 It can seem like a sunburn that lingers or won't go away. But over time, the facial redness becomes more persistent and visible blood vessels or bumps and pimples may start to appear. If you experience any one of these symptoms on your face, it could be an early warning sign of rosacea, a common facial disorder whose top trigger is the sun. 16 million Americans suffer from rosacea, but only a fraction are receiving medical treatment. Learn the early warning signs.