1. Department of Pediatric Dermatology; University Children's Hospital Zurich; Zurich Switzerland
2. Department of Dermatology; University Hospital Zurich; Zurich Switzerland
3. Ronald O. Perelman Department of Dermatology; School of Medicine; New York University; New York New York
4. Department of Pediatrics; University of California; San Francisco California
5. Department of Dermatology; University of California; San Francisco California
6. Department of Pathology; University of California; San Francisco California
7. Department of Pediatrics; Division of Dermatology; Seattle Children's Hospital and School of Medicine; University of Washington; Seattle Washington