SEX and the City” star Kristin Davis is seeing red in her quest to find the Fountain of Youth – but it’s a good thing!

The actress, who played Charlotte in the hit dramedy, wound up with an angry red rash, scratches and what ap­pears to be a red bruise on her face after having an ancient Chinese medicine treatment to make her look and feel younger.

Medical experts believe she underwent a technique called Gua Sha, which raises red welts on the body.

“IT INVOLVES SCRAPING the surface of the skin with a round­ed-edge instrument, breaking the capillaries close to the sur­face,” explained Dr. Stuart Zoll, a Florida-based acupuncturist. “Gua Sha is used to improve blood circulation.” It’s also used to treat respiratory conditions.

“She likely had a sinus prob­lem with chest congestion, which would explain the red marks on her face and chest,” Dr. Zoll explained.

And Dr. Tony Wilcox, acu­puncturist for Bon Jovi and the Florida Panthers added: “The redness on her face is possibly increased Qi or energy flow and blood flow from the acu­puncture needles, which helps increase collagen synthesis, giving a youthful appearance.”

Back in November 2011, the 47-year-old mom was spotted leaving the same clinic, L.A.’s Chinese Health Institute, which also offers electrical stimulation and other alternative health therapies. Kristin, a recovering alcoholic, has become totally focused on her health. “I don’t smoke, I eat well and I haven’t had a drink in 15 years,” she’s boasted. To stay in top shape, Kristin also practices Pilates and yoga, and she goes on hikes.

Said a friend: “She’s pretty adventurous.”