1. German Center for Health Services Research in Dermatology (CVderm) Institute for Health Services Research in Dermatology and Nursing (IVDP) University Medical Center Hamburg‐Eppendorf (UKE) Hamburg Germany
2. Division of Immunodermatology and Allergy Research Department of Dermatology and Allergy Hannover Medical School Hanover Germany
3. Center for Chronic Pruritus Department of Dermatology University Hospital Münster Münster Germany