial effects arising from infection with this pathogen. Published data robustly show that the infection is protective against asthma in mouse models. Epidemiological studies show that H. pylori is inversely associated with human allergy and asthma, but there is a paucity of mechanistic data to explain this. Since Th1 and Treg responses are reported to protect against allergic responses, we investigated if there were links between the human systemic Th1 and Treg response to H. pylori and allergen-specific IgE levels. The human cytokine and T-cell responses were examined using peripheral blood mononuclear cells (PBMCs) from 49 infected and 58 uninfected adult patients. Concentrations of total and allergen-specific plasma IgE were determined by ELISA and ImmunoCAP assays. These responses were analyzed according to major virulence factor genotypes of the patients' colonizing H. pylori strains. An in vitro assay was employed, using PBMCs from infected and uninfected donors, to determine the role of Treg cytokines in the suppression of IgE. Significantly higher frequencies of IL-10-secreting CD4(+)CD25(hi) Tregs, but not H. pylori-specific Th1 cells, were present in the peripheral blood of infected patients. Total and allergen-specific IgE concentrations were lower when there was a strong Treg response, and blocking IL-10 in vitro dramatically restored IgE responses. IgE concentrations were also significantly lower when patients were infected with CagA(+) strains or those expressing the more active i1 form of VacA. The systemic IL-10(+) Treg response is therefore likely to play a role in H. pylori-mediated protection against allergy in humans.

Atopic Dermatitis and Respiratory Allergy: What is the Link

Understanding the aetiology and progression of atopic dermatitis and respiratory allergy may elucidate early preventative and management strategies aimed towards reducing the global burden of asthma and allergic disease. In this article, we review the current opinion concerning the link between atopic dermatitis and the subsequent progression of respiratory allergies during childhood and into early adolescence. Advances in machine learning and statistical methodology have facilitated the discovery of more refined definitions of phenotypes for identifying biomarkers. Understanding the role of atopic dermatitis in the development of respiratory allergy may ultimately allow us to determine more effective treatment strategies, thus reducing the patient and economic burden associated with these conditions.

Effects of Air Pollution and the Introduction of the London Low Emission Zone on the Prevalence of Respiratory and Allergic Symptoms in Schoolchildren in East London: A Sequential Cross-Sectional Study

The adverse effects of traffic-related air pollution on children’s respiratory health have been widely reported, but few studies have evaluated the impact of traffic-control policies designed to reduce urban air pollution. We assessed associations between traffic-related air pollutants and respiratory/allergic symptoms amongst 8–9 year-old schoolchildren living within the London Low Emission Zone (LEZ). Information on respiratory/allergic symptoms was obtained using a parent-completed questionnaire and linked to modelled annual air pollutant concentrations based on the residential address of each child, using a multivariable mixed effects logistic regression analysis. Exposure to traffic-related air pollutants was associated with current rhinitis: NOx (OR 1.01, 95% CI 1.00–1.02), NO₂ (1.03, 1.00–1.06), PM₁₀ (1.16, 1.04–1.28) and PM_2.5 (1.38, 1.08–1.78), all per μg/m³ of pollutant, but not with other respiratory/allergic symptoms. The LEZ did not reduce ambient air pollution levels, or affect the prevalence of respiratory/allergic symptoms over the period studied. These data confirm the previous association between traffic-related air pollutant exposures and symptoms of current rhinitis. Importantly, the London LEZ has not significantly improved air quality within the city, or the respiratory health of the resident population in its first three years of operation. This highlights the need for more robust measures to reduce traffic emissions.

What factors are associated with the prevalence of atopic symptoms amongst adolescents in Greater Manchester?

INTRODUCTION

Atopy commonly manifests itself as atopic diseases (ADs), namely asthma, eczema and hay fever. The prevalence of AD is rising worldwide, and it is widely accepted as a major public health issue, due to the significant burden of AD on health care systems.

METHOD

Data were obtained from the youth survey of the European Urban Health Indicator System 2 project. The study participants were students aged 14-16 years from Greater Manchester. The main outcomes measured were the prevalence of atopic symptoms and the factors associated with the development of atopy.

RESULTS

Of the sample studied, 70% reported having had an AD during their lifetime. The lifetime prevalence of ever having asthma, eczema or hay fever was 33.4%, 28.1% and 49.0%, respectively. Gender, family affluence, body mass index, diet, smoking and worrying were all significantly associated with atopic symptoms. Smoking was the only variable to be significantly associated with all three ADs. Season of birth and pollution were not shown to be associated with atopic symptoms.

CONCLUSION

This study demonstrates that the prevalence of AD in Greater Manchester was high amongst adolescents. Several environmental, demographic and social factors were found to be significantly associated with the development of atopic symptoms. This study provides a baseline for future studies to further investigate the factors that are associated with AD and allow for the implementation of preventative public health policy.

Interrelationships between Atopic Disorders in Children: A Meta-Analysis Based on ISAAC Questionnaires

Purpose

To study the prevalence and interrelationship between asthma, allergic rhinitis and eczema using data obtained from ISAAC questionnaires.

Method

The Medline, Pubmed Publisher, EMBASE, Google Scholar and the Cochrane Controlled Clinical Trials Register databases were systematically reviewed to evaluate epidemiological data of children with atopic disorders. To study these interrelationships, a new approach was used. Risk ratios were calculated, describing the risk of having two different atopic disorders when the child is known with one disorder.

Results

Included were 31 studies, covering a large number of surveyed children (n=1,430,329) in 102 countries. The calculated worldwide prevalence for asthma, eczema and allergic rhinitis is 12.00% (95% CI: 11.99-12.00), 7.88% (95% CI: 7.88-7.89) and 12.66% (95% CI: 12.65-12.67), respectively. The observed prevalence [1.17% (95% CI: 1.17-1.17)] of having all three diseases is 9.8 times higher than could be expected by chance. For children with asthma the calculated risk ratio of having the other two disorders is 5.41 (95% CI: 4.76-6.16), for children with eczema 4.24 (95% CI: 3.75-4.79), and for children with allergic rhinitis 6.20 (95% CI: 5.30-7.27). No studied confounders had a significant influence on these risk ratios.

Conclusions

Only a minority of children suffers from all three atopic disorders, however this co-occurrence is significantly higher than could be expected by chance and supports a close relationship of these disorders in children. The data of this meta-analysis supports the hypothesis that there could be a fourth distinct group of children with all three disorders. Researchers and clinicians might need to consider these children as a separate group with distinct characteristics regarding severity, causes, treatment or prognosis.

