Validation of the International Study of Asthma and Allergies in Children (ISAAC) and U.K. criteria for atopic eczema in Ethiopian children

Validation of diagnostic criteria for atopic dermatitis and proposal of novel diagnostic criteria for adult and elderly Chinese populations: a multicentre, prospective, clinical setting-based study

BACKGROUND

A previous validation study showed a very low sensitivity and higher specificity associated with Hanifin and Rajka criteria (H&R) and the UK Working Party criteria (UKWP) in diagnosing AD vs. the Chinese criteria of atopic dermatitis (AD) for children (CCAD). However, their diagnostic efficacy in adult and elderly Chinese populations remains unknown.

OBJECTIVES

To validate the diagnostic efficacy of three sets of AD criteria in adult and elderly Chinese populations in a hospital setting.

METHODS

A total of 1034 patients (aged 19-95 years) from five university hospital dermatological clinics were recruited. Medical history, dermatological examination, AD diagnosis and evaluation of AD severity were done by dermatologists. Each patient was investigated by two dermatologist panels, one to establish a clinical diagnosis, and the other to identify and record the major or minor signs of H&R criteria, UKWP criteria and CCAD. Taking clinical diagnosis as the reference, the diagnostic efficacy of three sets of diagnostic criteria was evaluated. The χ2 test or rank sum test were used for between-groups comparisons.

RESULTS

CCAD had a higher sensitivity (84.0%), especially among mild and moderate cases of AD (72.7% and 90.3%, respectively), than the H&R (58.0%; P < 0.001) and UKWP criteria (56.0%; P < 0.001) in diagnosing AD. The specificity of CCAD (92.7%) was slightly lower than the H&R (97.3%; P < 0.001) or UKWP criteria (97.4%; P < 0.001). The CCAD had the highest Youden index (0.77), accuracy rate (0.90) and Kappa value (0.76) of the three sets of diagnostic criteria.

CONCLUSIONS

Consistent with results in a population of Chinese children, although the H&R and UKWP criteria had a high specificity for diagnosing AD, their low sensitivity limited their use in adult and elderly Chinese patients. Based on the high sensitivity and favourable diagnostic efficacy, the CCAD is proposed for AD diagnosis in adult and elderly Chinese populations, especially for cases of mild and moderate AD.

Endotoxin concentration and persistent eczema in early childhood

Although endotoxin concentration in the environment is negatively associated with atopic dermatitis (AD) onset in early childhood, the association between endotoxin concentration in the environment and eczema resolution in children with preexisting eczema is unclear. The aim of this study was to evaluate the association between endotoxin concentration in house dust and eczema persistence in young children. The authors used data from children participating in JECS (Japan Environment and Children's Study). In children who had AD or AD-like lesions at the age of 1 year, the authors investigated the association between the prevalence of eczema at the age of 3 years and endotoxin concentration (categorized by quartiles) in the dust on children's mattresses at the ages of 1.5 and 3 years. This study included 605 children. Eczema was significantly less prevalent among children whose mattresses were in the second and third quartiles of endotoxin concentration when they were 18 months old than among children whose mattresses were in the first quartile (adjusted odds ratio, 0.57 [95% confidence interval, 0.35-0.93] and adjusted odds ratio, 0.49 [95% confidence interval, 0.29-0.83], respectively). Moreover, of the children with eczema at age 3 years, those whose mattresses had endotoxin concentrations in the first quartile had significantly worse sleep disturbance caused by itchy rash (>1 time per week) than did those whose mattresses were in the third and fourth quartiles (20.0% vs 3.3% and 3.7%, both p values < 0.01). The findings indicate that low endotoxin exposure is associated with a higher prevalence of persistent eczema during early childhood.

A comparison of case definitions for infant atopic dermatitis in a multicenter prospective cohort study

This study identified two infant AD case definitions that were strongly associated with known AD risk factors. These case definitions can be used to study novel AD risk factors in large cohort studies, potentially providing new insights into the epidemiology of infant AD.

Prevalence and psychosocial impact of atopic dermatitis in Bangladeshi children and families

BACKGROUND

Skin conditions are the fourth leading cause of nonfatal disease globally, with atopic dermatitis (AD) a major and rising contributor. Though atopic dermatitis (AD) is rising in prevalence, little is known about its psychosocial effects on children and families in low- and middle-income countries (LMICs).

METHODS

We conducted a community-based, cross-sectional survey of 2242 under-5 children in rural Bangladesh using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire to measure AD prevalence and severity, the Patient-Oriented Eczema Measure (POEM) to measure severity, and the Infants' Dermatitis Quality of Life index (IDQoL) and Dermatitis Family Index (DFI) to measure quality of life.

FINDINGS

Overall AD prevalence in under-five children was 11.9% [95% confidence interval (CI) 10.6-13.3%]. Prevalence was highest in children age 30-35 months [16.2% (95% CI 11.4-21.0)]. IDQoL was significantly higher in males (2.67) vs. females (1.95, p = 0.015), the lowest (3.06) vs. highest (1.63) wealth quintile (p<0.001), and among mothers with < primary (2.41) vs. > secondary (1.43) education (p = 0.039). POEM severity was correlated with IDQoL (r = 0.77, p<0.001) and DFI (r = 0.56, p<0.001). Severe disease as rated by caretakers was correlated with POEM (r = 0.73, p<0.001), IDQoL (r = 0.82, p<0.001) and DFI (r = 0.57, p<0.001).

CONCLUSIONS

Severe AD significantly affects quality of life for children and families in Bangladesh. As access to healthcare expands in LMICs, identification and treatment of both the medical and psychosocial morbidities associated with the disease are needed.

Prevalence of atopic dermatitis, asthma and rhinitis from infancy through adulthood in rural Bangladesh: a population-based, cross-sectional survey

OBJECTIVE

Describe the pattern of atopic disease prevalence from infancy to adulthood.

DESIGN

Cross-sectional household survey.

SETTING

Community-based demographic surveillance site, Mirzapur, Bangladesh.

PARTICIPANTS

7275 individuals in randomly selected clusters within 156 villages.

PRIMARY AND SECONDARY OUTCOME MEASURES

The 12-month prevalence of atopic dermatitis (by UK Working Party Criteria (UK criteria) and International Study of Asthma and Allergies in Childhood (ISAAC)), asthma and rhinitis (by ISAAC); disease severity (by ISAAC); history of ever receiving a medical diagnosis.

RESULTS

Children aged 2 years had the highest prevalence of atopic dermatitis-18.8% (95% CI 15.2% to 22.4%) by UK criteria and 14.9% (95% CI 11.6% to 18.1%) by ISAAC- and asthma (20.1%, 95% CI 16.4% to 23.8%). Prevalence of rhinitis was highest among 25-29 year olds (6.0%, (95% CI% 4.5 to 7.4%). History of a medical diagnosis was lowest for atopic dermatitis (4.0%) and highest for rhinitis (27.3%) and was significantly associated with severe disease compared with those without severe disease for all three conditions (atopic dermatitis: 30.0% vs 11.7%, p=0.015; asthma; 85.0% vs 60.4%, p<0.001; rhinitis: 34.2% vs 7.3%, p<0.001) and having a higher asset-based wealth score for asthma (29.7% (highest quintile) vs 7.5% (lowest quintile), p<0.001) and rhinitis (39.8% vs 12.5%, p=0.003). Prevalence of having >1 condition was highest (36.2%) at 2 years and decreased with age. Having atopic dermatitis (ISAAC) was associated with significantly increased odds ratios (OR) for comorbid asthma (OR 5.56 (95% CI 4.26 to 7.26)] and rhinitis (3.68 (95% CI 2.73 to 4.96)). Asthma and rhinitis were also strongly associated with each other (OR 8.39 (95% CI 6.48 to 10.86)).

CONCLUSIONS

Atopic disease burden was high in this rural Bangladeshi population. Having one atopic condition was significantly associated with the presence of another. Low incidence of ever obtaining a medical diagnosis highlights an important opportunity to increase availability of affordable diagnosis and treatment options for all age groups.

