Why is trichloroacetic acid used in TCA CROSS?

TCA CROSS stands for chemical reconstruction of skin scars. A clinician places a high-strength trichloroacetic acid solution precisely into the openings of suitable depressed scars rather than spreading it across the whole face. The chemical action reaches the scar base and causes a local healing response. As the area recovers, new collagen and other repair tissue can make the depression look less sharply defined. Improvement is gradual and may require more than one session.

The method is mainly considered for narrow, deep atrophic acne scars. It is not a general resurfacing treatment, and the concentration, application method, and spacing between sessions need professional judgement. Skin tone, scar type, previous treatments, and the risk of pigment change all affect suitability.

Before treatment, share your history of dark marks, cold sores, active acne, eczema, allergies, and any products or medicines that irritate your skin. Afterward, follow the wound-care instructions, avoid picking or peeling the treated spots, and protect the healing skin from sun exposure. Temporary redness, crusting, tenderness, or darker marks can occur while the sites repair. Do not apply unapproved acids, retinoids, or fragranced products to the treated areas until your clinician says they are appropriate.

Contact the treating clinic if pain is increasing rather than settling, redness is spreading, swelling is marked, or the area develops pus, a bad smell, or fever. Seek prompt assessment for blistering, an unexpected severe reaction, or eye exposure. A persistent or worsening colour change also deserves review, particularly after the skin surface has healed.

Ask which scar types you have, why TCA CROSS is suitable for them, what concentration and aftercare will be used, and how pigment changes will be managed in your skin tone. You can also ask when to pause your current skincare products and which other scar treatments could be considered.