1. Department of Dermatology, Coimbra University Hospital, and Faculty of Medicine; University of Coimbra; 3000-075 Coimbra Portugal
2. Dermatology Department, Bispebjerg Hospital; University of Copenhagen; 2400 Copenhagen Denmark
3. Department of Dermatology and Allergy Centre; Odense University Hospital; 5000 Odense Denmark
4. Department of Occupational and Environmental Dermatology; Lund University Skåne University Hospital; 205 02 Malmö Sweden
5. Department of Social Medicine, Occupational and Environmental Dermatology; University Hospital Heidelberg; 69115 Heidelberg Germany
6. Unit of Dermatology, Department of Biomedical Science and Human Oncology; University of Bari; 70121 Bari Italy
7. Department of Dermatology, Hospital del Mar, Institut Mar d'Investigations Mediques; Universitat Autonoma; 08003 Barcelona Spain
8. Contact Allergy Unit, Department of Dermatology; University Hospital K. U. Leuven; 3000 Leuven Belgium
9. National Allergy Research Centre, Department of Dermatology and Allergy, Gentofte Hospital; University of Copenhagen; 2900 Hellerup Denmark
10. Dermatology; Leeds Teaching Hospitals NHS Trust; Leeds LS7 4SA UK
11. Finnish Institute of Occupational Health; 00250 Helsinki Finland