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.     

Assessment of the American Academy of Dermatology diagnostic criteria for pediatric atopic dermatitis and modification into a checkbox form: A cross-sectional study

Background/Objectives

Diagnostic criteria for atopic dermatitis (AD) are limited in their performance and/or usability. The American Academy of Dermatology (AAD) consensus criteria include hierarchical categories of disease features to improve these metrics but have not been validated. Our objective was to create and validate a checkbox form of the AAD consensus criteria in the pediatric population.

Methods

We performed a cross-sectional study of 100 pediatric patients with AD (n = 58) and diseases in the differential diagnosis of AD (n = 42).

Results

Having three or more “Essential,” ≥2 “Important,” ≥1 “Associated” features of the AAD criteria was optimal for the diagnosis of AD in children. This combination was 91.4% (95% CI, 84.2%–98.6%) sensitive and 95.2% (88.8%–100%) specific. The UK working party criteria and the Hanifin–Rajka criteria had sensitivities of 96.6% (95% CI 91.9%–100%) and 98.3% (95% CI 94.9%–100%) and specificities of 83.3% (95% CI 72.1%–94.6%) and 71.4% (95% CI 57.8%–85.1%), respectively. The AAD criteria had significantly greater specificity than the Hanifin–Rajka criteria (p = .002).

Conclusions

This study represents an important step in validating the AAD consensus criteria and formulating a useable checkbox form for diagnosing AD in the pediatric population.     

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

BACKGROUND: Reliable diagnostic criteria for atopic eczema (AE) are essential in order to make international comparisons and to identify possible disease risk factors. Little is known about the prevalence of atopic eczema and validity of diagnostic criteria for AE in developing countries where English is not the first language. OBJECTIVES: We sought to determine the prevalence of AE in an area of urban and rural Ethiopia, and to compare the predictive values of different questionnaire and examination methods for diagnosing AE in this population. METHODS: We conducted a cross-sectional survey of 7915 children aged 1-5 years living in and around the town of Jimma in southwest Ethiopia. AE prevalence was assessed in two ways: (i) by using the International Study for Asthma and Allergies in Childhood (ISAAC) questionnaire, and (ii) using the U.K. refinement of Hanifin and Rajka's diagnostic criteria. All possible cases identified by screening questions and random samples of controls were then examined by an experienced local paediatrician, who acted as a reference standard to determine the predictive value of the criteria used to diagnose AE. RESULTS: The overall 1-year period prevalence of AE according to ISAAC and U.K. criteria was 4.4%[95% confidence interval (CI) 3.95-4.85] and 1.8% (95% CI 1.5-2.1), respectively. Corresponding point prevalence estimates (symptoms in the last week) were 1.8% for ISAAC and 1.3% for the U.K. criteria. The positive predictive values of the ISAAC and U.K. criteria questions for AE symptoms still reported to be present (in the last week) at the doctor's examination were 48.8% and 55.5%, respectively. Corresponding negative predictive values were 90.5% and 90.1%, respectively. The sign of visible flexural dermatitis (a component of the U.K. criteria) when used alone had positive and negative predictive values of 57% and 91%, respectively. CONCLUSIONS: Neither the ISAAC nor U.K. criteria performed especially well in predicting cases of AE in this survey. Possible reasons include problems with questionnaire translation, cultural conceptions of terminology, asking parents rather than the child about symptoms, the transient nature of AE signs, and differences in what a doctor perceives to constitute a typical case of AE. The results do not preclude the use of standardized diagnostic criteria alongside a doctor's examination in future surveys of Ethiopian children, and knowledge of the criteria's limited predictive value should help to interpret study findings that have employed such criteria. Consideration should be given to adopting the sign of visible flexural dermatitis as a standard for estimating the point prevalence of AE throughout the world because it is less susceptible to problems with translation and interpretation.     

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.     

Evaluation of diagnostic criteria for atopic dermatitis: validity of the criteria of Williams et al. in a hospital-based setting

BACKGROUND: Surveys of the prevalence of atopic dermatitis (AD) have been carried out world-wide, but the results vary widely. The differences probably result from the use of different diagnostic criteria. Williams et al. proposed minimum, simplified, diagnostic criteria that require no invasive test and are easy to use. Pilot studies in European countries showed their suitability for implementation both in hospitals and in the community, and their high sensitivity and specificity. OBJECTIVES: To evaluate the potential practical value of the criteria of Williams et al. in the Chinese population. METHODS: The criteria of Hanifin and Rajka (gold standard), Williams et al. and Kang and Tian were applied and compared in 111 patients with AD and 121 control subjects with other skin diseases in three out-patient centres in China. RESULTS: The criteria of Williams et al. showed a similar diagnostic efficiency to that of the gold standard, with the sensitivity, specificity and kappa value reaching 95.50%, 97.52% and 0.93, respectively. No significant difference was found between the criteria of Williams et al. and those of Kang and Tian (chi2 = 0.69, P > 0.05). 'Onset under the age of 2 years', a criterion of Williams et al. could be used in subjects of any age. CONCLUSIONS: The diagnostic efficiency of the criteria of Williams et al. was basically similar to those of Hanifin and Rajka and of Kang and Tian in our out-patient settings. However, those of Williams et al. were easier to apply and required no invasive tests.     

