1. Department of Dermatology; University Hospital Antwerp; B-2650 Antwerp Belgium
2. Department of Dermatology; Cliniques Universitaires Saint-Luc U.C.L.; B-1200 Brussels Belgium
3. Private Dermatologist; B-8790 Waregem Belgium
4. Department of Dermatology; CHU Sart Tilman; B-4000 Liège Belgium
5. Private Dermatologist; B-1150 Brussels Belgium
6. Department of Dermatology; Imelda Hospital; B-2820 Bonheiden Belgium
7. Department of Dermatology; University Hospital Ghent; B-9000 Ghent Belgium
8. Department of Dermatology; UZ Brussels; B-1090 Jette Belgium
9. Department of Scientific Coordination and Biostatistics; University Hospital Antwerp; B-2650 Antwerp Belgium
10. Department of Dermatology; University Hospitals KU Leuven; B-3000 Leuven Belgium