1. Huidcentrum Limburg; Department of Dermatology; Reinaartsingel 50 Maastricht Netherlands
2. Maastricht University Medical Center; Department of Dermatology; Maastricht Netherlands
3. CAPHRI Research School, Maastricht University; Department of Epidemiology; Maastricht Netherlands 6200 MD
4. Erasmus Medical Center; Department of Dermatology; PO Box 2040 Rotterdam Netherlands 3000 CA