What's Ailing Pro Golfer Phil Mickelson?

Aug. 16, 2010— -- 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.

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.