1. Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia 2Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia
2. Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia
3. Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia
4. Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia