Are You at Risk for Psoriatic Arthritis?

Psoriatic arthritis can't be prevented or cured, but it can be treated. It's not easy to predict who will get this painful joint condition, but if you're at risk, it makes sense to watch for early symptoms such as swollen and painful fingers and toes.

Psoriatic arthritis symptoms can be mild or severe, depending on the individual, but either way, getting treatment sooner rather than later can help you avoid permanent joint damage.

Here are some reasons you may be at higher risk of psoriatic arthritis.

Having the skin condition psoriasis is the biggest risk factor for developing psoriatic arthritis. Both are autoimmune disorders caused by an immune attack on the body.

Between 5% and 10% of people with psoriasis develop psoriatic arthritis, so watch for joint trouble if you have the skin condition. In rare cases, some people develop psoriatic arthritis before psoriasis (or before it's obvious), says Guy Fiocco, MD, an assistant professor of medicine at the Texas A&M Health Science Center College of Medicine, in Bryan.

People with psoriasis who are obese in their teens may be more likely to get psoriatic arthritis, according to a 2010 study in the Archives of Dermatology.

Fat tissue may promote more circulating cytokines, the cell-signaling molecules linked to inflammation. In that study, body mass index (BMI) at age 18—but not current BMI—was linked to risk.

A previous study by the same group suggested current weight might, in fact, play a role. Still, more research is needed to prove the link.

People with psoriasis that affects their fingernails and toenails have a higher psoriatic arthritis risk than those with just the scaly skin patches.

About 80% of people with psoriatic arthritis have psoriasis of the nails. Other people can have psoriasis over their entire body, except their nails, and still be less likely to develop arthritis, says Dr. Fiocco, who is also director of rheumatology at Scott & White Healthcare in Temple, Texas.

In other words, the severity of psoriasis does not seem to be linked to psoriatic arthritis risk.

People diagnosed with psoriasis at a young age may be more likely to get psoriatic arthritis. This is probably because the longer you have psoriasis, the greater your chance of developing psoriatic arthritis, says Dr. Fiocco.

Nortin Hadler, MD, professor of medicine and microbiology/immunology at the University of North Carolina at Chapel Hill, says psoriasis tends to be diagnosed either in the late teens and 20s or during middle age. So if you have earlier onset psoriasis, keep an eye out for arthritis symptoms.

If you have a parent or sibling with psoriatic arthritis, you're more likely to get this type of arthritis too—but usually only if you also have psoriasis.

In reality, the genetic component is not that strong, Dr. Fiocco says.

Scientists aren't yet sure which genes are responsible for psoriatic arthritis risk, although it's probably more than one, says Dr. Hadler, an American College of Rheumatology spokesman.

It's possible, but not proven, that a joint injury may trigger psoriatic arthritis in some people who are at risk, says Dr. Hadler.

"There is a series of anecdotes of people with psoriasis who traumatize a joint, and lo and behold it gets inflamed and looks like psoriatic arthritis," he says. "A classic case was a carpenter who hit a finger with a hammer."

To be safe, take extra care to protect your joints. "It's thought that there's an inflammatory reaction that occurs after the trauma that seems to set off the arthritis," Dr. Fiocco says.

There's been some speculation that infection with streptococcal bacteria might trigger psoriatic arthritis.

"Some dermatologists believe there's an association between the activity of the psoriasis and...chronic strep infections," Dr. Fiocco says. "They feel sometimes there's a reaction to the infection that triggers the arthritis. Some dermatologists actually give antibiotics to keep the psoriasis under control."

Being infected with HIV can also increase psoriatic arthritis symptoms. In fact, an epidemic of people who suddenly had psoriatic arthritis flare-ups in the 1980s was an early clue that something—HIV—was circulating in the population, says Dr. Fiocco.

Treatment with HIV-fighting drugs may reduce psoriatic arthritis symptoms in HIV-infected individuals.

It's not clear if stress can increase the risk of psoriatic arthritis, but emotional stressors such as divorce, moving, or losing a job can aggravate any condition, and psoriatic arthritis is no exception.

It's a good idea to reduce stress in your life, even if you don't have psoriatic arthritis. The Arthritis Foundation recommends exercises such as walking, swimming, or yoga; eating a balanced diet; and keeping your weight at a normal level.