Skin and joint mystery solved

Jude is a handsome personable college kid who came in today to follow up on recent tests to try to figure out his mysterious joint pains. It was just a month ago that he presented with a fiery, scaly rash on his buttocks, now confirmed to be psoriasis by the dermatologist. The other piece of the puzzle-- pain in his neck, back, low back knees and feet is starting to come together. Tests for rheumatoid arthritis and ankylosing spondylitis were negative today. As he took off his pants and shoes to show me the joints more closely, there appeared the telltale clue -- sausage digit, a diffuse swelling of a single toe that resembles a sausage. There is only one thing that I know that can cause this finding -- psoriatic arthritis. It's not easy to tell a young man that he has a chronic illness, but hopefully with modern disease modifying drugs he can be relatively free of symptoms. He'll be off to the arthritis specialist next week.