Acne scars result from the inflammation and local tissue destruction as a result of acne. There are different types of acne scars classified broadly into atrophic (meaning loss of tissue) or hypertrophic (excessive tissue). On the face most acne scars tend to be atrophic and these are subdivided into 3 main subtype: rolling, boxcar, and ice pick scars. Rolling type acne scars present with irregular skin surface giving the appearance of hills and valleys with changes in the shadows at different angles of the light. Boxcar type acne scars tend to have a flat base of the scar and upright shoulders and can be small or large. Ice pick type acne scars tend to have narrow openings and deep bases.

TCA stands for an acid called trichloroacetic acid. CROSS stands for Chemical Reconstruction of Skin Scars. TCA CROSS therefore uses an acid to chemically reconstruct acne scars. TCA is widely used in dermatology but in most cases in low concentrations around 20-30%. In the management of acne scars TCA CROSS is used in higher concentrations ranging between 70 to 100% and is mostly effective in the subtypes ice pick and small boxcar acne scars. 

The procedure is fairly simple and straightforward. The skin will be cleansed with appropriate anti-septic cleanser and the treated scar will be stretched gently and the TCA solution is applied with a toothpick or small gauge needle to the base of the scar for few seconds until a typical white discolouration occurs which is termed “frosting”.  A barrier cream is then applied afterwards and appropriate aftercare given. In 2 to 3 days a scab will form which will fall off in around day 5 to 7. It is important that the scab is not removed prematurely and the skin is kept clean and moist with daily application of barrier cream on the treated scars. Initially the scars will appear pink to red and the treatment can be repeated at monthly intervals with a noticeable slow but gradual improvement. The number of treatments depends on the extent and severity of the scars and the initial response. TCA CROSS is a safe and effective treatment for acne scars and is usually performed in combination with other treatments.

Professor Firas Al-Niaimi has published many scientific articles on acne scars and these can be found in the publications section of the website.