Sensitization to thimerosal in atopic children

Thimerosal is an organic mercurial compound widely used as a preservative in vaccines, eyedrops, and contact lens cleaning and storage solutions. 5 infants, 2 female and 3 male, ranging in age from 7 to 28 months and affected by atopic dermatitis (AD) diagnosed according to the Hanifin and Rajka criteria, experienced an exacerbation of their clinical condition 2-10 days after mandatory vaccinations with vaccines containing thimerosal. Cutaneous lesions of nummular eczema appeared on the trunk, limbs and face. All patients were patch tested with serial dilutions of thimerosal in petrolatum. A positive patch test reaction to thimerosal 0.1% pet. was observed in all 5 children. 3 of them also showed a positive reaction at 0.01% and 0.05% pet. Despite their thimerosal-hypersensitivity, all children completed the entire series of mandatory vaccinations, care being taken to use different needles for injection and aspiration of the vaccine. The 2-year follow-up did not reveal other episodes of exacerbation of the AD after vaccination. The present study confirms the high frequency of sensitization to thimerosal in atopic children and suggests that vaccination can cause clinical symptoms in sensitized children. Nevertheless, sensitization to thimerosal does not prevent children from continuing with mandatory vaccinations.     

Comparative efficacy of Hanifin and Rajka''s criteria and the UK working party''s diagnostic criteria in diagnosis of atopic dermatitis in a hospital setting in North India

BACKGROUND: Diagnosis of atopic dermatitis (AD) depends on clinical features because no definitive diagnostic test exists. Criteria proposed by Hanifin and Rajka (Acta Derm Venereol (Stockh) 1980; Suppl 92: 44-47) were acceptable for hospital-based studies but were found not to be suitable for field studies. A UK working party formulated clinical diagnostic criteria that could be used in both hospital and epidemiological settings. Validation studies of the criteria showed widely variable results, probably due to different clinical settings and ethnicity. AIM AND OBJECTIVE: This study was undertaken to validate Hanifin and Rajka's criteria and to assess the comparative efficacy of their criteria and the UK working party's diagnostic criteria in the diagnosis of AD in a hospital setting in North India. SUBJECTS AND METHODS: This study serially included 101 patients with AD and 48 controls of paediatric age group. The study period was from July 2003 to December 2004. RESULTS: Hanifin and Rajka's criteria (sensitivity 96%, specificity 93.75%, positive predictive value 97% (PPV) and negative predictive value (NPV) 91.84%) had a statistical advantage over the UK working party's diagnostic criteria (sensitivity 86%, specificity 95.83%, PPV 97.75% and NPV 76.67%), with a P-value < 0.005.     

Validation and refinement of the Millennium Criteria for atopic dermatitis

There is no gold standard for a definite diagnosis of atopic dermatitis. For the time being, several lists of diagnostic criteria have been proposed, some of them in actual use. The Millennium Criteria have been proposed to diagnose atopic dermatitis and to differentiate it from atopiform dermatitis. Our aim was to further refine the Millennium Criteria into a manageable set that can differentiate between atopic and atopiform dermatitis and other entities. The hereby refined Millennium Criteria will be compared with the UK Working Party Criteria and the Hanifin & Rajka Criteria. Data of 210 included patients were used. After multiple logistic regression, a minimum set of five criteria was identified as best discriminators: (i) typical morphology; (ii) early age of onset; (iii) Dennie-Morgan fold; (iv) historical and (v) actual flexural involvement. The refined Millennium Criteria were constituted from these criteria. When comparing the different list for validity in diagnosing atopic dermatitis, the refined Millennium Criteria showed a sensitivity of 81.8% and a specificity of 98.8% compared to a sensitivity of 97.7% and specificity of 72.9% of the UK Criteria and a sensitivity of 100% and specificity of 48.8% of the Hanifin & Rajka Criteria. This refinement and validity study shows that the refined Millennium Criteria are a valid tool to diagnose atopic and atopiform dermatitis in a hospital-based setting and therefore could be incorporated in clinical practice and trials.     

