1 Dermatology Section, Department of Clinical Medicine and Immunological Science, University of Siena, Siena, Italy. Electronic address: file.russo@libero.it.
2 Pathology Section, Department of Medical Biotechnology, University of Siena, Siena, Italy.
3 Dermatology Section, Department of Clinical Medicine and Immunological Science, University of Siena, Siena, Italy.