1. Departments of Dermatology, Allergology and Venereology Helsinki University Central Hospital Meilahdentie 2, P.O. Box 160 00029 HUS Helsinki Finland
2. «Tattoo» Consultation Department of Dermatology Bichat‐Claude Bernard Hospital Assistance Publique‐Hôpitaux de Paris 46 rue Henri Huchard 75877 Paris Cedex 18 France
3. Department of Dermatology Université François Rabelais Centre Hospitalier Universitaire de Tours 37044 Tours Cedex 09 France