“TCA” (trichloroacetic acid) peels are a treatment used to improve the skin's appearance and exfoliate the skin surface by denaturing proteins, leading to coagulation of both living and dead keratinocytes (O'Connor, 2018; Roenigk, 1995; Soleymani, 2018). Peels can be performed with different strength concentrations of acid to achieve different depths of exfoliation. Superficial peels, for cosmetic indications, are often performed with a 10%–25% TCA solution (Lee, 2019). Because TCA can penetrate the stratum spinosum, the depth of dysplastic cells in actinic keratosis (AK), medium-depth 35% TCA peels may be used as an adjuvant therapy for AKs (Gambichler, 2006). This is further supported in a 2017 article, which found that TCA peels cleared 31% of the AKs in treated patients with only 25% displaying treatment failure after 12 months (Holzer et al., 2017).
Transformation of AKs to squamous cell carcinoma begins at the basal layer of the interfollicular epidermis (Ratushny et al., 2012). Given that medium-depth peels can be performed to reach the papillary and upper reticular dermis, there is the potential for TCA peels to destroy the cells capable of becoming squamous cell carcinomas (O'Connor et al., 2018). In a recent review, Sidiropoulou noted evidence that chemexfoliation treats clinical and subclinical and may be combined with 5-fluorouracil (5-FU) “to optimize outcomes and allow clinicians to tailor the treatment based on individual patient needs” (Sidiropoulou, 2020). Furthermore, a longitudinal comparative trial of topical 5-FU, TCA, and carbon dioxide laser therapy on AKs in immunocompetent patients showed similar efficacy between the three modalities, which was again supported by three other comparative trials (Hantash et al., 2006; Kurwa et al., 1999; Lawrence et al., 1995; Witheiler et al., 1997). This supports the usage of TCA peels because of their convenience and relatively low cost.
In a billing claims analysis for the Medicare Part B fee-for-service population, between 2007 and 2015, the number of cases of patients treated with AKs increased from 29.7 to 35.6 million. This has been associated with increased costs of treatment. The study reported that the medical costs for visits to treat AKs and actinic damage increased from $867 million in 2004 to $1.8 billion in 2013. Of note, Medicare Part D expenditures for topical AK therapy increased from $101 to $133 million between 2011 and 2015 (Yeung et al., 2018). Given the rise in aging population and rising costs associated with AKs, implementation of cost-effective treatment measures is needed (Carter et al., 2019).
Untreated, between 0.025% and 16% of individual AKs will evolve into squamous cell carcinomas. An individual patient with preexisting AKs has a 12%–25% of developing squamous cell carcinoma (Carter et al., 2019). Topical 5-FU is the standard of care of field therapy for treating AKs because of its long history of effective use in various populations (Carter et al., 2019). Although TCA peels may be reported as having similar efficacy in the immunocompetent population, they have not been as well studied in high-risk, immunosuppressed patients. TCA peels have specifically not been shown to prevent transformation of AKs to squamous cell carcinoma in solid-organ transplant recipients on high-dose immunosuppression, who may have multifold increases in susceptibility to developing skin cancer. That said, TCA exfoliation may decrease the keratotic burden, allowing for improved visualization of lesions and enhanced penetration of 5-FU or photodynamic therapy as an adjunct therapy. This is important because skin cancers occur at a higher rate than in the immunocompetent population. For example, squamous cell carcinomas are increased 65-fold, whereas basal cell carcinomas are increased 10-fold in the immunosuppressed population (Transplant Skin Cancer Network, n.d.).
The efficacy of TCA peel treatment for AKs is dependent on achieving adequate skin penetration (Hantash et al., 2006). Whether the desired penetration depth is achieved depends on the concentration of the TCA solution, whether a preparation agent was used before TCA administration, and the consecutive number of peels applied (Hantash et al., 2006).
There is no universally accepted standard operating procedure for the TCA peel protocol. The protocol herein is a summation of our experience and that published in the literature.
- − The TCA dilution (concentration) is selected to attain desired depth of penetration.
- − Prep the face by degreasing with alcohol and/or medical-grade acetone.
- − Immerse the cotton-tip applicator/folded gauze into the diluted TCA.
- − Gently apply TCA dilution to the areas to be treated with light, upward-facing strokes.
- − Frosting (a white sheen) will form on the surface and should be such that underlying erythema is still visible (pink sign), forming an intact superficial vascular plexus within the papillary dermis.
- − The provider may wash the solution from the treated areas immediately after the frost forms.
- − If an adverse reaction occurs, neutralization via washing should occur immediately.
- − An eye wash center must be available if the solution gets into the patient's eye.
- − Do areas of greatest likelihood for adverse effects last (e.g., perioral and periorbital).
- − A handheld fan may be used to control postoperative pain.
- − Reepithelialization will occur within 6–8 days.
- − The patient should apply white petrolatum twice a day and avoid ultraviolet light exposure for several weeks.
- − In addition, the patient should apply lightweight zinc or titanium chemical-free sunblock daily.
- − Washing may be done by gently patting the skin with water using the fingertips, avoiding rubbing, and gently pat drying with a towel.
- − Exercise should be avoided for 8 days posttreatment.
BENEFITS OF THE TECHNIQUE
- − A sequential approach minimizes the area of the skin that may be missed or overdone.
- − Application of TCA to the areas of greatest likelihood for adverse effects to last minimizes patient discomfort.
Because adequate TCA frosting depends on identifying underlying erythema, TCA peels may be less desirable for use in patients with Fitzpatrick Skin Types 5–6 because of the decreased ability to assess erythema and risk of postinflammatory pigmentary changes (Figure 1).
