Acne scars can be classified into three broad categories: ice pick, rolling, and boxcar. A palette approach to acne scarring yields the best results, because each individual technique is best suited for a particular type of scar. It is important to remember that improvement is the goal, and it is usually necessary to combine several techniques in each individual case. Various treatment modalities are used for reconstructing and improving the appearance of acne scars, including punch excision, punch elevation, subcutaneous incision (subcision), dermal fillers (liquid injectable silicone, hyaluronic acid), chemical skin resurfacing, and laser skin resurfacing. By combining these multiple modalities, it is possible to produce dramatic improvement in acne scars. It has proven difficult to repair deep rolling scars, especially in dark skin.
Trichloroacetic acid (TCA) has been used for over 50 years to rejuvenate and repair the skin in a variety of conditions. The CROSS Technique, (Chemical Reconstruction of Skin Scars) using 100% TCA, has the advantage of reconstructing acne scars by focusing on the dermal thickening and collagen production that occurs with higher TCA concentrations. It has proven very effective for acne scars in dark complexioned patients, including Asian and black skin (types IV-VI skin), known to readily develop reactive darkening. The CROSS Technique involves the focal application of TCA using a sharpened wooden applicator. It is pressed down firmly over the entire depressed area of the scar. It produces multiple, frosted white spots on each acne scar. Healing is more rapid and has a lower complication rate than conventional full-face medium to deep chemical resurfacing, because the normal tissue and adnexal structures around the scar are spared.
Before CROSS is performed, the skin will be primed with 8Quin nightly for 2 weeks, and thereafter for the duration of the sessions. Local anesthetics or sedation are not needed for CROSS. The area is cleansed and prepped with alcohol. The TCA is focally applied until a "frosted" appearance is achieved. Mild stinging is usually encountered, easily controlled with an electric fan. An antibiotic ointment is applied to the treated areas after the procedure, and used as needed until crust formation occurs. The skin will be cleansed daily with a non-drying cleanser and moisturized with a moisturizer-sunscreen. No antibiotic or antiviral therapy is needed with after CROSS. When the crusts fall off, usually within a week, 8Quin will be resumed at night, along with the cleanser and moisturizer-sunscreen. The application of makeup is allowed after CROSS. CROSS is repeated every month until maximal change is achieved, usually within 4-6 sessions.
Although possible, side effects or complications such as persistent redness, permanent darker or lighter skin color, bacterial infections or herpes simplex flare-up, or scarring are unlikely to occur. Patients sometimes encounter mild redness or temporary darker color, both disappearing in 4-6 weeks.
Repeated CROSS application can help normalize deep rolling and boxcar scars, and deep ice pick scars, but it is likely that other procedures will be used to obtain the most change. The degree of clinical improvement in the original study was proportional to the number of courses of CROSS treatment, with good improvement after three to six courses being recorded in more than 90% of cases. This technique can also treat chicken pox scars and dilated pores, as well as reconstructing depressed surgical scars.
The CROSS Technique is another color on the palette of therapies for acne scars and other depressed surgical scars. A consultation will be necessary to evaluate each patient's needs and develop a comprehensive and individualized approach to scar rejuvenation.