The Use of Chemical Reconstruction of Skin Scars (CROSS) Method With Trichloroacetic Acid (TCA) for Atrophic Scars: A Comprehensive Review on Application Techniques, Adjunct Therapies, and Complications

Atrophic scars have a significant psychosocial and functional impact on quality of life. Chemical reconstruction of skin scars (CROSS) using trichloroacetic acid (TCA) has emerged as an effective procedure for targeted treatment of atrophic scars, yet application methods and efficacy vary across scar types and patient populations.

To evaluate the methodology, indications, efficacy, and safety profile of the TCA CROSS technique in atrophic scarring and to compare TCA CROSS outcomes to other therapeutic modalities and assesses its adjunctive use.

A PubMed literature search was performed for clinical studies evaluating TCA application in scar management; inclusion criteria focused on studies using the CROSS technique published after 2002. Two reviewers independently screened 133 results: 34 publications (20 clinical trials, 4 comparative/cohort studies, 4 case series, 2 case reports, and 4 expert opinions) met eligibility criteria.

In total, 937 patients (predominantly female, aged 4-65 years, Fitzpatrick skin types I-V) were included. TCA CROSS was primarily used for ice pick and boxcar acne scars, but it was also used for varicella and leishmaniasis scars. Application techniques varied, with fine-gauge needles and paintbrushes enabling more precise delivery. Multiple sessions yielded greater improvement, and higher TCA concentrations increased the risk of complications. Patient satisfaction was generally high, with improvement rates of 50% to 80%. The most common adverse events were transient postinflammatory pigmentary changes.

TCA CROSS is a safe, effective option for treating atrophic scars. Methodical application and multimodality approaches optimize patient outcomes; further research should address technique standardization and efficacy across diverse skin types.