1 Department of Dermatology, Venereology and Dermatologic Surgery, Medical Institute of Ministry of Interior (MVR-Sofia), Sofia, Bulgaria. georgi_tchernev@yahoo.de.
2 Onkoderma - Policlinic for Dermatology and Dermatologic Surgery, Sofia, Bulgaria. georgi_tchernev@yahoo.de.
3 Onkoderma - Policlinic for Dermatology and Dermatologic Surgery, Sofia, Bulgaria.
4 Department of Dermatology and Venereology, Medical University of Plovdiv, Medical Faculty, Plovdiv, Bulgaria.