1. From the Department of Dermatology, Park Nicollet Health Services, Minneapolis, Minnesota, USA.
2. Department of Dermatology, Minneapolis Veterans Affairs Medical Center, Minneapolis, Minnesota, USA.
3. Department of Dermatology, University of Minnesota, Minneapolis, Minnesota, USA.
4. University of Minnesota Medical School, Minneapolis, Minnesota, USA.
5. Division of Dermatology, Sunnybrook Health Sciences Centre, University of Toronto, Ontario, Canada.
6. Department of Dermatology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
7. Department of Dermatology, The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA.
8. Division of Dermatology, CHU de Quebec, Laval University, Quebec City, Quebec, Canada.
9. Division of Dermatology, University of Ottawa, Ottawa, Ontario, Canada.
10. Department of Dermatology, Columbia University Irving Medical School, New York, New York, USA.
11. Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
12. Department of Dermatology, University of California, San Francisco, California, USA.
13. Department of Dermatology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
14. Department of Dermatology, Cleveland Clinic, Cleveland, Ohio, USA.
15. Department of Dermatology, Duke University Medical Center, Durham, North Carolina, USA.
16. Department of Dermatology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
17. Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, Colorado, USA.
18. Department of Dermatology, Geisinger Medical Center, Danville, Pennsylvania, USA.