A comparison between criteria for diagnosing atopic eczema in infants

BACKGROUND: Epidemiological studies have shown different estimates of the frequency of atopic eczema (AE) in children. This may be explained by several factors including variations in the definition of AE, study design, age of study group, and the possibility of a changed perception of atopic diseases. The role of IgE sensitization in AE is a matter of debate. OBJECTIVES: To determine the prevalence and cumulative incidence of AE in a group of unselected infants followed prospectively from birth to 18 months of age using different diagnostic criteria; to evaluate the agreement between criteria; and to describe the association between atopic heredity and postnatal sensitization, respectively, and the development of AE according to the different diagnostic criteria. METHODS: During a 1-year period a consecutive series of 1095 newborns and their parents were approached at the maternity ward at the Odense University Hospital, Denmark and a cohort of 562 newborns was established. Infants were examined and followed prospectively from birth and at 3, 6, 9, 12 and 18 months of age. AE was diagnosed using four different criteria, the Hanifin and Rajka criteria, the Schultz-Larsen criteria, the Danish Allergy Research Centre (DARC) criteria developed for this study and doctor-diagnosed visible eczema with typical morphology and atopic distribution. Additionally, the U.K. diagnostic criteria based on a questionnaire were used at 1 year of age. Agreement between the four criteria was analysed at each time point and over time, and agreement between the four criteria and the U.K. questionnaire criteria was analysed. RESULTS: The cumulative 1-year prevalence of AE using the Hanifin and Rajka criteria was 9.8% (95% confidence interval, CI 7-13%), for the Schultz-Larsen criteria it was 7.5% (95% CI 5-10%), for the DARC criteria 8.2% (95% CI 6-11%), for visible eczema 12.2% (95% CI 9-16%) and for the U.K. criteria 7.5% (95% CI 5-10%). The pairwise agreement between criteria showed good agreement, with rates varying between 93% and 97% and kappa scores between 0.6 and 0.8. Agreement analysis of diagnoses between the four criteria demonstrated that cumulative incidences showed better agreement than point prevalence values. CONCLUSIONS: Agreement between different criteria for diagnosing AE was acceptable, but the mild cases constituted a diagnostic problem, although they were in the minority. Repeated examinations gave better agreement between diagnostic criteria than just one examination. Atopic heredity was less predictive for AE than sensitization to common food and inhalant allergens in early childhood.     

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.     

Environmental associations with eczema in early life

BACKGROUND: Although atopic eczema (AE) is a common disease, little is known about its causes. OBJECTIVES: To investigate the role of dietary and environmental factors associated with the development of AE by the age of 2 years. METHODS: A cohort of children was recruited before birth from a consecutive series of newly pregnant mothers presenting for antenatal care at three general practices in Ashford, Kent, U.K. Data up to the age of 2 years were available for 624 (97%) of the original cohort. AE was defined using components of the U.K. diagnostic criteria for AE, maternal report of doctor-diagnosed eczema and maternally reported eczema. Exposures of interest were family history of allergic disease, dietary and breastfeeding patterns, family size and exposure to indoor domestic allergens. RESULTS: The cumulative prevalence of AE using the U.K. diagnostic criteria was 14% (95% confidence interval, CI 11-17%). The prevalence of maternally reported doctor-diagnosed eczema was much higher (31%, 95% CI 27-35%) and almost half (45%) the mothers reported that their child had ever had eczema (95% CI 41-49%). The relationship between parental atopy, parental history of allergic disease and the child's eczema was consistently stronger for the mothers than the fathers. There was a marked increase in the prevalence of eczema with increasing maternal education and in less crowded homes, associations that remained significant after controlling for other factors. CONCLUSIONS: The associations with environmental factors are consistent with the hypothesis that more crowded houses, increased family size and birth order, which may possibly increase early exposure to infections, may offer protection from subsequent development of eczema.     

