In order to maximize the effects of TCA and to overcome complications such as scarring, hyperpigmentation, and hypopigmentation, we suggest a technique consisting of the focal application of higher TCA concentrations by pressing hard on the entire depressed area of atrophic acne scars using a sharpened wooden applicator (Figure 1).11 Eventually it produces multiple, frosted white spots on each acne scar (Figure 2). This technique is called chemical reconstruction of skin scars (CROSS) by the authors; however, the technique itself has not been patented or restricted to prevent usage. The CROSS method, achieved with 65% or 100% TCA alone, has the advantage of reconstructing acne scars by focusing on the dermal thickening and collagen production that increase with high TCA concentrations.7 Healing is more rapid and has a lower complication rate than conventional full-face medium to deep chemical resurfacing, because the adjacent normal tissue and adnexal structures are spared. This technique does not involve the classic full-face chemical resurfacing, but rather it can be used on focal chemical scar reconstruction. We have used this technique successfully for treating facial acne scars and dilated pores for the past 10 years. The purpose of this study was to evaluate the clinical effects of the CROSS method on atrophic acne scars in dark-complexioned patients.
Figure 1. A) Sharpened wooden applicator and B) sharpened tip.
[Normal View ]
Figure 2. CROSS method: A) before and B) shortly after the procedure.
[Normal View ]
Materials and Methods
An analysis was conducted of 65 patients with atrophic acne scars who were treated with the CROSS method in our hospitals between July 1996 and July 2001. The CROSS method consists of the focal application of higher TCA concentrations by pressing hard on the entire depressed area of atrophic acne scars using a sharpened wooden applicator (Figure 1). TCA, 65–100% weight/volume, unbuffered, was made to order by a local pharmacy.
The patients' ages ranged from 25 to 45 years (mean 32.5 years). Fifty-five patients were women and 10 were men. All patients had Fitzpatrick skin types IV–V. Thirty-three patients were treated with 65% TCA CROSS and 32 with 100% TCA CROSS.
For independent clinical assessment, two blinded physicians evaluated the photographs taken before treatment and 6 months after completion of the treatment. Physicians categorized the improvement as follows: excellent, improvement greater than 70%; good, improvement of 50–70%; fair, improvement of 30–50%; poor, improvement less than 30%. The patient satisfaction rates were recorded from the interviews conducted 6 months after the last treatment. The physicians evaluated complications such as persistent erythema, permanent hyperpigmentation, hypopigmentation, herpes simplex flare-up, scarring, or keloids.
Patients were evaluated carefully before treatment about the factors considered important, including the patients' current and past medications and active acne lesion. Relevant history was obtained, including any history of prior hypertrophic scarring, keloids, allergies, or herpes simplex infection. Before CROSS, pretreatments such as tretinoin cream were not applied because of the risk of unpredictable and excessive TCA penetration.
Local anesthetics or sedation were not needed for CROSS. Patients were comfortable during the procedure. After facial washing with soap, the skin was cleansed with alcohol. And then either 65% TCA or 100% TCA was focally applied by pressing hard on the entire depressed area of atrophic acne scars using a sharpened wooden applicator (Figure 1). The skin was monitored carefully until it reached a "frosted" appearance after a single application. The frosted appearance is the result of coagulation of epidermal and dermal proteins and is used mainly to monitor the peel depth. Focal application of TCA produced even frosted spots on each acne scar within 10 seconds (Figure 2). After CROSS, an ointment-based antibiotic instead of an occlusive dressing was applied for moisturizing effect, but this application was discontinued after crust formation in order to avoid the risk of detaching the crust. Oral prophylaxis consisting of antibiotics and antiviral medications were not needed after CROSS. One to 2 weeks after CROSS, a moisturizer sunscreen cream consisting of 0.05% tretinoin, 5% hydroquinone, and a hydrobase was used in some patients for a minimum of 4 weeks. The application of makeup was allowed after CROSS. CROSS was repeatedly performed every 1–3 months to allow dermal thickening and collagen production.
