[1] Whipps Cross Hosp & Chest Clin, Dept Dermatol, London, England
[2] Barts & Royal London Hosp NHS Trust, Dept Dermatol, London, England
[3] Bromley Hosp NHS Trust, Dept Dermatol, London, England
[4] Queen Alexandra Hosp, Dept Dermatol, Portsmouth, Hants, England
[5] Royal Cornwall Hosp, Dept Dermatol, Truro, Cornwall, England
[6] Stoke Mandeville Hosp, Dept Dermatol, Aylesbury HP21 8AL, Bucks, England
[7] Princess Royal Hosp, Dept Dermatol, Kingston Upon Hull, Yorks, England
[8] pH Associates, Marlow, Bucks, England