Helicobacter pylori-Mediated Protection against Extra-Gastric Immune and Inflammatory Disorders: The Evidence and Controversies

A large number of studies link H. pylori infection with a reduced risk of developing extra-gastric conditions such as allergy, asthma, inflammatory bowel disease, coeliac disease and multiple sclerosis. The strength of the evidence for these protective associations is quite variable, and published studies often do not agree. This review article discusses some of the reasons for these discrepancies, and the difficulties faced when designing studies. Examples of some protective disease associations are described in detail, where the evidence is most abundant and thought to be more reliable. The most convincing of these are supported by published mechanistic data, for example with animal models, or incidence of disease exacerbation in humans following H. pylori eradication. Although controversial, this field is very important as the prevalence of H. pylori is decreasing throughout the world whilst many chronic diseases are becoming more common. These trends are likely to continue in the future, therefore it is important that we fully understand if and how H. pylori confers protection.

Developmental profiles of eczema, wheeze, and rhinitis: two population-based birth cohort studies

BACKGROUND

The term "atopic march" has been used to imply a natural progression of a cascade of symptoms from eczema to asthma and rhinitis through childhood. We hypothesize that this expression does not adequately describe the natural history of eczema, wheeze, and rhinitis during childhood. We propose that this paradigm arose from cross-sectional analyses of longitudinal studies, and may reflect a population pattern that may not predominate at the individual level.

METHODS AND FINDINGS

Data from 9,801 children in two population-based birth cohorts were used to determine individual profiles of eczema, wheeze, and rhinitis and whether the manifestations of these symptoms followed an atopic march pattern. Children were assessed at ages 1, 3, 5, 8, and 11 y. We used Bayesian machine learning methods to identify distinct latent classes based on individual profiles of eczema, wheeze, and rhinitis. This approach allowed us to identify groups of children with similar patterns of eczema, wheeze, and rhinitis over time. Using a latent disease profile model, the data were best described by eight latent classes: no disease (51.3%), atopic march (3.1%), persistent eczema and wheeze (2.7%), persistent eczema with later-onset rhinitis (4.7%), persistent wheeze with later-onset rhinitis (5.7%), transient wheeze (7.7%), eczema only (15.3%), and rhinitis only (9.6%). When latent variable modelling was carried out separately for the two cohorts, similar results were obtained. Highly concordant patterns of sensitisation were associated with different profiles of eczema, rhinitis, and wheeze. The main limitation of this study was the difference in wording of the questions used to ascertain the presence of eczema, wheeze, and rhinitis in the two cohorts.

CONCLUSIONS

The developmental profiles of eczema, wheeze, and rhinitis are heterogeneous; only a small proportion of children (∼ 7% of those with symptoms) follow trajectory profiles resembling the atopic march. Please see later in the article for the Editors' Summary.

β-Glucan supplementation, allergy symptoms, and quality of life in self-described ragweed allergy sufferers

This randomized, placebo-controlled, double-blind study compared the effects of daily supplementation for 4 week with 250 mg Wellmune WGP® β-1,3/1,6-Glucan (WGP) with placebo 250 mg/day (rice flour) on physical and psychological health attributes of self-described “moderate” ragweed allergy sufferers. Study participants (mean age = 36 ± 9 year; range 18–53 year) were recruited before the beginning of ragweed season (September) in Northeastern Ohio. Serum IgE concentration, allergy symptoms [via self-report, Visual Analog Scale (VAS), and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ)], psychological well-being [Profile of Mood States (POMS)], and physical function (RAND SF-36 Medical Outcomes Study) were measured immediately prior to and after supplementation with WGP (n = 24) or placebo (n = 24) for 4 weeks. Data were analyzed using repeated measures analyses of variance (ANOVA). Compared with placebo, WGP reduced total allergy symptoms (28%), symptom severity (52%), and symptom rating on the VAS (37%) (P < 0.05), but had no effect on serum IgE levels. As measured by the POMS, WGP increased participants' rating of vigor (10%), but reduced tension (34%), depression (45%), anger (41%), fatigue (38%), and confusion (34%) (P < 0.05). Study participants given WGP reported increased physical health (11%), energy (19%), and emotional well-being (7%) compared with study participants given the placebo (RAND SF-36 Medical Outcomes Study). The WGP group also reported decreased sleep problems (53%), reduced nasal symptoms (59%), eye symptoms (57%), non-nasal symptoms (50%), activities (53%), emotions (57%), and improved quality of life (QOL) (56%), as well as improved global mood state (13%). Supplementation with WGP for 4 weeks improved allergy symptoms, overall physical health, and emotional well-being compared with placebo in self-described “moderate” ragweed allergy sufferers during ragweed allergy season.

Recognition of allergic conjunctivitis in patients with allergic rhinitis

AIMS

To identify the incidence of allergic conjunctivitis in patients with allergic rhinitis.

METHODS

One hundred and eighty seven consecutive patients with allergic rhinitis (AR) were directly questioned if they have allergic conjunctivitis (AC) and this was clarified using standard screening questions relating to red, itchy and watery eyes recorded through a total ocular symptom score (TOSS). Patients were also asked about further symptoms that may be attributable to AC: eyelid dermatitis, frequent blinking; eye sensitivity and frontal headache from squinting or. blinking. All patients were given a drop of olopatadine hydrochloride 0.1% in each eye to help identify "silent" disease. 20 healthy non-atopic controls were also treated with olopatadine drops and questioned on ocular symptoms.

RESULTS

Fifty five percent of patients with AR were identified as having AC by direct questioning and the use of the TOSS questionaire. A further 41% were identifiable by asking additional questions and performing therapeutic challenge with olopadatine.

CONCLUSIONS

AC is a frequent comorbid condition occurring in 95% of our patients with AR. Only 55% of patients were able to identify that they had AC based on standard screening questions. Additional specific questioning and a therapeutic challenge in suspected patients can help identify patients who may benefit from treatment of AC.

Does change of residence affect pollinosis? A study of Japanese university students

The effects of change of residence on pollinosis symptoms remain unclear. We investigated the effects of geographical change of residence on pollinosis symptoms among university freshmen. All freshmen (n = 2142) entering Shinshu University in 2011 completed self-administered questionnaires. Associations between history of pollinosis and environmental factors were assessed. Subjects were classified into three groups according to pollen count at previous residences (stationary, low pollen, and high pollen). Pollinosis both before and after relocation were compared among and within the groups. Of the 1558 subjects, 540 (34.7%) developed pollinosis before and 483 (31.0%) after entering university. The rates of pre- and post-university entrance pollinosis were 40.0 and 32.5% in the high pollen group (P < 0.001) but were similar in the other two groups. Pollinosis symptoms decreased among students that moved from high to low pollen areas, indicating that pollinosis was affected by geographic environmental factors.

Sensitization to food allergens in Iranian children with mild to moderate persistent asthma

BACKGROUND

Asthma is the most common chronic respiratory disease in childhood. The clinical presentation of asthma may worsen after food allergen ingestion in sensitized patients. To avoid nonspecific dietary restrictions in children with asthma, laboratory-based advice about foods is potentially helpful. The purpose of this study was to determine food sensitization in children with asthma.

