1 Department of Dermatology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania. Electronic address: john.barbieri@uphs.upenn.edu.
2 Department of Dermatology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania; Department of Social Medicine, School of Public Health, China Medical University, Shenyang, Liaoning Province, People's Republic of China.
3 Department of Dermatology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.