Seborrheic keratosis is a common benign skin tumor treated with invasive methods like electrodessication, cryotherapy, or surgery. Topical therapy with trichloroacetic acid (TCA) may be a cheaper, non-invasive alternative with less complications. While TCA has been studied for other skin conditions, more research is needed on its use for seborrheic keratosis.

To compare the safety and efficacy of one time application of 80% TCA peel to 65% TCA peel in the clearance of raised seborrheic keratosis in Filipino patients.

One hundred one patients were randomized to either 80% or 65% TCA groups. Each participant underwent one session of treatment and was followed up after a month. Pre- and post-test size and thickness of lesions were compared between groups.

Based on Physician’s Lesion Assessment (PLA), both concentrations of TCA achieved high treatment success (TCA80: 66.7%, TCA65: 68%, p-value 0.89). A similar trend was observed based on Subject’s Self-Assessment (TCA80: 74%, TCA65: 74.5%, p-value 0.95). Similar reductions in lesion size and thickness were observed in both concentrations. In terms of safety, pain, pruritus, and erythema were mostly observed during and immediately after treatment, with little to no adverse events observed after 1 month in both groups.

One time application of either 80% or 65% TCA is effective in decreasing the size and thickness of seborrheic keratosis with little to no complications 1 month post- treatment. Both concentrations were safe, causing minimal and non-persistent pain, pruritus, and erythema immediately after application.