For patients undergoing treatment of the perioral area, herpes simplex virus prophylaxis is recommended to avoid reactivation of herpes labialis and spread to the treated area. The patient should begin 500-mg valacyclovir twice a day 2–3 days before the procedure and continue for 14 days thereafter. The dose may need adjusting depending on the patient's history of herpes simplex virus recurrences (Costa et al., 2017).
TCA peels can have adverse effects if not used properly and should be performed by a qualified provider. Currently, TCA supplies are sold over the counter both in stores and online. They are marketed to the public for the self-treatment of acne, acne scars, stretch marks, wrinkles, freckles, and hyperpigmentation in concentrations up to 90% (Ebay.com, n.d.; Walmart.com, n.d.). Given the relative risk for harm from erroneous use of higher concentrations of TCA by inexperienced hands, the authors recommend adherence to standard clinical peel procedures and to alert both providers and the public of the potential for complications with home use (Liu et al., 2016).
Carter A. J., Rogachefsky A., Lee K. (2019). Trichloroacetic acid
peels for actinic keratoses. The Dermatologist
, 27(8). https://www.the-dermatologist.com/article/trichloroacetic-acid-peels-actinic-keratoses
Costa I. M. C., Damasceno P. S., Costa M. C., Gomes K. G. P. (2017). Review in peeling complications. Journal of Cosmetic Dermatology
, 16(3), 319–326. https://doi.org/10.1111/jocd.12329
Gambichler T., Matip R., Moussa G., Altmeyer P., Hoffmann K. (2006). In vivo data of epidermal thickness evaluated by optical coherence tomography: Effects of age, gender, skin type, and anatomic site. Journal of Dermatological Science
, 44(3), 145–152. https://doi.org/10.1016/j.jdermsci.2006.09.008
Hantash B. M., Stewart D. B., Cooper Z. A., Rehmus W. E., Koch R. J., Swetter S. M. (2006). Facial resurfacing for nonmelanoma skin cancer prophylaxis. Archives of Dermatology
, 142(8), 976–982. https://doi.org/10.1001/archderm.142.8.976
Holzer G., Pinkowicz A., Radakovic S., Schmidt J. B., Tanew A. (2017). Randomized controlled trial comparing 35% trichloroacetic acid
peel and 5-aminolaevulinic acid photodynamic therapy for treating multiple actinic keratosis
. The British Journal of Dermatology
, 176(5), 1155–1161. https://doi.org/10.1111/bjd.15272
Kurwa H. A., Yong-Gee S. A., Seed P. T., Markey A. C., Barlow R. J. (1999). A randomized paired comparison of photodynamic therapy and topical 5-fluorouracil in the treatment of actinic keratoses. Journal of the American Academy of Dermatology
, 41(3, Pt. 1), 414–418. https://doi.org/10.1016/s0190-9622(99)70114-3
Lawrence N., Cox S. E., Cockerell C. J., Freeman R. G., Cruz P. D. Jr. (1995). A comparison of the efficacy and safety of Jessner's solution and 35% trichloroacetic acid
vs 5% fluorouracil in the treatment of widespread facial actinic keratoses. Archives of Dermatology
, 131(2), 176–181.
Lee K. C., Wambier C. G., Soon S. L., Sterling J. B., Landau M., Rullan P., Brody H. J. International Peeling Society. (2019). Basic chemical peeling: Superficial and medium-depth peels. Journal of the American Academy of Dermatology
, 81(2), 313–324. https://doi.org/10.1016/j.jaad.2018.10.079
Liu H., Khachemoune A., Rashid R. A. (2016). Chemical burn following 50% trichloroacetic acid
for acne: Presentation of a case and a focused review. Journal of Dermatology & Dermatological Surgery
, 20(1), 71–74. https://doi.org/10.1016/j.jdds.2015.06.001
O'Connor A. A., Lowe P. M., Shumack S., Lim A. C. (2018). Chemical peels: A review of current practice. Australasian Journal of Dermatology
, 59(3), 171–181. https://doi.org/10.1111/ajd.12715
Ratushny V., Gober M. D., Hick R., Ridky T. W., Seykora J. T. (2012). From keratinocyte to cancer: The pathogenesis and modeling of cutaneous squamous cell carcinoma. Journal of Clinical Investigation
, 122(2), 464–472. https://doi.org/10.1172/JCI57415
Roenigk H. H. Jr. (1995). Treatment of the aging face. Dermatologic Clinics
, 13(2), 245–261.
Sidiropoulou P., Gregoriou S., Rigopoulos D., Kontochristopoulos G. (2020). Chemical peels in skin cancer: A review. Journal of Clinical Aesthetic Dermatology
, 13(2), 53–57.
Soleymani T., Lanoue J., Rahman Z. (2018). A practical approach to chemical peels: A review of fundamentals and step-by-step algorithmic protocol for treatment. Journal of Clinical Aesthetic Dermatology
, 11(8), 21–28.
Transplant Skin Cancer Network. (n.d.). For transplant patients, risk factors for skin cancer. Retrieved March 1, 2020, from https://skincancer.ucsf.edu/transplant-patients
Witheiler D. D., Lawrence N., Cox S. E., Cruz C., Cockerell C. J., Freemen R. G. (1997). Long-term efficacy and safety of Jessner's solution and 35% trichloroacetic acid
vs 5% fluorouracil in the treatment of widespread facial actinic keratoses. Dermatologic Surgery
, 23(3), 191–196. https://doi.org/10.1111/j.1524-4725.1997.tb00020.x
Yeung H., Baranowski M. L., Swerlick R. A., Chen S. C., Hemingway J., Hughes D. R., Duszak R. Jr. (2018). Use and cost of actinic keratosis
destruction in the Medicare Part B fee-for-service population, 2007 to 2015. JAMA Dermatology
, 154(11), 1281–1285. https://doi.org/10.1001/jamadermatol.2018.3086