Atopic dermatitis and respiratory symptoms in Russian and northern Norwegian school children: a comparison study in two arctic areas and the impact of environmental factors

Abstract

Background: The increase in atopic diseases during recent decades has been related to environmental factors such as indoor and outdoor pollution and the ingestion of certain foods. On the other hand, studies from Eastern Europe (with heavy air pollution) have reported a lower prevalence of atopic diseases and sensitization in their schoolchildren than in children living in Western Europe.

Objectives: This study compares the frequency of atopic diseases and respiratory symptoms in two geographically close arctic areas and points to possible risk factors for development of the diseases.

Methods: A total of 1734 schoolchildren (1183 in Nikel and 551 in Sør-Varanger) were studied using identical, four-page, self-administered questionnaires.

Results: Atopic diseases were reported in 38.7% of Norwegian and in 24.2% of Russian children (P < 0.001). Atopic dermatitis (AD) (23.6% vs 7.9%; P < 0.001) and allergic rhinoconjunctivitis (AR) (20.6% vs 14.7%; P < 0.001) occurred more frequently in Sør-Varanger, whereas 'self-reported' asthma (12.3% vs 13.1%) was similar in both areas. However, respiratory symptoms such as coughing, wheezing, breathlessness and bronchitis were 3-4 times more frequent in Nikel (P < 0.001).

Conclusion: This study disproves a previous hypothesis, i.e. that air pollution must be a major risk factor for the development of atopic diseases. Nevertheless, respiratory tract symptoms may be provoked by environmental pollution. Possible explanations for the higher frequency of atopic diseases in Sør-Varanger may be found in socio-economic and lifestyle differences between the two populations.