[1] Univ Hosp Zurich, Dermatol Dept, Zurich, Switzerland
[2] Univ Zurich, Fac Med, Zurich, Switzerland
[3] Leiden Univ, Dept Dermatol, Med Ctr LUMC, Leiden, Netherlands
[4] Univ Hosp Birmingham, Ctr Rare Dis, Birmingham, W Midlands, England
[5] Stanford Univ, Dept Dermatol, Sch Med, Stanford, CA 94305 USA
[6] Columbia Univ, Dept Dermatol, New York, NY 10027 USA
[7] Univ Turin, Dept Dermatol, Turin, Italy