1. International Centre for Hidradenitis Suppurativa/Acne inversa (ICH), Department of Dermatology, Venereology and Allergology, Ruhr-University Bochum, 44791 Bochum, Germany
2. Skin Cancer Center, Department of Dermatology, Venereology and Allergology, Ruhr-University Bochum, 44791 Bochum, Germany
3. Dermatology Outpatient Service Cersid, 00100 Rome, Italy