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.     

Differenzialdiagnose des atopischen Ekzems in der Kindheit

Atopic eczema (AE) is a chronic inflammatory skin disease which affects 10 to 20% of children and 1 to 3% of adults. AE is usually diagnosed based on standard criteria such as those of Hanifin and Rajka, whereby the age-related variation must be considered. There are numerous other diseases which go along with AE or show a very similar clinical picture and represent important differential diagnostic considerations including parasitic diseases, immunodeficiency, nutritional diseases, certain neoplastic disorders and various corneal abnormalites. Additionally, it is important to consider diseases which can occur in association with AE, such as keratosis pilaris, alopecia areata or sweat disturbances.     

Associated diseases and differential diagnostic considerations in childhood atopic eczema

Atopic eczema (AE) is a chronic inflammatory skin disease which affects 10 to 20% of children and 1 to 3% of adults. AE is usually diagnosed based on standard criteria such as those of Hanifin and Rajka, whereby the age-related variation must be considered. There are numerous other diseases which go along with AE or show a very similar clinical picture and represent important differential diagnostic considerations including parasitic diseases, immunodeficiency, nutritional diseases, certain neoplastic disorders and various corneal abnormalities. Additionally, it is important to consider diseases which can occur in association with AE, such as keratosis pilaris, alopecia areata or sweat disturbances.     

The millennium criteria for the diagnosis of atopic dermatitis

Abstract: Atopic dermatitis forms an active area of basic and clinical research, where important new knowledge about genetics and immunopathogenesis has surfaced over the past years, and where simultaneous development of new and innovative therapies is under way. However, the inclusion of any patient in an atopic dermatitis study, whether it is on its genetics, pathogenesis or therapy, requires a diagnosis which is irrefutable. Since there is no simple and also no complicated laboratory procedure to reach a diagnosis of atopic dermatitis, different sets of clinical criteria have been developed for the purpose of making the diagnosis uniformly in different studies as well as in different study centers. The most commonly used are Hanifin and Rajka's set of diagnostic features, which have major and minor clinical criteria to be fulfilled in order to establish a diagnosis of atopic dermatitis. Recent developments in the immunology of atopy have clearly established the major abnormality in this syndrome, the preferential production of allergen-specific IgE. In this contribution, it is suggested that the presence of such antibodies in a given patient should be a mandatory criterium for the diagnosis of atopic dermatitis. Such a diagnostic test however establishes a diagnosis of atopic syndrome, not atopic dermatitis. Thus, for atopic dermatitis we have to rely, for the time being, on additional clinical criteria. The clinical features described in the literature are critically evaluated, and it is suggested that in addition to the mandatory presence of allergen-specific IgE, 2 of 3 principal criteria (pruritus, typical morphology and distribution, chronic or chronically relapsing) should be present for such a diagnosis. Finally, the minor features originally described by Hanifin and Rajka and later evaluated by others are revised and divided over 4 subcategories; a) related to subclinical eczema; b) related to dry skin; c) extra skin folds; and d) ophthalmological pathology. They are suggested to be used as additional criteria only, needed when clinical suspicion is high but the new mandatory and principal diagnositic criteria described here are inconclusive. For study purposes, we suggest that the mandatory and principal criteria are sufficient. They are now evaluated and validated in ongoing atopic dermatitis treatment studies.     

特应性皮炎临床特点和诊断标准的探讨

目的 探讨康克非和田润梅提出的特应性皮炎(AD)诊断标准(简称康田标准)的适用性。方法 用康田标准对917例经Hanifin和Rajka诊断标准(简称HR标准)确诊的AD患者进行诊断,并分析AD患者的遗传过敏史及其临床特点。结果 888例AD患者符合康田标准,占96.84%.有个人或家族过敏史者占83.21%.婴儿期AD患者面部皮炎的发生率高于儿童期和青少年、成人期,而其干皮症、鱼鳞病、毛周角化、眶周黑晕的发生率又低于儿童期和青少年、成人期。结论 遗传过敏史是AD诊断中的一个重要因素。康田标准是一个合理实用的诊断标准,值得推广使用。     

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.     

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.     

