BACKGROUND: Climate and sunlight (ultraviolet radiation) influence activity of atopic eczema. OBJECTIVE: To evaluate the effect of moving from a subarctic/temperate climate to a sunny subtropical climate on children's atopic eczema. METHODS: Children, 4-13 years, with severe atopic eczema were randomized to stay 4 weeks in Gran Canary (index patients = 30) and home in Norway (controls = 26), with a follow up of 3 months. SCORing of Atopic Dermatitis (SCORAD) was primary variable, and secondary were Children's Dermatology Life Quality Index (CDLQI), Staphylococcus aureus skin colonization and pharmacological skin treatment. RESULTS: SCORing of Atopic Dermatitis decreased from 37.2 (29.4-44.9) to 12.2 (9.0-15.4) [mean (95% confidence intervals)] after 4 weeks and 21.2 (17.2-25.1) 3 months thereafter in index patients (P