1. Research Centre for Hairdressers and Beauticians, Department of Dermato-Allergology; Copenhagen University Hospital Gentofte; 2900; Hellerup; Denmark
2. Department of Dermatology; VU University Medical Centre; De Boelelaan 1117; Nl-1081 HV; Amsterdam; The Netherlands
3. Clinic of Dermatology; University Hospital and Faculty of Medicine, Praceta Mota Pinto; 3000-075; Coimbra; Portugal
4. Department of Occupational and Environmental Dermatology; Skåne University Hospital Malmö, Lund University; S-205 02; Malmö; Sweden
5. Dermatology/Contact Allergy; University Hospital, KU Leuven; Kapucijnenvoer 33; B-3000; Leuven; Belgium
6. Department of Dermatology; Hospital del Mar, Universitat Autonoma de Barcelona; 08003 Barcelona; Spain
7. Cabinet de Dermatologie; Laboratoire de Dermatochimie 4 rue Blaise Pascal; 67081; Strasbourg; France
8. St John's Institute of Dermatology; St Thomas' Hospital; SE1 7EH; London; UK
9. Department of Social Medicine; Occupational and Environmental Dermatology; Thibautstr. 3; 69115; Heidelberg; Germany
10. Department of Dermatology and Allergy Centre; Odense University Hospital, University of Southern Denmark; DK-5000; Odense C; Denmark
11. Dermatologisk afd; Roskilde Sygehus; Køgevej 7-13; 4000; Roskilde; Denmark
12. Department of Dermatology; UCSF, School of Medicine; San Francisco; CA; 94143-0989; USA
13. Department of Dermato-Allergology; Copenhagen University Hospital Gentofte; 2900; Hellerup; Denmark
14. National Allergy Research Centre, Department of Dermato-Allergology; Copenhagen University Hospital Gentofte; 2900; Hellerup; Denmark