What's Ailing Pro Golfer Phil Mickelson?

Pro golfer Phil Mickelson announced last week that he has been diagnosed with psoriatic arthritis, a potentially debilitating joint condition that left him unable to walk, just days before the U.S. Open.

Mickelson said in Tuesday's pre-PGA Championship press conference that after two weeks of treatment, he feels back to "100 percent." And despite a rocky start to his U.S. PGA Championship bid, Mickelson's improvement in the final round of the tournament on Sunday seemed to lend credence to his statement.

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But doctors say the coast isn't clear for the three-time Masters Tournament winner.

Doctors say the years to come will be a delicate balance between treatment and training if Mickelson is to stay in the game.

"This is a lifelong condition. He's going to have to keep in mind how much stress he's putting on his joints when he plays. He's going to have to get plenty of rest and manage his condition carefully," says Dr. Christopher Ritchlin, professor of medicine at the University of Rochester Medical Center.

A War on Your Joints

Psoriatic arthritis is a chronic autoimmune disorder in which the body attacks the joints, causing pain, inflammation and joint damage. It is a relative of the well-known skin condition, psoriasis, that affects 7.5 million Americans, according to the National Institute of Health. Patients with one condition often develop the other.

"There's a spectrum of response. It can be a very rapid deterioration of the joint in a percentage of people. Some patients will eventually need joint replacement surgery. You want to treat it pretty aggressively," says Dr. Patience White, vice president of public health at the Arthritis Foundation.

Early and aggressive treatment is key, agrees Ritchlin, especially when the patient experiences "explosive presentation, as Mickelson did, with multiple joints swelling quickly."

Since his diagnosis, Mickelson says he's been put on injections of Enbrel, a drug that suppresses the immune system in order to hinder his body's attack on his own joints.

"I've been doing it for two weeks now and I seem to have some immediate progress. It's been great," Mickelson said Tuesday.

Mickelson May Underestimate Condition

Mickelson expressed a great deal of hopefulness for his future, noting that he may need to stay on Enbrel for just a year and that he didn't expect to have long-term problems with his condition.

Rheumatologists specializing in this disorder note that he might overly optimistic.

"Generally speaking, patients who get on Enbrel stay on Enbrel. It's very likely that stopping the medication would cause a flare-up. It's very rare for people to go into spontaneous remission. I hope he's one of them, but I wouldn't count on it," says Dr. Kenneth Kalunian, professor of Clinical Medicine at the University of California San Diego Division of Rheumatology.

Other treatments for psoriatic arthritis include steroidal injections into the joints or low-dose oral steroids, and Methotrexate, a form of chemotherapy. There is no cure for psoriatic arthritis and though there is a genetic component to the disease, how or why it comes on is not well understood.

Staying in the Game with Arthritis

Psoriatic arthritis has already put a halt to the professional career of one big-league golfer, Bob Murphy.

Though undiagnosed at the time, Murphy left pro-golf in the 1980s after his pain and swelling got to be unmanageable, Murphy told the New York Times.

"The stuff just exploded on me. That's how quickly it happened; you never knew what was going to hurt next," he said.

After being diagnosed and treated, Murphy recovered to the point where he could restart his career in the Senior PGA Tour, where he claimed eleven wins.

Given his early diagnosis and quick response to treatment, rheumatologists say there's a good chance Mickelson will be able to manage his disease while staying in the pros.

Because the immune-suppressant medication Mickelson is on will put him at increased risk for infection, he needs to be vigilant about monitoring his health and staying well rested, Kalunian says.

"Golf isn't high impact like football, but you still need to have high functioning small joints, especially those in your hands," says Ritchlin. "It's hard to say exactly how it will affect his game. You have to see how people respond in the first year or two [after diagnosis]."