What is TCA? 

TCA is an abbreviation for trichloroacetic acid, which is the chemical acid used for certain types of chemical peels as well as TCA Cross treatments.  “Cross” is an acronym for a method of chemical reconstruction of skin scars, using a strong trichloroacetic acid placed directly into atrophic scars. 

TCA Cross is primarily utilized for boxcar scars, rolling acne scars, ice-pick scars, and large pores. Minute amounts of TCA, in high concentrations (70 to 100%), are deposited directly into the surface of the atrophic scar. TCA that is utilized as an ingredient in some peel solutions in much lower concentrations (20 to 35%) when treating the entire face. The goal of TCA Cross is to aggressively stimulate the formation of new elastin and collagen is the very targeted areas of application.  

TCA Cross can be used on skin types 1 and 2 safely (TCA Cross is not suitable for skin types 3 or darker), with typically 3 to 6 treatments, spaced 2-8 weeks apart – for the best cosmetic results. For some patients with atrophic scars, TCA Cross works even better than aggressive ablative laser treatments. TCA Cross treatments are safe and effective, with minimal discomfort. 

What are the 3 main types of acne scars? 

1. Atrophic scars: which can be further divided into ice-pick scars (60% – narrow and deep), boxcar scars (25% – wide round or oval shallow depression) and rolling (15% – wavy-like texture depressions). Ice  

2. Hypertrophic scars 

3. Keloidal scars 

How does TCA Cross work for atrophic scars? 

TCA Cross treats the depression, or area of scarring itself, and not the surrounding skin. The acid is directly deposited with the tip of a toothpick or applicator, into the atrophic scar, leaving the entire skin surrounding the scar preserved.  

TCA Cross can also be used to treat deep open pores and more prominent pores. Depending on both the skin type, and the type of acne scar, up to 100% TCA is used to treat these deep ice pick scars (we will begin with the use of 70% at Ageless Living). The recovery time is generally less than one week from the procedure.  

Gentle skincare, including ample moisturization and sunscreen are recommended after the procedure (post-peel skincare kits can be utilized), as well as complete sun avoidance to mitigate the risk of hyperpigmentation. 

Depending on skin type and the severity of scars or pores, 3 to 6 sessions are needed to best improve the cosmetic appearance of the treated areas.  TCA Cross can also be combined with treatments such as CO2 resurfacing or RF microneedling – whereas the TCA Cross treatment is performed first followed by the energy-based device treatment.  

TCA Cross works on the scar by helping to denature the collagen within the scar tissue, at the layer of the dermis, and stimulate new, healthy, collagen production. New collagen production begins as early as 4 weeks after the procedure and continues to form up to 4 months after each TCA Cross treatment. As the new collagen remodels in the acne scars or prominent pores, new tissue is formed which produces noticeable improvement in the scars. 

How are TCA Cross treatments performed? 

Pre Treatment 

• TCA Cross should not be performed on skin that is sun damaged or which has recently had laser treatments, microneedling, chemical peels or other skin treatments (minimum of 4 weeks). 
• Discontinue use of all retinols, retinoids, Tazorac, alpha hydroxy acids or exfoliants for 3 days before TCA Cross is performed. 
• Patients who are predisposed or prone to hyperpigmentation may need to pre-treat with skin lightening creams (hydroquinone) for several weeks before the procedure. TCA Cross is not typically suitable for skin types 3 or darker. 
• Patients should avoid tanning and direct sun exposure for 2 weeks prior to each treatment. 
• Refrain from wearing makeup or using any other skin care products the day of the procedure. 

Treatment 

• The patient should be in a comfortable supine position and remain still during the procedure 
• At the start of the procedure, the skin is cleansed and then degreased with alcohol prior to the application of any trichloroacetic acid. 
• Photos are taken of the treatment area to document the progress of the procedure. 
• Great care should be taken to avoid sensitive surfaces (eyes, mucosal surfaces). Eyes and mouth should remain closed during the TCA application. 
• A fine blunt end-point instrument (such as a toothpick) is dipped into TCA and the excess is removed. 

• Each scar is carefully treated with between 50 and 100 % TCA, focally applied to the base of the atrophic scar. 
• The toothpick is removed at the start of frosting of the skin surface (usually within 10 seconds). The treated area initially turns white, and later red in color. 
• The entire treatment takes between 15 and 30 minutes, depending on the amount of acne scarring. 

Post Treatment 

• Frosting of the scar surface will last up to 12 hours. 
• The skin around the treated sites will be red and sore for 24 to 48 hours. 
• After 2 to 3 days a small scab will develop, which falls off after 3 to 7 days 
• Proper skin care and sunscreen use is reviewed after the procedure and strict sun avoidance is recommended. 
• Hydroquinone lightening creams are utilized for up to two weeks following treatment for applicable patients. 

• Refrain from makeup after the procedure for several days, until the skin heals and returns to normal. 

Potential Complications of TCA CROSS 

TCA Cross is generally well tolerated. Complications are rare when treatment is undertaken by an expert. They may include: 

• Prolonged local irritation and erythema. 

• Damage to mucosal surfaces, ie lip, nostril, conjunctiva or cornea (eye) leading to painful ulceration and potential scarring, if TCA is inadvertently deposited on these sites. 
• Post-inflammatory hyperpigmentation (usually transient) or hypopigmentation (this may be permanent). 
• Coalescence of adjacent scars to form larger scars. 
• Sub-optimal response or lack of improvement in scarring. 

References: 

Derm Net NZ 

https://dermnetnz.org/topics/tca-cross

Dr. Michele Green – Board Certified Cosmetic Dermatologist in NYC