METHODS

Seventy-nine children with mild to moderate persistent asthma were included in this study. Commercial food allergens including cow's milk, egg white, almond, potato, and soybean were used in skin prick tests. Specific IgE to 20 common food allergens was also measured in serum.

RESULTS

Twelve (15.2%) of the patients had a positive skin prick test to at least one of the five food extracts. Sensitization was detected by skin prick tests to cow's milk and egg white (each 6.3%), almond (3.8%), potato (2.5%) and soybean (1.3%). Specific IgE levels ≥0.35 kAU/L were detected in the serum of 47% of the children with asthma. The most common food allergens were cow's milk (26.6%), hazelnuts (25.3%), wheat flour (15.2%) and egg white (12.6%). Patients with a history of at least one hospital admission due to asthma attack had a higher rate of sensitization to egg.

CONCLUSIONS

In our study, food sensitization was frequent in Iranian children with asthma. Although clinical food allergy could not be evaluated because food challenge tests were not used in our study, skin prick tests and serum-specific IgE to common food allergens might be helpful in identifying children with food sensitization.

Pulmonary function test in transfusion-dependent β-thalassemia major patients: a pilot study

Lung involvement is one of known complications of thalassemia. The aim of this study was to determine predominant type of pulmonary dysfunction and its relationship to iron overload in β-thalassemia children. Fifty thalassemia major children with treatment of regular blood transfusion and desferrioxamine participated in the study. Thirty-three boys and 17 girls (median age 12.5 years) with β-thalassemia enrolled in the study. Other information including body mass index, hematocrit, and the number of years of blood transfusion were recorded. Serum ferritin level and hematocrit were 3346 ± 1667 mg/dL and 27.7 ± 2, respectively. Pulmonary function tests were performed in all subjects for detecting pulmonary dysfunction. Thirty-five patients (70%) with thalassemia had abnormal result of spirometry. Obstructive airway disease based on reduced forced expiratory volume in 1 second (FEV(1)) and FEV(1)/forced vital capacity (FVC) ratio <80% was detected in 4 patients (8%). Six patients (12%) showed restrictive pattern, as defined by a reduction FVC <80% and FEV(1)/FVC ratio ≥80%. In this study, small airway involvement based on presence of forced expiratory flow (FEF(25%-75%)) <60%, FEV(1)/FVC ratio >70%, and FVC >80% was detected in 25 subjects (50%). Decreased values of peak expiratory flow rate (PEF) were detected in 23 (46%) and low FEV(1) in 10 (20%) subjects. There was no significant correlation between abnormal pulmonary function test and serum ferritin level in children with thalassemia. This study showed small airway disease was predominant abnormality in thalassemia patients, although additional larger studies are needed to evaluate underlying mechanisms and validate these findings.

Immunochromatographic assay for measurement of total IgE in tears, nasal mucus, and saliva of patients with allergic rhinoconjunctivitis

OBJECTIVE

Measurement of total immunoglobulin E (IgE) is clinically important for the diagnosis of allergic diseases. The total serum IgE level is normally measured because of its widespread use and convenience, but little attention has been paid to the measurement of local IgE concentrations. We evaluated whether the measurement of local production of IgE in tears, saliva, and nasal mucus was useful for the diagnosis of allergic rhinoconjunctivitis.

METHODS

A prospective, nonrandomized, cross-sectional study was conducted in 33 consecutive patients with seasonal allergic rhinoconjunctivitis (allergic group) and in 30 age- and sex-matched healthy control subjects (control group). The total IgE level was measured in tears, saliva, and nasal mucus from all subjects. Using a 4- or 5-point scale, symptoms (sneezing, rhinorrhea, nasal obstruction, ocular itching, and lacrimation) were assessed in each subject along with the activities of daily living (ADL) score and total symptom score for allergic conjunctivitis.

RESULTS

Total IgE could be assayed within 10 minutes of collection in all samples. The scores for all symptoms were higher in the allergic group than in the control group (p < .00001). The IgE scores for tear fluid samples (p < .00001) and undiluted saliva (p = .00003) were significantly higher in the allergic group than in the control group. The total IgE score of tear fluid samples was strongly correlated with the severity of symptoms of allergic conjunctivitis, including ocular itching (r = 0.769, p < .00001), tearing (r = 0.560, p = .00035), and ocular symptom score (r = 0.329, p = .03452). On the contrary, the total IgE scores for both saliva and nasal mucus were correlated with the severity of rhinitis-related symptoms, including sneezing (saliva r = 0.897, p < .00001; nasal mucus r = 0.871, p = .00024), nose blowing (saliva r = 0.764, p < .00001; nasal mucus r = 0.829, p = .00080), and nasal obstruction (saliva r = 0.519, p = .00099; nasal mucus r = 0.745, p = .00429). The ADL score was correlated with the total IgE level in each specimen (tear r = 0.705, p < .00001; saliva r = 0.468, p = .00301; nasal mucus r = 0.479, p = .06816).

CONCLUSIONS

These results suggest that local production of IgE is closely correlated with local allergic symptoms. This rapid test for the measurement of local IgE is easy to perform on an outpatient basis and may be helpful in the diagnosis of allergic rhinitis and conjunctivitis.

BCG vaccination and allergy: a systematic review and meta-analysis

BACKGROUND

There is conflicting evidence on whether BCG vaccination might represent an effective primary preventative strategy against the development of allergic sensitization and disease.

OBJECTIVES

We sought to systematically review the relationship between BCG vaccination and the risk of sensitization, eczema/atopic dermatitis, allergic rhinoconjunctivitis, asthma, and other allergic conditions, such as food allergy and anaphylaxis.

METHODS

Four international databases were searched for published epidemiologic or interventional studies. Additional online study databases were searched and vaccine manufacturers and a panel of international experts were contacted in an attempt to locate unpublished or ongoing studies. Quality assessment was undertaken by using internationally established criteria. Meta-analyses were undertaken by using fixed- or random-effects modeling. Funnel plots were used to assess for the risk of publication bias.

RESULTS

We identified 767 articles, of which 17 satisfied our inclusion criteria; there was only 1 randomized controlled trial, with the remaining studies being epidemiologic investigations. Meta-analyses did not show any protective effect of vaccination against the risk of sensitization, as judged by specific IgE tests (odds ratio [OR], 1.31; 95% CI, 1.07-1.60) or skin prick testing (OR, 0.87; 95% CI, 0.67-1.13); the risk of atopic eczema/dermatitis (OR, 0.84; 95% CI, 0.64-1.09); or the risk of allergic rhinoconjunctivitis (OR, 1.07; 95% CI, 0.89-1.28). BCG vaccination was associated with a protective effect against the risk of asthma (OR, 0.73; 95% CI, 0.56-0.95), although this might be explained by publication bias.