Results
The patient treatment data indicated that 27 of 33 patients (82%) (the 65% TCA group) and 30 of 32 patients (94%) (the 100% TCA group) experienced a good clinical response (Table 1). In the 65% TCA group, 15 of 15 patients (100%) who received more than six courses of treatment demonstrated good or excellent results, as did 2 of 5 patients (40%) who received treatment three times (Table 1 and Figure 3). Of interest is that all patients in the 100% TCA group who received five or six courses of treatment showed excellent results (Table 1 and Figure 4). Table 1 shows that the clinical effects of 100% TCA CROSS were better than those of 65% TCA CROSS.
Table 1. Effectiveness of the CROSS Method on the Treatment of Acne Scars according to the Number of Courses
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Effects of CROSS Number of Courses
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3 4 5 6 No. of patients
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65% TCA
Excellent 1 (20) 1 (13) 2 (40) 8 (53) 12 (36)
Good 1 (20) 4 (50) 3 (60) 7 (47) 15 (46)
Fair 2 (40) 1 (13) 3 (9)
Poor 1 (20) 2 (25) 3 (9)
Total 5 8 5 15 33
100% TCA
Excellent 7 (41) 5 (63) 2 (100) 5 (100) 19 (59)
Good 8 (47) 3 (38) 11 (34)
Fair 2 (12) 2 (6)
Poor 0 (0)
Total 17 8 2 5 32
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Percentages are in parentheses.
Excellent, more than 70% of the lesions disappeared; good, 50–70% of the lesions disappeared; fair, 30–50% of the lesions disappeared; poor, less than 30% of the lesions disappeared.
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Figure 3. CROSS of the cheek with 65% TCA A) before and B) after three courses of treatment.
[Normal View ]
Figure 4. CROSS of the cheek with 100% TCA A) before and B) after six courses of treatment.
[Normal View ]
Good satisfaction rates in the 65% and 100% TCA groups were recorded in 27 of 33 patients (82%) and 30 of 32 patients (94%), respectively (Table 2). In the 65% TCA group, 16 of 33 patients (49%) and 11 of 33 patients (33%) were satisfied with this therapy absolutely and moderately, respectively (Table 2). In the 100% TCA group, 19 of 32 patients (59%) and 11 of 34 patients (34%) were satisfied absolutely and moderately, respectively (Table 2).
Table 2. Satisfaction Rates With the CROSS Method for the Treatment of Acne Scars
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Grade of
satisfaction TCA Concentration
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65% TCA 100% TCA No. of patients
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Absolutely 16 (49) 19 (59) 35 (54)
Moderately 11 (33) 11 (34) 22 (34)
Not at all 6 (18) 2 (6) 8 (12)
Total 33 32 65
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Percentages in parentheses.
Absolutely, satisfaction rate more than 70%; moderately, satisfaction rate 50–70%; not at all, satisfaction rate less than 50%.
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There were no cases of significant complication at the treatment sites such as persistent erythema, permanent hyperpigmentation, hypopigmentation, herpes simplex flare-up, scarring, or keloids. Relative to the 65% TCA CROSS treatment, 100% TCA CROSS did not increase the frequency of complications. Only mild erythema, which faded over 2–8 weeks, and transient postinflammatory hyperpigmentation, which disappeared over 6 weeks, occurred. Mild pustular eruptions occurred in only four patients and cleared within 1 week with the use of cefadroxil 500 mg three times a day. The two patients who received isotretinoin for 3 months before treatment showed good results without excessive scarring, although it should be noted that full-face medium to deep chemical resurfacing is relatively contraindicated in patients who have taken isotretinoin within the previous 6 months because of the increased risk of hypertrophic scarring.
The results indicated that higher treatment frequency of CROSS application on acne scars improved the therapeutic effect, and there were no significant complications. Furthermore, application of a higher TCA concentration was more effective in the treatment of atrophic acne scars.
