1. Servizio Centrale di Medicina del Lavoro e Igiene Industriale, Istituto Poligrafico e Zecca dello Stato, Rome, Italy
2. Department of Internal Medicine and Geriatrics, UCSC - Allergy Unit, C.I. Columbus, Rome, Italy
3. Centro di Medicina Occupazionale, “La Sapienza” University, Rome, Italy
4. Department of Dermatology, “La Sapienza” University, Rome, Italy
5. Institute of Occupational Medicine, “G. D'Annunzio” University, Chieti, Italy