Affiliation: | 1. Philadelphia Veterans Affairs Medical Center, Philadelphia, PA, U.S.A.;2. Department of Dermatology, University of Pennsylvania School of Medicine, Philadelphia, PA, U.S.A.;3. Division of Immunology and Rheumatology, Department of Dermatology and Medicine, Stanford University School of Medicine, Stanford, CA, U.S.A.;4. Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA, U.S.A.;5. Victoria P. Werth.;6. E‐mail: |