Discussion
Acne is a chronic inflammatory disease of the pilosebaceous unit and a condition commonly experienced in adolescents, but recent data indicate that the prevalence of clinical acne does not show a significant decrease in women between the ages of 25 and 44 years.12 Acne scars are more common in this persistent acne group, because acne scars correlate with the duration of acne. Minor acne scarring may occur in up to 95% of patients, but to a significant degree in only 22%.13,14
Recently acne scars have been classified into three types: icepick, rolling, and boxcar.15 Various treatment modalities are used for reconstructing and improving the appearance of acne scars, including punch excision, punch elevation, subcutaneous incision (subcision), chemical skin resurfacing, and laser skin resurfacing.16,17 By combining these multiple modalities, it is possible to produce dramatic improvement in acne scars.18 However, procedures that include chemical skin resurfacing have generally been limited to skin types IV–VI.9 So far, no appropriate and effective single treatment modality has been developed for reconstructing and ameliorating the appearance of acne scars.
Most surgeons want to use higher TCA concentrations because they produce increased dermal thickening and collagen volume.7 However, such use results in resurfacing difficulties and can produce severe scarring because of damage to the adjacent normal skin, although severe scarring usually does not occur in resurfacing with lower TCA concentrations because of reepithelialization from hair follicles and adjacent normal tissue that were spared from chemical damage. So peeling with higher TCA concentrations is very risky and definitely not recommended.19
We suggest the CROSS method, which consists of the focal application of higher TCA concentrations, even up to 100%, by pressing hard on the entire depressed area of atrophic acne scars using a sharpened wooden applicator. This technique, achieved with higher TCA concentrations of 65% or 100% TCA alone, has the great advantage of reconstructing the acne scars by focusing on the dermal thickening and collagen production that increases with high TCA concentrations. Of interest is that rather than being equivalent to the classic full-face chemical resurfacing, this technique can be used on focal chemical scar reconstruction. Moreover, this technique can avoid scarring and reduce the risk of developing hypopigmentation by sparing the adjacent normal skin and adnexal structures. We found that in using the CROSS method, application with 100% TCA was more effective in treating atrophic acne scars than with 65% TCA.
Repeated CROSS application can normalize deep rolling and boxcar scars, and a similar result can be achieved for deep icepick scars with higher TCA concentrations of up to 100%. Because clinical improvement is proportional to the number of courses of CROSS treatment, this method is effective for the treatment of all deep acne scar types. Furthermore, it can also be utilized for autologous soft tissue augmentation prior to performing the classic full-face resurfacing modalities for deeply pitted areas.20 Also, we have used this technique successfully for treating dilated pores. Recently we used the CROSS method for reconstructing depressed surgical scars.
No patient developed any significant complication such as persistent erythema, permanent hyperpigmentation, hypopigmentation, scarring, or keloids. The use of 100% TCA CROSS did not increase the frequency of complications compared with 65% TCA CROSS. All cases of mild erythema and transient postinflammatory hyperpigmentation faded over 1–2 months and focal skin infections were cleared by oral antibiotics. No herpes simplex flare-up occurred in the nine patients with a positive history of herpes without oral antiviral prophylaxis.
A history of drugs that depress adnexal glands, such as isotretinoin, is a relative contraindication to medium to deep chemical resurfacing because of the increased risk of developing hypertrophic scars.3 We believe that a drug history of isotretinoin is not a relative contraindication and does not influence the clinical results because CROSS may spare the adjacent normal skin. But further study is required to determine the effect of isotretinoin in CROSS.
We conclude that the CROSS method presented in this study is a safe and very effective single modality for the treatment of atrophic acne scars with no significant complications. The degree of clinical improvement 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. Most patients, 82% in the 65% TCA group and 94% in the 100% TCA group, were satisfied with the CROSS method. Furthermore, the CROSS method with 100% TCA was more effective in treating atrophic acne scars than with 65% TCA.
Commentary
This is a novel technique not yet reported in North America. The simplicity of this procedure makes this an easier procedure for the clinician and more patient friendly than more conventional dermabrasion or CO2 laser resurfacing. It also requires less equipment than nonablative laser treatments of scars. I hope that others will now try this technique so that more experience can be reported in our literature.
Gary Monheit, MD
