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.