[1] Guys & St Thomas NHS Fdn Trust, St Johns Inst Dermatol, London SE1 9RT, England
[2] Guys & St Thomas NHS Fdn Trust, Div Hlth & Social Care Res, London SE1 9RT, England
[3] CHU Hotel Dieu, Dept Dermatol, F-44035 Nantes, France
[4] Hosp Santa Creu & Sant Pau, Dept Dermatol, Pediat Dermatol Unit, Barcelona, Spain
[5] Aarhus Univ Hosp, Dept Dermatol, DK-8000 Aarhus, Denmark
[6] Univ Hosp Schleswig Holstein, Dept Dermatol, Kiel, Germany
[7] Univ Milan, Dept Pathophysiol & Transplantat, Milan, Italy
[8] Osped Maggiore Policlin, Fdn IRCCS Ca Granda, Milan, Italy
[9] Hosp Infantil Nino Jesus, Madrid, Spain
[10] Univ Amsterdam, Acad Med Ctr, Dept Dermatol, NL-1105 AZ Amsterdam, Netherlands
[11] Maasstadziekenhuis, Dept Dermatol, Rotterdam, Netherlands
[12] Kings Coll London, Dept Paediat Allergy, Div Asthma Allergy & Lung Biol, London, England
[13] Univ Bologna, Dept Specialised Expt & Diagnost Med, Bologna, Italy
[14] Royal Infirm Edinburgh NHS Trust, Dept Dermatol, Edinburgh, Midlothian, Scotland
[15] Lund Univ, Dept Dermatol, Inst Clin Res Malmo, Skane Univ Hosp, Malmo, Sweden
[16] Karolinska Inst, Dept Med Solna, Dermatol Unit, Stockholm, Sweden
[17] Univ Dresden, Ctr Evidence Based Healthcare, Dresden, Germany
[18] Univ Dresden, Dept Social & Occupat Med, Dresden, Germany