Effects of Botulinum Toxin Type A Treatment on Clinical and Biophysical Parameters in Patients With Erythematotelangiectatic Rosacea: A Prospective, Randomized, Controlled, Double-Blind Study

BACKGROUND Erythematotelangiectatic rosacea (ETR) lacks a gold-standard treatment. Recent studies show that intradermal Botulinum Toxin-A (BoNT-A) is effective for erythema, though objective data are limited. OBJECTIVE This study aims to evaluate the efficacy and tolerability of intradermal BoNT-A in patients with ETR. METHODS In this randomized, double-blind, split-face study, 30 patients were enrolled. One side of the face received 15 units of BoNT-A, reconstituted in 10 mL of saline, while the control side received saline injections. Assessments were made at baseline and 1-month posttreatment. Clinician's Erythema Assessment (CEA) scale and Patient Self-Assessment (PSA) scores were recorded. Erythema and Melanin Index measurements using a Mexameter. Background erythema was assessed through dermatoscopy, while vascular structure and density were evaluated using Investigative Global Assessment (IGA) scores through videocapillaroscopy. RESULTS The BoNT-A-treated side demonstrated significant reductions in CEA scores, Erythema Index, and dermatoscopic background erythema, while no significant changes were observed on the saline control side. IGA scores indicated a significant response to treatment on the BoNT-A side. Patient Self-Assessment scores improved on both sides. No serious adverse events requiring hospitalization were reported. CONCLUSION Intradermal BoNT-A effectively reduces erythema and vascular density in patients with ETR and is well-tolerated.