[1] Addenbrookes Hosp, Dept Dermatol, Box 46,Hills Rd, Cambridge CB2 0QQ, England
[2] Lausanne Univ Hosp Ctr, Hop Beaumont, Dept Dermatol & Venereol, Av Beaumont 29, CH-1011 Lausanne, Switzerland
[3] Addenbrookes Hosp, Dept Histopathol, Hills Rd, Cambridge CB2 0QQ, England