Strengths and limitations of the United Kingdom Working Party criteria for atopic dermatitis in adults

BACKGROUND

The United Kingdom Working Party's (UKWP) criteria were developed to improve epidemiological research in atopic dermatitis (AD), but have not been validated in an exclusively adult European population.

OBJECTIVE

To validate the UKWP criteria for AD in adults.

METHODS

In this cross-sectional study, three independent samples of adult individuals were drawn and interviewed: patients with a hospital diagnosis of AD or plaque psoriasis in adulthood, and general population controls. Various versions of the UKWP criteria for AD were utilized.

RESULTS

A total of 3490 (general population), 3834 (AD) and 4016 (psoriasis) adult individuals were enrolled in the study. The best combination of the UKWP criteria leads to a sensitivity of 0.71 and a specificity of 0.96 in the general population. The criteria better captured 'AD ever' compared with 'AD within the past 12 months' and had a higher sensitivity in patients with moderate (87.2-97.7%) or severe (95.8-100%) AD at the time of interview compared with those who where asymptomatic (12.6-36.8%). The UKWP criteria also captured high proportions of psoriasis patients (19.7-47.7%) when applied in a cohort of unique psoriasis patients.

CONCLUSIONS

It remains a challenge to accurately diagnose a history of AD in adulthood since symptoms are shared with other skin conditions and AD may have resolved or can be waxing and waning, in turn leading to recall bias. The UKWP criteria performed well in the general population for the purpose of determining the prevalence, but should be used cautiously when studying comorbidity.

Position Statement on Atopic Dermatitis in Sub-Saharan Africa: current status and roadmap

BACKGROUND

The first International Society of Atopic Dermatitis (ISAD) global meeting dedicated to atopic dermatitis (AD) in Sub-Saharan Africa (SSA) was held in Geneva, Switzerland in April 2019. A total of 30 participants were present at the meeting, including those from 17 SSA countries, representatives of the World Health Organization (WHO), the International Foundation for Dermatology (IFD) (a committee of the International League of Dermatological Societies, ILDS www.ilds.org), the Fondation pour la Dermatite Atopique, as well as specialists in telemedicine, artificial intelligence and therapeutic patient education (TPE).

RESULTS

AD is one of the most prevalent chronic inflammatory skin diseases in SSA. Besides neglected tropical diseases (NTDs) with a dermatological presentation, AD requires closer attention from the WHO and national Departments of Health.

CONCLUSIONS

A roadmap has been defined with top priorities such as access to essential medicines and devices for AD care, in particular emollients, better education of primary healthcare workers for adequate triage (e.g. better educational materials for skin diseases in pigmented skin generally and AD in particular, especially targeted to Africa), involvement of traditional healers and to a certain extent also patient education, bearing in mind the barriers to effective healthcare faced in SSA countries such as travel distances to health facilities, limited resources and the lack of dermatological expertise. In addition, several initiatives concerning AD research in SSA were discussed and should be implemented in close collaboration with the WHO and assessed at follow-up meetings, in particular, at the next ISAD meeting in Seoul, South Korea and African Society of Dermatology and Venereology (ASDV) meeting in Nairobi, Kenya, both in 2020.

[Diagnosis of allergy in asthma]

Allergy is a hypersensitivity reaction induced by immunological mechanisms. In asthma, allergy has a complex role and is usually IgE mediated. Allergy must be evaluated during the work up but evidence of IgE sensitivity does not mean that allergens play a role in the pathophysiology of the disease. The clinical relevance of the sensitivity has to be considered. This paper describes current available tools to screen for IgE sensitivity, allergen exposure and their role in asthma.

Different definitions of atopic dermatitis: impact on prevalence estimates and associated risk factors

Background

There is no objective test that can unequivocally confirm the diagnosis of atopic dermatitis (AD), and no uniform clinical definition.

Objectives

To investigate to what extent operational definitions of AD cause fluctuation in the prevalence estimates and the associated risk factors.

Methods

We first reviewed the operational definitions of AD used in the literature. We then tested the impact of the choice of the most common definitions of ‘cases’ and ‘controls’ on AD prevalence estimates and associated risk factors (including filaggrin mutations) among children aged 5 years in two population‐based birth cohorts: the Manchester Asthma and Allergy Study (MAAS) and Asthma in Ashford. Model performance was measured by the percentage of children within an area of clinical indecision (defined as having a posterior probability of AD between 25% and 60%).

Results

We identified 59 different definitions of AD across 45 reviewed studies. Of those, we chose four common ‘case’ definitions and two definitions of ‘controls’. The prevalence estimates using different case definitions ranged between 22% and 33% in MAAS, and between 12% and 22% in Ashford. The area of clinical indecision ranged from 32% to 44% in MAAS and from 9% to 29% in Ashford. Depending on the case definition used, the associations with filaggrin mutations varied, with odds ratios (95% confidence intervals) ranging from 1·8 (1·1–2·9) to 2·2 (1·3–3·7) in MAAS and 1·7 (0·8–3·7) to 2·3 (1·2–4·5) in Ashford. Associations with filaggrin mutations also differed when using the same ‘case’ definition but different definitions of ‘controls’.

Conclusions

Use of different definitions of AD results in substantial differences in prevalence estimates, the performance of prediction models and association with risk factors.

What's already known about this topic?

There is no objective test that can unequivocally confirm the diagnosis of atopic dermatitis (AD) and no uniform clinical definition.

This results in different definitions utilized in AD studies, raising concerns on the generalizability of the results and comparability across different studies.

What does this study add?

This study has shown that different definitions of ‘cases’ and ‘controls’ have major impacts upon prevalence estimates and associations with risk factors, including genetics, in two population‐based birth cohorts.

These findings suggest the importance of developing a consensus on AD definitions of both ‘controls’ and ‘cases’ to minimize biases in studies.

https://www.bjdonline.com/article/different-definitions-of-atopic-dermatitis-impact-on-prevalence-estimates-and-associated-risk-factors/

Linked Comment: https://doi.org/10.1111/bjd.18303.

https://doi.org/10.1111/bjd.18571 available online

Under-diagnosis of atopic dermatitis in Puerto Rican children

Background

Little is known about atopic dermatitis (AD) among children in Puerto Rico.

Objective

To examine risk factors and identify approaches to better diagnose AD in Puerto Rican children.

Methods

Case-control study of AD among 540 children aged 6-14 years in San Juan, Puerto Rico. AD was defined as: 1) physician-diagnosed AD, 2) RAST-AD: AD symptoms plus ≥1 positive IgE to allergens, and 3) STR-AD: AD-symptoms and skin test reactivity to ≥1 allergen. Logistic regression was used for the multivariable analysis. We also evaluated the diagnostic performance of various approaches by comparing their sensitivity, specificity, positive predicted value [PPV], negative predictive value [NPV], and area under curve [AUC]).

Results

Of the 70 children with STR-AD, only 5 (7.1%) had PD-AD. In children without asthma, a positive IgE to Dermatophagoides (D.) pteronyssinus and signs of mold/mildew at home were significantly associated with 3.3 and 5 times increased odds of STR-AD, respectively. Among children with asthma, private/employer-based health insurance and a positive IgE to D. pteronyssinus were each significantly associated with approximately twofold increased odds of STR-AD. A combination of current eczema symptoms and a positive IgE to D. pteronyssinus yielded a sensitivity ≥ 70%, specificity and NPV ≥ 95%, PPV ≥ 88%, and an AUC ≥ 0.85 for STR-AD. Replacing a positive IgE to D. pteronyssinus with a positive IgE to ≥1 allergen slightly increased sensitivity without affecting other parameters.

Conclusions

AD is markedly under-diagnosed by physicians in Puerto Rico. This could be improved by assessing eczema symptoms and measuring IgEs to common allergens.

