Cosmetic Skin


Excellent outcomes were achieved by all patients in the 100% TCA group who underwent five to six sessions. Furthermore, good satisfaction percentages were obtained by both the 100% TCA and the 65% TCA groups. Not a single major problem was present.

Conclusion: CROSS is a very safe and effective single modality therapy for treating atrophic acne scars without problems.

No significant interest has been indicated by J. B. LEE, MD; W. G. CHUNG, MD; H. KWAHCK, MD; or K. H. LEE, MD, with commercial supporters.

Tricholoroacetic acid, or TCA, is a highly safe superficial peel that can be used as part of a combination peel series for medium-depth acne scars. It has a long history of improving the skin’s histology and clinical appearance. When TCA is applied topically, it can cause necrosis of the collagen in the upper reticular dermis and papillary, as well as coagulative necrosis of the epidermal cells because it precipitates proteins. Over a few days, the necrotic layers shed and the skin reepithelialises thanks to the adnexal structures that were spared from the chemical injury. The chemical peel will continue to restructure skin collagen for several months. Researchers have discovered that TCA’s clinical benefits are the consequence of both a reorganization of the structural elements at the dermal level and an increase in dermal volume brought on by increases in collagen, elastin, and glycosaminoglycan content.

According to recent research, scarring promotes reticular dermal healing. It has been suggested that one of the greater hazards they believe to be connected with deeper TCA peels is the use of higher TCA concentrations for peeling, which is highly controversial. Furthermore, there is a dearth of information regarding the impact of high TCA concentrations on patients with dark complexions and Koreans (type IV–VI), who are known to acquire hyperpigmentation on the skin in a post-inflammatory sense.

To overcome hyperpigmentation, hypopigmentation, scarring, and other complications of this kind, as well as to maximize the effects of TCA, we have recommended applying higher concentrations of TCA focally to the depressed area surrounding atrophic acne scars, pressing firmly with a sharp wooden applicator. Every acne scar gradually develops a large number of frosty white patches. This method, which the authors have called chemical restoration of skin scars, is known as CROSS. But because the method isn’t patentable, its application is still limited. The CROSS technique, which uses either 100% or 65% TCA, maximizes skin thickening and collagen synthesis, both of which rise with high TCA concentrations, to rebuild acne scars. Compared to medium to deep chemical resurfacing, it has a lower complication rate and promotes healing much more quickly since it avoids adnexal structures and the normal tissue next to them. This method does not include traditional chemical resurfacing; instead, it is used for focused chemical scar restoration. With this approach, we have been able to effectively treat facial acne scars and dilated pores over the past ten years. The goal of this study is to assess the therapeutic effects of the CROSS technique on patients with dark complexion who have atrophic acne scars.


An analysis was performed based on the 65 patients who underwent CROSS treatment for atrophic acne scars in our hospitals between July 1996 and July 2001. The CROSS approach involves applying higher concentrations of TCA focally while pressing firmly on the depressed area where atrophic acne scars appear using a wooden applicator that has been sharpened. The unbuffered TCA was produced to order by a local pharmacy in weightvolume ratios of 65% and 100%.

Patients ranged in age from 25 to 45 years old, with a mean age of 32.5 years. Ten of the patients were male, and fifty-five were female. Fitzpatrick IV–V was the exact skin type shared by all of the responders. Thirty-three patients received 65% TCA CROSS treatment, whereas 32 patients received 100% TCA CROSS.

For an independent clinical evaluation, two physicians who were blinded to the treatment examined photos taken prior to and six months following the procedure. The following improvement categories were employed by these doctors: Good (improvement between 50% and 70%), Fair (improvement between 30% and 50%), Poor (less than 30% improvement), and Excellent (improvement of over 70%). Patients were surveyed six months following the last treatment in order to gauge their level of satisfaction. The doctors also assessed complications such chronic erythema, flare-ups, hypo- and hyperpigmentation, keloids, scarring, and herpes simplex.

