1. Department of Dermatology and Allergy University Hospital Bonn Bonn Germany
2. Christine Kühne‐Center for Allergy Research and Education Davos (CK‐CARE) Davos Switzerland
3. Department of Obstetrics and Prenatal Medicine University Bonn Medical School Bonn Germany
4. Department of Internal Medicine I University of Bonn Bonn Germany
5. Department of Dermatology and Center for Chronic Pruritus (KCP) University Hospital Münster Münster Germany