Atopic dermatitis, educational attainment and psychological functioning: a national cohort study

BACKGROUND

Atopic dermatitis (AD) might adversely affect academic performance, possibly through influences on psychological functioning such as stress resilience.

OBJECTIVES

To investigate the association of atopic dermatitis with stress resilience, cognitive function and educational attainment.

METHODS

We used data from a national cohort of men who underwent a military conscription examination at ages 17-20 years in Sweden between 1969 and 1976. All potential conscripts met a physician who assessed current or previous history of AD. Stress resilience was measured by a psychologist using a semistructured interview. The conscription assessment included a written cognitive function test. The highest level of education achieved was identified through record linkage.

RESULTS

The study population included 234 715 men, 1673 (0·7%) of whom had a diagnosis of AD. AD was associated with a greater risk of low stress resilience [adjusted relative risk ratio (RRR) 1·60, 95% confidence interval (CI) 1·38-1·86]. AD was associated with higher cognitive function (β-coefficient 0·15, 95% CI 0·05-0·24) and higher educational level (RRR 1·29, 95% CI 1·13-1·47). However, adjustment for socioeconomic characteristics of the family of origin attenuated the magnitude of the associations and eliminated the statistical significance (β-coefficient 0·06, 95% CI -0·03 to 0·15; RRR 1·16, 95% CI 1·00-1·35).

CONCLUSIONS

Swedish men with AD had lower stress resilience in late adolescence but did not have lower cognitive function or poorer educational attainment. The lower stress resilience associated with AD is consistent with an increased risk of possible long-term adverse health outcomes.

Prevalence of Atopy following Mass Drug Administration with Albendazole: A Study in School Children on Flores Island, Indonesia

BACKGROUND

In many rural areas of tropical countries such as Indonesia, the prevalence of soil-transmitted helminths (STH) infections remains high. At the same time, the burden of allergic disorders in such rural areas is reported to be low and inversely associated with helminth infections. To reduce the morbidity and transmission of helminth infections, the world health organization recommends preventive treatment of school children by providing mass drug administration (MDA) with albendazole. Here, we had an opportunity to evaluate the prevalence of skin reactivity to allergens before and after albendazole treatment to get an indication of the possible impact of MDA on allergic sensitization.

METHODS

A study was conducted among 150 school children living in an area endemic for STH infections. Before and 1 year after anthelminthic treatment with albendazole, stool samples were examined for the presence of STH eggs, skin prick tests (SPT) for cockroach and house dust mites were performed, blood eosinophilia was assessed, and total immunoglobulin E (IgE) and C-reactive protein (CRP) were measured in plasma.

RESULTS

Anthelminthic treatment significantly reduced the prevalence of STH from 19.6 before treatment to 6% after treatment (p < 0.001). Levels of total IgE (estimate: 0.30; 95% CI 0.22-0.42, p < 0.0001), CRP (estimate: 0.60; 95% CI 0.42-0.86, p = 0.006), and eosinophil counts (estimate: 0.70; 95% CI 0.61-0.80, p < 0.001) decreased significantly. The prevalence of SPT positivity increased from 18.7 to 32.7%. Multivariate analysis adjusted for confounding factors showed an increased risk of being SPT positive to any allergen (OR 3.04; 95% CI 1.338-6.919, p = 0.008).

CONCLUSIONS

This study indicates that 1 year of MDA with albendazole was associated with a reduced prevalence of STH infections. This study shows that the prevalence of allergic sensitization increases after 1 year of albendazole treatment. Placebo-controlled and larger studies are needed to further substantiate a role of deworming treatment in an increased risk of allergic sensitization.

Public Health Burden and Epidemiology of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disorder with significant morbidity and quality-of-life impairment. The epidemiology of AD is complex and challenging to study. The 1-year US prevalence of AD was 12.98% in children in 2007-2008 and 7.2%-10.2% in adults in 2010-2012. There is considerable statewide and countrywide variation of AD prevalence and severity. The prevalence of childhood AD dramatically increased over the past few decades but may be leveling off in developed nations. AD is associated with increased direct and indirect costs to payers and patients, thereby contributing toward a considerable public health burden.

Prevalence of Atopic Dermatitis in Chinese Children aged 1-7 ys

Prevalence of atopic dermatitis (AD) is increasing worldwide. Up to date, there has been no face-to-face nation-wide study in China. We aim to explore the prevalence of clinical diagnosed AD in children aged 1-7 ys in China. Twelve metropolises were chosen from different areas of China. In each region, we selected 4-10 kindergartens and 2-5 vaccination clinics randomly. A complete history-taking and skin examination were performed by dermatologists. The definite diagnosis of AD and the severity were determined by two or three dermatologists. All criteria concerned in UK diagnosis criteria, characteristic presentation of AD and atypical manifestations were recorded in detail. A total of 13998 children from 84 kindergartens and 40 vaccination clinics were included. The prevalence of AD was 12.94% by clinical diagnosis of dermatologists overall, with 74.6% of mild AD. Comparatively, prevalence of AD based on UK diagnostic criteria was 4.76%. This is the first face-to-face nation-wide study in Chinese children aged 1-7 ys, revealing that the prevalence of AD in children is closer to that of wealthier nations.

The impact of the National Institute for Health Research Health Technology Assessment programme, 2003-13: a multimethod evaluation

BACKGROUND

The National Institute for Health Research (NIHR) Health Technology Assessment (HTA) programme supports research tailored to the needs of NHS decision-makers, patients and clinicians. This study reviewed the impact of the programme, from 2003 to 2013, on health, clinical practice, health policy, the economy and academia. It also considered how HTA could maintain and increase its impact.

METHODS

Interviews (n = 20): senior stakeholders from academia, policy-making organisations and the HTA programme. Bibliometric analysis: citation analysis of publications arising from HTA programme-funded research. Researchfish survey: electronic survey of all HTA grant holders. Payback case studies (n = 12): in-depth case studies of HTA programme-funded research.

RESULTS

We make the following observations about the impact, and routes to impact, of the HTA programme: it has had an impact on patients, primarily through changes in guidelines, but also directly (e.g. changing clinical practice); it has had an impact on UK health policy, through providing high-quality scientific evidence - its close relationships with the National Institute for Health and Care Excellence (NICE) and the National Screening Committee (NSC) contributed to the observed impact on health policy, although in some instances other organisations may better facilitate impact; HTA research is used outside the UK by other HTA organisations and systematic reviewers - the programme has an impact on HTA practice internationally as a leader in HTA research methods and the funding of HTA research; the work of the programme is of high academic quality - the Health Technology Assessment journal ensures that the vast majority of HTA programme-funded research is published in full, while the HTA programme still encourages publication in other peer-reviewed journals; academics agree that the programme has played an important role in building and retaining HTA research capacity in the UK; the HTA programme has played a role in increasing the focus on effectiveness and cost-effectiveness in medicine - it has also contributed to increasingly positive attitudes towards HTA research both within the research community and the NHS; and the HTA focuses resources on research that is of value to patients and the UK NHS, which would not otherwise be funded (e.g. where there is no commercial incentive to undertake research). The programme should consider the following to maintain and increase its impact: providing targeted support for dissemination, focusing resources when important results are unlikely to be implemented by other stakeholders, particularly when findings challenge vested interests; maintaining close relationships with NICE and the NSC, but also considering other potential users of HTA research; maintaining flexibility and good relationships with researchers, giving particular consideration to the Technology Assessment Report (TAR) programme and the potential for learning between TAR centres; maintaining the academic quality of the work and the focus on NHS need; considering funding research on the short-term costs of the implementation of new health technologies; improving the monitoring and evaluation of whether or not patient and public involvement influences research; improve the transparency of the priority-setting process; and continuing to monitor the impact and value of the programme to inform its future scientific and administrative development.

