Treatments | TCA Cross

TCA Cross is the chemical reconstruction of skin scars (CROSS) using trichloroacetic acid (TCA). It is most often used as an outpatient clinic procedure to treat atrophic acne scars. TCA is inexpensive, safe, and efficient.

What is TCA?

TCA is an abbreviation for Trichloracetic acid, which is typically used in low concentration (20-35%) for a chemical peel and improves the appearance of facial scars and skin ageing.

What is TCA Cross and, how does it work?

Acne is a common inflammatory skin condition and may result in atrophic, hypertrophic, or keloid scars. Acne scars can cause significant psychological distress and social impact.

The TCA CROSS procedure involves depositing small amounts of TCA concentration onto the surface of the atrophic scar. The TCA causes a local inflammatory reaction leading to the formation of new collagen fibres.

The decision to perform TCA CROSS depends on:

The type and severity of acne scarring
Patient preference and expectations
Clinician experience and expectations

TCA CROSS helps to treat the following types of atrophic scar:

Boxcar acne scars
Rolling acne scars
Ice-pick scars

Assessment of acne scars

Acne scar severity can be graded using Goodman and Baron’s qualitative acne scar grading system to allow objective pre and post-treatment comparisons.

Macular Scars

Macular scars can be erythematous, hyperpigmented (brown), or hypopigmented (pale) flat marks. They do not represent a problem of contour like other scar grades but of colour.

Mild atrophic or hypertrophic scars

Mild atrophic (thin) or hypertrophic (thick) scars may not be obvious at social distances of 50 cm or greater and may be covered adequately by make-up or the normal shadow of shaved beard hair in men or normal body hair.

Moderate atrophic or hypertrophic scars

Moderate atrophic or hypertrophic scarring is obvious at social distances of 50 cm or greater. It is not covered easily by makeup or the normal shadow of shaved beard hair in men or body hair if extra facial but is still able to be flattened by manual stretching of the skin (if atrophic).

Severe atrophic or hypertrophic scars

Severe atrophic or hypertrophic scarring is evident at social distances greater than 50 cm and is not covered easily by makeup or the normal shadow of shaved beard hair in men or body hair if extra facial and is not able to be flattened by manual stretching of the skin.

How is TCA CROSS performed?

TCA Cross is technically straightforward to perform and can be undertaken in a matter of minutes, depending on the number of scars being treated. It is generally repeated on several occasions at 2 to 4-week intervals.

The patient should be in a comfortable semi-recumbent position and remain still during the procedure.
The skin is cleansed with chlorhexidine/saline-soaked gauze.
A fine blunt end-point instrument (such as a toothpick) is dipped into TCA and the excess is removed.
TCA is applied to the base of the atrophic scar.
The instrument is removed at the start of frosting of the skin surface (usually within 10 seconds).
The procedure is repeated for appropriate remaining scars.
The skin is cleansed using saline/chlorhexidine soaked gauze.