According to Teen Vogue, healing acne lesions incite inflammation of the skin, which causes the hyper-pigmentation of dark spots. They are referred to as post-inflammatory pigmentary alterations and are temporary, fading over the course of several months with or without treatment. These marks differ from the semi-permanency of acne scarring. Acne scars are formed from the destruction of healthy skin tissue that is then replaced by fibrous tissue.
Teen Vogue advises refraining from touching, picking, popping or breaking pimples. The more a lesion is agitated or forced open after bursting, the more chance for it to heal abnormally with non-uniform pigmentation and texture. Additionally, broken blood vessels can create the appearance of red and purple marks underneath the skin. People with lighter skin tones are less likely to get dark marks; instead they sometimes notice redness. Topical creams containing glycolic acid can help dark marks begin to fade.
StyleList recommends chemical peels or bleaching to speed up the removal of lighter discolorations. Medium and dark discolorations are more effectively removed with an initial laser treatment followed up with a chemical peel. Cortisone injections given directly to the pimple itself can help prevent marks from forming or reduce the severity of the pigmentation.