The term “ingrown scars” refers to depressed, pitted, or sunken areas of skin resulting from tissue loss below the surface. Medically known as atrophic scars, these indentations form when the healing process fails to generate sufficient collagen to replace tissue damaged by trauma, severe acne, or infections like chickenpox. Unlike raised scars, which involve collagen overproduction, atrophic scars represent a structural deficit where the skin’s foundation has collapsed. Treatment focuses on physically releasing the depression or stimulating new collagen growth to fill the void, depending on the scar’s specific depth and shape.
Identifying Depressed Scar Types
Accurately classifying the type of depressed scar is essential, as each morphology requires a different treatment approach. Atrophic scars are separated into three categories based on their visual characteristics and depth within the dermis. This classification guides practitioners in determining the necessary depth of intervention.
Icepick scars are the most challenging to treat due to their narrow, deep, V-shaped appearance, resembling a puncture wound. These scars, typically less than 2 millimeters wide, extend deep into the dermis. Boxcar scars are broader, round or oval depressions with sharp, vertical walls and a flat base. They result from inflammatory destruction of collagen confined to the skin’s upper layers.
Rolling scars present as shallow, wide indentations that give the skin a wavy texture. These scars are caused by fibrous bands of tissue that form deep within the skin, tethering the epidermis to the underlying subcutaneous fat. The tension from these bands pulls the surface downward, creating sloping edges and an uneven contour.
At-Home and Topical Remedies
At-home treatments cannot fully correct deep atrophic scarring, but they offer a maintenance strategy and minor texture improvement, especially for shallow scars. Consistent use of specific topical agents supports the skin’s natural regeneration by encouraging cell turnover and mild collagen synthesis.
Topical retinoids, such as retinol or prescription tretinoin, are effective for long-term skin remodeling. These vitamin A derivatives increase cellular turnover and stimulate fibroblasts to produce new collagen within the dermis. While significant improvement requires months of application, these products improve overall skin texture. Vitamin C (L-ascorbic acid) also supports healing by acting as a powerful antioxidant necessary for collagen biosynthesis. Silicone-based gels and sheets can improve the texture of depressed scars by creating a hydrating, occlusive barrier that supports collagen remodeling.
Minimally Invasive Clinical Treatments
Clinical treatments focusing on controlled injury and resurfacing are the first line of professional defense for shallow to moderate depressed scars. These methods intentionally damage the outer layers of the skin or upper dermis to trigger the body’s wound-healing cascade, leading to new collagen formation. These procedures are less invasive than surgery and typically require minimal downtime.
Chemical Peels
Chemical peels involve applying an acidic solution to exfoliate the skin’s surface layers. Medium-depth peels often utilize trichloroacetic acid (TCA) for atrophic scars. A specific technique called TCA CROSS applies a high concentration of acid only to the base of icepick scars. This induces localized inflammation and collagen production, effectively raising the deep pit.
Microneedling
Microneedling uses fine needles to create thousands of microscopic punctures in the skin. This mechanical process stimulates growth factors and encourages the synthesis of new collagen and elastin fibers. Adding radiofrequency (RF) energy delivers heat into the deeper dermis, causing immediate tissue tightening and a more robust, long-term stimulation of collagen compared to traditional microneedling alone.
Laser Resurfacing
Laser resurfacing uses focused light energy to either remove the outer layer of skin (ablative lasers, like Fractional CO2) or heat the underlying tissue (non-ablative lasers). Ablative fractional lasers create micro-columns of injury, vaporizing tissue and promoting significant collagen remodeling, making them effective for boxcar and superficial rolling scars. Non-ablative lasers work more gently by heating the dermis to stimulate collagen production while minimizing recovery time.
Advanced Procedures for Deep Scars
More aggressive procedures are required for the deepest, most stubborn, or tethered atrophic scars to physically alter the scar tissue structure or replenish lost volume. These advanced techniques reach the deeper dermal and subcutaneous layers where significant collagen loss or fibrous anchoring has occurred. They are typically performed under local anesthesia and can often be combined for optimal results.
Subcision
Subcision is a minor surgical technique effective for rolling scars tethered by fibrous bands. A specialized needle or cannula is inserted beneath the scar and manipulated to manually cut and release these constricting bands. Releasing the fibrous tissue allows the depressed skin to rise and encourages the formation of new collagen and blood vessels in the space created, which helps lift the scar over time.
Dermal Fillers
Dermal fillers provide an immediate physical lift by injecting a substance, such as hyaluronic acid or a biostimulatory agent, directly beneath the scar depression. Hyaluronic acid fillers restore lost volume, instantly elevating the base of the scar to the level of the surrounding skin. Biostimulatory fillers encourage the body to produce its own new collagen over several months, offering a longer-lasting correction.
Punch Excision
Punch excision is a surgical technique reserved for deep icepick or narrow boxcar scars that do not respond to other methods. This procedure uses a small, circular cutting tool to completely remove the scar tissue. The resulting defect is then closed with fine sutures, converting the deep, pitted scar into a small, linear scar that is easier to treat with subsequent laser resurfacing. Alternatively, a skin graft may be placed into the defect to immediately fill the void.