Introduction of the Reliable Estimation of Atopic Dermatitis in ChildHood: Novel, Diagnostic Criteria for Childhood Atopic Dermatitis

Purpose

Questionnaire-based diagnostic criteria for atopic dermatitis (AD) have been proposed to detect the major group of AD with flexural dermatitis. We aimed to develop novel, questionnaire-based diagnostic criteria for childhood AD, which can detect more comprehensive AD including non-flexural type.

Methods

The draft version of questionnaire to detect childhood AD was prepared to be used for preliminary hospital- (n=1,756) and community-based (n=1,320) surveys. From analysis, the Reliable Estimation of Atopic dermatitis of ChildHood (REACH) was derived and verified in derivation (n=1,129) and validation (n=1,191) sets by community-based surveys.

Results

The REACH consists of 11 questions including 2 major and 9 minor criteria. AD is diagnosed as the major group of 'eczema on the antecubital or popliteal fossa' to fulfill the 2 major criteria (2M), and the minor group of 'eczema on the non-antecubital or popliteal fossa' to fulfill the 1 major plus 4 or more minor criteria (1M+4m). In the validation set, the overall 1-year AD prevalence by the REACH was estimated as 12.3% (95% CI, 10.5%-14.2%), and the REACH showed a sensitivity of 75.2%, a specificity of 96.1%, and an error rate of 6.4%. The REACH demonstrated better diagnostic performance than the ISAAC in terms of the number of misclassification (10.0%).

Conclusions

We propose the REACH as new full, questionnaire-based diagnostic criteria for childhood AD in epidemiological surveys. Further studies are warranted to validate the REACH in different populations or countries in the context of large-scale, epidemiological surveys.

Various diagnostic criteria for atopic dermatitis (AD): A proposal of Reliable Estimation of Atopic Dermatitis in Childhood (REACH) criteria, a novel questionnaire-based diagnostic tool for AD

Atopic dermatitis (AD) is a heterogeneous disease that manifests with a wide variety of clinical symptoms and signs. Due to the lack of definitive biomarkers for AD, it is very difficult to set up standard diagnostic criteria for AD which cover the entire spectrum of AD patients. Various instruments have been proposed for AD diagnosis, and they can be classified into a hospital setting or a community setting. From the preventive medicine viewpoint, questionnaire-based diagnostic criteria in a community setting are important to detect and manage childhood AD patients properly. In this article, various diagnostic criteria for AD in hospital and community settings will be reviewed. Additionally, the Reliable Estimation of Atopic Dermatitis in Childhood (REACH), a new full questionnaire-based diagnostic tool for childhood AD, will be reviewed.

Guidelines of care for the management of atopic dermatitis: section 1. Diagnosis and assessment of atopic dermatitis

Atopic dermatitis (AD) is a chronic, pruritic, inflammatory dermatosis that affects up to 25% of children and 2% to 3% of adults. This guideline addresses important clinical questions that arise in the management and care of AD, providing updated and expanded recommendations based on the available evidence. In this first of 4 sections, methods for the diagnosis and monitoring of disease, outcomes measures for assessment, and common clinical associations that affect patients with AD are discussed. Known risk factors for the development of disease are also reviewed.

The global burden of skin disease in 2010: an analysis of the prevalence and impact of skin conditions

The Global Burden of Disease (GBD) Study 2010 estimated the GBD attributable to 15 categories of skin disease from 1990 to 2010 for 187 countries. For each of the following diseases, we performed systematic literature reviews and analyzed resulting data: eczema, psoriasis, acne vulgaris, pruritus, alopecia areata, decubitus ulcer, urticaria, scabies, fungal skin diseases, impetigo, abscess, and other bacterial skin diseases, cellulitis, viral warts, molluscum contagiosum, and non-melanoma skin cancer. We used disability estimates to determine nonfatal burden. Three skin conditions, fungal skin diseases, other skin and subcutaneous diseases, and acne were in the top 10 most prevalent diseases worldwide in 2010, and eight fell into the top 50; these additional five skin problems were pruritus, eczema, impetigo, scabies, and molluscum contagiosum. Collectively, skin conditions ranged from the 2nd to 11th leading cause of years lived with disability at the country level. At the global level, skin conditions were the fourth leading cause of nonfatal disease burden. Using more data than has been used previously, the burden due to these diseases is enormous in both high- and low-income countries. These results argue strongly to include skin disease prevention and treatment in future global health strategies as a matter of urgency.

Prevalence of atopic dermatitis in Korea: analysis by using national statistics

We attempted to investigate the prevalence of atopic dermatitis (AD) in Korea by using national statistics. Data on AD patients who received medical service at least once a year from 2003 through 2008 were collected from health insurance research team of National Health Insurance Corporation. Data of estimated populations during the same period were obtained from the Statistics Korea. In 2008, the prevalence of AD was 26.5% in aged 12-23 months and decreased substantially to 7.6% at age 6 yr, 3.4% at age 12 yr and to 2.4% at age 18 yr. In males, the prevalence was higher than females until 2 yr of age, while the opposite was shown in children aged 2 yr or older. In children aged less than 24 months, the prevalence of AD has increased from 19.8% to 23.8% between the years 2003 and 2008, while the prevalence showed no increase in the older age group. In conclusion, the prevalence of AD in 2008 peaked during infancy up to 26.5% and decreased thereafter. Our findings also suggest that increasing prevalence of AD in children less than 24 months might be responsible for the recent increase in the prevalence of AD in Korean children.

Effects of Helicobacter pylori, geohelminth infection and selected commensal bacteria on the risk of allergic disease and sensitization in 3-year-old Ethiopian children

BACKGROUND

Epidemiological studies have suggested that gastro-intestinal infections including Helicobacter pylori, intestinal microflora (commensal bacteria) and geohelminths may influence the risk of asthma and allergy but data from early life are lacking.

OBJECTIVE

We aimed to determine the independent effects of these infections on allergic disease symptoms and sensitization in an Ethiopian birth cohort.

METHODS

In 2008/09, 878 children (87% of the 1006 original singletons in a population-based birth cohort) were followed up at age 3 and interview data obtained on allergic symptoms and potential confounders. Allergen skin tests to Dermatophagoides pteronyssinus and cockroach were performed, levels of Der p 1 and Bla g 1 in the child's bedding measured and stool samples analysed for geohelminths and, in a random subsample, enterococci, lactobacilli, bifidobacteria and H. pylori antigen. The independent effects of each exposure on wheeze, eczema, hayfever and sensitization were determined using multiple logistic regression.

RESULTS

Children were commonly infected with H. pylori (41%; 253/616), enterococci (38.1%; 207/544), lactobacilli (31.1%; 169/544) and bifidobacteria (18.9%; 103/544) whereas geohelminths were only found in 8.5% (75/866). H. pylori infection was associated with a borderline significant reduced risk of eczema (adjusted OR 0.49, 95% CI 0.24-1.01, P=0.05) and D. pteronyssinus sensitization (adjusted OR 0.42, 95% CI 0.17-1.08, P=0.07). Geohelminths and intestinal microflora were not significantly associated with any of the outcomes measured.

CONCLUSION AND CLINICAL RELEVANCE

Among young children in a developing country, we found evidence to support the hypothesis of a protective effect of H. pylori infection on the risk of allergic disease. Further investigation of the mechanism of this effect is therefore of potential therapeutic and preventive value.

Point and period prevalences of eczema in rural and urban schoolchildren in Ghana, Gabon and Rwanda

BACKGROUND

Eczema is a growing problem in Africa, particularly amongst children.

OBJECTIVES

To investigate the point-prevalences of eczema by physical examination in schoolchildren living in rural and urban areas and with different socioeconomic backgrounds in Ghana, Gabon and Rwanda. In Ghana period-prevalences were also estimated by questionnaire and compared with the point-prevalences.

METHODS

In total, 4839 schoolchildren in Ghana, Gabon and Rwanda were seen by at least one dermatologist. The point-prevalences of eczema were estimated on the basis of physical examination. Period-prevalences were measured in Ghana with questionnaire based-interviews adapted from the International Study of Asthma and Allergies in Childhood (ISAAC).