The excess of atopic eczema in East Germany is related to the intrinsic type

BACKGROUND: Prevalence data for atopic eczema based on a dermatological examination have not so far been available for East and West Germany. Possible differences in the proportions of extrinsic and intrinsic types of eczema, and how far these could explain differences in the prevalence of eczema, need to be clarified. OBJECTIVES: To compare the prevalence of atopic eczema in pre-school children between different locations in East and West Germany, and over a period of 7 years, at three time points. Additionally, to determine the proportions of intrinsic and extrinsic types of eczema by taking skin prick test reactivity into account. METHODS: Repeated cross-sectional studies in 1991, 1994 and 1997 in 5-6-year-old pre-school children at five different locations in West Germany (n = 2075) and six in East Germany (n = 1926) were carried out. Individuals with eczema were identified by an examination performed by physicians of the Department of Dermatology. In addition, a skin prick test and a standardized questionnaire were used. RESULTS: The overall prevalence of atopic eczema in these children was 10.4%. At all three times of investigation (1991, 17.5% vs. 11.2%; 1994, 12.6% vs. 8.7%; 1997, 11.2% vs. 4.5%) and in the total group (12.9% vs. 8.2%), the prevalence was significantly higher in East than in West Germany. After controlling for influences of sex, parental history of atopic diseases, observer and socio-economic status in multiple logistic regression analyses, these differences remained significant for 1991, 1994 and for the overall group (odds ratio, OR 1.78, 95% confidence interval, CI 1. 43-2.21). Girls (OR 1.56, 95% CI 1.27-1.92) and children whose parents had a higher level of school education (OR 1.17, 95% CI 1. 00-1.37) were affected more frequently. Of all children, 26.6%, and of those with eczema, 41.9% exhibited at least one reaction in the prick test (OR 2.21, 95% CI 1.75-2.80; sensitization in eczema vs. no eczema). Whereas 50.4% of the children with eczema in West Germany were sensitized, only 36.5% of the diseased children in East Germany reacted positively in the prick test (OR 1.77, 95% CI 1.12-2. 79). CONCLUSIONS: These results are in accordance with findings regarding allergic sensitization and hay fever and might indicate that factors other than allergy are responsible for the higher prevalence of atopic eczema in East Germany.     

Prominent pruritic periumbilical papules: A diagnostic sign in pediatric atopic dermatitis

Establishment of diagnostic criteria for atopic dermatitis has been a subject of controversy and frequent reevaluation. The diagnostic criteria of Hanifin and Rajka are those most frequently cited. In order to fit the diagnosis, a patient must demonstrate three major criteria plus four or more minor criteria. Although individually the minor criteria are not diagnostic, their presence suggests the possibility of atopic dermatitis. Recently we evaluated several children who developed prominent periumbilical papules as a major component of their atopic dermatitis. This finding, while not present in all children with atopic dermatitis, can provide a specific clue to diagnosis and should be considered as a new minor criterion for atopic dermatitis in children.     

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.     

Transepidermal water loss, serum IgE and beta-endorphin as important and independent biological markers for development of itch intensity in atopic dermatitis

BACKGROUND: Although itch is the predominant symptom of atopic dermatitis (AD), it is poorly characterized and subjective. The objective assessment of itch intensity is important for treatment and follow-up in patients with AD. OBJECTIVES: To determine what objective clinical parameter(s) could be used as biomarker(s) for itch intensity in patients with AD. METHODS: This is a retrospective and cross-sectional study. Seventy-five patients, aged 7 months-49 years with equal sex ratio, were enrolled in 2000 according to criteria proposed by Hanifin and Rajka. Thirty-five age- and sex-matched subjects who visited the dermatological clinic but were otherwise healthy served as controls. Subjective itch intensity was divided into four grades of severity. Disease severity was measured by SCORAD index, which also includes itch intensity as part of the measurement. Transepidermal water loss (TEWL) and skin surface pH were measured by noninvasive methods in clinically normal skin on the forearm. Serum beta-endorphin and vasoactive intestinal peptide (VIP) were determined by radioimmunoassay. Ordinal logistic regression was used to assess the trend of the subjective itch intensity and SCORAD index by serum IgE, beta-endorphin, VIP, TEWL and skin pH. RESULTS: There were significant trends for itch intensity with IgE, beta-endorphin and TEWL. After adjustment for sex, age and other variables, the odds ratio (OR) for itch intensity by log IgE, beta-endorphin and TEWL was 2.103 [95% confidence interval (CI) 1.222-3.618], 1.100 (95% CI 1.005-1.203) and 1.081 (95% CI 1.009-1.158), respectively. The OR for disease severity by log IgE, beta-endorphin and TEWL was 2.250 (95% CI 1.149-4.407), 1.156 (95% CI 1.086-1.231) and 1.071 (95% CI 0.971-1.182), respectively. In contrast, there was no association between serum VIP concentration and itch intensity. CONCLUSIONS: Beta-endorphin and IgE are both useful biomarkers for itch and disease severity in patients with AD, while TEWL is a good biomarker for itch intensity. These biomarkers provide a way to assess the itch intensity in patients with AD.