1. Washington Dermatology Center; Rockville MD U.S.A.
2. Department of Dermatology; George Washington University; Washington DC U.S.A.
3. Institute of Internal Medicine; Catholic University of Sacred Heart of Rome; Rome Italy
4. Gastroenterological Area; Gastroenterology and Endocrine-Metabolic Sciences Department; Fondazione Policlinico Universitario A. Gemelli; Rome Italy