RESULTS

The point-prevalences were 1.5% and 1.6% in the two Ghanaian studies; 4% in Gabon and 0.8% in Rwanda. The period-prevalences were 2.6% and 4.4% in the two Ghanaian studies. The prevalences of eczema were not significantly different when comparing the urban and rural groups as well as the different socioeconomic levels. The sensitivity and positive predictive value to identify eczema cases based on the questionnaires compared to the diagnoses by physical examination were only 33% and 22% in the first Ghanaian study and 10% and 4% in the second Ghanaian study respectively.

CONCLUSIONS

The point-prevalences of eczema in the three African countries studied were low compared with industrialized countries. Physical examination by a dermatologist is still the gold standard to identify eczema cases because the sensitivity and the positive predictive value to identify eczema cases with questionnaires were low in the two Ghanaian studies.

A longitudinal study of allergy and intestinal helminth infections in semi urban and rural areas of Flores, Indonesia (ImmunoSPIN Study)

Background

The prevalence of asthma and atopic disease has been reported to be low in low income countries, however helminth infections are likely to be high among these communities. The question of whether helminth infections play a role in allergic diseases can best be addressed by intervention studies. None of the studies so far have been based on a large scale placebo-controlled trial.

Method/Design

This study was designed to assess how intestinal helminth infections can influence the immune response and atopic and allergic disorders in children in Indonesia. The relations between allergic outcomes and infection and lifestyle factors will be addressed. This study was set up among school-age children in semi urban and rural areas, located in Ende District of Flores Island, Indonesia. A randomized placebo-controlled anthelmintic treatment trial to elucidate the impact of helminth infections on the prevalence of skin prick test (SPT) reactivity and symptoms of allergic diseases will be performed. The children living in these semi-urban and rural areas will be assessed for SPT to allergens before and after 1 and 2 years of treatment as the primary outcome of the study; the secondary outcome is symptoms (asthma and atopic dermatitis); while the tertiary outcome is immune responses (both antibody levels to allergens and cellular immune responses).

Discussion

The study will provide information on the influence of helminth infections and anthelmintic treatment on immune response, atopy and allergic disorders.

Trial registration

Current Controlled Trials ISRCTN: ISRCTN83830814

Allergic characteristics of urban schoolchildren with atopic eczema in Ghana

BACKGROUND

Atopic eczema is an increasing clinical problem in Africa.

OBJECTIVE

To determine allergic characteristics and to identify possible risk factors for eczema among schoolchildren in an urbanized area in Ghana.

PATIENTS AND METHODS

Schoolchildren aged 3-16 years with eczema were recruited. For each patient, one to three age- and sex-matched controls were selected. All children completed a questionnaire and were skin prick tested with a panel of allergens. Blood was drawn to determine the total and allergen-specific IgE. Conditional logistic regression models with the matching factors included in the model were used to calculate the odds ratios and to adjust for possible confounders.

RESULTS

A total of 52 children with eczema (27 boys and 25 girls) and 99 controls were included. Levels of total IgE were found to be 9.1 (1.1; 78.4) times more often elevated in children with eczema. This association was mainly driven by elevated IgE levels against cockroach antigen. Children with eczema were found to have 2.0 (0.87; 4.7) times more often positive skin prick tests (SPT), but this association diminished to 1.2 (0.40; 3.6) after adjustment for total IgE levels. Frequent washing with soap was identified as a risk factor for the development of eczema among these children.

CONCLUSION

Schoolchildren with eczema in Ghana were characterized by elevated IgE levels especially against cockroach antigen. The association between eczema and positive SPT was much weaker suggesting immune hyporesponsiveness of the skin. After adjustment for IgE level, SPT were less suitable to distinguish children with and without eczema.

Validation of epidemiological tools for eczema diagnosis in Brazilian children: the ISAAC's and UK Working Party's criteria

Background

Instruments for field diagnosis of eczema are increasingly used, and it is essential to understand specific limitations to make best use of their strengths. Our objective was to assess the validity of ISAAC and UK Working Party criteria for field diagnosis of eczema in children.

Methods

We performed a cohort study in urban Brazil. Parents/guardians of 1,419 children answered ISAAC phase II questionnaire. Children were examined for skin lesions (UKWP protocol). Two dermatologists examined most cases of eczema (according to ISAAC or UKWP), and a sample without eczema.

Results

Agreement between repeat questionnaires on the filter question was poor (kappa = 0.4). Agreement between the 2 dermatologists was fair (kappa = 0.6). False positive reports included scabies in 39% of ISAAC cases and 33% of UKWP cases. Sensitivity and PPV were low (ISAAC: 37.1% and 16.1%; UKWP: 28.6% and 23.8%). Specificity and NPV were high (ISAAC: 90.0% and 96.6%; UKWP: 95.3% and 96.2%). One-year prevalence of eczema was 11.3% (ISAAC), 5.9% (UKWP) and 4.9% (adjusted dermatologist diagnosis). Point prevalence of scabies (alone or not) was 43%, 33% and 18%, in eczemas according to ISAAC, to UKWP and to dermatologists. The reasons why children with eczema were not identified by ISAAC or UKWP were wrongly denying dry skin, itchy rash or personal history of atopic diseases. A limitation is that questionnaire was already validated in Brazil, but not field tested in this specific setting.

Conclusions

Studies using UKWP or ISAAC criteria should include a validation arm, to contribute to the understanding of potential limitations of their use in different contexts and to explore solutions. We list specific recommendations.

A half of schoolchildren with 'ISAAC eczema' are ill with allergic contact dermatitis

BACKGROUND

Similarity in clinical symptoms between atopic eczema (AE) and allergic contact dermatitis (ACD) may lead to misdiagnoses in both clinical practice and epidemiological studies. As patch testing for contact allergy does not seem popular among paediatric allergists, the resulting bias leads mainly to under diagnosing of ACD and over diagnosing of AE in children and adolescents.

OBJECTIVES

To assess the frequency of AE and ACD among children and adolescents who answered affirmatively the eczema module of ISAAC questionnaire.

METHODS

Of 9320 schoolchildren involved in an allergy screening programme, 143 consecutive participants were recruited for the present study. The inclusion criterion was affirmative answers to questions from the eczema module of the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. The children were examined by two allergists: a paediatrician and a dermatologist, and the children underwent patch testing.

RESULTS

We diagnosed AE in 46 (55.4%) children and 18 (30.0%) adolescents, whereas 32 (38.6%) children and 31 (51.7%) adolescents were diagnosed with ACD, with a considerable overlap of both diseases. Nine of 46 (19.6%) children and 13 of 25 (52.0%) adolescents with affirmative answers to the question about flexural eczema were diagnosed with ACD, while lacking features sufficient for the diagnosis of AE according to Hanifin and Rajka. Based on the indices from the whole population tested (9320 pupils), a rough estimate of the general ACD prevalence was 5.8% for adolescents, and 8.5% for children, which is close to the figure of 7.2% observed previously in Danish schoolchildren.

CONCLUSIONS

Our data demonstrate that 'ISAAC eczema' is an epidemiological entity that embraces comparable portions of cases of atopic eczema and allergic contact dermatitis, and possibly also other less frequent pruritic dermatoses. Each case of chronic recurrent dermatitis in children requires differential diagnosis aimed at allergic contact dermatitis and inflammatory dermatoses other than atopic eczema, even when predominantly localized in flexural areas.

Prevalence and risk factors of wheeze and eczema in 1-year-old children: the Butajira birth cohort, Ethiopia

BACKGROUND

The rising global prevalence of asthma and other allergic conditions has been linked to potential aetiological factors influencing the developing immune system.

OBJECTIVE

To investigate the prevalence and associated risk factors for wheeze and eczema in 1-year-old children in a birth cohort from Butajira, Ethiopia.

METHODS

In 2005/6, a population-based cohort of 1065 pregnant women was established. At 1 year of age, data on wheeze and eczema in the children were collected from the mother via an interview-administered questionnaire, along with numerous demographic and lifestyle factors. A stool sample was also obtained from the child for geohelminth analysis.

