What’s wrong with MICHAEL J. FOX’s face?

That’s the question raised by a heartbreaking new photo of the Parkinson’s disease-stricken star – and The ENQUIRER has the answer in a sad but inspiring story.

“Michael has always looked younger than his age and was able to play teenagers well into his twenties, but now his skin has turned blotchy,” a close source told The ENQUIRER.

 “It’s a shock to see how bad his complexion has gotten.”

On Jan. 10, the beloved 51-year-old “Back to the Future” star was photographed entering David Letterman’s show – and his appearance was alarming. In a business where looks are so important, his have clearly taken a turn for the worse.

It’s yet another blow for Fox, who was diagnosed with Parkinson’s at age 30 in 1991.

Despite the ailment, the courageous actor is making a remarkable comeback. He has a recurring role on the CBS hit “The Good Wife” and will star in a new sitcom about a newscaster with Parkinson’s in the fall.

In an exclusive report, The ENQUIRER digs deep to reveal what is REALLY wrong with Fox and how it will affect his showbiz future.

It’s news you won’t want to miss – and you’ll find it ONLY in The ENQUIRER!