Community validation of the U.K. diagnostic criteria for atopic dermatitis in Japanese elementary schoolchildren

BACKGROUND: A simple list of diagnostic criteria for atopic dermatitis for use in epidemiological studies was developed by a U.K. working party. This list served well for both hospital patients with skin diseases and in general population within the U.K. OBJECTIVES: To validate the U.K. diagnostic criteria in Japanese elementary schoolchildren, we collected the questionnaires on regular health checkups, which had been completed by parents of schoolchildren in 2001/2002 and 2004/2005. METHODS: Elementary schoolchildren were examined by dermatologists in eight areas (16,152 children) in 2001/2002 and in three areas (3849 children) in 2004/2005. The questionnaire was distributed to the parents 2 weeks before the skin examination, completed by the parents and collected after the survey. RESULTS: In 2002/2002 comparing the U.K. diagnostic criteria with the findings on clinical examination used as the reference standard, the U.K. criteria (1-year prevalence measure) showed a sensitivity of 71.8%, specificity of 89.3% and positive predictive value of 44.7%. In 2004/2005 we confirmed that the U.K. criteria for a point prevalence measure showed a higher positive predictive value (59.9%) compared with that for 1-year prevalence measure (49.3%). CONCLUSION: Now that we know the sensitivity and specificity of the U.K. criteria in the population examined in this study, we will be able in the near future to estimate the prevalence of atopic dermatitis in a similar population with reverse operation by questionnaires alone using these criteria without examination by dermatologists. Therefore, the validation study of U.K. criteria could be useful for future epidemiologic surveys.     

Accuracy of SIAscopy for pigmented skin lesions encountered in primary care: development and validation of a new diagnostic algorithm

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.     

Community validation of the United Kingdom diagnostic criteria for atopic dermatitis in Romanian schoolchildren

Although the U.K. modification of Hanifin and Rajka's diagnostic criteria for atopic dermatitis (AD) for use in epidemiological studies has demonstrated good validity and repeatability when previously tested in a U.K. community setting, little is known about its performance in other countries where different cultural, educational and linguistic factors could impair validity. We used a questionnaire to test the validity of the U.K. criteria as a point prevalence measure of AD in 1114 Romanian schoolchildren aged 6–12 years against the clinical diagnosis of a dermatologist with an interest in AD, who was unaware of the questionnaire content and responses. The sensitivity and specificity of the U.K. criteria for AD in this setting was 74% and 99%, respectively, an improvement rather than a deterioration in validity when compared with the previous U.K. study. Test–retest repeatability for all of the questions pertaining to the U.K. criteria using the chance-corrected kappa statistic was high, with values of 0.72 and over. The positive predictive value of the criteria was lower than in the U.K. study (63% compared with 80%, respectively) due to the very low prevalence of AD in this study (2.4%). The validity of a parental report of 'eczema' was poor, with a sensitivity of 22%, specificity of 97% and positive predictive value of 18%. This study suggests that the U.K. criteria perform well in settings outside the U.K., although care has to be taken when using the criteria to ascertain cases in settings where the prevalence of AD is very low.     

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.     

Validation of the U.K. diagnostic criteria for atopic dermatitis in a population setting

Summary One reason why so little is known about the epidemiology of atopic dermatitis (AD) is lack of suitable diagnostic criteria. A simple list of diagnostic criteria for AD for use in epidemiological studies has recently been developed by a U.K. working party. These have performed well in hospital validation studies of subjects with skin diseases. This study sought to validate the newly proposed criteria for AD in a population setting by conducting a cross-sectional survey of 695 schoolchildren aged 3–11 years in three randomly selected primary schools in West Lambeth, London. As a point prevalence measure, the U.K. criteria had a sensitivity of 70%, a specificity of 93%, and a positive predictive value of 47% when compared with a dermatologist's examination findings. Subsequent analysis suggested that most children classified as false positives had suffered from AD in the last year, but were inactive at the time of examination. When adjusted for these cases, the sensitivity and specificity increased to 80 and 97%, respectively, corresponding to positive and negative predictive values of 80 and 97%, respectively. The U.K. diagnostic criteria for AD appear to work well as a 1-year period prevalence measure in London schoolchildren. Further validation in adults and other countries are needed.     

Validation and reproducibility of the International Study of Asthma and Allergies in Childhood (ISAAC) Written Atopic Eczema Questionnaire for telephone survey in children aged 6–7 years

