1. Department of Dermatology, Radboud University Medical Center, Nijmegen, The Netherlands
2. Department of Dermatology, Elisabeth-TweeSteden Ziekenhuis, Tilburg, The Netherlands
3. Department of Dermatology, St Antonius Ziekenhuis, Nieuwegein, The Netherlands
4. Department of Dermatology, Dermatologisch Centrum Isala, Zwolle, The Netherlands
5. Department of Rheumatology, Sint Maartenskliniek, Nijmegen, The Netherlands
6. Radboud University, Nijmegen, The Netherlands