CONCLUSIONS

BCG vaccination is unlikely to be associated with protection against the risk of allergic sensitization and disease. The observed possible benefit in relation to the development of asthma is unlikely to be due to allergic sensitization.

Disparate geographic prevalences of asthma, allergic rhinoconjunctivitis and atopic eczema among adolescents in five Canadian cities

To assess concordance of prevalence rates of asthma, allergic rhinoconjunctivitis and atopic eczema symptoms among adolescents in five Canadian cities. The International Study of Asthma and Allergies in Childhood Phase 3 written questionnaires were answered by 8334 adolescents aged 13 to 14 in Vancouver, Saskatoon, Winnipeg, Hamilton and Halifax, Canada. Prevalence rates of current symptoms ranged from 13.7-33.0% for wheezing, 14.6-22.6% for allergic rhinoconjunctivitis and 8.2-10.4% for atopic eczema. Using Hamilton as reference, the prevalence of wheezing was significantly higher in Halifax (OR = 1.58; 95% CI 1.36-1.84) and Saskatoon (1.27; 1.07-1.50) and significantly lower in Vancouver (0.51; 0.44-0.59). In contrast, allergic rhinoconjunctivitis was significantly more prevalent in Winnipeg (1.39; 1.16-1.68) and Halifax (1.36; 1.14-1.61) and trended lower in Saskatoon (0.81; 0.66-1.00). Atopic eczema was significantly more prevalent in Winnipeg (1.31; 1.01-1.69) and Vancouver (1.28; 1.04-1.58). Multivariable logistic regression analyses showed the region of residence, being born in Canada, recent use of acetaminophen and heavy exposure to traffic exhaust were significantly associated with all three allergic conditions, while obesity and having two or more smokers at home was only associated with increased risk for wheezing. Chinese ethnicity decreased that risk. Among five Canadian centres, the highest prevalence rates of allergic rhinoconjunctivitis or atopic eczema were not observed in the same regions as the highest prevalence rates of wheezing. This disparity in regional variations in the prevalence rates suggests dissimilar risk factors for the development or expression of wheezing (asthma), allergic rhinoconjunctivitis and atopic eczema.

Antibiotics and allergic disorders in childhood

AIM

This paper explores the possible association between antibiotics prescribed in infancy and allergic disorders, mainly eczema and asthma, in childhood.

BACKGROUND

No-one fully understands why childhood asthma and eczema have become so common. Some authorities suggest that there may be an association between eczema and asthma and antibiotics prescribed in childhood; however, others disagree. METHOD/EVALUATION: The available literature was reviewed to examine the links between prescribed antibiotics and childhood eczema and asthma. FINDINGS/KEY ISSUE: Some, but not all, research indicates that antibiotic administration in pregnancy, childbirth or infancy may be linked to childhood asthma and eczema, but much uncertainty remains. None of the papers identified stated the doses of antibiotics prescribed. In addition, we were unable to locate studies reporting the interactions between antibiotics and the developing immune system.

CONCLUSION

Health care professionals should be selective when prescribing antibiotics. Further prospective work is needed to guide the prescribing of antibiotics in childbirth and infancy.

Pharmacotherapy of allergic eye disease

Allergic eye disease is a term that refers to a number of disease processes that affect about one-fifth of the world's population. Although the more advanced forms of the disease can be sight threatening, the most disabling effects are due to the clinical manifestations, and hence quality of life, with some patients having seasonal exacerbations of their symptoms, whereas others have symptoms that are present throughout the year. Recent increased understanding of the cellular and mediator mechanisms that are involved in the various disease manifestations has greatly facilitated the development of more effective treatment options. Newer topical medications are being used that have multiple actions, such as an antihistaminic effect coupled with mast-cell stabilisation, and which require reduced daily dosing due to their longer duration of action. With greater research into newer therapies and more effective modes of delivery, improved healthcare outcomes with a lower economic burden will be achieved for patients with allergic eye disease.

Treating the ocular component of allergic rhinoconjunctivitis and related eye disorders

CONTEXT

Allergy symptoms that affect the eyes are common in adults and children worldwide, and are often associated with nasal allergy symptoms, prompting the term 'rhinoconjunctivitis' to describe the condition. However, this condition has not always been recognized, and earlier literature reported allergic conjunctivitis only within a subset of nasal allergy patients.

EVIDENCE ACQUISITION

To assess the current state of ocular allergy epidemiology, pathophysiology, and currently available treatment options, we performed a MEDLINE search for articles regarding ocular allergy, rhinoconjunctivitis, vernal keratoconjunctivitis (VKC), atopic keratoconjunctivitis (AKC), and giant papillary conjunctivitis (GPC).

EVIDENCE SYNTHESIS

The more severe forms of ocular allergy are not only distressing, but can also threaten a patient's vision. Each type of ocular allergy is associated with ocular redness, itching, and tearing; however, AKC and VKC can threaten the cornea, and research has revealed that involvement of different immune cell populations (mast cells, eosinophils, and lymphocytes) may cause these more severe symptoms. A variety of treatment options exist to control ocular allergy symptoms. Nonpharmacologic options include allergen avoidance and lubrication with saline, and if these fail to be sufficiently effective, symptom relief may be provided by medicinal agents that are either applied topically to the eye or taken orally. Recent evidence suggests that nasal allergy treatments applied topically to the nose may also positively affect ocular allergy symptoms, which raises the interesting possibility that a parasympathetic nasal-ocular neural reflex pathway may be involved in the stimulation of allergic responses in the eye.

CONCLUSIONS

Ocular allergy is underdiagnosed and has a significant impact on the life of the patient. It is vital to reach a better understanding of ocular allergic mechanisms and inflammation, which may lead to improved treatment.

Entry age into day care and later development of allergic disorders--results from the city of Leipzig cohort of the LISA study

The situation in early childhood is supposed to be a risk factor for later development of allergic diseases. The birth cohort from the LISA (Lifestyle-Immune System-Allergy) study gave us the opportunity to investigate the relationship between early childhood situation and the development of allergic diseases. This paper describes our findings regarding to the relationship between entry age into day care and obstructive bronchitis as well as allergic rhinitis and atopic eczema. Study was designed as a longitudinal birth cohort study. Children were examined by a physician at birth, 1/2 year, 1 year, 1 1/2 year, 2 years, 3 years and 4 years. Further information was collected using a structured questionnaire which was answered by the parents. Outcomes under investigation were atopic eczema, allergic rhinitis, wheezing (with and without cold), obstructive bronchitis and asthma (after 2nd year of life). Logistic regression analysis adjusted for infectious diseases of the mother during pregnancy, vaccination of the mother during pregnancy, antibiotics, prenatal smoking of the mother or other persons in the apartment and vaccination state showed an significant promoting effect of entry age into day care against obstructive bronchitis over the first three years of life (OR 1/2 year: 8.55; 95%CI: 2.93...24.97; OR 1st year: 4.96; 95% CI: 1.73...14.24; OR 2nd year: 3.06 95% CI: 1...9.37). A further significant effect was found for crowding against asthma in the fourth year of life (OR 25.7; 95%CI: 1.65...400.17). No significant effects were found between the other periods under investigation (1st year until 4th year of life). On the base of our findings we recommend an entry age into day care of more than six months to prevent effects shown.

