1 Department of Dermatology, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania, USA; Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania, USA. Electronic address: margo@pennmedicine.upenn.edu.
2 Department of Dermatology, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania, USA.
3 Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania, USA.