BackgroundThe prevalence of atopic eczema is unknown in many countries. The International Study of Asthma and Allergies in Childhood (ISAAC) is an epidemiological landmark in the study of allergic diseases.ObjectiveTo validate and assess the reproducibility of the ISAAC Written Atopic Eczema Questionnaire (WAEQ) for children aged between 6 and 7 years by telephone contact.MethodsObservational study through interviews with guardians of children aged 6 to 7 years using the ISAAC atopic eczema module questionnaire in three different phases separated by 2 weeks: telephone interviews in the first and third contacts and in-person interviews under supervision in the second contact. Reproducibility was estimated using the Kappa index and validation using the sensitivity and specificity coefficients.ResultsData from 88 children (32 from the atopic eczema group) were analyzed. Reproducibility showed almost perfect agreement for the questions “Recurrent pruritic lesions” and “Lesions in typical locations” (Kappa between 0.81–0.82), while a substantial agreement was observed for all other indicators (Kappa variation between 0.66 and 0.78). The validation showed high specificity (≥ 80.4%) and sensitivity (≥ 87.5%) for all questions, except those related to chronicity and medical diagnosis (34.4% and 40.6%, respectively).Study limitationsNon-random selection, no sample size calculation, participants from a tertiary hospital and study period coincident with the Coronavirus pandemic.ConclusionsOur results showed that the ISAAC atopic eczema module questionnaire by telephone interviews has good reproducibility and high agreement with the clinical diagnosis of atopic eczema. It may be an appropriate alternative tool in epidemiological studies of childhood atopic eczema, especially in periods of social isolation.     

Prevalence of atopic eczema in the community: the Lothian atopic dermatitis study

Summary An epidemiological study of atopic eczema (AE), based on a semirural community in Scotland, using sound diagnostic criteria, has yielded prevalence data for all age groups including infants and adults. The overall 1-year period prevalence, age-standardized to the Scottish population, was 2.3%. The 1-year period prevalence was highest in the under 2s(9.8%), and showed a continuous reduction with increasing age. Over the age of 40, AE was found to be relatively rare, with a 1-year period prevalence of 0.2%. Adults over 16 years made up 38% of all patients with AE.     

Prevalence of atopic dermatitis and serum IgE values in nursery school children in Ishigaki Island, Okinawa, Japan

There have been many studies of the prevalence of atopic dermatitis (AD), but few population-based epidemiologic studies measure the prevalence in Japan among children aged 5 years and younger. We examined the prevalence of AD, serum total IgE levels and specific IgE antibodies to 10 common allergens among children in Ishigaki Island, Okinawa, Japan in 2001. We also obtained information on the predictability of the U.K. Working Party diagnostic questionnaire criteria for AD in this population. Five hundred and sixty five children aged 5 years and younger were enrolled in this study with informed consent from their parents. The questionnaire of the U.K. Working Party diagnostic criteria for AD was translated into Japanese, and the parents completed the questionnaire sheet. Physical examination and blood sampling were done for all children. Thirty-nine out of the 565 (6.9%) children were diagnosed with AD by physical examination. The total and specific IgE levels were significantly higher in the children with AD than in those without AD. High levels of total IgE were found in 33.3% of the children with AD. A specific IgE to one or more allergens was detected in 64.1% of children with AD. However, a substantial population of children without AD also had high levels of total IgE (12.7%) and a specific IgE to one or more allergens (30.2%), and the increment of total and specific IgE levels was significantly associated with age. The percentage of positive answers to the questionnaire of the U.K. Working Party diagnostic criteria for AD was significantly higher in children with AD (59.0%) than in children without AD (5.3%) (P<0.0001). Its specificity was 94.7%. The false negative rate was 41%. In conclusion, the prevalence of AD was relatively low in children in Ishigaki Island. High levels of total IgE were found in only one third of children with AD under 5 years of age. The Japanese translated form of the questionnaire of the U.K. Working Party diagnostic criteria for AD should be refined to improve its sensitivity.     

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.     

Is the question ‘Have you had childhood eczema?’ useful for assessing childhood atopic eczema in adult population surveys?

Atopic eczema (AE) is a major risk factor for hand eczema. In Scandinavian population‐based studies, the occurrence of AE in childhood has often been assessed by the question ‘Have you had childhood eczema?’ In the present study, this question was validated. A questionnaire was sent to 600 cases with AE and 600 controls without eczema or allergic disease, identified in school medical records from the 1960s. The response rate was 70.5%, and the mean age of the respondents was 36.7 years. The specificity of the question was 70.7% and the sensitivity 89.9%. The sensitivity was higher and the specificity lower in a subgroup with current hand eczema compared with a group without hand eczema. The results showed that the question overestimated the prevalence of AE in childhood by a factor of 1.6. When used for risk assessment, the question provided a better estimate of the risk of current hand eczema as compared with the lifetime risk of hand eczema. In conclusion, the validated question overestimated prevalence of childhood AE and may overestimate AE as a risk factor for hand eczema in adult population surveys.     

Prevalence of atopic dermatitis, asthma, allergic rhinitis, and hand and contact dermatitis in adolescents. The Odense Adolescence Cohort Study on Atopic Diseases and Dermatitis

BACKGROUND: Atopic diseases are common in children and adolescents. However, epidemiological knowledge is sparse for hand eczema and allergic contact dermatitis in this age group. Furthermore, no population-based studies have evaluated the prevalence of atopic diseases and hand and contact dermatitis in the same group of adolescents. OBJECTIVES: To assess prevalence measures of atopic dermatitis (AD), asthma, allergic rhinitis and hand and contact dermatitis in adolescents in Odense municipality, Denmark. METHODS: The study was carried out as a cross-sectional study among 1501 eighth grade school children (age 12-16 years) and included questionnaire, interview, clinical examination and patch testing. RESULTS: The lifetime prevalence of AD was 21.3% (girls 25.7% vs. boys 17.0%, P < 0.001) using predefined questionnaire criteria. The 1-year period prevalence of AD was 6.7% and the point prevalence 3.6% (Hanifin and Rajka criteria). In the interview the lifetime prevalence of inhalant allergy was estimated as 17.7% (6.9% allergic asthma, 15.7% allergic rhinitis). The lifetime prevalence of hand eczema based on the questionnaire was 9.2%, the 1-year period prevalence was 7.3% and the point prevalence 3.2%, with a significant predominance in girls. A significant association was found both between AD and inhalant allergy, and between AD and hand eczema using lifetime prevalence measures. The point prevalence of contact allergy was 15.2% (girls 19.4% vs. boys 10.3%, P < 0.001), and present or past allergic contact dermatitis was found in 7.2% (girls 11.3% vs. boys 2.5%). Contact allergy was most common to nickel (8.6%) and fragrance mix (1.8%). CONCLUSIONS: High prevalence figures were found for atopic diseases, hand eczema and allergic contact dermatitis, and the diseases were closely associated. A considerable number of adolescents still suffers from AD, and a considerable sex difference was noted for hand eczema and allergic contact dermatitis. Nickel allergy and perfume allergy were the major contact allergies. In the future this cohort of eighth grade school children will be followed up with regard to the course and development of atopic diseases, hand eczema and contact dermatitis.     

What’s new in atopic eczema? An analysis of systematic reviews published in 2007 and 2008. Part 1. Definitions,causes and consequences of eczema

This review summarizes clinically important findings from nine systematic reviews indexed in bibliographical databases between August 2007 and August 2008, dealing with the definitions, causes and consequences of atopic eczema (AE). One review of diagnostic criteria found that out of 10 sets of criteria, only the UK refinement of the Hanifin and Rajka criteria have been adequately tested (in 19 studies). Another review of 20 named outcome measures found that only three [SCORing Atopic Dermatitis (SCORAD), the Eczema Area and Severity Index (EASI) and the Patient Oriented Eczema Measure (POEM)] had been tested and found to perform adequately. In terms of risk factors for developing disease, a review found that birth by caesarean section increased the risk of asthma and hay fever but not eczema in offspring. A review of cohort studies also found evidence that adverse psychological factors in early life predispose to more atopic disease and a worse prognosis. Another review found that filaggrin gene mutations were a consistently strong risk factor for AE, with a person carrying one of these mutations being over three times more likely to exhibit eczema. It has been suggested that eczema might protect against some forms of cancer, and a detailed systematic review of brain cancers that included 53 233 participants from eight case–control and cohort studies found that having atopic disease was associated with a 39% reduction in glioma risk, a finding that was also present for just those with AE (odds ratio 0.69, 95% CI 0.58–0.82). A further review of case–control and cohort studies failed to find any association between keeping furry pets at birth and subsequent risk of eczema, although pet fur might still exacerbate established disease. In terms of disease consequences, a review found that eczema was the commonest cause of chronic sleep loss in young people, affected the whole family. A review of four economic studies from the US found that the annual cost of AE in the States was as high as $3.8 billion when indirect costs are included.     