Formulas containing hydrolysed protein for prevention of allergy and food intolerance in infants

BACKGROUND

Allergies and food reactions are common and may be associated with foods including adapted cow's milk formula. Formulas containing hydrolysed proteins have been used to treat infants with allergy or food intolerance. However, it is unclear whether hydrolysed formula can be advocated for prevention of allergy and food intolerance in infants without evidence of allergy or food intolerance.

OBJECTIVES

To determine the effect of feeding hydrolysed formulas on allergy and food intolerance in infants and children compared to adapted cow's milk or human breast milk. If hydrolysed formulas are effective, to determine what type of hydrolysed formula is most effective including extensively and partially hydrolysed formulas. To determine which infants benefit, including infants at low or high risk of allergy and infants receiving early, short term or prolonged formula feeding.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used. The review was updated with searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2006), MEDLINE (1966-March 2006), EMBASE (1980-March 2006) and CINAHL (1982-March 2006) and previous reviews including cross references.

SELECTION CRITERIA

Randomised and quasi-randomised trials that compare the use of a hydrolysed infant formula to human milk or cow's milk formula. Trials with >80% follow up of participants were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Eligibility of studies for inclusion, methodological quality and data extraction were assessed independently by each review author. Primary outcomes included clinical allergy, specific allergies and food intolerance. Meta-analysis was conducted using a fixed effects model.

MAIN RESULTS

Two trials compared early, short term hydrolysed formula to human milk feeding. No significant difference in infant allergy or childhood cow's milk allergy (CMA) were reported. No eligible trial compared prolonged hydrolysed formula to human milk feeding. Two trials compared early, short term hydrolysed formula to cow's milk formula feeding. No significant benefits were reported. One large quasi-random study reported a reduction in infant CMA of borderline significance in low risk infants (RR 0.62, 95% CI 0.38, 1.00). Ten eligible studies compared prolonged feeding with hydrolysed formula versus cow's milk formula in high risk infants. Meta-analysis found a significant reduction in infant allergy (seven studies, 2514 infants; typical RR 0.79, 95% CI 0.66, 0.94), but not in the incidence of childhood allergy (two studies, 950 infants; typical RR 0.85, 95% CI 0.69, 1.05). There was no significant difference in infant eczema (eight studies, 2558 infants, typical RR 0.84, 95% CI 0.68, 1.04), childhood eczema incidence (two studies, 950 infants, typical RR 0.83, 95% CI 0.63, 1.10), childhood eczema prevalence (one study, 872 infants; RR 0.66, 95% CI 0.43, 1.02), or infant or childhood asthma, rhinitis and food allergy. One study reported a significant reduction in infants with CMA with confirmed atopy (RR 0.36, 95% CI 0.15, 0.89). Subgroup analysis of trials blinded to formula found no significant difference in infant allergy (four studies, 2156 infants; typical RR 0.87, 95% CI 0.69, 1.08) or childhood allergy incidence (one study, 872 infants; RR 0.91, 95% CI 0.73, 1.14). No eligible trial examined the effect of prolonged hydrolysed formula feeding on allergy beyond early childhood. There is evidence that preterm or low birthweight infants fed a hydrolysed preterm formula have significantly reduced weight gain, but not in other growth parameters (head circumference or length). Studies in term infants report no adverse effects on growth. Subgroup analysis of trials of partially hydrolysed versus cow's milk formula found a significant reduction in infant allergy (six studies, 1391 infants; typical RR 0.79, 95% CI 0.65, 0.97) but not childhood allergy, or infant or childhood asthma, eczema or rhinitis. Methodological concerns were the same as for the overall analysis. Analysis of trials of extensively hydrolysed formula versus cow's milk formula found no significant differences in allergy or food intolerance. Infants fed extensively hydrolysed formula compared with partially hydrolysed formula had a significant reduction in food allergy (two studies, 341 infants; typical RR 0.43, 95% CI 0.19, 0.99), but there was no significant difference in all allergy or any other specific allergy incidence. Comparing extensively hydrolysed casein containing formula with cow's milk formula, one study (431 infants) reported a significant reduction in childhood allergy incidence (RR 0.72, 95% CI 0.53, 0.97). Meta-analysis found a significant reduction in infant eczema (three studies, 1237 infants; typical RR 0.71, 95% CI 0.51, 0.97). One study reported a significant reduction in childhood eczema incidence (RR 0.66, 95% CI 0.44, 0.98) and prevalence (RR 0.50, 95% CI 0.27, 0.92).

AUTHORS' CONCLUSIONS

There is no evidence to support feeding with a hydrolysed formula for the prevention of allergy compared to exclusive breast feeding. In high risk infants who are unable to be completely breast fed, there is limited evidence that prolonged feeding with a hydrolysed formula compared to a cow's milk formula reduces infant and childhood allergy and infant CMA. In view of methodological concerns and inconsistency of findings, further large, well designed trials comparing formulas containing partially hydrolysed whey, or extensively hydrolysed casein to cow's milk formulas are needed.

[Asthma on the island of Reunion: an analysis of the severity and therapeutic management]

INTRODUCTION

Asthma is a common condition on the island of La Reunion but there are no epidemiological studies that analyse the prevalence, severity and management of the patients.

METHODS

Two studies were undertaken: a CPAM (health insurance) study of 187 patients and an analysis of the data from 253 patients attending a specialist hospital clinic.

RESULTS

In these two studies we found 40% of patients were in GINA group 3 compared with 10% in metropolitan France. Recourse to the emergency department and admission to intensive care were common. There was under-evaluation by the treating physicians who did not classify patients correctly. This under-evaluation also occurred in prescribing with only 1/3 of asthmatics in stages 2 and 3 receiving inhaled corticosteroids. Patient education was poor with 30% receiving a demonstration of inhaler technique and 31% a functional evaluation.

CONCLUSION

These studies show that the severity profile of asthma on La Reunion is comparable to that in other oceanic countries like Australia and New Zealand rather than metropolitan France. A population study is needed to assess the prevalence of asthma on the island of La Reunion.

