[1] Univ Manchester, Fac Med & Human Sci, Sch Med Sci, Stopford Bldg,Oxford Rd, Manchester M13 9PT, England
[2] Mid Cheshire NHS Fdn Trust, Macclesfield, England
[3] Guys & St Thomas NHS Fdn Trust, Guys Hosp Canc Ctr, St Johns Inst Dermatol, Dermatol Surg & Laser Unit, London, England
[4] Manchester Royal Infirm, Dept Otolaryngol, Manchester, England