1. Dermatology Department Leiden University Medical Centre Leiden 2333 ZA the Netherlands
2. DynaMed Plus EBSCO Health 10 Estes Street Ipswich MA 01938 U.S.A.
3. Department of Medicine University of Western Ontario London Canada
4. Department of Dermatology Amsterdam University Medical Centre Amsterdam the Netherlands
5. Skin Patients Netherlands (Huidpatiënten Nederland) Nieuwegein the Netherlands
6. Biostatistics and Health Informatics King's College London London U.K
7. Institute of Psychiatry, Psychology and Neuroscience London U.K
8. Independent Researcher and Consumer Referee Quebec Canada