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Notes: Severity scoring of atopic dermatitis (SCORAD) was introduced as a standard tool but has not been used in a population-based epidemiological study; the objective of the present study was to determine the practicability of this instrument in this setting. We assessed the distribution of the severity of atopic eczema in the community and investigated differences between east and west Germany. A factor analysis was then carried out to characterize the variables of this scoring system and to analyse possible relationships within them. A multicentre cross-sectional study was carried out in five east German and two west German locations in 1994; pre-school children (5–6 years old) were investigated and cases of atopic eczema identified by a dermatological examination. The SCORAD was used to determine the severity of atopic eczema and the results assessed using analysis of variance and principal component analysis (varimax rotation). In all, 1511 (76·2%) of the children originally contacted participated and 11·3% were diagnosed with atopic eczema at the time of examination. The median severity score was 21·4 (interquartile range 13·5) and there was a tendency to higher scores in west Germany for the mean overall score, the intensity score and the extent. ‘Erythema’ (1·30 vs. 1·06; P= 0·006) and ‘excoriation’ (0·77 vs. 0·36; P= 0·002) were significantly more prominent in children with eczema from west Germany (adjusted for observer). Interobserver variabilities of the SCORAD parameters were calculated, adjusted for location and were in accordance with earlier findings. Principal component analysis identified three independent factors accounting for 54·1% of the total variance. A severity factor, characterized by ‘extent’, ‘lichenification’, ‘excoriation’ and ‘pruritus’, was separated from a factor with an acute eczema-type profile (‘erythema’, ‘oedema’, ‘oozing’) and a factor whose major characteristics were ‘extent’, ‘dryness’, and ‘sleep loss’. We conclude that atopic eczema is frequent in pre-school children. The SCORAD proved to be readily applicable and useful in epidemiological studies, but further validation is needed.

Notes: Schäfer T, Ring J. Epidemiology of allergic diseases.The escalation of allergic diseases (hay fever, asthma, atopic eczema) over recent decades has been linked to an increase in environmental pollutants. The prevalence of hay fever is associated with genetic predisposition, and some reports show an association with urban areas, socioeconomic status, and combined high allergen and automobile exhaust exposure. In asthma, there is also some evidence for geographical variations in prevalence; exercise challenge tests prove positive more often in urban areas than in rural areas. Although genetic predisposition is the strongest single risk factor for atopic eczema, air pollutants may aggravate the condition by acting as unspecific irritants and immunomodulators, leading to increased immunoglobulin E expression. In a study of 678 pre-school children, the influence of maternal smoking habits on individual measures of atopy revealed a positive association between smoking during pregnancynactation, and a positive history of atopic eczema. An East-West German comparative study examining different types and levels of air pollution, i.e. sulphurous (industrial; East) and oxidising (urban; West), showed that the prevalence of atopic eczema was greatest in East Germany. When various direct and indirect parameters of air pollution exposure were measured, the greatest association with atopic eczema was found with NOx exposure (indoor use of gas without a cooker hood), and close proximity to roads with heavy traffic. The increased prevalence of atopic eczema cannot be explained by changes in study methodology over time, or conventional risk factors alone; environmental risk factors may be an important contributing factor.