Wheezing and eczema in relation to infant anthropometry: evidence of developmental programming of disease in childhood

Early life factors and, in particular, the fetal environment have been suggested to programme risk of allergic disease in later life. Diversion of nutrients away from immune organs towards the brain, a process termed brain sparing, has been proposed as a mechanism underpinning this association. The study population was a group of 256 seven-year old children from the UK recruited from two general practitioner surgeries. Historical anthropometric data from birth to age three and current anthropometry were assessed as predictors of parent-reported wheeze and eczema. Eczema at seven years was not related to any anthropometric indices at birth or during infancy. A smaller head circumference at 10-15 days of age was noted in children with current wheeze at age 7 years (P = 0.018) and this relationship persisted after adjustment for current anthropometry and confounders. Comparison of children with head circumference over 36.5 cm at 10-15 days with those with head circumference under 35.5 cm, showed reduced odds for wheeze at 7 years (OR 0.12, 95% CI 0.03-0.44, P(trend) = 0.009). These data suggest that factors that determine fetal growth may be associated with wheeze in childhood and support the developmental origins of health and disease hypothesis. Brain sparing does not appear to play a role in this early life programming.

[Clinical study of Supranettes pads in the treatment of seasonal or perennial allergic conjunctivitis in children]

PURPOSE

Ocular allergy is a common disease that is on the rise. Seasonal and perennial conjunctivitis are the most common forms of ocular allergy. Itching, hyperemia, foreign body sensation, irritation, blurred vision or ocular dryness sensations, tearing, and photophobia are the clinical signs observed in patients. A topical antiallergic treatment is prescribed associated with ocular cleaning to contribute to an antigen washing of the ocular surface. Our study aimed to evaluate the use of Supranettes pads as supplementation treatment in children for seasonal or perennial conjunctivitis.

MATERIAL AND METHODS

Our prospective study was done in children with a diagnosis of seasonal or perennial clinical ocular allergy. Every symptom was rated from 0 to 4 according to the intensity described by the children and their parents. Twenty children (range, 4-10 years) presenting an ocular allergy were included in the study. A topical antiallergic treatment membrane stabilizer or antihistamine and Supranettes pads were prescribed for ocular cleaning of one randomized selected eye four times a day. Patients were seen in consultation 1 month later to evaluate the treatment. The ocular comfort of each eye, one treated with Supranettes pads and the other not treated by Supranettes pads, was evaluated by the child helped by parents on a graduated self-evaluation scale (range, 0-10). The Mann-Whitney statistical test was used to differentiate the two groups.

RESULTS

Of the 20 patients, eleven presented seasonal conjunctivitis and nine perennial conjunctivitis. Six of them presented conjunctivitis with a slight to moderate superficial punctuate keratitis. At the consultation on day 28+/-3, patients who were first treated showed clear improvement of clinical signs with the prescribed treatment. The statistical comparison of the two groups confirmed a significant difference (p<0.05) to the advantage of the group using the Supranettes pads.

DISCUSSION

Ocular washing is essential in the treatment of allergic conjunctivitis. The new galenic form of ocular cleaning by physiological serum-impregnated pads is simple to use for children. An objective significant difference is difficult to observe in 1 month.

CONCLUSION

This study underlines the importance of the comfort of Supranettes pads evaluated in the treatment of children's conjunctivitis. It confirms the advantage of developing evaluation studies including patient satisfaction and quality of life in ophthalmology.

Prevalence and severity of asthma, rhinitis, and atopic eczema in 13- to 14-year-old schoolchildren from southern Brazil

The objective of this study was to investigate the prevalence and severity of asthma, rhinitis, and atopic eczema in schoolchildren from southern Brazil. A cross-sectional study was carried out with the International Study of Asthma and Allergies in Childhood phase III written questionnaire. The questionnaire was self-applied by 2,948 randomly selected schoolchildren aged 13 to 14 years. The lifetime prevalence rates of symptoms were as follows: wheezing, 40.8%; rhinitis, 40.7%; eczema, 13.6%; self-reported asthma, 14.6%; rhinitis, 31.4%; eczema, 13.4%. Rhinitis was reported by 55% of adolescents with current asthma (60% females vs 46.9% males). Girls 13 to 14 years of age had higher prevalence rates of asthma, rhinitis, and eczema than boys had. Atopic eczema was reported by 42.7% of girls and 31.4% of boys with asthma. The prevalence rates were statistically significant for symptoms of asthma, rhinitis, and atopic eczema in females. However, there were no statistically significant differences between the sexes in regard to reported asthma and bronchospasm induced by exercise.

Relationship between aeroallergen and food allergen sensitization in childhood

BACKGROUND

Previous studies measuring the prevalence of allergen sensitization have been relatively small and used small numbers of allergens. To effectively evaluate children with atopic disease, we need an accurate knowledge of which allergens are important.

OBJECTIVE

To measure the prevalence of sensitization within a large unselected birth cohort, to examine the associations between sensitization to different allergens and determine whether atopy can be defined by a small panel of allergens.

METHODS

The Avon Longitudinal Study of Parents and Children is a population-based birth cohort of 13,638 singletons surviving to 4 weeks of age. The cohort was skin tested at 7 years of age to house dust mite (Dermatophagoides pteronyssinus), grass pollens, cat, peanuts, mixed tree nuts and egg and one of three other panels: animal danders, foods or aeroallergens. Sensitization was defined as a weal diameter of > or =3 mm. The strength of associations between sensitization to different allergens was tested by calculating the odds ratio adjusted for sensitization to D. pteronyssinus and grass pollen and gender.

RESULTS

Valid data were obtained from 6412 singletons. Sensitization was most common to aeroallergens: grass pollens (8.5%), D. pteronyssinus (7.8%), cat (4.9%), D. farinae (3.6%), dog (2.7%), horse (1.4%), rabbit (1.4%). Of the foods tested, the most common sensitization was to peanut (1.4%) and mixed tree nuts (1.0%). More than 95% of subjects with sensitization to any of the 29 allergens tested were sensitized to one of grass, D. pteronyssinus or cat allergen. There were strong associations of multiple sensitizations both within and between different allergen classes (pollens, animals, foods, peanut and tree nuts).

CONCLUSIONS

Seven-year-old children in the UK are primarily sensitized to aeroallergens, but also to peanuts and tree nuts. There are strong associations between sensitization within allergen groups as well as between allergen groups. Further studies are required to observe whether similar associations are seen with clinical allergy to these allergens.

Prevalence of asthma among Qatari schoolchildren: International Study of Asthma and Allergies in Childhood, Qatar

The aim of the present study is to determine the prevalence of asthma and allergic diseases among schoolchildren aged 6-14 years in the State of Qatar, based on a questionnaire designed by the International Study of Asthma and Allergy in Childhood (ISAAC). A cross-sectional study of 3,283 school children living in both urban and rural areas (average age, 9.03 +/- 1.99 years; 52.3% boys and 47.7% girls) was conducted between February 2003-February 2004. The population sample had a high prevalence of diagnosed asthma (19.8%), allergic rhinitis (30.5%), eczema (22.5%), and chest infection (11.9%). The frequency of asthma, allergic rhinitis, and eczema among parents reflected the same pattern as seen in their children. Overall, males had more asthma, allergic rhinitis, and chest infections than females. In general, the prevalence rate of asthma and allergic rhinitis decreased with age. The prevalence rate of asthma was significantly higher in mothers (11.8%) than in fathers (9.0%), but the frequency of allergic rhinitis symptoms was comparable (mothers, 18.5%; fathers, 17.5%). The prevalence rate of asthma (19.8%) in Qatari schoolchildren is very close to that in the neighboring Gulf country, Oman (20.7%), and higher than in some developing countries. Genetic factors related to the high rates of consanguinity may play an important role in the high prevalence rates noted in the Qatari population, but changes in lifestyle and environmental factors cannot be discounted as possible causes of the high prevalence noted in this study.

