1. Department of Dermatology and Dermatopathology Northwestern University, Feinberg School of Medicine Chicago Illinois USA
2. Department of Pediatrics, Section of Dermatology Children's Hospital of Philadelphia Philadelphia Pennsylvania USA
3. Department of Dermatology Hospital of the University of Pennsylvania Philadelphia Pennsylvania USA
4. Department of Pathology and Laboratory Medicine Children's Hospital of Philadelphia Philadelphia Pennsylvania USA
5. Perlman School of Medicine, University of Pennsylvania Philadelphia Pennsylvania USA