Prevalence of atopic dermatitis in Japanese adults

BACKGROUND: Adult atopic dermatitis (AD) in Japan has become a significant social problem, with as many as one-third of adult patients with severe AD absenting themselves from work or classes due to aggravation of the disease. Reports of such patients have become increasingly common in recent years. Despite the pressing need for epidemiological studies to clarify the prevalence and distribution of AD and to determine its aetiology, no previous research has been carried out on the prevalence of AD within the adult population in Japan. OBJECTIVES: To clarify the prevalence of adult AD in Japan, using the U.K. Working Party's diagnostic criteria. METHODS: The subjects of this study were mostly government officials or their family members visiting the Medical Center of Health Science, Toranomon Hospital in Tokyo for annual health check-ups in the period from September 1997 to August 1998. Questionnaires completed by 10 762 persons (8076 men and 2686 women) aged 30 years or above were analysed. The questionnaire consisted of 14 questions on allergic disease. The U.K. Working Party's diagnostic criteria were used after translation into Japanese. Three types of prevalence were used as indicators of prevalence: point, 1-year and lifetime prevalence. RESULTS: The point prevalence, 1-year prevalence and lifetime prevalence of AD in Japanese adults were 2.9%, 3.0% and 3.3%, respectively. No significant statistical differences were observed between the sexes or among age groups within each sex. The survey indicated that 88.6% of those who had ever had AD were currently affected by active AD, while 93.4% of those who had had at least one episode of AD in the past had experienced an episode over the previous year. CONCLUSIONS: This study gives the first indication of the prevalence of adult AD among the Japanese, based on the U.K. criteria. Both the internal and external validity of this study are believed to be high; it would be safe to conclude that the 1-year prevalence of AD in Japanese adult populations living in urban areas is 3.0%.     

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.     

Early allergen exposure and atopic eczema

BACKGROUND: The relationship between exposure to indoor aeroallergens in early life and subsequent eczema is unclear. We have previously failed to show any significant associations between early life exposure to house dust mite and cat fur allergens and either sensitization to these allergens or wheeze. We have also previously reported a lower prevalence of parent-reported, doctor-diagnosed eczema by age 2 years for children exposed to higher concentrations of house dust mite, but no other associations with other definitions of eczema or for exposure to cat allergen. OBJECTIVES: To extend the exposure-response analysis of allergen exposure and eczema outcomes measured up to age 8 years, and to investigate the role of other genetic and environmental determinants. METHODS: A total of 593 children (92 x 4% of those eligible) born to all newly pregnant women attending one of three general practitioner surgeries in Ashford, Kent, were followed from birth to age 8 years. Concentrations of house dust mite and cat allergen were measured in dust samples collected from the home at 8 weeks after birth. The risk of subsequent eczema as defined by the U.K. diagnostic criteria was determined according to different levels (quintiles) of allergen exposure at birth. RESULTS: By age 8 years, 150 (25 x 3%) children had met the diagnostic criteria for eczema at least once. Visible flexural dermatitis was recorded at least once for 129 (28 x 0%). As in other studies, parental allergic history was positively associated with most eczema outcomes, as were higher maternal education and less crowded homes. No clear linear associations between early exposure to house dust mite or cat allergen were found, regardless of the definition of eczema used. The risk of eczema appeared to increase for the three lowest quintiles of house dust mite allergen exposure (odds ratio, OR 1 x 37 for third quintile compared with first), and then to fall for the two highest quintiles (OR 0 x 66 and 0 x 71) even after controlling for confounding factors. CONCLUSIONS: The lack of any clear exposure-disease relationship between allergens in early life and subsequent eczema argues against allergen exposure being a major factor causing eczema. If the lower levels of eczema at higher levels of house dust mite are confirmed, then interventions aimed at reducing house dust mite in early infancy could paradoxically increase the risk of subsequent eczema.     

The prevalence of atopic dermatitis in Oregon schoolchildren

BACKGROUND: Although surveys from many parts of the world have shown that the prevalence of atopic dermatitis (AD) in schoolchildren has increased greatly in the past 40 years, there is no current prevalence information from the United States. OBJECTIVE: Our objective was to investigate the utility of a recently developed European questionnaire to estimate the prevalence of AD in urban and rural Oregon schoolchildren. METHODS: The self-administered Schultz-Larsen questionnaire (SLQ) of AD symptoms and history was completed by the parents of a broad socioeconomic and ethnic mix of 5- to 9-year-old schoolchildren from 6 urban and 2 rural elementary schools in Oregon. Validation assessments included comparisons of the questionnaire scores with clinical examination in a group of age-matched children and with specific history components known to correlate with AD. RESULTS: Data showed a prevalence of 17.2% using standard scoring criteria for the SLQ and with a lower limit of 6.8% according to highly stringent criteria derived from the validation study using dermatologic examination. A single question ("Has a doctor ever said that your child has eczema?") was highly concordant with the questionnaire determination, yielding very high predictive accuracy (91.2%). CONCLUSION: This study of childhood AD frequency indicates a high prevalence of AD in the United States, comparable to that recently observed from studies in Europe and Japan. (J Am Acad Dermatol 2000;43:649-55.).