Research Letter
Onset of psoriatic arthritis during ustekinumab treatment for psoriasis: a case series of seven patients
Funding sources: None.
Conflicts of interest: K.C.D. has served on the scientific and marketing advisory boards of Amgen; served as a consultant to Amgen, Janssen, Pfizer and Eli Lilly receiving honoraria; received payments for lectures from AbbVie, Amgen and Janssen; and served as an investigator for AbbVie, Amgen, Janssen, Pfizer, Eli Lilly and Vascular Biologics Limited. G.G.K. has received fees as a consultant or advisory board member for AbbVie, Amgen, ApoPharma, Astellas, Boehringer Ingelheim, Bristol Myers Squibb, Eli Lilly, Idera, Isis, Janssen, L'Oréal, Novartis, Pfizer, UCB and Vascular Biologics Limited. G.G.K. has also received partial stipend support for a clinical research fellowship from AbbVie, Amgen and Centocor/Janssen, and in the last 12 months has received lecture fees from Abbott, Amgen and Janssen.
