1. Division of Dermatology, Department of Medicine, Washington University School of Medicine in St Louis, St Louis, Missouri
2. Center for the Study of Itch, Washington University School of Medicine in St Louis, St Louis, Missouri
3. Department of Anesthesiology, Washington University School of Medicine in St Louis, St Louis, Missouri
4. Department of Pathology and Immunology, Washington University School of Medicine in St Louis, St Louis, Missouri