1. Department of Occupational and Environmental Dermatology; Skåne University Hospital, Lund University; SE-205 02 Malmö Sweden
2. Department of Dermatology and Allergy Centre; Odense University Hospital; Odense 5000 Denmark
3. Department of Dermatology; Faculty of Medicine, University Hospital; Coimbra P3000-175 Portugal
4. Contact Allergy Unit, Department of Dermatology; U.Z.K.U.; Leuven 3000 Belgium
5. Department of Dermato-Allergology; National Research Centre, Gentofte Hospital, University of Copenhagen; Hellerup 2900 Denmark
6. Department of Dermatology, School of Medicine, University of California; Box 0989, Surge 100 San Francisco CA 94143-0989 USA
7. Department of Dermatology; Free University Hospital; Amsterdam NL-1081 HV The Netherlands
8. Cabinet de Dermatologie & Laboratoire de Dermatochimie; 67070 Strasbourg France
9. Department of Cutaneous Allergy; St John's Institute of Dermatology; London SEI 7EH UK