1. Department of Social Medicine; Occupational and Environmental Dermatology; University Hospital Heidelberg; Thibautstraße 3 69115 Heidelberg Germany
2. Department of Occupational and Environmental Dermatology; University Hospital Malmö; S-20502 Malmö Sweden
3. Department of Dermatology; Azienda Ospedaliera Papa Giovanni XXIII, Bergamo; Centro Studi GISED - FROM Presidio Ospedaliero Matteo Rota; Via Garibaldi 13/15 24122 Bergamo Italy
4. Occupational and Environmental; Dermatology Unit; State University Hospital; P.O. Box 30.001, NL-9700 RB Groningen the Netherlands
5. Klinik für Dermatologie und dermatologische Allergologie; Klinikum der FSU Jena; Erfurter Str. 35 D-07740 Jena Germany
6. Clinica de Dermatologia; Hospital da Universidade Praceta Motal Pinto; Rua Infanta D.Maria; n 30-A-3D P-3000-075 Coimbra Portugal
7. Department of Dermatology, University Hospital Malmö; S-20502 Malmö Sweden