Patients underwent a complete evaluation before to therapy, covering essential aspects such active acne lesions and previous and current drug histories. Additionally, the histories of previous allergies, herpes simplex infections, hypertrophic scarring, and keloids were collected. Pre-treatment medication such as tretinoin cream was not used prior to CROSS in order to minimize the potential of excessive and unanticipated TCA penetration.

There is no need for anesthesia or local anesthetics while using the CROSS procedure. In general, patients felt rather comfortable throughout the process. After washing the face with soap, the skin was then cleansed with alcohol. After that, the 100% or 65% TCA was applied focally to the depressed area of the atrophic acne scars by applying pressure with a sharpened wooden applicator. The skin was closely observed after a single application until a “frosted” appearance was achieved. This frosted look, which is created when the dermal and epidermal proteins congeal, is essential for tracking the depth of the peel. The targeted application of TCA resulted in frosted patches on each acne scar in less than 10 seconds. Instead of using an occlusive dressing after CROSS, an antibiotic based on ointment was administered for a moisturizing effect. To prevent the crust from coming off, this was stopped as the crust formed. Antiviral drugs and antibiotics were not required as oral prophylaxis following CROSS. 

Some patients utilized a moisturizer sunscreen with a hydro base that contained 0.05% tretinoin and 5% hydroquinone for at least four weeks following CROSS. Makeup was also allowed after CROSS. CROSS was carried out again every one to three months in order to prevent collagen formation and skin thickening.


Clinical response to treatment was good in 95% (30 out of 32 patients) of the 100% TCA group and 82% (27 out of 33 patients) of the 65% TCA group, as indicated by Table 1 of the patient treatment data. As seen in Figure 3 and Table 1, all 15 of the patients in the 65% TCA group had outstanding outcomes after more than six courses of treatment, compared to 40% (2 out of 5) of the patients who had treatment only three times. It is significant to note that all of the patients who underwent five or six rounds of 100% TCA treatment showed outstanding outcomes in Table 1 and Figure 4. Table 1’s findings leads us to the conclusion that 100% TCA CROSS shown superior clinical effects in comparison to 65% TCA CROSS.

Table 2 presents patient satisfaction rates. Of the patients in the 100% and 65% TCA groups, respectively, 94% (30 out of 32) and 82% (27 out of 33) had given good satisfaction rates. Table 2 shows that of the patients in the 65% TCA group, 16 out of 33 patients reported being “absolutely” satisfied with the therapy, whereas 11 out of 33 patients reported being only “moderately” satisfied. Table 2 further demonstrates that only 34% (11 out of 34) of the patients in the 100% TCA group were “moderately” satisfied, compared to 59% (19 out of 32) of the patients in that group who were “absolutely” satisfied.

None of the cases showed signs of scarring, hypopigmentation, lasting hyperpigmentation, keloids, persistent erythema, flare-ups of herpes simplex, or other problems at the treatment sites. Compared to the 65% TCA CROSS treatment, the frequency of problems did not rise with 100% TCA CROSS. The only things that happened were moderate erythema, which went away in two to eight weeks, and post-inflammatory hyperpigmentation, which lasted about six weeks. Four patients developed moderate pustular eruptions, which resolved in a week after taking 500 mg of cefadroxil three times a day. Even though they had been on isotretinoin for three months before to the therapy, two patients had good results without leaving large scars. It should be emphasized, though, that because hypertrophic scarring is likely to result, chemical resurfacing is typically not advised for patients who have taken isotretinoin during the six months before to the procedure.

The therapeutic impact was greatly improved, and the higher frequency of the CROSS treatment on acne scars did not result in any notable problems, according to the results. Furthermore, applying a higher dose of TCA proved to be more beneficial for atrophic acne scars due to its greater effectiveness.


