Trichloroacetic Acid Reduces Scars by Promoting the Production of Collagen (and May Help Acne by Exfoliating the Skin)
The Essential Info
Trichloroacetic acid (TCA) is an acid used for the treatment of acne scars, most notably icepick scars.
It works to treat acne scars by increasing the production of a skin protein called collagen, which fills in the indentation left by the scar.
The procedure is performed by a doctor or nurse who puts some TCA on the tip of a toothpick and presses it into each icepick scar one by one. This creates a frosting on the skin and scabbing in the days after the procedure, followed by increased collagen production. It must usually be repeated several times to achieve a desired correction in icepick scars.
Trichloroacetic acid is also sometimes used as an all-over scar-correction peel to reduce rolling or boxcar scars.
Can It Treat Acne? Yes. Similar to other acids used in chemical peels for acne, it should help, but from the few studies performed thus far, it appears to be less effective than a salicylic acid chemical peel for this purpose.
- How TCA Works on Acne Scars
- How TCA May Work on Acne
- TCA Side Effects
- How Well TCA Works on Acne Scars and Acne
Trichloroacetic acid (TCA) is an acid mainly used for the treatment of acne scars, and not acne itself. However, three studies so far also show it may hold promise in treating acne itself as well.1-3
How TCA Works on Acne Scars
There are three main types of indented (atrophic) acne scars, and TCA is most commonly used to treat icepick scars.
- Icepick scars: Doctors treat icepick scars by spot treating them one by one with TCA using a method called the TCA CROSS method.
- Rolling scars: Doctors can also use TCA as an all-over peel to treat rolling scars.
- Boxcar scars: Doctors can also use TCA as an all-over peel to treat boxcar scars.
How TCA CROSS works to treat icepick scars
TCA is most often used in a series of steps called the TCA CROSS (Chemical Reconstruction Of Skin Scars) method:
- A doctor applies TCA to the tip of a toothpick and presses it firmly into each icepick scar one by one. After application, TCA causes skin proteins to stick to each other, causing cell death and creating a “white frost” appearance on the skin.
- A few days after treatment, the dead skin cells form a crust on the surface of the skin that look like small scabs.
- In an attempt to repair itself, the skin is forced produce more collagen, which can fill in the depression caused from the scar. Ultimately, the crust falls off the skin, which reveals newly formed skin layers and a less pronounced scar.
Icepick scars are usually deep, and TCA is unlikely to immediately eliminate them. It usually takes multiple treatments over the course of several months before an acne scar will refill with collagen to an acceptable degree.
TCA Side Effects
Trichloroacetic acid, whether used in the CROSS method or in an all-over peel, can cause mild side effects, including:
- Skin discomfort
- Mild or moderate stinging pain
- Skin redness
- Skin discoloration (mainly in darker-skinned individuals)
Since high-concentration TCA can cause people with darker skin to develop dark marks, darker-skinned people should use caution when using high-concentration TCA.1,4
How Well TCA Works on Acne Scars and Acne
Researchers have performed several studies investigating the effectiveness of TCA on the treatment of acne scars, both using the TCA CROSS method and as an all-over peel.
TCA CROSS method: Results show various concentrations of TCA producing producing very good to excellent improvement in most people after 3 – 6 treatments. A review article of 12 studies showed over 70% improvement in icepick scars in over 70% of patients after 4 sessions, spaced 2 weeks apart.
All-over peel: Results show various concentrations of TCA producing fair to good results in most people.
The takeaway here is that TCA works particularly well when used in the TCA CROSS method, specifically on icepick scars, and may work less well when used as an all-over peel on general acne scarring.
Expand to read details of studies on the TCA CROSS method
Expand to read details of studies on using an all-over TCA peel to treat acne scars
How TCA May Work on Acne
There are several types of acids used in chemical peels, most notably glycolic acid and salicylic acid, and TCA likely works in similar ways to these other acids. However, because TCA is not typically used in chemical peels for acne, we don’t have enough concrete evidence to know for certain how TCA works if it is applied as an all-over chemical peel treatment for acne.
