[1] Massachusetts Gen Hosp, Boston, MA 02114 USA
[2] Brigham & Womens Hosp, Boston, MA 02114 USA
[3] Harvard Univ, Sch Med, Dept Dermatol, Boston, MA 02115 USA
[4] Univ Utah, Hlth Sci Ctr, Salt Lake City, UT USA
[5] Mt Sinai Sch Med, New York, NY USA
[6] Toronto Western Hosp, Ctr Prognosis Studies, Univ Hlth Network, Toronto Western Res Inst,Psoriat Arthritis Progra, Toronto, ON M5T 2S8, Canada
[7] Univ Penn, Dept Dermatol, Philadelphia, PA 19104 USA
[8] Univ Penn, Ctr Clin Epidemiol & Biostat, Philadelphia, PA 19104 USA
[9] Evanston NW Hlthcare, Div Dermatol, Skokie, IL USA
[10] Case Western Reserve Univ Hosp, Cleveland, OH USA
[11] NYU, Ronald O Perelman Dept Dermatol, New York, NY 10003 USA