1. Department of Dermatology, Duke University Medical Center, Durham, NC, USA.
2. Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC, USA.
3. Department of Dermatology, Minneapolis Veterans Affairs Medical Center, Park Nicollet Health Services, University of Minnesota, Minneapolis, MN, USA.
4. Department of Dermatology, Columbia University Irving Medical Center, New York, NY, USA.
5. Division of Dermatology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada.
6. Department of Dermatology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
7. Department of Dermatology, George Washington University School of Medicine and Health Sciences, Washington, DC, USA.
8. Department of Dermatology, Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA.
9. Department of Dermatology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
10. Division of Dermatology, McGill University Health Centre, Montreal General Hospital, Montreal, Canada.
11. Division of Dermatology, University of Ottawa, The Ottawa Hospital, Ottawa, Canada.
12. Department of Dermatology, Dartmouth Hitchcock Medical Center, Lebanon, NH, USA.
13. Department of Dermatology, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA.
14. Division of Dermatology, Centre Hospitalier Universitaire de Quebec, Laval University, Quebec City, Canada.