Researchers have only performed three studies on the ability of TCA to treat acne. All three studies found that an all-over TCA peel improved acne to some degree. However, two of the three studies only gave descriptions like “significant improvement” but did not provide any numbers for how much acne actually improved.8,10 The third study found that four sessions of all-over TCA peels reduced the number of acne lesions by 69%.11
Expand to read details of studies on using an all-over TCA peel to treat acne
Trichloroacetic acid (TCA) is a chemical treatment applied by a professional for the treatment of acne scars. It works to treat acne scars by stimulating the production of the skin protein, collagen, which helps to fill in the depression.
Less is known about using TCA to treat acne, but research investigating the effect of TCA on acne has found that TCA is somewhat effective at clearing acne. However, it is less effective than salicylic acid.
- Bhardwaj, D. & Khunger, N. An assessment of the efficacy and safety of CROSS technique with 100% TCA in the management of ice pick acne scars. J Cutan Aesthet Surg 3, 93 – 96 (2010). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2956965/
- Fabbrocini, G. et al. Acne scars: Pathogenesis, classification and treatment. Dermatol Res Pract 2010, 1 – 13 (2010). https://www.ncbi.nlm.nih.gov/pubmed/20981308
- Kaur, J. & Kalsy, J. Subcision plus 50% trichloroacetic acid chemical reconstruction of skin scars in the management of atrophic acne scars: A cost-effective therapy. Indian Dermatol Online J 5, 95 – 97 (2014). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3937506/
- Lee, J. B., Chung, W. G., Kwahck, H., Lee, K. H. & Monheit, G. Focal treatment of acne scars with trichloroacetic acid: Chemical reconstruction of skin scars method. Dermatol Surg 28, 1017 – 1021 (2002). https://www.ncbi.nlm.nih.gov/pubmed/12460296
- El Garem, Y. F., Ghabrial, E. E. & Embaby, M. H. Chemical reconstruction of skin scars technique using trichloroacetic acid in different types of atrophic acne scars. Egypt J Dermatol Venereol 33, 37 – 41 (2013). http://www.ejdv.eg.net/article.asp?issn=1110-6530;year=2013;volume=33;issue=2;spage=37;epage=41;aulast=Garem
- Kravvas, G. & Al-Niaimi, F. A systematic review of treatments for acne scarring. Part 1: Non-energy-based techniques. Scars Burn Heal 3, 2059513117695312 (2017). https://www.ncbi.nlm.nih.gov/pubmed/29799567
- Garg, S. & Baveja, S. Combination therapy in the management of atrophic acne scars. J Cutan Aesthet Surg 7, 18 – 23 (2014). https://www.ncbi.nlm.nih.gov/pubmed/24761094
- Sharquie, K., Noaimi, A. & Al-Janabi, E. Treatment of active acne vulgaris by chemical peeling using TCA 35%. Journal of Cosmetics, Dermatological Sciences and Applications 3, 32-35 (2013). https://m.scirp.org/papers/39965
- Puri, N. Efficacy of modified Jessner’s peel and 20% TCA versus 20% TCA peel alone for the treatment of acne scars. J Cutan Aesthet Surg 8, 42-45 (2015). https://www.ncbi.nlm.nih.gov/pubmed/25949022
- Abdel Meguid, A. M., Elaziz Ahmed Attallah, D. A. & Omar, H. Trichloroacetic acid versus salicylic acid in the treatment of acne vulgaris in dark-skinned patients. Dermatol Surg 41, 1398 – 1404 (2015). https://www.ncbi.nlm.nih.gov/pubmed/26551771
- Al Hussein, S., Buicu, F., Maier, D., & Hussein, H., Ciurba, A., Al Hussein, H., & Dogaru, M. Efficacy of trichloroacetic acid peel versus 15% topical azelaic acid gel in the treatment of acne vulgaris – a comparative study. Acta Medica Marisiensis 61, 25-30 (2015). http://actamedicamarisiensis.ro/eficacy-of-trichloroacetic-acid-peel-versus-15-topical-azelaic-acid-gel-in-the-treatment-of-acne-vulgaris-a-comparative-study/