RESULTS

The prevalence of wheeze was 11.5% (103/899) and eczema 8.6% (77/899). Independent predictors of wheeze were maternal allergic history [adjusted OR (AOR)=3.00, 95% CI 1.23-7.36], paternal allergic history (AOR=2.59, 95% CI 1.08-6.25), increasing household size (P for trend=0.023; AOR=3.54, 95% CI 1.31-9.56 for 7+ vs. 1-3 individuals) and paracetamol use by the child (overall P<0.001; AOR 11.04, 95% CI 4.30-28.31 for 4+ tablets in past month vs. never). Factors independently associated with eczema were maternal allergic history (AOR=3.68, 95% CI 1.54-8.77), household size (overall P=0.035; AOR=0.45, 95% CI 0.23-0.87 for 4-6 individuals relative to 1-3) and place of sleeping (overall P<0.001; AOR=0.29, 95% CI 0.10-0.82 for floor vs. bed/platform).

CONCLUSION

These findings support the hypothesis that eczema in early life in these children is a manifestation of allergy, while wheezing is probably due to infection as well as allergy.

Is the prevalence of asthma declining? Systematic review of epidemiological studies

Asthma prevalence has increased very considerably in recent decades such that it is now one of the commonest chronic disorders in the world. Recent evidence from epidemiological studies, however, suggests that the prevalence of asthma may now be declining in many parts of the world, which, if true is important for health service planning and also because this offers the possibility of generating and testing new aetiological hypotheses. Our objective was to determine whether the prevalence of asthma is declining worldwide. We undertook a systematic search of EMBASE, Medline, Web of Science and Google Scholar, for high quality reports of cohort studies, repeat cross-sectional studies and analyses of routine healthcare datasets to examine international trends in asthma prevalence in children and adults for the period 1990-2008. There were 48 full reports of studies that satisfied our inclusion criteria. The large volume of data identified clearly indicate that there are, at present, no overall signs of a declining trend in asthma prevalence; on the contrary, asthma prevalence is in many parts of the world still increasing. The reductions in emergency healthcare utilization being reported in some economically developed countries most probably reflect improvements in quality of care. There remain major gaps in the literature on asthma trends in relation to Africa and parts of Asia. There is no overall global downward trend in the prevalence of asthma. Healthcare planners will for the foreseeable future, therefore, need to continue with high levels of anticipated expenditure in relation to provision of asthma care.

Atopic eczema or atopiform dermatitis

Age period prevalence of atopic eczema (AE), a very common skin disease, has increased during the past decennia. This expansion seems to be ending in wealthy countries, while an increase is observed in developing nations, for which there is no firm explanation. Recent steps in understanding AE are the detection of skin barrier related filaggrin null mutations in approximately 25% of patients and the recognition of IL-31 as a molecule possibly involved in the itch (pruritus). Also interesting are the recognition of thymus and activation-regulated chemokine (TARC) and proliferating-inducing ligand (APRIL), as being associated with AE severity and activity. Immunocentric and corneocentric views on pathogenesis (the inside-outside paradigm) and the diagnostic entity atopiform dermatitis (AFD) are discussed here. We emphasize that diagnosing AE is not simple but challenging. We accentuate that a diagnosis of AE is only possible when there is allergen-specific IgE. Advice as to the need for elimination of allergens and adjustment of lifestyle are only proficient in patients having atopy and true AE, not in those having AFD.

Prevalence of adult atopic dermatitis among nursing staff in a Taiwanese medical center: a pilot study on validation of diagnostic questionnaires

BACKGROUND

Atopic dermatitis (AD) is a chronic, relapsing dermatosis. Previous studies have focused mostly on pediatric patients, and investigations emphasizing adult AD have been limited.

OBJECTIVE

We set out to determine the 1-year prevalence and evaluate the validity of the International Study of Asthma and Allergies in Childhood (ISAAC) and United Kingdom Working Party (UKWP) AD questionnaires of adult AD in Taiwan.

METHODS

We conducted a cross-sectional study among nursing staff at a university hospital. The 1-year prevalence of AD was assessed by ISAAC and UKWP questionnaires. Subsequently, the dermatologists' diagnosis based on Hanifin and Rajka criteria was used as a reference for validation.

RESULTS

The overall response rate was 92.9%, equivalent to 1131 complete questionnaires. Ninety adult patients with AD (8%) were identified by dermatologists' diagnosis whereas ISAAC identified 107 (9.5%); sensitivity and specificity were 36.7% and 92.9%, respectively. UKWP identified 42 (3.7%) patients with AD; sensitivity and specificity were 42.2% and 99.6%, respectively. Using the receiver operating characteristic curve analysis, the UKWP criteria performed significantly better than its ISAAC counterpart. Further analysis indicated that modification of these criteria resulted in significant improvement in their diagnostic efficacy. More specifically, modified ISAAC showed 90.0% and 55.2% sensitivity and specificity, respectively, whereas modified UKWP demonstrated 82.2% and 94.2% sensitivity and specificity, respectively.

LIMITATION

Most of the study subjects were female with a high educational background.

CONCLUSION

Currently available questionnaire instruments do not perform well in the identification of adult patients with AD. Modification of the original questionnaires may allow for future large-scale epidemiologic studies.

How well do questionnaires perform compared with physical examination in detecting flexural eczema? Findings from the International Study of Asthma and Allergies in Childhood (ISAAC) Phase Two

BACKGROUND

Questionnaires are widely used in epidemiological studies to measure eczema symptom prevalence, but there are concerns regarding their accuracy if used as a diagnostic tool.

OBJECTIVES

To compare the performance of a validated eczema symptom questionnaire and a standardized skin examination protocol employed in the second phase of the International Study of Asthma and Allergies in Childhood (ISAAC).

METHODS

A total of 30,358 schoolchildren aged 8-12 years from 18 countries were examined for flexural eczema. Parents also completed an eczema symptom questionnaire. We compared prevalence estimates at the population level based on the questionnaire vs. physical examination. We also compared the skin examination and the ISAAC questionnaire in making a diagnosis of flexural eczema.

RESULTS

The point prevalences for flexural eczema at centre level based on a single examination were lower than the questionnaire-based 12-month period prevalences (mean centre prevalence 3.9% vs. 9.4%). Correlation between prevalences of both outcome measures was high (r = 0.77, P < 0.001). At the individual level, questionnaire-derived symptoms of 'persistent flexural eczema in the past 12 months' missed < 10% of cases of flexural eczema detected on physical examination. However, between 33% and 100% of questionnaire-based symptoms of 'persistent flexural eczema in the past 12 months' were not confirmed on examination.

CONCLUSIONS

ISAAC questionnaire-derived symptom prevalences are sufficiently precise for comparisons between populations. Where diagnostic precision at the individual level is important, questionnaires should be validated and potentially modified in those populations beforehand, or a standardized skin examination protocol should be used.

Parents' smoking habit and prevalence of atopic eczema in 6-7 and 13-14 year-old schoolchildren in Spain. ISAAC phase III

BACKGROUND AND AIMS

Atopic eczema (AE) is the most frequent inflammatory skin disease in childhood in the western world. Several studies have reported a significant increase of prevalence in recent decades and the environmental factors implicated in its aetiology, including environmental tobacco smoke. This study aims to investigate the possible association of AE prevalence in Spanish schoolchildren aged 6-7 and 13-14 years in relation to their parents' smoking habits.

METHODS

We conducted a cross-sectional population-based study with 6-7 year-old (n = 27805) and 13-14 year-old (n = 31235) schoolchildren from 10 Spanish centres. AE prevalence was assessed using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire, and the Spanish Academy of Dermatology criteria, used in Spain to diagnose AE.

