Mechanism of Action
The acid causes protein coagulation and controlled injury within the deep dermis at the base of the scar. The subsequent wound healing process stimulates neocollagenesis, gradually raising the scar floor. Because the acid is applied strictly inside the scar depression, the surrounding healthy skin remains untouched—unlike full-face chemical peels. This provides a "bottom-up" approach for deep scars that "top-down" modalities like lasers or microneedling cannot reach.
Ideal Candidates & Indications
Ice pick scars—the primary indication; deep, narrow boxcar scars; and enlarged post-acne pores. It is not indicated for broad rolling scars (which require subcision), hypertrophic or keloid scars, nor is it a stand-alone replacement for a comprehensive treatment plan. TCA CROSS is typically one component of a multi-modality regimen, combined with fractional CO2 laser or RF microneedling for other scar types on the same face.
Why Must It Be Performed by a Physician?
The acid concentration used is exceptionally high; any spillage onto healthy skin can cause chemical burns, secondary scarring, or permanent depigmentation. A physician selects the appropriate concentration based on scar depth and skin type, applies a micro-droplet precisely into each scar, and monitors the clinical endpoint of "frosting" before neutralizing or stopping. Performing this procedure at home with online-purchased TCA solutions is a frequent cause of severe scarring and worsening hyperpigmentation.
Treatment Sessions and Expected Results
Typically 3–6 sessions spaced 4–6 weeks apart. Treated points form small scabs that shed within 5–7 days. The scar depth gradually becomes shallower and the scar opening tightens with each session; the degree of improvement depends on initial depth and individual healing response. Darker skin phototypes carry a higher risk of temporary post-inflammatory hyperpigmentation (PIH) at the treated spots—strict sun protection is essential.
At BonBoz Clinic
A dermatologist examines your skin, maps out each individual ice pick and deep boxcar scar, selects the precise acid concentration, manually performs focal application point by point, and integrates resurfacing modalities for the remaining scars according to your tailored treatment plan.
