1. Department of Dermatology; University Hospital Gent; 9000, Ghent Belgium
2. Department of Occupational and Environmental Dermatology; Lund University, Skåne University Hospital; 205 02, Malmö Sweden
3. Department of Dermatology; University Hospital KU Leuven; 3000, Leuven Belgium
4. Department of Dermatology; University of Groningen, University Medical Centre Groningen; 9700 RB, Groningen The Netherlands