The purpose of this study is to evaluate the efficacy of guselkumab treatment in participants with active psoriatic arthritis (PsA) by assessing the reduction in signs and symptoms of PsA.

The purpose of this study is to further evaluate the safety of infliximab, ustekinumab, and guselkumab in patients with plaque psoriasis, and other all forms of psoriasis (such as plaque psoriasis and psoriatic arthritis occurring together). The registry study will tr...