WWW- Did Tom Cruise insist on purifying Katie Holmes before anointing her his betrothed?

Celebrity watchdogs are buzzing that the hideous red marks that erupted around Holmes’ mouth shortly after the couple announced their romance in early May are the nasty side effects of a Church of Scientology “detoxification” procedure involving the vitamin niacin.

Science-fiction writer and Scientology founder L. Ron Hubbard maintained that taking niacin in combination with exercise and sauna sessions helps purge the body of “radiation,” Hubbard’s shorthand for negative alien substances in the body.

These days Scientologists promote a purification regimen called Purif. Two years after 9/11, the Church set up a purification clinic for New York firefighters, ostensibly to rid them of toxins.

Some took advantage of the free service – which made liberal use of niacin – but others dismissed it as quackery.

The B-complex vitamin – which is used in traditional medicine to decrease cholesterol and improve circulation – can cause a red flush on the face and a diffuse itchy rash on the body when taken in large doses.

So was niacin the cause of Katie’s temporary disfigurement?

At Lowdown’s request, Manhattan dermatologist Paul Frank examined photographs of the future Mrs. Cruise.

“Although I can’t say for sure, this looks like a cold-sore attack,” Frank said. “Niacin shouldn’t trigger cold sores.”

Well then, what does?

“Stress is the No. 1 cause,” he replied. “God knows Scientology stresses me out!”

Reps for Cruise and Holmes didn’t return phone calls, and a Scientology official said: “Whatever you see on her face has got nothing to do with us. It’s insulting that you would ask such a thing.”