[1] Univ Copenhagen, Roskilde Hosp, Dept Dermatol, Copenhagen, Denmark
[2] Univ Copenhagen, Bispebjerg Hosp, Dept Dermatol, Copenhagen, Denmark
[3] Natl Res Ctr Working Environm, Copenhagen, Denmark
[4] Univ Heidelberg, Dept Social Med Occupat & Environm Dermatol, Heidelberg, Germany
[5] Univ Copenhagen, Dept Biostat, Copenhagen, Denmark