1 Charité-Universitätsmedizin Berlin, Department of Dermatology and Allergy, Clinical Research Center for Hair and Skin Science, Charitéplatz 1, 10117, Berlin, Germany. Electronic address: jan.kottner@charite.de.
2 CNRS, University of Lyon 1, UMR 5305, LBTI, Lyon, France.
3 University of Nebraska Medical Center, College of Nursing, Omaha, NE, USA.