Acne scarring is a complication of the skin’s inflammatory healing process, where deep, inflamed lesions damage surrounding dermal tissue. Not all marks left behind by a breakout are permanent scars; many are temporary discolorations that resolve without intervention. True acne scars, however, represent a permanent change to the skin’s physical structure, involving the loss or overproduction of collagen and elastin fibers in the deeper layers of the dermis. While these structural scars will not disappear on their own, modern dermatological treatments offer significant reduction and improvement in their appearance.
Understanding the Difference Between Marks and True Scars
Many people mistake the residual discoloration following a pimple for a permanent scar, but these marks are typically a temporary healing response known as post-inflammatory hyperpigmentation (PIH) or post-inflammatory erythema (PIE). These marks are flat and do not involve damage to the underlying skin architecture, which is the defining characteristic of a true scar.
Post-inflammatory hyperpigmentation (PIH) appears as brown, black, or tan patches caused by the overproduction of melanin following an inflammatory event. When the skin is inflamed, it triggers melanocytes to deposit excess pigment, creating the dark spot. These marks fade naturally over months or years as the skin turns over pigmented cells, though sun exposure can prolong their existence.
Post-inflammatory erythema (PIE) manifests as persistent red or pink spots caused by damage or dilation of small blood vessels near the skin’s surface. This vascular damage occurs when inflammation disrupts the integrity of these tiny blood vessels. Unlike PIH, which is a pigment issue, PIE is a vascular issue resulting from blood flow trapped near the surface. PIE fades over time as the vessels heal, a process often accelerated with specific light-based therapies.
Classifying Permanent Acne Scars
True permanent acne scars result from either an insufficient amount or an excessive amount of collagen production during the wound healing process. These structural changes are categorized into two main types: atrophic scars, which are indented, and hypertrophic scars, which are raised. Atrophic scars are the most common type and form when the skin loses underlying support due to collagen destruction during severe inflammation.
Atrophic scars are further divided based on their depth and shape. Icepick scars are narrow, V-shaped indentations that extend deep into the dermis, making them difficult to treat. Boxcar scars are wider, U-shaped depressions with sharp, defined vertical walls, giving the skin a pitted appearance.
Rolling scars are typically wider than boxcar scars and create a wave-like texture. This appearance is caused by fibrous bands of tissue that form between the dermis and the subcutaneous fat, pulling the epidermis downward. Conversely, hypertrophic or keloid scars are raised formations that occur when the body produces too much collagen during healing. Hypertrophic scars remain within the boundary of the original injury, while keloids grow aggressively beyond the initial wound site.
Professional Treatments for Scar Reduction
Since true acne scars involve permanent changes to the skin’s collagen structure, professional intervention is necessary to improve their appearance. The best treatment approach often involves a combination of procedures tailored to the specific types of scars present. The goal of many treatments is to either physically resurface the skin or stimulate the production of new, healthy collagen to remodel the damaged tissue.
Resurfacing Techniques
Resurfacing techniques, such as fractional laser therapy and deep chemical peels, work by removing precise layers of damaged skin. Fractional lasers create microscopic columns of thermal injury, forcing the body to produce new collagen and elastin, which smooths the texture of atrophic scars. Deep chemical peels use concentrated acids to exfoliate the skin, allowing fresh, undamaged skin to rise to the surface.
Collagen Induction Therapy
Collagen induction therapy, including microneedling and radiofrequency (RF) microneedling, uses fine needles to create controlled micro-injuries in the dermis. This deliberate trauma initiates the skin’s natural wound healing cascade, resulting in the creation of new collagen (neocollagenesis). RF microneedling adds heat energy to the deeper layers, which further tightens tissue and enhances the collagen-remodeling effect.
Structural Treatments
For depressed scars, particularly rolling and deep boxcar scars, procedures addressing underlying structural tension are highly effective. Subcision involves inserting a needle beneath the scar to mechanically break up the fibrous bands that tether the skin down. Dermal fillers, such as hyaluronic acid, are often injected immediately following subcision to physically lift the scar and prevent the bands from reattaching. Raised hypertrophic and keloid scars typically require injections of corticosteroids to suppress excessive collagen production and flatten the scar tissue.