Acne Scars

Acne scars are the permanent changes in skin texture that remain after active acne has resolved. They form when the inflammation of a cyst, papule or pustule damages the dermis deeply enough that the normal architecture of collagen and elastic tissue cannot fully rebuild. The resulting scars fall into several distinct types, and correctly identifying which type is present is the single most important step in planning treatment, because the right treatment for one scar morphology can be almost entirely useless for another. The main categories are atrophic scars (the most common, where tissue has been lost), hypertrophic scars and keloid scars (where tissue has over-healed and sits raised above the surrounding skin). Atrophic scars are further divided into ice-pick scars (narrow, deep, V-shaped depressions), rolling scars (broader, shallower undulations caused by dermal tethering), and boxcar scars (wide, sharply-defined depressions with vertical walls). A patient often has several types simultaneously, which is why a stepped, combined approach produces better results than relying on a single technique. Post-inflammatory hyperpigmentation and erythema often coexist, particularly in deeper skin phototypes, adding a colour component that needs to be addressed alongside the texture. The UK aesthetics response combines several modalities. Microneedling, using a motorised pen or medical dermaroller, creates controlled micro-injuries across the scarred area, triggering collagen and elastin remodelling. It is particularly effective for rolling and shallow boxcar scars, and is often combined with PRP therapy, where the patient's own platelet-rich plasma is applied topically or injected to enhance the healing response. Chemical peels, from superficial glycolic or salicylic acid peels through to medium-depth TCA and Jessner's peels, address pigmentation and the most superficial textural changes, and the TCA CROSS technique delivers high-concentration TCA into individual ice-pick scars to remodel them from the base upwards. Laser resurfacing, using fractional non-ablative or ablative lasers, is the most aggressive non-surgical option and produces the most visible textural change for deeper or mixed scarring, with longer downtime and greater risk of post-inflammatory pigmentation, particularly in deeper phototypes. Subcision (release of the fibrous tethers beneath rolling scars) is sometimes performed alongside these treatments to improve results. Active acne must be controlled before scar treatment begins, because treating over active breakouts risks worsening the scarring. Patients with darker phototypes, a history of keloid scarring, or recent isotretinoin use need careful staging and often adjusted protocols to minimise risk.