Therapeutic Update on Acne Scarring

June 2014 | Volume 13 | Issue 6 | Features | 651 | Copyright © June 2014

Amy E. Rose MD

New York University, The Ronald O.
Perelman Department of Dermatology,
New York, NY

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Acne affects 80% of people 11 to 30 years old with up to 95% of these patients ultimately left with some degree of scarring.1 Acne is the most common cause of facial scarring and results in considerable physical and psychiatric morbidity. Of those patients who end up in our offices seeking help, the choice of treatment is generally dictated by several factors including the severity and morphology of lesions, patient expectations, cost, and the side effect profile.
Before initiating treatment, it is important to give the patient a handheld mirror and explain to them the difference between active acne lesions, post-inflammatory hyperpigmentation (PIH), and true scarring. Too often a patient is frustrated by what they perceive as extensive scarring when they truly have severe PIH, thus requiring a very different set of treatments than those used for scarring. Acne scars can be either hyertrophic or atrophic. Hypertrophic scars respond well to repeated intralesional injections of corticosteroids, which is generally considered the first-line therapy.2 Intralesional 5-fluorouracil (5FU), which has been shown to reduce fibroblast proliferation, is also very effective, especially when combined with the 585-595nm pulsed dye laser (PDL).3 Fitzpatrick describes a protocol of using 0.9cc of 50mg/cc of 5-FU (ie, 45mg) combined with 0.1cc of 10mg/cc of Kenalog in the same syringe with 0.05cc injected per site, with 1cm between sites.3 Injections are combined with PDL treatment at 6 J/cm2 with the laser being performed first. Injections are initially performed as often as 2 to 3 times per week until response is noted at which point the interval can be increased to every 2 to 4 weeks.
The majority of acne scars are atrophic and can be categorized based on morphology as rolling, boxcar, or icepick.4 Rolling scars are depressed, distensible scars that, of the three types, are generally considered the most responsive to treatment.
Boxcar scars are punched-out, u-shaped scars that often require punch excision techniques. Ice pick scars are narrow, v-shaped scars that extend to the subcutaneous fat and also often require surgical intervention. Approaches to the treatment of atrophic acne scars can be divided into three general categories: resurfacing techniques, dermal fillers, and surgical techniques. It is critical when treating acne scars to appropriately manage patient expectations, explaining that scarring is permanent. Thus the goal of treatment is always improvement of, not elimination of their scars. It is also important for providers to keep in mind that what might seem like a minor, even trivial improvement to us, may be life changing for a patient who has had a face full of scars looking back at them in the mirror for 20 years.

Resurfacing Techniques

Dermabrasion removes the epidermis and part of the upper dermis and thus can be utilized to treat shallow, rolling, or boxcar scars. The outcome is largely technique and operator dependent with potential risks including sustained erythema and PIH. The technique has somewhat fallen out of favor with the advent of the fractional resurfacing lasers, but dermabrasion still has a place in the armamentarium as a low-cost treatment option with relatively little down time. Dermabrasion can also be performed prior to chemical peels to increase the depth of penetration of the peeling agent.
Chemical Reconstruction of Skin Scars (CROSS)
Trichloroacetic acid (TCA) CROSS involves the serial application of 90 to 100% TCA to scars using a narrow wooden applicator until a white frost appears. The application of TCA results in necrosis of the epidermis and of dermal collagen with subsequent reorganization of the dermis and an ultimate increase in volume.5 The procedure is repeated at 4 week intervals for 3 to 4 treatments. TCA CROSS is a relatively quick and easy office procedure with minimal down time and low cost to both patient and practitioner. TCA CROSS may offer some degree of efficacy even for ice pick scars that would otherwise require punch excision. Because the treatment area is so focal, CROSS can be safely utilized in patients with skin of color, although most advise priming with hydroquinone 4% and tretinoin 2 weeks before treatment.6 Risks of TCA CROSS include atrophy that typically improves spontaneously as well as post-inflammatory hyperpigmentation (PIH), which