Psoriatic arthritis in severe psoriasis.

Of 100 patients admitted to hospital for treatment of psoriasis, 32 had clinical or radiologic evidence of psoriatic arthritis and 17 had both types of evidence. Eight had radiologic evidence of spinal or sarroiliac involvement without symptoms and seven had clinical evidence of peripheral arthritis without radiologic evidence. Patients with psoriatic sacroilitis and spondylitis were most likely to have typical radiograpic changes. It was concluded that psoriatic arthritis is common in patients with severe psoriasis and that is associated with more extensive skin disease than is found in patients without arthritis.