RESULTS

An association was found in school-children aged 6-7 (adjusted for gender, presence of asthma, presence of rhinitis, siblings and mother's level of education) between AE being clinically diagnosed with the mother's smoking habit (RPRa 1.40, 1.10-1.78) and there being more than 2 smokers at home (RPRa 1.34, 1.01-1.78). Regarding the presence of itchy rash, an association was observed with fathers who smoke (RPRa 1.40, 1.13-1.72). Among the 13-14 year-olds, no association was observed in relation to either clinically diagnosed AE or the appearance of itchy rash with parents' smoking habit.

CONCLUSIONS

Our results indicate the risk for children of being exposed to environmental tobacco smoke in terms of AE, especially when they are younger.

Climate and prevalence of atopic eczema in 6- to 7-year-old school children in Spain. ISAAC phase III

Atopic eczema (AE) is a chronic skin disease. Recent reports indicate that the worldwide prevalence of AE is increasing and that various environmental factors are implicated in its aetiology. Climatic conditions have been related with AE prevalence, and Spain has varying climatic conditions. The aim of this study is to document the possible climatic influence on the prevalence of AE in schoolchildren aged 6-7 years in three different climatic regions in Spain. We conducted a cross-sectional population-based survey of 28,394 schoolchildren aged 6-7 years from 10 Spanish centres in three different climatic regions. The mean participation rate was 76.5%. AE prevalence was assessed using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and the Spanish Academy of Dermatology criteria used in Spain to diagnose AE. The data, including annual temperature, precipitation, relative humidity and the annual number of sunny hours per climatic region, were obtained from the Spanish National Institute of Meteorology. Different AE prevalences were found in all three climatic regions studied: Atlantic, 32.9; Mediterranean 28.3; and Continental 31.2 per 100 children studied (p < 0.005). AE was positively associated with precipitation and humidity, and was negatively associated with temperature and the number of sunny hours. The results show that AE is significantly dependent on meteorological conditions.

Environmental factors influencing the prevalence of respiratory diseases and allergies among schoolchildren in Chiang Mai, Thailand

Air quality has seriously deteriorated as a consequence of population growth and urbanisation and respiratory diseases increased among residents of urban areas in Chiang Mai Province, Thailand. An International Study of Asthma and Allergies in Childhood (ISAAC) study was conducted among children attending schools located in the selected sites to assess the potential impacts of air pollution on health. The results showed that the prevalence of asthma was similar in all of the schools (approximately 5%; p = 1.000) but that the prevalence of rhinitis [24.3% (CI = 19.4-30.1) vs. 15.7% (CI = 10.3-23.0); p = 0.029] and atopic dermatitis [12.5% (CI = 9.1-16.8) vs. 7.2% (CI = 3.7-12.6); p = 0.093)] was higher in the urban schools, which were exposed to more pollution. Logistic regression analysis identified factors that may be involved, including air pollution, some components of the diet and contact with animals.

Time trends of the prevalence of asthma and allergic disease in Austrian children

After a substantial increase in the prevalence of atopic disease in Europe, recent studies indicate that a plateau has been reached. However, variation across countries and age groups exists. We studied the prevalence and time trends of asthma and allergic disease among schoolchildren in Austria, a country with traditionally low rates of asthma, hay fever, and eczema. As part of the International Study of Asthma and Allergies in Childhood (ISAAC), symptoms and physician diagnoses of asthma and allergic disease of 13,399 Austrian children aged 6-7 yr and 1516 children aged 12-14 yr were surveyed between 1995 and 1997. A similar survey was conducted between 2001 and 2003. Among children aged 6-7 yr, significant increases were seen in the prevalence of physician-diagnosed asthma (+16%; p = 0.013), hay fever (+22%; p < 0.001), and eczema (+37%; p < 0.001) between 1995 and 2003. These changes were paralleled by an increase in the prevalence of symptoms typical for hay fever (itchy eyes and runny nose), but not by an increase in wheeze. Among children aged 12-14 yr, the lifetime prevalence of diagnosed asthma increased by 32%, of hay fever by 19%, and of eczema by 28% (all, p < 0.001). These changes were paralleled by increases in the prevalence of wheezing as documented by both questions before and after a video showing wheezing children but not by symptoms typical for hay fever such as itchy eyes and runny nose. In conclusion, in Austria, contrary to other European countries, the prevalence of asthma and allergic disease increased among schoolchildren. Additional studies are needed to continue monitoring the dynamics of the prevalence of asthma and allergic disease in Austria and to explore trends in their risk factors.

Diagnostic criteria for atopic dermatitis: a systematic review

BACKGROUND

Atopic dermatitis (AD) has a wide spectrum of dermatological manifestations and despite various validated sets of diagnostic criteria that have been developed over the past decades, there is disagreement about its definition. Nevertheless, clinical studies require valid diagnostic criteria for reliable and reproducible results.

OBJECTIVE

To summarize the evidence concerning the validity of diagnostic criteria for AD.

METHODS

All data sources were identified through searches on Medline, Embase and Cochrane databases. The Quality Assessment of Diagnostic Accuracy tool (QUADAS) was used. Results are presented in a receiver operating characteristic (ROC) plot.

RESULTS

Out of the 20 articles that met the criteria, 27 validation studies were identified. In two studies concerning Hanifin and Rajka diagnostic criteria sensitivity and specificity ranged from 87.9% to 96.0% and from 77.6% to 93.8%, respectively. Nineteen validation studies of the U.K. diagnostic criteria showed sensitivity and specificity ranging from 10% to 100% and 89.3% to 99.1%, respectively. Three validation studies concerning the Schultz-Larsen criteria showed sensitivity from 88% to 94.4% and specificity from 77.6% to 95.9%. In one article concerning the criteria of Diepgen, the sensitivity ranged from 83.0% to 87.7% and the specificity from 83.9% to 87.0%. One article studied the Kang and Tian criteria and reported 95.5% sensitivity and 100% specificity. One article validating the International Study of Asthma and Allergies in Childhood (ISAAC) criteria showed a positive and negative predictive value of 48.8% and 91.1%, respectively.

CONCLUSION

With this systematic review of the existing sets of diagnostic criteria for AD a varying number of validation studies with varying methodological quality was found. The U.K. diagnostic criteria are the most extensively validated. However, improvement of methodological design for validation studies and uniformity in well-validated and applicable diagnostic criteria are needed to improve future intervention studies and to compare study results.

Environmental factors, parental atopy and atopic eczema in primary-school children: a cross-sectional study in Taiwan

BACKGROUND

Parental atopy and environmental exposure are recognized risk factors for atopic eczema (AE) in childhood. However, the relative contributions of specific risk factors and the overall contributions of hereditary and environmental exposure remain unexplored.

OBJECTIVES

To identify risk factors, estimate the population attributable risk (PAR) of environmental exposure, and compare the AE data for boys vs. girls in primary-school children.

METHODS

During a February to June 2001 cross-sectional, Taiwan-based questionnaire survey, we investigated 23 980 children from 22 primary schools, all located within 1 km of an air-monitoring station.

RESULTS

The 12-month prevalence of AE was reported as 6.1% in boys and 4.9% in girls. In both sexes, the risk of AE was strongly associated with parental atopy and perceived ambient air pollution. The presence of cockroaches [odds ratio (OR) 1.18, 95% confidence interval (CI) 1.00-1.40] and visible mould on walls at home (OR 1.46, 95% CI 1.22-1.70) were also significantly related to AE for girls; however, only visible mould on walls (and not the presence of cockroaches) at home was related to AE for boys (OR 1.40, 95% CI 1.18-1.66). While mutually adjusted models were applied, we found adjusted ORs and PARs were similar in boys and girls in hereditary and outdoor environmental factors. The PAR of indoor environmental factors was higher in girls (8.4%) than in boys (5.5%). There was no interaction between parental atopy and environmental factors.

CONCLUSIONS

Parental atopy contributed more to AE than indoor or outdoor environmental factors. Girls may be more susceptible to indoor environmental factors than boys.

