1. Department of Dermatology, St Pierre, Brugmann and Children's University Hospitals Université Libre de Bruxelles Bruxelles Belgium
2. Department of Dermatology Hôpital Bichat – Claude Bernard Paris France
3. Dermatology Department Groupe Hospitalier Paris Saint Joseph Paris France
4. Department of Dermatopathology Hôpital Saint Louis Paris France
5. Clinique Saint‐Exupery Toulouse France
6. Nail Disease Center Cannes France