A Prospective Single-Subject Triple-Blinded Single-Center Pilot Study of Laser-Assisted 5-Fluorouracil Versus...

Keloids are common in genetically predisposed individuals and in darker skin types, and treatment is especially challenging; the most commonly used therapeutic options return inconsistent results and often result in recurrence. Despite their prevalence and therapeutic challenges, keloids remain understudied and are often conflated with hypertrophic scars in the literature, though these conditions likely have distinct biomechanical etiologies. There remains a need for better optimization and comparison of existing treatment modalities to more effectively manage keloidal scarring.

Thirteen patients with two similar keloids or one large keloid completed four treatments of a fractionally ablative erbium YAG laser, followed by application of either triamcinolone 10 mg/mL solution to one keloid or one half of the keloid or 5-fluorouracil solution 50 mg/mL solution to the second keloid or the other half of the keloid. Photos and measurements of the keloids were taken at each visit. The Patient and Observer Scar Assessment Scale (POSAS) score was recorded by the participants and the blinded physician observer at each visit. Blinded dermatologist observers completed the Hamilton score based on the scar photographs.

The overall POSAS scores improved after four treatments compared to the pre-treatment POSAS scores within both the TAC and 5-FU treatment arms. There was, however, no statistically significant difference in the change from the first to the final POSAS score between the arms (p = 0.53). There was also no statistically significant difference in the Hamilton Score at the final visit between the two arms (p = 0.30). Scar volume and surface area decreased in both arms. The 5-FU arm had a mean volumetric change from baseline of -368.7 cm³, and the TAC arm had a mean volumetric change from baseline of -310.7 cm³; there was not a statistically significant difference between the two (p = 0.06). The 5-FU arm had a mean surface area change from baseline of -38.3 cm², and the TAC arm had a mean surface area change from baseline of -20.8 cm²; there was not a statistically significant difference between the two (p = 0.56). Ten out of 13 patients were Fitzpatrick skin types IV-VI. There were no serious adverse events reported.

In this pilot study of keloid patients, POSAS scores significantly improved after both laser-assisted TAC delivery and laser-assisted 5-FU delivery, with no statistically significant difference between the two treatment arms. However, there was a noted discrepancy in patient reports of post-procedural hyperpigmentation, with more patients experiencing this adverse effect within the 5-FU arm than in the TAC arm. While fractionally ablative laser-assisted drug delivery with either 5-FU or TAC is a safe and effective method to treat keloids, special attention should be paid to hyperpigmentation as a possible adverse effect in patients with darker skin tones, who are disproportionately affected by both keloids and hyperpigmentation.