Psoriatic arthritis.
Psoriatic arthritis is an inflammatory arthritis associated with the skin disorder psoriasis. The exact etiology of psoriatic arthritis is unknown, although more than 40% of people with the cutaneous disease of psoriasis are estimated to also have joint involvement. This article presents an overview of psoriatic arthritis, including the origin, genetic influence, and immunologic factors involved in its evolution. The clinical features of psoriatic arthritis are also reviewed in this article, and a discussion of the diagnosis and treatment is included.