Got Psoriasis? 7 Signs You Have Arthritis Too

Psoriatic arthritis, a type of arthritis that affects people with the skin condition psoriasis, can attack the joints and tendons.

About 22% of people with psoriasis who have not been diagnosed with psoriatic arthritis appear to have symptoms of the condition, such as joint pain, swelling, and warmth, according to a 2011 survey by the National Psoriasis Foundation (NPF).

Based on the survey, which included 477 people and was funded by pharmaceutical companies, the NPF now recommends that doctors ask psoriasis patients these seven questions.

Sixty-seven percent of the people in the survey who had psoriatic arthritis reported joint pain, and their pain often moved from one joint to another. But even 21% of psoriasis-only patients had joint pain.

Mark McGraw, 52, had joint pain for more than 15 years before he mentioned it to his doctor. "I just figured it was from playing tackle football or breaking horses at my ranch," he says. When the topic finally came up, his doctor asked why he had never mentioned it before.

"'Because you're my dermatologist,'" he recalls saying. "'We talk about skin, not joints.'"

In the survey, 34% of psoriasis patients with an arthritis diagnosis had joint stiffness for more than two hours after waking, and trouble getting in and out of a car. (So did 14% of those without an arthritis diagnosis.)

McGraw takes medication that provides some relief and delays joint damage. But he still has pain and stiffness, especially if he doesn't get enough rest.

Since he's often on the road for his medical-sales job, his company allowed him to use an SUV that lets him step up into the driver's seat rather than bend down.

Psoriatic arthritis can be any kind of joint inflammation, says Soumya Reddy, MD, codirector of the Psoriasis and Psoriatic Arthritis Center at NYU Langone Medical Center, in New York City. "That doesn't mean just pain or swelling," she says. "It could be psoriatic arthritis if it feels like there's fluid inside the joints, or if the joints feel warm or have a red appearance."

In the survey, 28% of psoriatic arthritis patients said their joints sometimes felt hot—but so did 9% of those who had only a psoriasis diagnosis.

Psoriatic arthritis can cause swelling in the wrists, knees, ankles, and fingers. In the survey, 48% of those with arthritis—and 14% without—had swollen joints, while 27% and 11%, respectively, had have trouble wearing rings or watches.

This can be misdiagnosed as rheumatoid arthritis, but unlike RA, psoriatic arthritis may not affect both sides of the body the same way.

"I pointed to my fingers, my left wrist, and my right ankle," McGraw says he recalls doing when speaking with his doctor. "'Now that you mention it, my joints are painful and swollen.'"

In addition to swelling around the joints, psoriatic arthritis also can cause inflammation of the entire tendon that runs along the fingers and toes, known as dactylitis.

In the survey, 28% of psoriatic arthritis patients (as well as 9% of psoriasis-only patients) said their fingers and toes occasionally became swollen, making them look like sausages.

Because this symptom is much less common in other types of arthritis, it can help doctors distinguish it from other types of arthritis.

Nail discoloration, separation from the nail bed, or pitting (when small depressions form in fingernails or toenails) are symptoms of psoriasis regardless of whether a patient has psoriatic arthritis, says Dr. Reddy.

It's much more prevalent in people who have both conditions, however.

"That can be a tip-off to doctors that the person might have psoriatic arthritis, but there have to be other symptoms," such as joint pain and inflammation, she says.

"Psoriatic arthritis affects not just areas that people tend to think of as joints, like...their hands or wrists or knees," Dr. Reddy says. "It can affect the spine, so that's why we often ask about pain in the lower back."

Indeed, 49% of the survey's psoriatic arthritis patients—and 31% of those without an arthritis diagnosis—reported back pain. Often the back pain includes stiffness and burning.

Back pain sometimes is the only symptom of psoriatic arthritis, Dr. Reddy says. But the condition also can cause pain in the neck, feet, and pelvis.

Like McGraw, 44% of survey participants had psoriatic arthritis symptoms for a year or longer before being diagnosed.

Dr. Reddy says she isn't surprised, and says that several independent studies have found psoriatic arthritis to be an underdiagnosed condition.

The longer arthritis goes untreated, however, the more damage it can do. It also affects quality of life: In the survey, 63% of psoriatic arthritis patients reported not being as active as they once were, and 47% said their disease impairs their ability to work.

McGraw, who was diagnosed eight years ago, gave up running for more joint-friendly cycling, and sits near the back of long work meetings so he can stand up and stretch if his back hurts.

But he's thankful he caught the disease before it did further damage. He says he believes his active lifestyle helped keep his arthritis at bay.

"This year alone I've probably climbed eight mountains," he says. "And I do a lot of weightlifting. In fact, I find that when I miss the gym, that's when I start to get sore."