1. Department of Dermatology, Tampere University Hospital, 33521 Tampere, Finland
2. School of Medicine, University of Tampere, 33014 Tampere, Finland
3. Unit of Family Practice, Central Finland Central Hospital, and Unit of Primary Health Care, Kuopio University Hospital, 70211 Kuopio, Finland
4. Valkeakoski Regional Hospital, Department of Medicine, 37600 Valkeakoski, Finland
5. Department of Gastroenterology and Alimentary Tract Surgery, Tampere University Hospital, P.O. Box 2000, 33521 Tampere, Finland