<qa>  What is the name of the type of arthritis that you have been diagnosed with?Individuals may be eligible to enroll in this study if they suffer from psoriasis covering at least 10 of the body, and: - have had two or more swollen, tender or painful joints for at least 3 months or: - have lower back pain which your physician has diagnosed as sacroiliitis or spondylitis in one or more joints or: - have been diagnosed with active psoriatic arthritis 