[1] Royal Liverpool & Broadgreen Univ Hosp Trust, Liverpool, Merseyside, England
[2] Univ Liverpool, Oral Pathol, Liverpool, Merseyside, England
[3] Guys Hosp, St Johns Inst Dermatol, Clin Immunodermatol, London, England
[4] Glan Clwyd Gen Hosp, Dept Dermatol, Rhyl, Wales