Association between sibship size and allergic diseases in the Glasgow Alumni Study

BACKGROUND

Recent epidemiological studies consistently report an inverse association between sibship size and allergic disease, but evidence from individuals born before the 1980s is inconsistent. As information on relative permanence of this finding may offer clues to its biological explanation, the association between sibship size and allergic disease in individuals born between 1918 and 1952 was investigated.

METHODS

Cross sectional surveys conducted by the Student Health Service at the University of Glasgow (1948-68) provided data on 14 140 men and women aged 16-30 years at the time of examination. The main outcome measures studied were self-reported asthma, eczema-urticaria, and hay fever.

RESULTS

A total of 1677 individuals (11.9%) provided a positive history of at least one of the three allergic diseases: 457 (3.2%) asthma, 594 (4.2%) eczema-urticaria, and 885 (6.3%) hay fever. Compared with those without siblings (reference odds ratio = 1), the odds ratios (95% confidence intervals) for having any allergic disease among those with one, two or three siblings were 0.86 (0.75 to 0.99), 0.80 (0.69 to 0.93), and 0.70 (0.60 to 0.83), respectively (p(trend)<0.001). Increasing birth order and low socioeconomic position in childhood were associated with a lower risk of allergy. Adjustment for birth order, year of birth, age, sex, socioeconomic position in childhood, and family history of allergy did not materially alter the results.

CONCLUSIONS

There is a robust inverse association between sibship size and allergic disease even among people born in the first half of the 20th century. These results favour relatively time-independent explanations for this phenomenon (such as the hygiene hypothesis or parity related changes in the intrauterine environment) over new environmental exposures.

Is living in a rural area good for your respiratory health? Results from a cross-sectional study in Scotland

STUDY OBJECTIVES

We aimed to investigate the epidemiology of self-reported chronic respiratory disease throughout Scotland, and to explore the relationship between quality of life and geographic location in those reporting disease.

DESIGN

A cross-sectional study. Self-reported data on age, gender, socioeconomic factors, smoking habits, selected illnesses (major respiratory and atopic diseases, and other major conditions), respiratory symptoms, use of medicines and health services, and quality of life were collected using a postal questionnaire.

PARTICIPANTS

A total of 4,560 adults registered with 1 of 57 family practices (22 rural and 35 urban) throughout Scotland.

RESULTS

The response rate was 60%. Following adjustment for potential confounders, participants from rural areas reported a significantly lower prevalence of any chest illness (adjusted odds ratio [OR], 0.72; 95% confidence interval [CI], 0.58 to 0.91), asthma (adjusted OR, 0.59; 95% CI, 0.46 to 0.76), and eczema/dermatitis (adjusted OR, 0.67; 95% CI, 0.52 to 0.87). Rural location was less likely than urban location to be associated with the reporting of persistent cough and phlegm and different symptoms (types of breathlessness and wheeze) indicative of asthma. No difference in prevalence was found for other respiratory problems. Participants from rural areas reporting COPD or emphysema, or cough or phlegm symptoms had significantly better quality of life scores than their urban counterparts.

CONCLUSIONS

In this study, living in a rural area was associated with a lower prevalence of asthma but not other chronic respiratory disorders, and a lower prevalence of some respiratory symptoms (including wheeze). Although the prevalence of COPD or emphysema did not differ between rural and urban areas, rural residency appeared to be associated with better health status among subjects with these conditions.

The prevalence, severity and seasonal variations of asthma, rhinitis and eczema in Taiwanese schoolchildren

The prevalence of asthma is increasing in Taiwan but data remain limited. The aim of this study was to determine the prevalence, severity, demographic and seasonal variations of asthma, rhinitis, and eczema in Taiwan. Using a one-stage stratified cluster random sampling, first grade (aged 6-8) and eighth grade (aged 13-15) students from Taoyuan, northern Taiwan, were invited to participate in this survey. The results showed a total of 6190 students, 3079 aged 6-8 and 3111 aged 13-15, completed this survey. In general, children aged 6-8 had significantly higher prevalence rates of diagnosed asthma, rhinitis, and eczema than children aged 13-15 (12.2%, 29.8%, and 10.2% vs. 9.6%, 18.3%, and 4.7%, respectively). Similarly, children aged 6-8 had significantly higher proportions of allergic symptoms, except for exercise-induced wheezing (5.8% vs. 17.8%, p < 0.0001). Among those with allergic disorders, children aged 6-8 presented a greater severity of wheezing attacks in the last 12 months. As regards gender, boys aged 6-8 had a significantly higher proportion of asthma or rhinitis symptoms than girls aged 6-8 but not in children aged 13-15. In children aged 6-8, asthma and rhinitis peaked in winter, especially in December. However, children aged 13-15 had two peaks (winter and summer) for asthma or rhinitis.

[Ocular allergies]

Recent developments indicate that ocular allergy is more than an IgE-mediated allergic conjunctivitis. Ocular allergy is a disease affecting the entire ocular surface including conjunctiva, lids, cornea, lacrimal gland and tear film. Besides an IgE-mediated reaction, a complex chronic inflammation is involved in the pathogenesis of many ocular allergies. According to their pathogenesis and clinical picture, ocular allergies are classified into mild forms, such as seasonal and perennial allergic conjunctivitis as well as giant papillary conjunctivitis, and chronic, potentially blinding forms such as atopic keratoconjunctivitis and vernal keratoconjunctivitis. New therapeutics act on the entire inflammatory process or try to modulate the allergic reaction early and specifically. The association with non-ocular allergic symptoms requires an interdisciplinary approach.

Serum ovalbumin-specific immunoglobulin G responses during pregnancy reflect maternal intake of dietary egg and relate to the development of allergy in early infancy

BACKGROUND

The value of allergen elimination diets during pregnancy for primary prevention of infant allergy has been questioned. However, dietary compliance may influence effectiveness.

OBJECTIVES

To monitor egg intake during a randomized controlled trial of egg avoidance throughout pregnancy and lactation by serial measurements of serum ovalbumin (OVA) IgG concentration in conjunction with dietary diary record and also, to analyse specific IgG concentrations at birth in relation to infant allergic outcome.

