1. Department of Dermatology; Erasmus University Medical Centre; P.O. Box 2040 3000 CA Rotterdam the Netherlands
2. Department of Biostatistics; Erasmus University Medical Centre; P.O. Box 2040 3000 CA Rotterdam the Netherlands
3. Department of Pathology; Isala Hospital; Zwolle the Netherlands
4. Department of Dermatology; Maastricht University Medical Centre; Maastricht the Netherlands
5. Department of Pathology; Erasmus University Medical Centre; P.O. Box 2040 3000 CA Rotterdam the Netherlands
6. Department of Dermatology; Maasstad Hospital; Rotterdam the Netherlands
7. Department of Dermatology; Isala Hospital; Zwolle the Netherlands