A giant screen can magnify even the tiniest facial blemish, so a conspicuous skin condition such as rosacea could become a significant career roadblock for an actress if it goes undiagnosed and untreated. Fortunately for TV, stage and movie actress Cynthia Nixon, co-star of "Sex in the City," a dermatologist was able to put a name to her vexing facial inflammation before her rosacea got out of hand.

"Up until five years ago, I had no idea why my skin would get so red," the 46-year-old actress said. "I thought it was just because of my fair complexion. The problem was, it never really went away."

Cynthia sought the help of a dermatologist, who diagnosed her with subtype 1 (erythematotelangiectatic) rosacea and started her on a course of oral rosacea therapy. The doctor also advised Cynthia on proper skin care for sensitive rosacea skin.

"Over the years, I have tried a lot of skin-care products," Cynthia said. "Before I was diagnosed with rosacea, I took a slash-and-burn approach, using scrubs and astringents to remove dead skin and keep my pores clear. When I was finally diagnosed, it was helpful to know that I was actually doing my skin more harm than good."

As an actress, Cynthia often must wear more makeup than she would like, but she said she has learned the benefits of a gentle, sensible skin-care routine. With the help of her dermatologist, she determined which products work best for her, and she doesn't stray from them.

In addition, Cynthia was able to pinpoint several triggers of her rosacea flare-ups, such as sun, exercise, spicy foods and red wine, and now she minimizes her exposure to those factors.

"My Dad is from Texas, so I'm a hard-core jalapeño and barbecue sauce girl," she said, but added that she now knows those things trigger her rosacea and works hard to avoid them.

Cynthia is eager to help others who suspect they may have rosacea or are just perplexed, as she was, about their frequent flushing and blushing. She recently recorded a series of public service announcements and informational videos about rosacea to help raise awareness about the condition. (The videos can be viewed on YouTube.com.)

"Rosacea might always be on your mind, but it doesn't have to be on your face," Cynthia said. "If you think you might have rosacea, go see a dermatologist. Trust me — it'll be so much better."