Post acne red marks are caused by enlargement of microscopic capillaries. Fortunately, pink spots will usually fade without special treatment in a few weeks after your active Acne is over. All you need to, is prevent new pimples with a good mild anti-acne cream and use an oil free sunscreen each morning. If needed, persistent pink can be also treated with light sources, called Intense Pulse light (IPL). These IPL’s produce intense pulses of light very similar to camera flash. The light is absorbed in small capillaries in the spots causing them to fade fatser.