Nuno Gomes1, Filomena Azevedo1, Inês Brito2, Cármen Lisboa1,3. 1. Centro Hospitalar Universitário de São João, Dermatovenereology Department, Porto, Portugal. 2. Centro Hospitalar Universitário de São João, Clinical Hematology Department, Porto, Portugal. 3. Microbiology Division of Pathology Department and Center for Health Technology and Services Research (CINTESIS), Faculty of Medicine, University of Porto, Portugal.