1. Department of Occupational and Environmental Dermatology; Skåne University Hospital, Lund University; S-205 02 Malmö Sweden
2. Department of Dermatology; Uddevalla Hospital; S-451 80 Uddevalla Sweden
3. Department of Dermatology; University of Copenhagen, Bispebjerg Hospital; 2400 Copenhagen Denmark
4. Department of Dermatology and Allergy Centre; Odense University Hospital, University of Southern Denmark; DK-5000 Odense Denmark
5. Allergy Unit, Department of Dermatology; University Hospital; CH-4031 Basel Switzerland
6. Department of Social Medicine; Occupational and Environmental Dermatology, Thibautstr. 3; D-69115 Heidelberg Germany
7. Unit of Dermatology, Department of Biomedical Science and Human Oncology; University of Bari; I-70124 Bari Italy
8. Department of Dermatology; Hospital del Mar, Universitat Autònoma; Barcelona 08003 Spain
9. Department of Dermatology, University Hospital and Faculty of Medicine; University of Coimbra; P-3000-075 Coimbra Portugal
10. Department of Dermatology; University Hospital, K. U. Leuven; B-3000 Leuven Belgium
11. The National Allergy Research Centre; Department of Dermato-Allergology, Gentofte Hospital, University of Copenhagen; DK-2900 Hellerupn Denmark
12. Cabinet de Dermatologie; 87 Avenue des Vosges; F-67000 Strasbourg France
13. Department of Dermatology UCSF; School of Medicine, San Francisco; CA 94143-0989 USA