Acne scars are the result of inflammation within the dermal layer of brought on by acne and are estimated to affect 95% of people with acne vulgaris. The scar is created by an abnormal form of healing following this dermal inflammation. Scarring is most likely to occur with severe nodulocystic acne but may occur with any form of acne vulgaris. Acne scars are classified based on whether the abnormal healing response following dermal inflammation leads to excess collagen deposition or collagen loss at the site of the acne lesion.