1. Department of Dermatology, Radboud University Medical Center, Nijmegen, the Netherlands
2. Department of Rheumatology, Sint Maartenskliniek, Nijmegen, the Netherlands
3. Department of Dermatology, Ziekenhuis Groep Twente, Hengelo, the Netherlands
4. Department of Dermatology, Sint Anna Ziekenhuis, Geldrop, the Netherlands
5. Department of Dermatology, Ziekenhuis Groep Twente, Almelo, the Netherlands
6. Department of Dermatology, Gelre ziekenhuizen, Apeldoorn, the Netherlands
7. Department of Dermatology, Slingelandziekenhuis, Doetinchem, the Netherlands
8. Department for Health Evidence, Radboud University Medical Center, Nijmegen, the Netherlands