Acne scarring: current treatment options

Dermatology Nursing, April, 2006 by Miranda Frith, Christopher B. Harmon

Acne vulgaris is one of the most common skin disorders seen in dermatology, constituting about 30% of all dermatologic visits each year (Marcus, 2004). Up to 34% of men and 27% of women report having active acne lesions at any given time (Fien, Ballard, & Nouri, 2004). Acne can have a significant psychological and social impact, affecting 40 to 50 million people in the United States. Post-acne scarring can be especially devastating.

Acne is a disease of the pilosebaceous unit. It has a multifactorial etiology. The primary etiologic factors include excessive sebum production secondary to androgen stimulation, abnormal follicular keratinization resulting in follicular plugging, proliferation of Propionbacterium acnes (an anaerobic organism normally present in the follicle), and inflammation following chemotaxis and the release of various pro-inflammatory mediators (Wolf, 2002). Scarring typically results from a severe inflammatory response to P acnes bacteria.

Two types of lesions occur in acne: non-inflammatory lesions such as open or closed comedones, and inflammatory (papular, nodular, or cystic) lesions. Acne scarring typically starts with an inflammatory lesion that ruptures into the hair follicle, resulting in a perifollicular abscess. Under normal conditions, the inflammatory reaction is encapsulated by the epidermis and appendageal structures. This allows the abscess to be repaired without scarring, usually within 7 to 10 days. If this fails to happen, further rupture occurs, leading to the appearance of multi-channeled, fistulous tracts. The extent and depth of the inflammation, in combination with the host's response to the inflammation, will determine the amount, type, and depth of scarring. Severe inflammation of the dermis can lead to total necrosis of the follicle. This may lead to sloughing of the follicle, producing a focal scar. Ruptures that occur deeply in the follicle may result in inflammation that extends beyond the hair follicle, into the surrounding subcuticular area, along the vascular channels, and around the sweat glands. This causes deep scarring and destruction of the subcuticular fat, leading to rolling scars (Goodman, 2000).

Currently, there is no universally accepted classification of acne scarring. Scars are typically visible to the observer if they are abnormally colored or shaped, have an altered contour or textures, or are longer than about 1 cm in length (Goodman, 2000). Many different terms have been used in describing acne scars. Commonly used terms include ice pick, sharp shouldered, atrophic, and undulated or rolling. Jacob, Dover, and Kaminer (2001) proposed a three-term system: ice pick, rolling, and boxcar. Ice-pick scars are described as narrow, deep, sharply demarcated tracts that extend vertically into deep dermis or subcutaneous layer. Rolling scars occur from dermal tethering of otherwise relatively normal looking skin. They are usually wider than 4 to 5 mm. Boxcar scars appear as round or oval depressions with sharply demarcated vertical edges. They are wider than ice-pick scars, and don't taper to a point at the base. They may be shallow or deep. Determining the types of scarring present is an important aspect in choosing a treatment course.

Evaluation

Pre-operative evaluation of patients with acne scarring is crucial. As previously mentioned, the most important aspect in determining a treatment plan involves determining the type of scarring present, as well as determining what is most bothersome to the patient. The contour of the scar is usually the most important and variable characteristic (Goodman, 2000). The patient's skin type should be ascertained (Fitzpatrick types I-VI). Lighter skin types (I-II) typically have the best response to resurfacing techniques. Types III to IV are more likely to become transiently hyper-pigmented 4 to 8 weeks after the procedure and hypopigmented 12 to 18 months after surgery (Harmon, 2001). The extent of scarring should be determined as well. A patient with only a few scars will have a different treatment regimen than one with many scars (Jacob et al., 2001). Once a general assessment has been made, a treatment course can be recommended. In general, acne should be in remission. Exacerbations are a frequent occurrence and should be anticipated and discussed preoperatively. Exacerbations result from either the shock of adnexal injury or the use of occlusive dressings after resurfacing procedures.

A thorough medical history should be obtained. Close attention should be paid to several key points. A history of hypertrophic scarring or keloids may require a test spot prior to a resurfacing procedure. Patients should be asked about previous isotretinoin therapy. Patients should be at least 6 to 12 months beyond isotretinoin therapy prior to acne scar treatments. Isotretinoin therapy can delay re-epithelialization and produce hypertrophic scarring. Special consideration should be given to patients with bleeding disorders, immunosuppression, and those who have received prior radiation therapy, as these may cause delayed healing and increased risk for infection. Prior cosmetic procedures, including previous treatments for acne scarring, should be discussed.