Strawberry marks, or hemangiomas, are bright red, protrude from the skin and often go away without treatment. Both types are formed by masses of small blood vessels in abnormal locations. Strawberry marks can be treated more frequently, and fine broken vessels on the face as often as once a month. The laser, which uses a yellow light absorbed only by red, reacts with a blood cell protein in the birthmark's vessel mass. The blood vessels absorb the laser's energy and convert it into heat that damages the vessels.
Treatment is repeated until all visible vessels are gone or lightened.