[1] Univ Copenhagen, Gentofte Hosp, Dept Dermatoallergol, Natl Allergy Res Ctr, DK-2900 Hellerup, Denmark
[2] Finnish Inst Occupat Hlth, Occupat Med, Helsinki 00250, Finland
[3] Univ Copenhagen, Bispebjerg Hosp, Dept Dermatol, DK-2400 Copenhagen, Denmark
[4] Univ Southern Denmark, Odense Univ Hosp, Dept Dermatol, DK-5000 Odense, Denmark
[5] Univ Southern Denmark, Odense Univ Hosp, Allergy Ctr, DK-5000 Odense, Denmark
[6] Univ Basel Hosp, Dept Dermatol, Allergy Unit, CH-4031 Basel, Switzerland
[7] Univ Basel, CH-4031 Basel, Switzerland
[8] Lund Univ, Skane Univ Hosp, Dept Occupat & Environm Dermatol, SE-20502 Malmo, Sweden
[9] Hosp Municipal Vicente Lopez Prof Bernard Houssay, Buenos Aires, DF, Argentina
[10] Univ Autonoma Barcelona, Hosp Mar, Dept Dermatol, E-08003 Barcelona, Spain
[11] Univ Hosp, Dept Dermatol, P-3000075 Coimbra, Portugal
[12] Univ Coimbra, Fac Med, P-3000075 Coimbra, Portugal
[13] Univ Hosp KU Leuven, Dept Dermatol, Contact Allergy Unit, B-3000 Leuven, Belgium
[14] Univ Osnabruck, Dept Dermatol, Environm Med, Hlth Theory, D-49069 Osnabruck, Germany
[15] Karolinska Inst, Inst Environm Med, SE-17177 Stockholm, Sweden
[16] Univ Hosp Orebro, Dept Dermatol, SE-70185 Orebro, Sweden
[17] Univ Hosp Erlangen, Dept Dermatol, Allergy Unit, D-91054 Erlangen, Germany
[18] SLSO, Ctr Occupat & Environm Med, Unit Occupat & Environm Dermatol, SE-11365 Stockholm, Sweden
[19] Vrije Univ Amsterdam Med Ctr, Dept Dermatol, NL-1081 HV Amsterdam, Netherlands
[20] Jagiellonian Univ, Dept Expt Dermatol & Cosmetol, Coll Med, PL-30688 Krakow, Poland
[21] CHRU Besancon, Dept Dermatol, F-25030 Besancon, France
[22] St Thomas Hosp, St Johns Inst Dermatol, Dept Cutaneous Allergy, London SE1 7EH, England
[23] Spire Hosp, Leeds LS8 1NT, W Yorkshire, England
[24] Univ Erlangen Nurnberg, Dept Med Informat Biometry & Epidemiol, D-91054 Erlangen, Germany