Worsening of Acne Scars from Trichloroacetic Acid CROSS Delivered via Micropipette: A Case Report

Application of trichloroacetic acid (TCA) via the "Chemical Reconstruction of Skin Scars" (CROSS) method is a well-established treatment for acne scars. Generally, an applicator, such as a needle, is repeatedly moved between the TCA container and the patient, potentially resulting in accidental spills. To mitigate this risk, we investigated a repeating electronic micropipette with self-contained fluid reservoir as a novel TCA applicator. A 46-year-old African American male patient with long-standing ice pick and boxcar acne scars on the face initially underwent six 100% TCA CROSS treatments using a 30-gauge needle, which resulted in significant improvement in scarring. Immediately after 100% TCA CROSS treatment using a repeating electronic micropipette, the patient experienced increased pain and hyperpigmentation. Two months later, the patient had more prominent scars with persistent erythema and increased atrophy. An additional treatment with 100% TCA CROSS using a 30-gauge needle led to subsequent improvement. TCA CROSS delivered via a repeating electronic micropipette may result in less precise application of TCA relative to a 30-gauge needle, with subsequent necrosis of adjacent healthy tissue and worsening of acne scars. Miniscule volumes of concentrated TCA should be applied with a precision applicator, such as a 30-gauge needle, to prevent TCA spread to adjacent healthy skin.