Does psoriasis cause psoriatic arthritis? Or is the psoriasis a symptom of the broader autoimmune disorder? 

There’s a simple answer, but like most things associated with arthritis, the simple answer isn’t always the only answer.

“Most everyone who gets psoriatic arthritis gets the skin disease first,” says Eric Matteson, MD, chair of Mayo Clinic’s rheumatology department in Rochester, Minn. “Studies show anywhere between 5 and 30 percent of people with psoriasis will develop psoriatic arthritis. It’s probably closer to 10 percent,” he says.

However, he adds, “Some get [psoriatic] arthritis with no skin involvement; it’s unusual, but it can happen.”

People who have psoriasis should talk to their doctor about recurrent joint pain. Those who are older most likely have osteoarthritis, the most common type of arthritis. It has no connection to psoriatic arthritis, he says. If it turns out they do have psoriatic arthritis, they can get timely treatment, which is critical for avoiding or minimizing joint damage.

The problem is this, Matteson says: “Most people have no idea there is a disease called psoriatic arthritis. It’s important that that changes.”