Although the pilosebaceous unit experiences the chronic inflammatory condition known as acne, usually in adolescence, new research on women aged 25 to 44 reveals that the prevalence of clinical acne does not truly decline with age. Furthermore, because acne scarring—which is really more common in this age group—is strongly correlated with the length of the acne. 95% of patients will have moderate acne scarring, but only 22% of patients will have substantial scarring.

Three new categories of acne scars have been developed recently: icepick, boxcar, and rolling. Many procedures, including punch elevation, chemical skin resurfacing, subcision or subcutaneous incision, laser skin resurfacing, and punch excision, can be utilized to ameliorate and even repair the occurrence of acne scars. The results of treating acne scars with a combination of these therapies can be much better. However, operations involving chemical skin resurfacing are limited to N-VJ skin types. However, there is currently no proven single therapy method for the improvement and repair of acne scars.

Most surgeons prefer this because larger concentrations of TCA result in increased collagen volume and skin thickening. But because the surrounding normal skin is often injured, this could leave extensive scarring and make resurfacing difficult. However, using lesser concentrations of TCA during resurfacing does not leave significant scarring since the chemical damage is generally spared from nearby normal tissues and hair follicle reepithelialization takes place. Therefore, due of the hazards associated, using larger dosages of TCA is not advised.

The CROSS approach is recommended, which involves applying higher concentrations of TCA up to 100% focally on the depressed area of atrophic acne scars using a wooden applicator that has been sharpened. This approach has a huge benefit when employing 100% or 65% TCA alone since it targets the formation of collagen and dermal thickening, both of which increase with high concentrations of TCA. Above all, this method is not a substitute for the more conventional full-face chemical resurfacing; rather, it can be used to restore chemical scars focally. Moreover, this method preserves the normal skin next to the treated area as well as the adnexal tissues, significantly lowering or even eliminating the chance of hypopigmentation and scarring. It has been discovered that using the CROSS technique to apply 100% TCA is far more successful than using 65% TCA.

Deep icepick scars, boxcar and rolling scars can all be normalized with many CROSS administrations of 100% TCA. Since clinical progress is strongly correlated with the frequency of CROSS treatment, it is effective in treating deep acne scars. Moreover, this can be employed for autologous soft tissue augmentation prior to full-face resurfacing procedures for extensively pitted areas. This method has also been effectively used to cure dilated pores. We have lately learned that the CROSS technique can restore even deep surgical scars.

None of the patients experienced significant side effects such keloids, chronic erythema, hypopigmentation, or permanent hyperpigmentation. There was no rise in the frequency of problems with 100% TCA CROSS compared to 65% TCA CROSS. Sporadic skin infections were treated with oral antibiotics, and moderate occurrences of erythema and temporary post-inflammatory hyperpigmentation resolved in one to two months. There was not a herpes simplex flare-up among the nine individuals with a history of the condition who did not get oral antiviral prophylaxis.

As medium to deep chemical resurfacing increases the risk of hypertrophic scarring, it is typically not advised to take isotretinoin or other medications that depress the adnexal glands. A history of isotretinoin use is not a relative contraindication for CROSS, and it has no clinically significant impact on the outcome. CROSS typically protects the nearby normal skin. However, further research is still needed to fully understand the effects of isotretinoin in CROSS.

This study concludes that CROSS is, in fact, a minimally invasive, safe, and effective treatment for atrophic acne scars. Ninety percent of the subjects showed good recovery after three to six courses, and the number of CROSS treatments administered was closely correlated with the level of clinical improvement shown. 94% of patients in the 100% TCA group and 82% of patients in the 65% TCA group expressed satisfaction with the CROSS approach. Furthermore, 100% TCA CROSS was a more effective treatment for atrophic acne scars than 65% TCA.


In North America, this innovative method is still widely used. Compared to more traditional techniques like CO2 laser resurfacing or dermabrasion, this process is more patient-friendly and easier for the clinician to conduct. This technique also uses less equipment than nonablative laser scar treatments. We encourage more people to attempt this method so that we can add more experienced writers to our literature.


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