1 a The Dermatology Centre, Manchester Academic Health Science Centre, Barnes Building, Salford Royal NHS Foundation Trust , Manchester , United Kingdom.
2 b Department of Dermatology , Kaiser Permanente Los Angeles Medical Center , Los Angeles , CA , USA.
3 c Radboud University Nijmegen Medical Centre , the Netherlands.
4 d Memorial University of Newfoundland , St. Johns , NL , Canada.
5 e International Psoriasis Council , St. Louis , MO , USA.
6 f Dept. of Dermatology , Aarhus University Hospital , Aarhus C , DK , 8000 , Denmark.