[1] Univ Bonn, Dept Dermatol & Allergy, D-5300 Bonn, Germany
[2] GSF Natl Res Ctr Environm & Hlth, Inst Epidemiol, Neuherberg, Germany
[3] Univ Bonn, Dept Med Biometry & Epidemiol, D-5300 Bonn, Germany
[4] ZAUM, GSF Natl Res Ctr Environm & Hlth, Dept Dermatol & Allergy, Munich, Germany
[5] Tech Univ Munich, Munich, Germany
[6] GSF Natl Res Ctr Environm & Hlth, Neuherberg, Germany