METHODS

Pregnant women, with personal or partner atopy, were randomized to complete dietary egg exclusion or an unmodified healthy diet before 20 weeks gestation. The infants were evaluated for atopy at 6 months of age. Serum food-specific IgG concentrations were determined by ELISA in maternal samples collected at study recruitment and during labour, and in infant samples at birth (umbilical cord).

RESULTS

Serum-specific IgG to OVA, but not the unrelated allergen, cow's milk beta-lactoglobulin, decreased over pregnancy in egg-avoiding women only (P<0.001). Cord OVA IgG concentration correlated with maternal IgG at delivery (r=0.944; P<0.001), and for infants born to atopic women, cord concentration was higher than that of their mother's (P<0.001). Infants with the lowest and highest cord IgG concentrations were the least likely, and those with mid-range concentrations were the most likely, to be atopic by 6 months of age (P=0.008).

CONCLUSION

Serum OVA IgG concentration reflects egg consumption, thereby indicating dietary allergen doses to which the developing immune system might be exposed. Trans-placental maternal IgG must be considered among early life factors that regulate infant atopic programming.

A review of olopatadine for the treatment of ocular allergy

Ocular allergy affects > 20% of the general population and many therapeutic preparations are available to individuals experiencing the most common forms--seasonal and perennial allergic conjunctivitis. 0.1% Olopatadine topical ophthalmic solution is currently approved for the treatment of allergic signs and symptoms in patients > or = 3 years of age. Olopatadine is available in Europe as Opatanol) and in > 30 other countries as Patanol. It inhibits mast cell degranulation and antagonises histamine receptors to manage the itching, redness, chemosis, tearing and lid swelling of the ocular allergic reaction, and its mast cell stabilising ability has been demonstrated both in vitro (using human conjunctival mast cells) and in vivo (human clinical experience). This article reviews both the laboratory and clinical information available on olopatadine, prefaced by a discussion of the current understanding of the ocular allergic reaction and followed by the future implications for this compound. Both laboratory and clinical studies have established the efficacy, safety and comfort of olopatadine in several study design models and comparisons to other antiallergy medications. The application of olopatadine, specifically in the management of lid swelling, an allergic sign recalcitrant to therapy and nasal allergic symptoms has also been established. In the future, a new formulation containing 0.2% olopatadine exhibits a duration of action up to 24 h, supporting once-daily dosing.

Asthma and other allergic conditions in Colombia: a study in 6 cities

BACKGROUND

No detailed information is available on the burden and impact of allergic diseases simultaneously for adults and children in Colombia and most Latin American countries.

OBJECTIVES

To investigate the prevalence of asthma, allergic rhinitis, and atopic dermatitis symptoms in 6 cities in Colombia; to measure patient expenses and school days and workdays lost; to describe disease severity; and to determine levels of total and specific IgE in asthmatic subjects.

METHODS

A multistage stratified random sample selection of schools with subjects aged 5 to 18 years in each city was used. Guardian subjects selected were contacted, and home visits were arranged. Subjects aged 1 to 4 years and older than 19 years were also selected randomly by systematic sampling based on the addresses of the subjects aged 5 to 18 years. Subjects with asthma symptoms were invited to provide a blood sample.

RESULTS

Information was obtained from 6,507 subjects. The prevalence of asthma, rhinitis, and atopic dermatitis symptoms in the past 12 months was 10.4% (95% confidence interval [CI], 9.7%-11.1%), 22.6% (95% CI, 21.6%-23.6%), and 3.9% (95% CI, 3.4%-4.4%), respectively. Thirty-eight percent of asthmatic subjects had visited the emergency department or have been hospitalized, and 50% reported lost school days and workdays. Seventy-six percent of sampled asthmatic patients were considered to be atopic.

CONCLUSIONS

The burden of disease and societal consequences of allergic entities in urban settings in countries such as Colombia are of concern but are largely ignored, perhaps because of the misconception that these diseases are of public health importance only in industrialized nations.

Allergic rhinitis in children : diagnosis and management strategies

The incidence of allergic rhinitis has been increasing for the last few decades, in keeping with the rising incidence of atopy worldwide. Allergic rhinitis has a prevalence of up to 40% in children, although it frequently goes unrecognized and untreated. This can have enormous negative consequences, particularly in children, since it is associated with numerous complications and comorbidities that have a significant health impact on quality of life. In fact, allergic rhinitis is considered to be a risk factor for asthma. There are numerous signs of allergic rhinitis, particularly in children, that can alert an observant clinician to its presence. Children with severe allergic rhinitis often have facial manifestations of itching and obstructed breathing, including a gaping mouth, chapped lips, evidence of sleep deprivation, a long face, dental malloclusions, and the allergic shiner, allergic salute, or allergic crease. The medical history is extremely important as it can reveal information regarding a family history of atopy and the progression of atopy in the child. It is also important to identify the specific triggers of allergic rhinitis, because one of the keys to successful management is the avoidance of triggers. A tripartite treatment strategy that embraces environmental control, immunotherapy, and pharmacologic treatment is the most comprehensive approach. Immunotherapy has come to be viewed as potentially prophylactic, capable of altering the course of allergic rhinitis. The most recent guidelines for the management of allergic rhinitis issued by the WHO recommend a tiered approach that integrates diagnosis and treatment, in which allergic rhinitis is subclassified both by frequency, as either intermittent or persistent, and by severity, as either mild or moderate to severe. Oral or topical antihistamines and intranasal corticosteroids are the mainstay of pharmacologic therapy for allergic rhinitis, depending upon its severity, and several agents have been approved for use in children aged 5 years old and younger.

Longitudinal study of grass pollen exposure, symptoms, and exhaled nitric oxide in childhood seasonal allergic asthma

BACKGROUND

Exhaled nitric oxide (NO) has been proposed as a marker of airway eosinophilic inflammation in asthma. There is currently a paucity of longitudinal data relating it to allergen exposure and asthma symptoms.

METHODS

Forty four children (6-16 years) with seasonal allergic asthma were sequentially followed before and during the grass pollen season. Asthma symptoms, lung function, NO levels, and pollen counts were recorded. The relationship between exhaled NO and both the pollen levels and asthma control were assessed longitudinally, comparing a subject's measurements with their previous ones.

RESULTS

The median exhaled NO concentration was significantly increased during the pollen season (6.2 v 9.2 parts per billion (ppb), p<0.002; median change 2.9 ppb, 95% confidence interval 1.5 to 5.4). Exhaled NO was best associated with the mean pollen count in the week before measurement. It was also significantly associated with asthma control.

CONCLUSIONS

The results suggest that, within a longitudinal model, the exhaled NO concentration is related to preceding allergen exposure and asthma control. It may be clinically more useful to compare exhaled NO values with a subject's previous values than to compare them with a population based normal range.