1. Department of Dermato-Allergology; National Allergy Research Centre, Gentofte University Hospital; 2820, Ledrebrog Allé 40 Gentofte Denmark
2. Department of Environmental Science; Aarhus University; Roskilde 4000, Frederiksborgvej 399 Aarhus Denmark
3. St John's Institute of Dermatology, St Thomas' Hospital; London SE1 7EH Lambeth Palace Road UK
4. Laboratoire de Dermatochimie; CNRS and University of Strasbourg; 67091 Strasbourg France
5. Institute of Environmental Medicine, Karolinska Institutet; SE-171 77 Stockholm Sweden
6. Department of Medical Informatics, Biometry and Epidemiology; Friedrich-Alexander University; 91054 Erlangen, Waldstr. 4-6 Erlangen Germany