Hi,
Fractional CO2 laser is the best modality for the treatment of boxcar scars. Ice-pick scars may also be treated with fractional laser although treatment response is suboptimal.
TCA cross may be used only to treat ice-pick scars. It should not be used to treat boxcar scars as scar widening and worsening may occur. TCA cross remains a difficult treatment modality with a narrow margin of treatment safety. Alternative treatments of ice-pick scars include punch excision.