All About Acne Scars and Their Treatments

Introduction to acne scars

Acne scars are permanent marks that form on the skin after acne episodes, especially when they are severe or poorly managed. They result from the body’s natural healing process, which, in trying to repair the damage caused by inflammation of the pilosebaceous follicles, may produce either an excess of tissue (forming hypertrophic scars or keloids) or insufficient tissue (leading to atrophic scars).

Scars can cause significant distress, affecting self-esteem and quality of life. Effective dermatological treatments are available to improve their appearance by reducing thickness and pigmentation, filling volume deficits in the skin, or restoring epidermal texture, thereby lessening the psychosocial impact of these marks. The treatment approach varies by scar type and severity, and often requires a combination of methods for optimal results.

Causes of Acne Scarring^{1 2}

Acne scars result from interconnected factors affecting the structure and function of the skin’s pilosebaceous units. Key mechanisms include:

Formation of Acne Lesions

Acne develops from:

• Increased and altered quality of sebum, becoming more viscous.
• Hyperkeratinisation of the pilosebaceous units, clogging the pores.
• Heightened activity of androgenic hormones.
• Proliferation of Cutibacterium acnes, triggering an inflammatory response.
  
  The deeper and more inflammatory the lesions, such as nodules, cysts, or even abscesses, the higher the risk of scarring.

Scarring Process

Inflammation is a normal immune response that initiates lesion repair through a cascade of cellular and molecular events, which factors like sun exposure and lesion manipulation can exacerbate.
 

• Granulation tissue formation: following inflammation, damaged tissue is repaired and new capillaries form. Fibroblasts migrate and proliferate, producing collagen.
   
• Matrix remodelling: fibroblasts and keratinocytes reorganise tissue layers. An imbalance can lead to atrophic scars, if collagen production is insufficient, or to hypertrophic scars if the scarring response is excessive.

Aggravating Factors

• Lesion manipulation: excessive picking or squeezing can worsen inflammation and promote scarring.
   
• Sun exposure: accelerates inflammation and prolongs healing.
   
• Inadequate or delayed treatment: late or unsuitable acne therapy increases the risk of scarring.

Treatments and Solutions for Acne Scars^{1 2 3}

Many medical, dermatological, and surgical treatments are available for acne scars. They should be tailored individually and may be combined.

Skin Resurfacing

These treatments target superficial skin layers to stimulate regeneration and reduce scar appearance:

• Chemical peels: use chemical solutions to exfoliate dead cells and promote their renewal.
• Indications: boxcar and rolling scars.
  Dermabrasion/microdermabrasion: mechanical exfoliation of the upper epidermis and upper dermis (dermabrasion) or superficial epidermis (microdermabrasion) to smooth shallow scars.
• Indications: boxcar, rolling, and superficial ice pick scars.
• Laser therapy: removes or ablates the superficial skin layer or stimulates collagen production in deeper layers.
  Indications: ice pick, rolling, boxcar, and hypertrophic scars.
• Microneedling: creates micro-perforations with fine needles to stimulate collagen and elastin production.
  Indications: rolling, boxcar, and mild hypertrophic scars.

Reconstructive Techniques

These methods alter scar structure to improve skin appearance:

• Chemical reconstruction of scars (CROSS technique): applies high-strength trichloroacetic acid directly into deep ice pick scars to stimulate collagen.
• Punch excision and elevation: surgical removal of atrophic scars followed by suturing of healthy skin edges.
  Indications: ice pick and narrow boxcar scars.
• Subcision: uses a needle to sever fibrotic attachments between the dermis and subcutaneous tissue.
  Indications: rolling scars.

Filling Techniques

• These treatments add volume under scars to make them less visible:
  Autologous fat grafting and fillers: inject the patient’s own fat or hyaluronic acid under scars to level the skin.
• Indications: rolling and boxcar scars.
• Skin grafting: transfers skin from another body area to fill depressed scars.
  Indications: rolling and boxcar scars.

Other Treatments

• Corticosteroid injections: reduce inflammation and flatten hypertrophic scars and keloids.
• Cryotherapy: shrinks hypertrophic scars and keloids with extreme cold.
• Radiofrequency: uses radio waves to heat deep skin layers, promoting collagen remodelling.
  Indications: rolling, boxcar, ice pick, and mild hypertrophic scars.
• Topical retinoids or alpha-hydroxy acids (AHAs): Promote cell turnover and reduce scars by accelerating exfoliation and improving skin texture.
  Indications: superficial atrophic scars.

Tips to Prevent Acne Scars⁴

Importance of Early Acne Treatment

Recommended Dermocosmetic Products

Select non-comedogenic cleansers and moisturisers specially formulated for acne-prone skin to minimise pore obstruction and new lesion development.