What is Otezla? Otezla inhibits an enzyme within your immune system that can affect certain cells and contribute to inflammation in the body. Otezla is used to treat the symptoms of active psoriatic arthritis in adults. Otezla can relieve tenderness and swelling in and around the joints, but this medicine is not a cure for psoriatic arthritis. Otezla is also used to treat moderate to severe plaque psoriasis in people who may also receive phototherapy or other treatments for psoriasis.