It's a valid concern, but TCA Cross is considered a gold-standard for isolated ice pick scars precisely because it's so targeted. A highly skilled practitioner uses a tiny instrument to apply a high-concentration TCA solution *only* to the walls of the scar, which causes frost-ing and then promotes collagen as it heals, pushing the scar upward. Healing is usually 7-10 days of a dark scab that falls off. The key is the practitioner's precision.