Increasing prevalence of atopic eczema in Taiwanese adolescents from 1995 to 2001

BACKGROUND

The prevalence of atopic eczema in adolescents has recently been reported as increasing in many countries, a phenomenon yet to be fully explained. This study compared the prevalence of atopic eczema among Taiwanese adolescents with individual-level risk factors and community-level data of temperature, relative humidity, and air pollutants to determine whether changes in these factors could explain the observed change in prevalence.

METHODS

We conducted two nationwide, cross-sectional surveys of atopic illness and symptoms among Taiwanese 12-15-year-old schoolchildren in 1995-1996 and 2001. The effects of personal and environmental factors were assessed and temporal changes of outdoor monitoring data were also compared with the prevalence difference of atopic eczema.

RESULTS

A total of 42 919 adolescents from the 1995 to 1996 survey and 10 215 adolescents from the 2001 survey attended schools located within 1 km of 22 monitoring stations. The 12-month prevalence of atopic eczema increased significantly during this period [adjusted prevalence ratio (PR)=1.43, 95% confidence interval (CI) 1.21-1.70 in boys; PR=1.77, 95% CI 1.49-2.10 in girls]. After adjustment for potential risk factors, the prevalence differences were statistically unchanged. Although parental education level contributed the most, changes in personal and environmental factors might not explain the observed prevalence increases of atopic eczema. Temporal change in the relative humidity was significantly associated with prevalence increase among boys but its contribution was also small.

CONCLUSION

Correlates of the investigated risk factors that have changed over time still underlie the prevalence increases of atopic eczema in Taiwanese adolescents. The exact reasons for the rising trends remain to be elucidated.

Validation of the U.K. Working Party diagnostic criteria for atopic eczema in a Xhosa-speaking African population

BACKGROUND

Reliable diagnostic criteria for eczema are important for epidemiological comparisons. Although the U.K. diagnostic criteria for atopic eczema have performed well in an English language setting, limited data are available from other countries where cultural and linguistic factors may affect their validity.

OBJECTIVES

We sought to determine the validity of the U.K. criteria for eczema in relation to clinical assessment by a dermatologist in a Xhosa-speaking South African population.

METHODS

A cross-sectional survey of 3067 children aged 3-11 years was conducted in rural, peri-urban and urban settings in South Africa. The prevalence of atopic eczema was determined using the U.K. diagnostic criteria and a clinical assessment by a dermatologist. Questions were translated into the local language (Xhosa). Trained researchers administered the questions to the children's parents or carers. The validity of the U.K. criteria was then determined by calculating the sensitivity, specificity, positive and negative predictive values, and Youden's Index in relation to the dermatologist's examination.

RESULTS

The point prevalence of atopic eczema according to a dermatologist was 1.0% [95% confidence interval (CI) 0.6-1.4], while the prevalence of visible flexural eczema according to the U.K. protocol was 1.8% (95% CI 1.3-2.2). The sensitivity and specificity of the U.K. criteria in this setting was 43.7% (95% CI 26.3-62.3) and 97.9% (97.3-98.4), respectively. The positive and negative predictive values of the U.K. criteria were 18.4% (95% CI 10.4-28.9) and 99.4% (95% CI 99.0-99.6), respectively. The presence of visible flexural eczema according to the U.K. photographic protocol was the best predictor of atopic eczema, with a sensitivity and specificity of 81.2% (95% CI 63.5-92.7) and 99.0% (95% CI 98.6-99.3), respectively, and a positive and negative predictive value of 48.1% (95% CI 34.3-62.1) and 99.8% (95% CI 99.5-99.9), respectively.

CONCLUSIONS

The validity of the full question-based version of the U.K. diagnostic criteria for atopic eczema in this South African setting is low, which may be due to a combination of translational and cultural issues. However, the one physical sign of visible flexural eczema performed well, suggesting that it alone might be a useful tool for future international comparative prevalence studies.

Allergic disorders in African countries: linking immunology to accurate phenotype

Identification and characterization of risk and protective factors for allergy is important for developing strategies for prevention or treatment. The prevalence of allergy is clearly higher in affluent countries than in developing countries like, e.g. Africa. Especially in urban areas of developing countries, allergy is however on the increase. In Africa, we have the unique opportunity to investigate risk and protective factors and the influence of urbanization and westernization, i.e. almost to take a look at Europe, Australia or the USA as they were before their allergy epidemics. Moreover, migrants from developing to affluent countries experiencing an increased burden of allergy provide new insights into risk and protective factors. Allergen exposure, diet and infections are the major exogenous influences playing a role as risk and protective factors. Depending on the nature, timing, chronicity and level of exposure, each of them can promote or inhibit allergy. Perhaps with the exception of infections, availability of data from Africa on their role in the development of allergy is limited. Detailed epidemiological studies in rural and urban Africa combined with basic immunological research are needed to unravel mechanisms of increase in allergy and of protection. The maturation of the immune system at young age under influence of exogenous factors results in differences in T-cell-skewing (Th1/Th2/Treg) and humoral responses. It is essential to perform studies from a 'non-Eurocentric' angle (e.g. local allergens, locally validated questionnaires and diagnostic procedures). Such studies will provide the affluent countries with new leads to combat the allergy epidemic and more importantly help prevent it in Africa.

Trends in prevalence of asthma, allergic rhinitis and atopic dermatitis in 5-7-year old Swiss children from 1992 to 2001

BACKGROUND

Changing occurrence rates of asthma, allergic rhinitis and atopic dermatitis are of public health concern and require surveillance. Changes in prevalence rates of these atopic diseases were monitored during 10 years and their trend with time was determined taking into account the influence of personal and environmental risk factors.

METHODS

Four cross-sectional surveys in 5-7-year old children were performed in seven different communities in Switzerland between 1992 and 2001. Prevalence of respiratory and allergic symptoms and of affecting risk factors including parental environmental concern were assessed using a standardized parental questionnaire.

RESULTS

A total of 988 (74.1%), 1778 (79.0%), 1406 (82.6%) and 1274 (78.9%) children participated, respectively, in the 1992, 1995, 1998 and 2001 surveys. Prevalence rates of asthma and hay fever symptoms remained quite stable over time (wheeze/past year: 8.8%, 7.8%, 6.4% and 7.4%, sneezing attack during pollen season: 5.0%, 5.6%, 5.4% and 4.6%). Rates of reported atopic dermatitis symptoms (specific skin rash/past year: 4.6%, 6.5%,7.4% and 7.6%) showed an increase over time, but those of diagnosis of eczema did not show a clear pattern (18.4%, 15.7%, 14.0% and 15.2%). Stratified analysis by parental environmental concern and by parental atopy showed similar trends. Rates of atopic dermatitis symptoms showed significant increase in girls but stayed stable in boys.

CONCLUSION

Results of these four consecutive surveys suggest that the increase in prevalence of asthma and hay fever in 5-7-year old children living in Switzerland may have ceased. However, symptoms of atopic dermatitis may still be on the rise, especially among girls.

The role of helminth infections in protection from atopic disorders

PURPOSE OF REVIEW

The observation that allergies are less prevalent in developing countries, especially in rural areas, has stimulated considerable research to identify environmental factors associated with protection against allergic disorders. Here, we review recent studies conducted in developing countries.

RECENT FINDINGS

Epidemiological studies conducted in South America, Asia and Africa have attempted to identify factors associated with differences in prevalence of atopy, asthma and atopic dermatitis. Particular attention is given to the complex relationship between helminth infections and allergies. In answer to the question of whether helminth infections are associated with protection against allergic disorders, conflicting data have been generated. In addition to epidemiological studies, animal models have been utilized to gain insight into the immunological mechanisms involved in the interaction between helminth infections and allergies. These animal studies are discussed. The possible explanations for discrepancies found within both human and murine studies have been considered, highlighting the need for further research.

SUMMARY

An in-depth understanding of the relevant protective mechanisms against allergic disorders will open the possibility of developing novel therapeutics to prevent the allergic march worldwide.