including 88 patients.
AKs remain an ongoing health concern because of their potential to become malignant, and chemical peels are among the recommended options for field therapy, wrote Angela J. Jiang, MD, from the department of dermatology at the Henry Ford Health System, Detroit, and colleagues. “Although most dermatologists agree on the importance of field treatment, cryotherapy still remains the standard of care for treatment of AKs,” they noted, adding that the safety and efficacy of chemical peels for AK field therapy have not been well studied.
Chemical peels offer the benefit of a single treatment for patients, which eliminates the patient compliance issue needed for successful topical therapy, the researchers said. In fact, “patients report preference for the tolerability of treatment with chemical peels and the shorter downtime, compared with other field treatments,” they added.
In the study published in Dermatologic Surgery, they reviewed data from five prospective studies on the safety and efficacy of chemical peels as AK field treatments published from 1946 to March 2020 in the National Library of Medicine’s PubMed database. Of the 151 articles on the use of chemical peels for AKs, the 5 studies met the criteria for their review.
One split-face study evaluated glycolic acid peels (published in 1998), two split-face studies evaluated a combination of Jessner’s and 35% trichloroacetic acid (TCA) peels (published in 1995 and 1997), and two randomized studies evaluated TCA peels alone (published in 2006 and 2016).
Overall, the studies showed efficacy of peels in reducing AK counts, with minimal adverse events. In the glycolic acid study, 70% glycolic acid plus 5-fluorouracil (5-FU) yielded a 91.9% mean reduction in AKs at 6 months’ follow-up. A combination of Jessner’s solution and 35% TCA showed a significant reduction in AKs at 12 and at 32 months post treatment – a 75% reduction at 12 months in one study and 78% at 32 months in the other – similar to results achieved with 5-FU.
In studies of TCA alone, 30% TCA peels were similar in AK reduction (89%) to 5-FU (83%) and carbon dioxide laser resurfacing (92%). In another TCA study, 35% TCA was less effective at AK reduction at 12 months, compared with aminolevulinic acid photodynamic therapy (ALA-PDT), but the 35% peel was applied at a more superficial level than in the study of 30% TCA, the authors wrote.
Chemical peels also demonstrated effectiveness in preventing keratinocytic carcinomas, the researchers wrote. In the 30% TCA study, the rate of keratinocyte carcinoma development was 3.75-5.25 times lower in patients treated with 30% TCA peels, compared with 5-FU and carbon dioxide laser resurfacing (CO2) after 5 years.
Chemical peels were well tolerated overall, although side effects varied among the studies. Patients in one study reported no side effects, while patients in other studies reported transient erythema and discomfort. In the study comparing TCA with PDT treatment, PDT was associated with greater pain, erythema, and pustules, the researchers wrote; however, patients treated with 35% TCA reported scarring.
From patients’ perspectives, chemical peels were preferable because of the single application, brief downtime, and minimal adverse effects. From the provider perspective, chemical peels are a more cost-effective way to treat large surface areas for AKs, compared with 5-FU or lasers, the researchers said.
The study findings were limited by several factors including the small number of prospective studies and relatively small number of patients, they noted. “The small number of included studies is partially due to the lack of studies that performed AK counts before and after treatments,” they said. The dearth of literature on chemical peels for AKs may stem from lack of residency training on the use of peels, they added.
However, the results support the use of chemical peels as an effective option for field treatment of AKs, with the added benefits of convenience and cost-effectiveness for patients, they concluded.
The study received no outside funding. The researchers had no financial conflicts to disclose.